Papers : Rubber and Other Crops
Ong T.S. 1987. Refinement on young budding technique in rubber. Presented at 1987 TPSB Managers Seminar.
Ong T.S. 1988. Corynespora leaf fall disease of Hevea. Paper for TPSB/AAR meeting held on 7 June.
Ong T.S. 1989. Status report of tree dryness survey by AARSB. Presented at IRRDB Workshop on tree dryness – 26-27 June.
Ong T.S. 1989. Further results of cutback height trial in young budding nursery and proposed production schedule for future budding nurseries. Presented at TPSB/AAR meeting on 6 July.
Ong T.S. 1991. Sulphur dusting to control Oidium SLF in rubber estates with knapsack duster. Annual Report. Pahang Planters Assoc.
Ong T.S. 1992. AAR’s experience in sulphur dusting with motorised knapsack duster. Presented at RRIM Colloquium on 12 December.
Ong T.S. 1995. AAR observations and experience in leaf disease control of rubber. Talk delivered at MRPC-AC/RRIM Interactive Meeting at Cinta Sayang Sg. Petani on 23 November.
Ong T.S., Chan W.H. and Heh W.Y. 1997. Towards maximum growth of young rubber with improved planting materials and agronomic practices. Proc. International Planters’ Conference on Plantation Management for the 21st century. Incorporated Society of Planters, Kuala Lumpur : 323-338
Ong T.S. and Chan W.H. 1998. Selection of rubber clones for future replanting-RRIM 2000 series (1st and 2nd Selection) TPSB Managers Conference, Awana, GentingHighlands.
Ooi L.H. and Chew P.S. 1985. The performance of some Malayan Dwarf x Tall coconut hybrids and local coconut varieties on marine clay soil in Peninsular Malaysia.Oleagineux 40(7) : 373-383.
Ooi L.H. and Chew P.S. 1986. Present status and prospects for coconuts. In : Ti T.C. and Yee W. (eds). Proc. IDS Seminar on Revitalization of Industrial Crop Investments in Sabah. Institute for Development Studies (Sabah) : 95-112.
Teoh K.C., Chan K.S. and Chew P.S. 1986. Dry matter and nutrient composition in hybrid coconuts (MAWA) and cocoa on coastal clay soils. Proc. International Conference on cocoa and coconuts : Progress and Outlook. Incorporated Society of Planters, Kuala Lumpur : 819 835.
Teoh K.C., Chan W.H. and Ooi L.H. 1987. Effect of palm oil sludge cake on early growth of newly planted oil palm, rubber and cocoa in the field. The Planter. Incorporated Society of Planters, Kuala Lumpur 62 : 368-382.
Records 31 to 44 of 44
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Papers : Rubber and Other Crops
Chan W.H. 1985. A speculative look at an extended productive life cycle for hevea. The Planter. Incorporated Society of Planters, Kuala Lumpur : 61, 249-261.
Chan W.H. 1989. Commercial performance of clones planted in the last 15 years in a large group of rubber estates. Proc. RRIM Rubber Growers’ Conference : 36-52
Chan W.H. 1989. Field experience of controlled pruning in immature rubber. Selangor Planters’ Association Annual Journal/Report : 74-91
Chan W.H. 1992. Patent on Rainguard. March ‘92
Chan W.H. 1992. Patent on Jacket System April ‘92
Chan W.H. 1993. Further results of AAR jacket system. Presented at TPSB Assistants Conference on 9/1/93.
Chan W.H. 1995. AAR Jacket System. Proc. RISDA National Conference.
Chan W.H. 1996. Survey of tree dryness on panels BO-1 and BO-2 of clone PB260 in a large group of rubber estates. The Planter. Incorporated Society of Planters, Kuala Lumpur : 72, 55-65.
Chan W.H.. 1997. Performance of clone PB260 in a large Plantation Group in Peninsular Malaysia. The Planter. Incorporated Society of Planters, Kuala Lumpur : 73, 403-418.
Chan W.H. 1997. A Brief History of Natural Rubber in Malaysia. Taiko Newsletter.
Chan W.H. 2004. Manuring in rubber : need for re-evaluation based on case study. The Planter. Incorporated Society of Planters, Kuala Lumpur 80 (942) : 551-560.
Chan W.H. 2004. Early growth and secondary characteristics of RRIM200 series clones in trial and commercial plantings. Presented at International Conference on Natural Rubber Industry : Responding to Globalization. Rubber Research and Development Board, Kuala Lumpur. Preprint.
Chan W.H. 2005. Use of short cuts to extend lifespan of PB260. Preprints of papers International Natural Rubber Conference : opportunities and trends in natural rubber production. Rubber Research Institute of India : 311-319.
Chan W.H. 2005.New perspective for rubber planting in a large plantation group.Proc. Rubber Planters’ Conference 2005 : 46-57.
Chan W.H. 2006. Short cuts on basal and high level virgin bark. Preprints of Papers International Natural Rubber Conference. IRRDB and Rubber Research Institute of Vietnam : 16-23. Revised version in the Planter. Incorporated Society of Planters, Kuala Lumpur 83 (973) : 253-261.
Chan W.H. 2006. New perspective in rubber cultivation. Presented at Rubber Markets, Singapore.
Chan W.H. 2007. Growth and early yield of RRIM2000 series clones in trial and commercial plantings.Proc.International Rubber Conference.IRRDB : 243-252.
Chan W.H. 2009. Re-evaluation of controlled pruning in young rubber in a large group of estates.The Planter. Incorporated Society of Planters, Kuala Lumpur : Vol.85(995) 79-87.
Chan W.H. and McQuistan J.G. 1986.Preliminary observations of Paclobutrazol on Immature Rubber.Annual Report.Negeri Sembilan Planters Association.
Chan W.H. and Teoh K.S. 1986. Early results of PP333 (Cultar) trials on young rubber. ICI Workshop on Cultar, Malacca.
Chan W.H., Ho J. P., Choo I.F., David O., Lim J.K. and Laili D. 1987. Further puncture tapping trial results in Hevea. Proc. RRIM Planters Conference : 207-224
Chan W.H. and Rahman O. 1990.Evaluation of 3 types of rainguards.The Planter. Incorporated Society of Planters, Kuala Lumpur 66 : 523-535.
Chan W.H., Wong C.P. and Wong C.C. 1991. Control of White Root Disease in immature rubber with 3 systemic fungicides.The Planter. Incorporated Society of Planters, Kuala Lumpur 62 : 251-265.
Chan W.H. and Ong T.S. 1992. AAR jacket system : a promising improved system of extracting latex from rubber trees. The Planter. Incorporated Society of Planters,Kuala Lumpur, 68 : 587-596
Chan W.H. and Ong T.S. 1994. Prospective solutions to current problems in hevea exploitation in a large group of estates. Proc. International Planters’ Conference. Incorporated Society of Planters, Kuala Lumpur : 337-349.
Chan W.H. and Ong T.S. 1995. Current status of trials on AAR jacket system of exploitation in rubber. Proc. RRIM Growers’ Conference. Kuala Lumpur 135-144
Chan W.H. and Goh K.J. 1997. A Short note on effective advisory service in the private sector. ISOPA Newsletter Vol 6:1-3
Chan W.H. and Ong T.S. 2000. Enhancing sustainability of rubber plantations in P. Malaysia. MEOA Seminar on Survival of the Rubber Industry. RRIM, Sungei Buloh.
Chan W.H., Tan K.S. and Ong T.S. 2004. Early growth and secondary characteristics of RRIM 2000 series clones in a large plantation group. The Planter. Incorporated Society of Planters, Kuala Lumpur 79 (926) : 295-307.
Records 1 to 30 of 44
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Cocoa: Pests and Diseases
Cocoa is very susceptible to pests and diseases right from the moment the seeds are sown.
All the plant parts including the pods are affected by various pests (Conway, 1971; Pang & Syed, 1971; Shah, 1976 and Mainstone, 1978) and diseases (Liu & Liew, 1975; Turner & Shepherd, 1978 and Varghese, 1985). Some of them eg. rodents, pod borer, Helopeltis and Phytophthora are capable of causing very high crop losses while VSD has destroyed many young plantings, debilitated mature cocoa bushes and reduced yield in Sabah recently.
Currently the most important pest disease in Malaysia are the moth pod borer, Conopomorpha cramerella and Vascular Streak Dieback (VSD) caused by a fungus Oncobasidium theobromae . The former is confined to Sabah and Sarawak. VSD is present throughout Malaysia.
Conopomorpha cramerella (cocoa pod borer)
The cocoa pod borer was first reported in Sabah in late 1980. The pest if left to build up is capable of destroying the entire crop. Several control measures have been tried to contain the pest including rampassen (i.e. total removal of all pods susceptible to attack) with varying degree of success (Wood, 1980; Day, 1983; and Mumford, 1984).
Currently, no single control measure is entirely satisfactory on its own. A combination of control measures (integrated control) including cultural, biological and chemical methods usually produces better results.
The most common control methods currently practised are:-
- clean and frequent harvesting and breaking of pods as soon as possible and destroying/bagging/burying of husks to prevent pupation.
- selective spraying of moth resting sites i.e. on the undersides of the branches inclined at less than 45ofrom the horizontal and
- sleeving of young pods to prevent the moths from laying eggs.
Mass rearing of parasitic wasps, Trichogrammatoidea bactrae fumata Nagaraja for release against pod borer eggs and the use of synthetic pheromone for trapping male moths and to disrupt mating are reported to be promising and are still being evaluated. Lately, the Commonwealth Institute of Biological Control (CIBC) in collaboration with EMPA/MCGC have also started a search for exotic natural enemies.
Oncobasidium theobromae (VSD)
The disease causes dieback of canopy and can kill the young bushes. The problem is more serious during the establishment phase. Mature cocoa can usually survive the attack, but varying degrees of yield losses may be expected depending on the severity of the disease and the susceptibility of the cocoa.
Vascular Streak Dieback (VSD) is present throughout Malaysia. Lately, the disease became very serious in Sabah, destroying numerous nurseries and young plantings. Even the mature cocoa bushes were debilitated resulting in vast crop losses.
Byrne (1976) reported 25 to 40% losses in PNG. Taylor and Chong (1983) reported 30% losses when the VSD infested bushes were severely pruned in Lower Perak.
Numerous control measures including pruning, shade adjustment, manuring, fungicide spraying and isolation of nursery and new plantings have been tried. However, the disease was so virulent in 1984/85 that widespread planting failures and high crop losses were reported despite desperate attempts made to control the disease with all the control measures known. It is hoped that 1984/85 were exceptional years in Sabah and that the disease would not be as virulent in the “drier years” when the environment is not as conducive for VSD.
1) Chemical control
A wide range of fungicides have been evaluated in Malaysia and PNG. While none of the fungicide trials carried out in PNG showed any promise, Chung (1983) reported that Bitertanol (Baycor 25% wp) at 0.05% a.i. + 0.05% Agridex sprayed to slight run-off at 14 days interval gave complete protection to nursery seedlings.
Bitertanol is reported to be a protectant and has no curative properties.
Musa & Tay (1984) reported that Benomyl (Benlate), Pyracarbolid and Triforine totally inhibited the growth of VSD mycelium in vitro (lab test). Benomyl applied as soil drench was translocated to the leaves with a residual effect of 1 month. However the efficacy of the fungicides has not been evaluated in the field and therefore cannot be recommended on the basis of actual field trial results.
It must be pointed out here that Benomyl has been reported to be not effective against VSD in the field. Chung (1983) reported that Benomyl did not provide any control at all. Instead the VSD incidence of the Benomyl treated seedlings was higher than the control. More field trials on Benomyl are needed.
Varghese (1985) reported that Triadimenl, Paropiconazole and PP969 are promising in invitro screening.
Currently, Bitertanol appears to be the only fungicide proven to be effective against VSD, although there were some conflicting reports from Sabah. Its application is mainly restricted to the nursery at present. As it has no curative effect, the chemical must be applied in the first instance as soon as the seed starts to emerge followed by a second spray when the first leave emerges and the application continued regularly for as long as the protection is needed.
2) Isolation/Barrier
Under normal conditions, VSD fungal spores do not travel for more than 200 m. An isolation belt of more than 200 m would normally reduce the inoculum potential sufficiently to reduce the chances of infection.
Isolation is most useful for nursery. Isolated nurseries generally have less VSD problem.
In very high inoculum areas, covering the nurseries with ultra-violet light resistant polythene sheets has been reported to confer protection in PNG. The main effect is to keep the leaves dry and hence not conducive to fungal spore germination.
3) Disease avoidance
Avoid planting cocoa during maximum risk period i.e. when the weather is unusually wet for a prolonged period and when the inoculum potential is very high.
Presently, there is insufficient information to define high risk periods accurately. However the following factors taken together may be considered to constitute a high period:-
- in very wet years when rainfall is more than 2000 mm per year.
- When there is continuous wet weather for 4 or more days.
- When very high incidence of VSD is noted and hence high disease pressure.
4) Pruning
Pruning to control VSD is a much debated and controversial subject in Malaysia and deserves a special mention here. The subject has been dealt by numerous authors (Kean & Turner, 1971; Jayawardena et al. 1978; prior, 1980 and Taylor & Chong, 1983).
In Papua New Guinea, it was reported that pruning to remove all VSD tissues and 20 cm beyong the streaking at 2-3 weeks intervals to keep the disease inoculum low is able to control the disease in young cocoa i.e. before the canopy closes over (Odonohue, Pers Comm.)
However, others noted that if pruning is too severe, it could cause more harm and wondered if it is better to leave the bushes alone to allow them to grow out of the disease. The trouble is, not all of them can. At the same time the diseased bushes provide a constant source of inoculum which could result in alarming outbreaks in conducive environments. To derive the best results from pruning, the disease must be controlled in its early stages when it is possible to keep the inoculum at a very low level through regular and frequent prunings.
5) Disease resistance/tolerance
Selection for disease resistance/tolerance is probably the best long term solution for VSD control.
The cocoa industry in PNG was nearly destroyed by VSD at one time. However, with the introduction of VSD resistant/tolerant clones, VSD is now no longer a problem in PNG. Tan (1983) reported that the resistance is polygenic and is not likely to break down easily.
6) Rehabilitation
Varying degree of success have been reported by budding VSD infested bushes with VSD tolerant clones, mainly in Lower Perak.
The approach appears promising.
7) Cultural practice/nutrition
Good cultural practices and nutrition can go a long way to help the bushes to combat the disease. Healthy and vigorous bushes are certainly in a better position to withstand the disease infection and if infected will have a greater chance of recovery.
Manipulation of shade to ensure good aeration and reduction of humidity can also reduce the chances of infection. However, it is important that young cocoa should not be over exposed by excessive shade removal.
Helopeltis, rodents and black pod
Apart from VSD and pod borer, Helopeltis spp (Theivora and theobromae) and rodent pests (mainly rats and squirrels) are also capable of causing very high crop losses in excess of 90%. (Tan, 1974; Mainstone, 1978 and Han, 1982).
The main rodent pests in Malaysia are rats and squirrels. Han and Subash (1980) found that both the rats and squirrels consumed 2.5 to 3.0 pods per feeding in a cage trial. This works up to about 30 to 36 kg of dry bean per rodent per year assuming one feeding per day. The same authors estimated the population of rats and squirrels in an estate in Bagan Serai could reach as high as 100 to 300 and 30 to 90 per hectare respectively. It is therefore not surprising to find the entire cocoa crop lost to the rodents.
The most effective way to control rats in cocoa plantation is baiting with anti-coagulant poison (Friend, 1971; Ooi, 1977 and Han 1982)
Squirrels may be controlled by a combination of trapping with ordinary drop-door rat traps using jack fruit baits (Artocarpus heterophyllus) and shooting. A combination of baiting for rats and trapping/shooting for squirrels is able to reduce the pod damage by rodents to less than 5%. (Wanless, Pers. Comm.)
As Helopeltis initial outbreaks are usually in localized patches, the pest is best controlled at this stage with 2 consecutive sprays of insecticides such as Gama BHC or Propoxur at 10-14 days intervals. To achieve the best results, the pest must be monitored and detected by an Early Warning System and sprayed selectively to prevent major outbreaks (Wills, 1984)
Phytophthora black pod disease is a potentially very serious disease in Malaysia. Shepherd et al. (1977) reported that up to 5% of the crop could be lost to the disease in Lower Perak. The losses are probably higher in the wetter areas such as in Jerangau and certain areas in Sabah. Elsewhere in the world, crop loses of as high as 75% have been quoted by Gregory (1974).
A combination of cultural practices aim at reducing the inoculum pressure through frequent harvesting and proper disposal of diseased pods, pruning to improve aeration and finally chemical control when the infections have reached beyong 5-10% if advocated by Varghese (1985).
McGregor (1982) reported that metalaxyl and cuprous oxide were effective in controlling the black pod disease in Papua New Guinea.
Minor pests/diseases
The other common but less serious pest and diseases recorded in Malaysia include the following:-
- Colletotrichum leaf spot and phytophthora blight in the nursery
- Civets, monkey, Dichrocrocis punctiferalis , Porthesia similis and Conopia spp . pod pests.
- Botryodiplodia theobromae brown pod disease.
- Zuezera coffeae , Endoclita hosei , Xyleborus spp and Inderbella biciblaga stem/bark borers.
- Phytophthora stem canker, pink disease (Corticium salmonicolor) and Marasmius thread blight diseases on the stem.
- A wide range of Coleopteran, Lepidopteran and Orthopteran leaf eating pests
- White root (Rigidoporus lignosus) and brown root (Phellinus noxius) diseases
From the foregoing, it is not difficult to see that pest and disease control is a very important aspect of cocoa estate management.
Reference
Ooi L.H. and Chew P.S. 1985. Some important agronomic and agricultural practices in cocoa estates. TDMB Plantation Management Seminar, Kuala Trengganu
Note: The full list of references quoted in this article is available from the above paper.
Papers : Oil Palm Breeding and Tissue Culture
Soh A.C. 1990. Oil palm breeding – breeding into the 21st century. Plant Breeding Abstr. 60 : 1437-1444. The Planter. Incorporated Society of Planters, Kuala Lumpur 67 (782) : 208-215.
Soh A.C. 1991. Potential for Oil Palm improvement through clones. Presented at Workshop on Problems in Oil Palm Clones. Palm Oil Research Institute of Malaysia, Kuala Lumpur. Preprint.
Soh A.C. 1991. Strategies in breeding and selection for oil palm clones. Presented at Workshop on Problems in Oil Palm Clones. Palm Oil Research Institute of Malaysia, Kuala Lumpur. Preprint.
Soh A.C., Lee C.H., Yong Y.Y., Chow C.W, Tan Y.P., Rajanaidu and Phua P.K. 1991. The Precision of Oil Palm breeding experiments in Malaysia. Proc. Symposium on Application of Statistics to Perennial Tree Crop Research. International Society for Oil Palm Breeders/Palm Oil Research Institute of Malaysia, Kuala Lumpur, Kuala Lumpur : 41-50.
Soh A.C. 1992. Breeding plans and selection methods in oil palm. Presented at ISOPB-Symposium in Montpellier, France on July 1-3, 1992. Preprint.
Soh A.C. 1992. Developments in oil palm planting material. Presented at Seminar on Advances in cocoa and oil palm in meeting future challenges. Incorporated Society of Planters, Lahad Datu, Sabah. Preprint.
Soh A.C. and Chow C.S. 1992. Index selection utilising plot and relative information in oil palm. Elaeis, Palm Oil Research Institute of Malaysia, Kuala Lumpur 5: 27-37.
Soh A.C., Yong Y.Y., Ho Y.W., and Rajanaidu N. 1993. Commercial potential of oil palm clones : early results of their performance in several locations. Proc. Tissue Culture Symposium on recent developments in oil palm tissue culture and biotechnology, International Society of Oil Palm Breeders, Selangor : 134-144.
Soh A.C. 1994. Ranking parents by best linear unbraised prediction (BLUP) breeding values in oil palm. Euphytica, The Netherlands 76 : 13-21.
Soh A.C., Chow C.S., Iyawa S. and Yamada Y. 1994. Candidate traits for index selection in oil palm for clonal propagation. Euphytica, The Netherlands 76: 23-32.
Soh A.C., Rajanaidu N. and CheahS.C. 1994. Oil palm breeding : the previous and the next 50 years. Proc. International Planters Conference on Management for enhanced profitabiltity in plantations. Incorporated Society of Planters, Kuala Lumpur : 35-52.
Soh A.C., Tan H., Lee C.H., Rajanaidu N., Cheah S.C., Low F.C. and Ooi L.H. 1994. Genetic improvement of plantation crops in Malaysia. Proc. 1st National Congress on Genetics. Genetics Society of Malaysia : 55-69.
Soh, A.C. 1995. Commercial potential of oil palm clones: early results of their performance in several locations. Proc. Recent Developments in Oil Palm Tissue Culture and Biotechnology. International Society of Oil Palm Breeders, Selangor : 134-144.
Soh A.C. 1996. Review of ortet selection in oil palm. Presented at 1996 PIPOC Satellite Workshop on Oil Palm Clones : Where Are We?. The Planter. Incorporated Society of Planters, Kuala Lumpur 74(865) : 217-226.
Soh A.C. and Hor T.Y. 2000. Combining ability correlations for bunch yield and its components in outcrossed populations of oil palm. In: Rajanaidu, N. and Ariffin, D. (eds.). Proc. Intermational Symposium On Oil Palm Genetic Resources and Utilization. Malaysian Palm Oil Board. Kuala Lumpur : M1-M14.
Soh A.C., Wong G., Hor T.Y. and Tan C.C. 2000. Expected genetic improvements inoil palm planting materials. Oils and Fats International Congress 2000 (OFIC 2000) held from 4 to 8/9/2000. Bulletin Malaysian Oil Science and Technology Vol.11 No. 2/02 : 86-91.
Soh A.C., Wong G., Tan C.C., Chew P.S., Hor T.Y., Chong S.P. and Gopal K. 2001. Recent advances towards commercial production of elite oil palm clones. Proc. International Palm Oil Congress on cutting-edge technologies for sustained competitiveness. Malaysian Palm Oil Board, Bangi : 33-44
Soh A.C. 2002. Narrowing the yield gap in oil palm between potential and realisation. Guest Editorial : The Planter. Incorporated Society of Planters, Kuala Lumpur 78 (919) : 541-544.
Soh A.C. 2002. Breeding plans and selection methods in oil palm. In: N. Rajanaidu and B.S. Jalani (eds.). Proc. Symposium on the Science of Oil Palm Breeding. Palm Oil Research Institute of Malaysia, Kuala Lumpur : 65-95
Soh A.C. and Goh K.J. 2002. Elevating the national oil palm productivity – breeding and agronomic R&D aspects. Malaysian Palm Oil Board seminar on elevating the national oil palm productivity held 6+7/5/02. Preprint.
Soh A.C., Rajanaidu N., Hor T.Y. and Gan H.H. 2002. Combining abilities of selected parents of PORIM’s Nigerian oil palm prospection in introgressed progenies with AAR’s advanced breeding parents. In: Rajanaidu, N. and Jalani, B.S. (eds). Proc. Seminar on PS1 and PS2 Oil Palm Planting Materials, Palm Oil Research Institute of Malaysia, Kuala Lumpur: 30-53
Soh A.C., Gan H.H., Wong G., Hor T.Y. and Tan C.C. 2003. Estimates of within family genetic variability for clonal selection in oil palm. Euphytica, Kluwer Academic Publishers, Netherlands133 : 147-163.
Soh A.C., Wong G., Hor T.Y., Tan C.C. and Chew P.S. 2003. Oil palm genetic improvement. In: Janick, J. (ed). Plant Breeding Reviews Vol. 22. John Wiley & Sons, New Jersey : 165-219.
Soh A.C., Wong G., Tan C.C., Hor T.Y. and Wong C.K. 2003. Revisited cloning seedlings of reproduced best DxP cross strategy. Paper presented at ISOPB Seminar at Medan, Oct. 6 to 7, 2003. Preprint.
Soh A.C. 2004. Selecting the ideal plant : what you see is not necessarily what you get. Journal of oil palm research Vol. 16 No. 2 : 121-128. Also presented at Malaysian Palm Oil Board’s PAC Seminars. Bangi, April 2004. Preprint
Soh A.C.,Wong C.K., Tan C.C., Wong G. and Hor T.Y. 2005. Super yielding oil palms – strategic breeding plan. Presented at National Seminar on Advances in Breeding and Clonal Technologies for Super Yielding Planting Materials. Malaysian Palm Oil Board, Bangi. Preprint.
Soh A.C., Wong G., Tan C.C., Choo C.N., Nor Azura and Ho Y.W. 2006. Progress and challenges in commercial mass propagation of clonal oil palm. Pre-edited Proc. International Oil Palm Conference on optimum use of resources : challenges and opportunities for sustainable oil palm development. International Oil Palm Research Institute, Indonesia : AG14
Soh A.C., Wong G., Tan C.C., Chong S.P., Choo C.N., Nor Azura A., and Ho Y.W. 2006. Advances and issues in commercial propagation of oil palm clones. Presented at Workshop on clonal and quality replanting material : towards increasing national productivity by 1 t ha-1 yr-1 on 10/8/06. Malaysian Palm Oil Board, Bangi. Preprint.
Soh A.C., Wong G., Tan C.C., Chew P.S., Chong S.P., Ho Y.W., Wong C.K., Choo C.N., Norazura A. and Kumar K. 2011. Commercial-scale propagation and planting of elite oil palm clones:research and development towards realization. Jr. Oil Palm Research (23):935-952. Also reproduced in The Planter, Incorporated Society of Planters, Kuala Lumpur 87(1028) : 835-856.
Records 31 to 60 of 69
Papers : Oil Palm Breeding and Tissue Culture
Cheah S.C., Sharma M. and Soh A.C. 2004. Novel oil palm planting materials from breeding and biotechnology – implications on crop management in 2020. Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 43-60
Choo C.N., Wong C.K., NurAkilla M.R., Ee C.C., Ilham A.A., and Tan C.C. 2014. Genotype effect on oil palm tissue culture callogenesis and embryogenesis. Proc. International Oil Palm Conference (IOPC). International Oil Palm Research Institute, Bali, Indonesia. Preprint.
Chow C.S. and Soh A.C. 1990. Factor analysis of some agronomic and physiological traits in two oil palm breeding trials. Proc. Symposium on Application of Statistics to Perennial Tree Crops Research. International Society for Oil Palm Breeders/Palm Oil Research Institute of Malaysia, Kuala Lumpur : 86-96.
Heriansyah and Tan C.C. 2005. Nursery practices for production of superior oil palm planting materials. The Planter. Incorporated Society of Planters, Kuala Lumpur 81 (948) : 159-171
Ho Y.W. 2007. AAR clonal oil palm performance. Presented at Asgard Seminar on planting materials and nursery management held from 23 and 24 August. Preprint.
Ho Y.W. 2008. Biotechnological approaches in producing oil palm planting material – a success story. Presented at SOPOPRAD & ICAR National Oil Palm Conference held from 2 to 4 February at Vijayawada. Preprint.
Ho Y.W., Tan C.C., Soh A.C., Wong G., Chong S.P., Choo C.N.and Norazurah A. 2008. Tissue culture research at Applied Agricultural Resources Sdn. Bhd. – towards quality planting materials. Presented at 5th National Seed Congress held from 11 to 12 March. Preprint
Hor T.Y., Soh A.C., Chan K.S., Chew P.S. and Goh K.J. 1998. Studies of oil palm bunch characteristic effects on oil extraction rates. In: Rajanaidu N., Henson I.E. and Jalani B.S. (eds). Proc. International Conference on Oil and Kernel Production in Oil Palm – A Global Perspective, 1996. International Society for Oil Palm Breeders and Palm Oil Research Institute of Malaysia, Kuala Lumpur : 229-255
Koh C.L and Soh A.C. 1986. Designer Genes Anyone? Genetic Engineering of Crop Plants in Perspective. The Planter. Incorporated Society of Planters, Kuala Lumpur, 63 : 183-188.
Lee Y.P., Goh K.J. and Teh B.S.C. 2011. Induction of A13+ and H+ toxicities of oil palm (elaeis guineensis) seedlings and their effects on photosynthesis and nutrient uptake. Proc. Soil Science Conf. on soil fertility and plantation productivity. Malaysian Society of Soil Science :261-266. Poster
Loong H.Y., Choo C.N., Wong C.K. and Wong W.C. 2013. The mantled phenotype in oil palm and an optimised protein extraction protocol from inflorescence tissues of oil palm to study this. 2013 In Vitro Biology Meeting. 15 – 19 June 2013, Rhode Island, USA.
Ng C.L., Paranjothy K., Mak C and Soh A.C. 1993. Assaying endogenous cytokinin levels in inflorescences of normal and mantled oil palm ramets . Proc. Tissue Culture Symposium on recent developments in oil palm tissue culture and biotechnology. International Society for Oil Palm Breeders, Bangi : 98-115
Ooi L.H. 2005.How Much to Pay ForClonal Oil Palm? The Planter. Incorporated Society of Planters, Kuala Lumpur, 81(954) : 547-566
Ooi S.E., Choo C.N., Zamzuri I., and Ong-Adullah M. 2012. A candidate auxin-responsive expression marker gene, EgIAA9, for somatic embryogenesis in oil palm (Elaeis guineensis Jacq.). Plant Cell Tiss Organ Cult, 110: 201-212.
Ooi S.E, Choo C.N., Zamzuri I., and Ong-Adullah M. 2013. Candidate hormone-responsive markers for callogenesis of oil palm (Elaeis guineensis Jacq.). Journal of Oil Palm Research, vol. 25(1): 9-21.
Paranjothy K., Rohani O., Tan C.C., Wong G. and Soh A.C. 1993. Incidence of abnormalities in relation to in vitro protocols. Proc. Tissue Culture Symposium on recent developments in oil palm tissue culture and biotechnology. International Society for Oil Palm Breeders, Bangi : 77-85.
Periasamy A., Gopal K. and Soh A.C. 2002. Productivity improvements in seed processing techniques for commercial oil palm seed production. The Planter. Incorporated Society of Planters, Kuala Lumpur 78 (917): 429-442.
Rajanaidu N., Jalani B.S., Soh A.C., Tek J., Musa B., Chin C.W. and Yong Y.Y. 1996. Performance of second generation of PORIM Nigerian material evaluated in Malaysia. Proc. International Palm Oil Congress on Competitiveness for the 21st Century. Palm Oil Research Institute of Malaysia, Kuala Lumpur : 32-45.
Soh, A.C. 1984. Book Review: Efficiency in Plant Breeding 1984. Proc. 10th Congress European Association for Research on Plant Breeding (EUCARPIA). SABRAO Journal 17: 92-95.
Soh, A.C., R.V. Frakes, D.O. Chilcote and D.A. Sleper, 1984. Genetic variation in acid detergent fiber, neutral detergent fiber, hemicellulose, crude protein and their relationship with in vitro dry matter digestibility in tall fescue. Crop Science 24 : 721-727.
Soh, A.C. 1986. Expected yield increase with selected oil palm clones from current DxP seedling materials and its implications on clonal propagation, breeding and ortet selection. Oleagineux 41(2): 51-56. (Also presented at 5th SABRAO International Congress, Bangkok, Nov. 1985).
Soh A.C. 1986. Abnormal oil palm clones – possible causes and implications : Further discussions. The Planter. Incorporated Society of Planters, Kuala Lumpur 63 : 59-65.
Soh A.C. 1986. Current Issues in oil palm breeding. Malaya Applied Biology 16 : 101-108
Soh A.C. 1986. Anticipated yield increase with selected oil palm clones from current DxP seedling materials and its implications on clonal propagation, breeding and ortet selection. Proc. 5th Int. Congress of SABRAO : 533-544. Also in Oleagineux 41 : 51-56.
Soh, A.C. 1986. Strategies in breeding and selection for oil palm clones. Proc. Colloquium on Breeding and Selection for Clonal Oil Palms. International Society for Oil Palm Breeders/Palm Oil Research Institute of Malaysia, Bangi : 52-62.
Soh A.C. 1987. Indirect selection for oil yield in oil palm clones. Proc. International Oil Palm/Palm Oil Conferences : Progress and Prospect. Incorporated Society of Planters, Kuala Lumpur : 167-172.
Soh A.C., Lee C.H. and Chin C.W. 1988. Suitable plot sizes and replications in Oil Palm Breeding Experiments. SABRAO Journal 21 : 143-150
Soh, A.C. 1988. Oil palm micropropagation.Unexpected variation in field tests.Agricell Report 11:34
Soh A.C., Tan C.C. and Wong G. 1988. Clonal propagation of oil palm, current experiences and their implications to breeding and cloning. Presented at the Moet Hennessy-Louis Vuiton Conference on advanced technology and plant breeding strategy.
Records 1 to 30 of 69
Cocoa: Fertilizer Requirements
Introduction
In modern cocoa cultivation, the aim is to maximize early growth and obtain high early yields and sustained peak yields subsequently. To achieve this, it is necessary to have a good understanding of the factors affecting growth and yield of cocoa and to put in the necessary management practices on time as required by the cocoa plant. An essential ingredient in most cocoa growing situations is high fertilizer input. However, the agronomy of cocoa is much more complex than with other crops eg. oil palm and there is very strong interaction between nutrition and other agronomic factors in cocoa such as shade, planting density, pests and diseases etc. To achieve high yields therefore, these factors should not be limiting.
In this paper, the technique for drawing up fertilizer recommendations for the crop is outlined and the interrelationship of the agronomic factors in cocoa plantations with nutrition is discussed. It is hoped that this will enable managers to understand the need for ensuring that planting practices are correct in order to obtain the maximum yield responses from fertilizer applications made.
Nutrient requirement of cocoa
The cocoa plant in its native habitat on the ground storey of the Amazon jungle is very heavily shaded and grows slowly with very low yields. Under these circumstances, nutrient requirements are probably very low.
Nutrients are taken up by cocoa in growth and for yield. The nutrients may be immobilized in the plant or recycled as leaf litter when the plant are mature and the nutrients are exported in the pods that are removed from the field.
The growth and yield potential of cocoa is primarily determined by management factors, soil, climate and the availability of nutrients for growth and yield. The former factors determine the potentials largely and to assess nutrient requirements accurately, a good assessment of the potential growth and yield under the prevailing soil and climate conditions and expected management inputs is necessary.
The most important management factors are probably the types of planting materials affecting the yield potential and growth and nutrient uptake characteristics, nursery practices affecting the quality of seedlings, early growth and yields, shade regimes which interact very strongly with most other factors and determine the growth and yield that will be obtained, weed control practices determining the extent of competition for nutrients and soil moisture, plant density determining the overall yield and nutrients immobilized as well as pests and diseases which affect the total dry matter production and growth rates and thereby nutrient requirements.
The shade regime and the types of shade trees used are important as growth rates will be affected markedly. The extent of competition by the shade tree could be very significant e.g. in the cocoa/coconut cropping system as compared to monococoa with a nitrogen fixing shade tree such as Gliricidia.
The main climatic factors affecting nutrient requirements are probably the rainfall affecting soil moisture, temperatures affecting overall growth and also degree of moisture stress and light available determining the energy available to the plant for dry matter production and also having a bearing on the soil moisture requirement by the plants.
The third important factor is the soil. Although individual soil properties are measured and determined, they are finally intergrated to determine its ability to supply and store moisture and nutrients for the plant and its properties as a medium of growth for the roots and root activity which determine in turn its ability to exploit the soil moisture and nutrient contained therein.
These factors discussed so far determine the growth and yield potentials for cocoa in an area. An estimate is now required of the nutrients required by the cocoa plant for their growth and yield. Several estimates have been made of the nutrient requirements of cocoa e.g. Thong and Ng (1978), Teo and Chew (1984). These estimates obtained depend on the growth and yield expected under the growth conditions prevailing. It is necessary however to make these estimates to try and quatify the amounts of nutrients that are required and the important nutrients taken up by the plant.
For the purpose of this paper, the data provided by Thong and Ng (1978) i.e. where the nutrient requirements for growth and yield in monoculture cocoa on an inland soil are discussed. Table 8 shows dry matter production and distribution in cocoa plants of different ages. Dry matter accumulation in cocoa increases very rapidly up to the fifth year after planting and stabilizes after that.
The nutrients immobilized in the plant are shown in Figure 4 where the early very rapid growth rate is reflected in the very rapid nutrient uptake especially of potassium and nitrogen in the first 5 years.
Table 8 : Dry matter production and distribution in cocoa plants
|
Age of plants (months) |
Total dry matter (kg/plant) |
% Distribution |
||||
|
Leaves |
Stem |
Branches |
Fruits |
Roots |
||
|
5 |
0.027 |
51.9 |
29.6 |
– |
– |
18.5 |
|
12 |
0.68 |
26.4 |
38.7 |
13.2 |
– |
21.8 |
|
28 |
11.92 |
32.1 |
15.8 |
30.8 |
3.3 |
18.0 |
|
39 |
21.41 |
25.9 |
11.1 |
30.2 |
11.5 |
24.5 |
|
50 |
31.84 |
24.0 |
13.3 |
34.0 |
9.5 |
19.2 |
|
61 |
44.91 |
21.7 |
13.8 |
45.3 |
2.7 |
16.6 |
|
72 |
39.95 |
20.6 |
11.6 |
43.8 |
5.1 |
18.9 |
|
87 |
56.11 |
15.3 |
16.4 |
51.2 |
1.9 |
15.3 |
(Thong and Ng, 1978)
Figure 4 : Nutrient uptake of cocoa (Ling, 1983)
The total nutrients immobilized in 5 year old cocoa in 2 inland soils in Malaysia when the cocoa canopies have reached the plateau in growth rate are given in Table 9. The very high accumulation in the cocoa plants of potassium and nitrogen is clearly seen. Taking the mean values of 250 kg/ha N and 300 kg/ha K, this is equivalent to 1.1 kg ammonium sulphate and 0.6 kg muriate of potash taken up by each cocoa bush. These nutrients are locked up within the bushes and only become available again to the plant through recycling of the leaf litter and from leaching particularly of K from the leaves in rainfall.
Cocoa leaf litter production and nutrient contents is shown in Table 10. Very high amounts of nutrients are recycled in the leaf litter particularly for N, K, Mg, Ca and after the sixth year. Nutrient cycling is still not high in the fourth year.
Beside nutrients removed from the soil and immobilized in the bushes, nutrients are exported as yield is removed in the pods harvested. The pods have very high nutrient contents equivalent to 31 kg N, 54 kg K, 4.9 kg P, 5.2 kg Mg and 4.9 kg Ca at a yield level of 1 ton dry beans/ha/year (Table 11). The beans are particularly high in N and P and the pods in K contents. The nutrients removed vary with age and yield levels. If the husks are recycled, considerable quantities of nutrients especially K and N, are returned and they have a marked effect on the nutrient availability of the soil as seen in Table 12. Nutrient requirements may then be markedly reduced.
In the monocropping system therefore, the cocoa bushes have very high nutrient requirement for growth and yield, increasing very rapidly in the first 5 years and then reaching a plateau after that with subsequent increases depending mainly on export of nutrients in increased yield. Even then, the nutrient requirements are reduced if husks of the pods which form a very substantial portion of the nutrients removed are recycled to the fields. In addition, in mature areas, nutrient recycling in the litter is significant. Overall nutrient requirements in mature cocoa may therefore not be high.
The above discussion deals with the basic factors involved in estimating nutrient requirements in cocoa. However, as the variables cannot always be assessed accurately, it is useful to employ additional checks to determine if nutrition of the cocoa trees is good. Commonly, the techniques adopted are to check for nutrient deficiency symptoms (Loue, 1962) to sample the leaves and check leaf nutrient levels, to take growth measurements of the cocoa to ascertain the growth rates and also to determine if the yield levels are up to expectation for the agronomic conditions involved.
Nutrient deficiency symptoms are described and illustrated in Wood (1975) and examples of interpretations of leaf nutrient levels are given in Tables 13 and 14 for major nutrients and minor nutrients respectively.
Table 9 : Nutrients immobilized in 5 year old cocoa (Ling, 1983 )
|
Nutrient |
kg/ha |
|
|
Munchong |
Bungor |
|
|
N |
256 |
246 |
|
P |
27 |
22 |
|
K |
354 |
272 |
|
Mg |
81 |
87 |
|
Ca |
198 |
141 |
|
Dry matter |
27,775 |
25,830 |
Table 10 : Cocoa litter production and nutrient contents (Ling, 1983 )
|
Age (years) |
Dry matter (kg/ha) |
kg/ha |
||||
|
N |
P |
K |
Mg |
Ca |
||
|
4 |
2538 |
38 |
2 |
33 |
15 |
30 |
|
6 |
5032 |
80 |
4 |
80 |
28 |
67 |
|
8 |
4560 |
72 |
4 |
81 |
27 |
56 |
|
10 |
5556 |
87 |
5 |
91 |
31 |
71 |
Table 11 : Nutrients in pod production (Ling, 1983 )
|
Ages |
Dry bean yield |
Component |
(kg) |
||||
|
N |
P |
K |
Mg |
Ca |
|||
|
3 |
450 |
Beans |
9.2 |
1.6 |
4.7 |
1.2 |
0.5 |
|
Husk |
4.9 |
0.6 |
20.3 |
1.2 |
1.8 |
||
|
Total |
14.1 |
2.2 |
25.0 |
2.4 |
2.3 |
||
|
5 |
1000 |
Beans |
20.4 |
3.6 |
10.5 |
2.7 |
1.1 |
|
Husk |
10.6 |
1.3 |
43.3 |
2.5 |
3.8 |
||
|
Total |
31.0 |
4.9 |
53.8 |
5.2 |
4.9 |
||
|
7 |
1400 |
Beans |
28.6 |
5.0 |
14.7 |
3.8 |
1.5 |
|
Husk |
15.4 |
2.0 |
63.1 |
3.6 |
5.6 |
||
|
Total |
44.0 |
7.0 |
77.8 |
7.4 |
7.1 |
||
Table 12 : Effects of pod husks on soil chemical properties (0-15 cm) (Ling, 1983 )
| Parameter |
Treatment |
|
|
Without pod husks |
Pod husks (10 kg dry/tree) |
|
| PH |
4.4 |
4.4 |
| Total N (%) |
0.139 |
0.138 |
| Avail. P (ppm) |
58 |
63 |
| Org. C (%) |
1.13 |
1.35 |
| Acid Ext. K (meg/100 g) |
1.69 |
2.13 |
| Acid Ext. Mg |
0.95 |
0.99 |
| Acid Ext. Ca |
1.16 |
1.21 |
(Modified after Murray, 1966)
|
Nutrient |
% on D.M. |
||
|
Deficient |
Low |
Normal |
|
|
N |
< 1.80 |
1.8 – 2.0 |
> 2.00 |
|
P |
< 0.13 – 1.15 |
0.15 – 0.20 |
> 0.20 |
|
K |
< 1.20 – 1.40 |
1.40 – 2.00 |
> 2.00 |
|
Ca |
< 0.30 |
0.30 – 0.50 |
> 0.50 |
|
Mg |
< 0.20 |
0.20 – 0.45 |
> 0.45 |
(Southern and Dicks, 1969)
|
Nutrient |
ppm on D.M. |
|
|
Critical level |
Deficient level |
|
|
Mn |
30 |
15 |
|
Fe |
50 |
30 |
|
Zn |
30 |
20 |
|
Cu |
6 |
4 |
|
B |
25 |
15 |
Nutrient deficiencies may be indicated from the analysis results especially in gross deficiencies. However non-nutritional factors eg. pests and diseases or drainage may sometimes affect interpretation. Interpretation of leaf analysis in cocoa is not as advanced as in other crops due to difficulties in correlating leaf nutrient levels with yields, probably a result of the high number of variables which affect leaf nutrient levels in the crop.
After consideration of the above factors, in particular, the growth and yield potential of the cocoa, the amount of nutrients required for the expected growth and yield and the nutrient supplying powers of the soil, it is possible to estimate the nutrients required by the cocoa to attain the growth and yield aimed for and to formulate fertilizer recommendations.
Fertiliser recommendations for cocoa
To draw up the fertilizer recommendations for cocoa, the choice of fertilizers to be used, methods and areas of fertilizer applications and factors affecting efficiency of fertilizers used have to be considered.
There is usually a wide choice of fertilizers available. It is necessary particularly to consider the availability and expected efficiency of uptake of the nutrients in the fertilizers, any possible effects on the soil and finally the cost/unit nutrient uptake which is expected. An example may be urea which is the cheapest N fertilizer. However, volatilization losses of N from this fertilizer may be 30 – 50% and in situations where leaf litter is very thick and the fertilizer applied not to be in contact with the soil, N blow-off may be very nearly complete so that no response is obtained from the fertilizer (HRU unpublished report). Ammonium sulphate as another example is usually considered to be an efficient source of N and leaching losses are lower. However, of the nitrogenous fertilizers, it has the highest acidifying effect on the soil and may therefore not be as suitable as less acidifying nitrogenous such as ammonium nitrate in more acid soil conditions. A final example on the importance of choosing the correct fertilizers is the use of the slowly available rock phosphate. In deficient conditions, high rates are required and the rock phosphate used must be finely ground to ensure efficacy.
The method of fertilizer application may determine the efficiency of nutrient uptake especially in marginal soil conditions. Also the fertilizers should be applied over the areas of active root activities to ensure good uptake. Poor application techniques are detrimental in view of the scorching and damage caused to the superficial root system especially in immature cocoa. Frequent use is made of alkaline materials eg. limestone dust. Interaction between fertilizers may be caused if areas overlap with nitrogenous fertilizer applications. Allowance should be made for this in the areas of application. Recommendations on areas of fertilizer application are given in Table 15. All fertilizers should be broadcast evenly over the areas of application to ensure good uptake by the plant.
After the choice of fertilizers for use and the methods and areas of fertilizer application, it is still necessary to schedule applications to take into account the crop nutrient requirements eg. peak cropping period, competition from weeds, rainfall patterns and soil factors such as topography and susceptibility to erosion to draw up the schedule of fertilizer applications that should be made to ensure maximum nutrient uptake for maximum growth and yield by the plants.
A final step is still required to check the estimated fertilizer requirements against fertilizer trial results available, in particular those that have similar factors affecting growth and yield and similar soil conditions. If these results differ significantly from the recommendations, then a thorough reexamination of the factors assumed should be carried out. Unfortunately, many fertilizer trials published have inadequate details to carry this out meaningfully and therefore they are of limited value. In such cases, in view of the systematic approach carried out in the method drawn up for estimating the fertilizer requirements of cocoa, it is often preferred to stick to the estimates drawn up by the system rather than on doubtful information, the basis of which are poorly known.
Economics of fertilizer application
As fertilizers are costly materials, and as nutrient excess or deficiency affect yields and costs of production, it is necessary to ensure that fertilizer applications are beneficial and economic. This is more easily carried out in mature cocoa areas by checking the results of fertilizer trials and responses obtained in these trials and working out the profitability. Strict economic computations are however not always possible in view of the long term nature of cocoa cultivation and the uncertainty of predicting price levels for the product. For immature cocoa, it is not possible to estimate accurately the economic benefits in view of the lack of crop but the very high nutrient requirements of the plant at this stage and the need to ensure good establishment and a uniform stand justify the high application rates of fertilizers at immaturity.
It is timely here to emphasise again the importance of correct assessment of fertilizer requirements in relation to the other growth factors affecting cocoa and the correct usage of fertilizers as otherwise little or no benefits may accrue from the expenditure on fertilizers.
Conclusion
Cocoa will respond well to fertilizer applications if the management factors, soil and climatic conditions are favourable for good growth and yield and if the soils cannot supply the nutrients required on time. This is in view of the strong interaction between nutrients and the management factors to produce good growth and yields. Fertiliser programmes drawn up consider many factors which are assessed on experience and from trial data and the schedules drawn up should be followed for best results to be obtained.
Table 16 : Recommended areas of fertilizer application in cocoa
|
Age of cocoa in field |
Circle sizes (m) |
Area of fertilizer application (m) |
Weeding method |
|
0-6 months (yr. 1) |
0.5 |
0.1-0.3 |
Hand |
|
7-12 months (yr. 1) |
0.75 |
0.1-0.5 |
Herbicide |
|
12-24 months (yr. 2) |
0.75 |
0.2-0.75 |
Herbicide |
|
25-36 months (yr. 3) |
1.0 |
0.2-1.0 |
Herbicide |
|
37-48 months (yr. 4) |
1.25 |
0.2-1.25 |
Herbicide |
|
49-60 months (yr. 5) |
– |
evenly over inter-rows |
Herbicide |
- Sizes all refer to radius from tree base
- All fertilizer to be applied evenly over area of application
- Minimum distance from stem as stipulated
- All magnesium/calcium limestone to be applied between 0.6-1.5m except otherwise stipulated.
Reference
Ooi L.H. and Chew P.S. 1985. Some important agronomic and agricultural practices in cocoa estates. TDMB Plantation Management Seminar, Kuala Trengganu
Note: The full list of references quoted in this article is available from the above paper.
Papers : Oil Palm Agronomy
Liew Y.A., Ng H.C., Chen Z.Y. and Goh K.J. 2014. Efficient and sustainable nutrient management in oil palm plantations.Seminar on synergizing sustainability and profitability in oil palm plantations – challenges & opportunities. The East Malaysia Planters’ Association, Sabah. Preprint.
Lim F.S., Teo T.M. and Goh K.J. 2014. Mitochondrial DNA marker development for oil palm pollinating weevils using Cytochrome Oxidase C Subunit 1 (COX1). International Symposium of insects 1 to 3/12. Entomological Society of M’sia, Kuala Lumpur. Poster (Best Poster).
Lim K.H., Goh K.J., Kee K.K. and Henson I.E. 2004. Climatic effects on oil palm performance and some ameliorating measures. Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 351-372
Lim K.H., Goh K.J., Kee K.K. and Henson I.E. 2008. Climatic requirements of oil palm. Proc. Seminar on agronomic principles and practices of oil palm cultivation. Agricultural Crop Trust:1-28. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:1-46.
Loong H.Y., Gan H.H., Kee K.K. and Goh K.J. 2013. Nutriomics and its potential application to the oil palm industry. Journal of Oil Palm Research.(In press, mini-review)
Mahamooth T.N., Sim C.C., Gan H.H., Kee K.K. and Goh K.J. 2007. Water cycling in mature oil palm on rolling terrain. In: Hamdan J., Goh K.J., Che Fauziah I., Melling L., Ahmad O.H., Jalloh M.B., Sayok A. and Siva K.B. (eds). Proc. Soils Conference on peat and other soil factors in crop production. Malaysian Society of Soil Science and Department of Agriculture Sarawak, Sibu, Malaysia: 327-330. Poster.
Mahamooth T.N., Gan H.H., Kee K.K. and Goh K.J. 2008. Water requirements and cycling of oil palm. Proc. Seminar on agronomic principles and practices of oil palm cultivation.Agricultural Crop Trust:57-96. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:89-144.
Ng H.C.P., Chew P.S., Goh K.J. and Kee K.K. 1999. Nutrient requirements and sustainability in mature oil palms – an assessment. Presented at Seminar on Effective Fertiliser Management. Incorporated Society of Planters, Kluang, Johore. Edited paper in The Planter, Incorporated Society of Planters, Kuala Lumpur 75 (880): 331-345
Ng H.C.P.and Tan C. C. 2003. Towards the establishment of a good oil palm planting. Annual Report 2002. Royal Johore Planters’ Association : 22-30.
Ng H.C.P. and Goh K.J. 2003. Basic principles of fertiliser management in Miri-Bintulu Sarawak. Presented at Seminar on Managing Soils of the Miri-Bintulu area, Sarawak, 8-11/12/03. Malaysian Society of Soil Science. Preprint.
Ng H.C.P., Gan H.H. and Goh K.J. 2004. Soil nutrient changes in ultisols under oil palm in Johore, Malaysia. Presented at Oils and Fats International Congress (OFIC) in Module on Agriculture, Biotechnology and Sustainability (ABS). Malaysian Oil Scientists and Technologies Association, Kuala Lumpur. Preprint.
Ng H.C.P. and Goh K.J. 2004. Oil palm does not necessarily exhibit visual toxicity symptoms to excessive fertiliser application. In: Zakaria Z.Z., Balasundram S.K., Goh K.J., Hanafi M.H., Izham A., Fauziah C.I. amd Halimi M.S. (eds). Proc. Conference on Innovations in Soil Science for Sustainable Agriculture. Malaysian Society of Soil Science, Kuala Lumpur : 121-123. Poster.
Ng H. C., Goh K. J., Gan H. H. and Zaharah A. R. 2006. Impact of phosphate rock and legume planting system on P uptake and dry matter production of Mucuna bracteata under oil palm. In: Fauziah I., Shamshuddin J., Zin Z.Z., Zauyah S.D., Goh K.J., Jalloh M.B., Osumanu H.A. and Rosazlin A. (eds). Proc. Soils on Strategies for Enhanced Soil and Crop Quality. Malaysian Society of Soil Science, Kuala Lumpur : 63 – 67.
Ng H.C.P., Goh K.J., Mahamooth T.N. and Petronella G.A.T. 2013. Challenges in fertiliser and cover crop management. Proc National Seminar on Confronting management challenges in the oil palm industry. Incorporated Society of Planters, Kuala Lumpur : 129-148
Ng P.H.C., Goh K.J. and Tasren N.M. 2014. Prevention of soil degradation for oil palm sustainability. The 20th World Congress of Soil Science on Soils Embrace Life and Universe held from 8 to 13 June. International Union of Soil Sciences, Jeju. Korea. Poster.
Ng P.H.C., Goh K.J., Gan H.H., Shahrakbah Y. and Zaharah A.R. 2014. The use of reactive phosphate rocks in oil palm and legume systems to enhance sustainability. Seminar on highly reactive phosphate rock for plantation tree crops held on 12 August. Union Harvest, Kuala Lumpur.
Ng P.H.C., Arif S., Goh K.J., Tasren, N.M. and Petronella, G.A.T. 2014. The role of fertilizers in sustainable palm oil production. ISOPA Seminar held on June 16, 2014,Bali. International Society of Oil Palm Agronomists: Preprint.
Ng P.H.C., Goh K.J. and Zaharah A.R. 2014.Direct applications of phosphate rocks on sustainability of oil palm plantations. In: Benites, V.M., Junior, A.O., Pavinato, P.S., Teixeira, P.C., Moraes, M.F., Leite, R.M.V.B.C. and Oliveira, R.P. (eds). Proc. 16th World Fertilizer Congress on Technological Innovation for a Sustainable Tropical Agriculture. Int. Scientific Centre of Fertilizers (CIEC), Rio de Janeiro, Brazil: 135 – 137.
Ng P.H.C., Goh K.J. and Zaharah A.R. 2014.Use of phosphate rocks and leguminous cover crops in a sustainable oil palm system. Crops For the Future Research Centre Workshop held on 20 November, Kuala Lumpur. Presentation.
Ooi L.H., Tan C.C., Gan H.H. and Heng Y.C. 2004. Yield variation and seasonality in oil palm. Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 301-315
Ooi, L.H. and Kodiappan P. 2005. Optimum replanting age of oil palms. Proc. International Palm Oil Congress on Technological Breakthroughs and Commercialization – The Way Forward. Malaysian Palm Oil Board, Kuala Lumpur : 305-329
Ooi L.H., Lee K.H., Chan K.S., Ho C.W. and Vijayarajan V. 2006. Zero-waste zero discharge method of treating palm oil mill effluent and empty fruit bunch. Pre-edited Proc. International Oil Palm Conference on optimum use of resources : challenges and opportunities for sustainable oil palm development. IOPRI, Indonesia : CTE19. Also presented at the 15th International Oil Palm Conference, September 19 – 22, 2006, Cartagena de Indias, Colombia.
Ooi L.H. 2008. Agronomic principles and practices of replanting oil palm. Proc. Seminar on agronomic principles and practices of oil palm cultivation. Agricultural Crop Trust. Preprint. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:171-197.
Petronella G.A.T., Mohd Kamil Yusoff, Nik Muhamad Majid, Goh K.J. and Gan H.H. 2009. Effect of N and K fertilizers on nutrient leaching and groundwater quality under mature oil palm in Sabah during the monsoon period. Am. Jr. of Appl. Sciences 6 (10):1788-1799
Shahrakbah Y., Arif S. and Kee K.K. 2008. Soil and water conservation under oil palm cultivation. Proc. Seminar on agronomic principles and practices of oil palm cultivation. Agricultural Crop Trust. Preprint. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:483-509.
Sim C.C., Teo C.B. and Tey S.H. 2009. Replanting for sustainable high yield. The Planter. Incorporated Society of Planters, Kuala Lumpur : Vol.84 No.992, 739-751.
Sim C.C., Zaharah A.R., Sharifah S.R.S.A and Goh K.J. 2013. Differential growth responses and potassium uptake of three oil palm crosses under adequate and deficient potassium supplies. Proc. XVII International Plant Nutrition Colloquium and Boron Satellite Meeting. Sabanci University, Istanbul.ISBN 978‐605‐4348‐62‐6 :561-562
Soh, A.C., Kee K.K., Goh K.J., Ang B.N. and Ooi L.H.2008. Oil Palm. In : Janick, J. and Paul R.E. (eds). Book chapter. Encyclopedia of Fruits and Nuts. CABI International, United Kingdom:118-127
Records 91 to 120 of 136
Papers : Oil Palm Agronomy
Goh K.J. and Chui S.B. 2006. Mucuna bracteata, a cover crop and living green manure: future work and a generalised policy for its establishment. In: Goh K.J. and Chui S.B. (eds). Mucuna bracteata: A cover crop and living green manure. Agricultural Crop Trust (ACT), Kuala Lumpur: 143-163.Goh K.J., Gan H.H., Kee K.K., Chew P.S. and Teoh K.C. 2006. Boron requirement and distribution in the oil palm (Elaeis guineensis Jacq.) and some implications on manuring practices. In: Xu F.; Goldbach H.E.; Brown P.H.; Bell R.W.; Fujiwara T.; Hunt C.D.; Goldberg S. and Shi L. (eds). Proc. International Symposium on All Aspects of Plant and Animal Boron Nutrition, Springer, The Netherlands: 189-202
Goh K.J. 2007. The cultivation of Mucuna bracteata – A pictorial guide. In: Goh K.J. and Chui S.B. (eds). Mucuna bracteata: A cover crop and living green manure. Agricultural Crop Trust (ACT), Kuala Lumpur: 165-170.
Goh K.J. and Teo C.B. 2008. Agronomic principles and practices of fertilizer management of oil palm. Proc. Seminar on agronomic principles and practices of oil palm cultivation. Agricultural Crop Trust:157-210. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:241-318.
Goh K.J., Ng, H.C.P, Gan H.H., Yacob S., Kee K.K. and Teo C.B. 2008. Introduction of shade-tolerant leguminous cover crop, Mucuna bracteata, enhances the sustainability of oil palm (Elaeis guineensis). Proc. 5th Int. Crop Science Congress, Jeju, Korea, 13-18 April. Poster
Goh K.J., Ng H.C. and Lee C.T. 2009. Fertiliser management and productivity of oil palm in Malaysia. In: E. Pushparajah (ed). Proc. International Planters Conference on Plantation Agriculture and Environment. Incorporated Society of Planters, Kuala Lumpur : 49-87
Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust, Kuala Lumpur.
Goh K.J., Teo C.B., Ng H.C. and Kee K.K. 2012. AAR approach to determining oil palm fertiliser requirements. Presented at XVII International Oil Palm onference held in Cartagena, Colombia from 26 to 28/9/13.
Goh K.J. 2014. Carbon assimilation, dry matter production and partitioning of growth and yield in oil palm. Kuala Lumpur Kepong Mini Conf. for Junior Managers and Senior and Junior Assistant Managers, February 22-24, 2014. Applied Agricultural Resources, Kuala Lumpur Kepong Bhd., Kuala Lumpur: Preprint
Goh K.J., Ng H.C., Wong C.K. and Arif S. 2014. Yield potential of oil palm and its attainment in Malaysia. Presented at National Seminar (NATSEM) Plantation Industry: Sustaining the competitive edge. The Planter. Incorporated Society of Planters, Kuala Lumpur Vol. 90 (1060) : 503-520.
GohYt.K., Lai C.H., Wong K.L., Tasren N.M., Gan H.H., Goh Y.K. and Goh K.J. 2014. Contact and systemic herbicides’ control of Mucunabracteata DC. Ex Kurz legume cover crop in immature oil palm. Proc. 8th International Conference on Plant Protection in the Tropics. Malaysian Plant Protection Society: 98-99. Poster
GohYt.K., Lai C.H., Tasren N.M., Gan H.H., Goh Y.K. and Goh K.J. 2014. Chemical control of MucunaBracteata DC. Ex Kurz Legume cover crop. Oil Palm Bulletin. Malaysian Palm Oil Board, Kuala Lumpur: 64:16-24.
Han K.J. and Chew P.S. 1984. Growth and nutrient contents of leguminous covers in oil palm plantations in Malaysia. Proc. International Planters Conference : The Oil Palm in Agriculture in the 80’s Vol. II. Incorporated Society of Planters, Kuala Lumpur : 235 252.
Kee K.K., Goh K.J. and Chew P.S. 1993. Induced manganese deficiency in mature oil palm in Malaysia. Fert. Research 40 : 1-6. Presented as poster in PORIM International Palm Oil Congress : Update and Vision, 1993 : 16pp.
Kee K.K. and Chew P.S. 1993. Oil palm responses to nitrogen and drip irrigation in a wet monsoonal climate in P. Malaysia. Proc. 1991 PORIM International Palm Oil Conference : Progress, Prospects and Challenges towards the 21st Century. Palm Oil Research Institute Malaysia, Kuala Lumpur : 321 339.
Kee K.K., Goh K.J., Chew P.S. and Tey S.H. 1994. An integrated site specific fertilliser recommendations system (INFERS) for high productivity in mature oil palms. In: Chee K.H. (ed). Proc. International Planters’ Conference on Managing Oil Palms for Enhanced Profitability. International Society of Planters, Kuala Lumpur : 83-100.
Kee K.K., Chew P.S. and Goh K.J. 1995. Manganese deficiency in mature oil palms in Malaysia deficiency symptoms, foliar levels and responses. Fertilizer Research No. 40 : 1-6.
Kee K.K., Goh K.J. and Chew P.S. 1995. Investigation into manganese deficiency in mature oil palms (E. guineensis) in Malaysia. Fertilizer Research 40. Kluwer Academic Publishers, The Netherlands : 1-6
Kee K.K. 1995. Fertiliser management in oil palms. Presented at BEA group internal audit department on 6 January.
Kee K.K. and Chew P.S. 1996. Nutrient losses through surface runoff and soil erosion – implications for improved fertiliser efficiency in mature oil palms. Proc. International Palm Oil Congress – Competitiveness for the 21st century. Palm Oil Research Institute of Malaysia, Kuala Lumpur : 153-169.
Kee K.K. and Chew P.S. 1997. Nutrients recycled from pruned fronds in mature oil palm (Elaeis guineensis Jacq.). In: Ando T. et al. (eds). Plant Nutrition – for sustainable food production and environment. Kluwer Academic Publication. Tokyo, Japan : 601-602.
Kee K.K., Chew P.S., Gan H.H. and Goh K.J. 1999. Validation of a site yield potential model for oil palms in Malaysia. In: Jatmika A., Bangun D., Asmono D., Sutarta E.S., Kabul P., Guritno P., Prawirosukarto S., Wahyono T., Herawan T., Hutomo T., Darmosarkoro W., Adiwiganda Y.T. and Poeloengan Z. (eds). Proc. 1998 International Oil Palm Conference On Commodity of the Past, Today and Future. International Oil Palm Research Institute, Bali, Indonesia : 150-163
Kee K.K., Goh K.J. and Chew P.S. 2000. Water cycling and balance in mature oil palm agroecosystem in Malaysia. Proc. International Planters’ Conference on Plantation Tree Crops in the new millennium : the way ahead. Incorporated Society of Planters, Kuala Lumpur : 251-275
Kee K.K. and Soh A.C. 2002. Management of oil palms on slopelands in Malaysia. International Oil Palm Conference on enhancing oil palm industry development through environmentally friendly technology. IOPRI, Bali, 8-12/7/02. Preprint.
Kee K.K., Goh K.J. and Soh A.C. 2003. R&D efforts in efficient utilisation of natural resources in oil palm cultivation. In: Pushparajah E. and Chee K.H. (eds). Proc. International Planters Conference on globalisation and its impact on the palm oil industry. Incorporated Society of Planters, Kuala Lumpur : 175-209.
Kee K.K., Goh K.J., Chow K.C. and Teo L. 2004. Improvement of efficiency of fertiliser applications. Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 269-291
Kee K.K. 2004. Nutrient reserves and recycling from oil palm (Elaeis guineensis Jacq.) trunks at replanting Poster paper in International Crop Science Congress. Brisbane, Australia. (http://www.cropscience.org.au/icsc2004/poster/2/2/376_keekk.htm).
Kee K.K. and Goh K.J. 2006. Efficient fertilizer management for higher productivity and sustainability in oil palm production.Proc. International Planters Conferenceon higher productivity and efficient practices for sustainable plantation agriculture. Incorporated Society of Planters, Kuala Lumpur : 157-182
Kee K.K. and Goh K.J. 2006. Integrated management of fertilization for sustainable oil palm.To be presented at the 15th Int. Oil Palm Conference, September 19 – 22, Cartagena de Indias, Colombia. Unedited.
Kok T.F., Goh K.J., Chew P.S., Gan H.H., Heng Y.C., Tey S.H. and Kee K.K. 2000. Advances in oil palm agronomic recommendation. In: Pushparajah E. (ed). Proc. International Planters Conference on Plantation Tree Crops in the New Millenium: The Way Ahead. Incorporated Society of Planters, Kuala Lumpur : 215-232
Records 61 to 90 of 136
Papers : Oil Palm Agronomy
Goh K.J.and Chew P.S. 1995. Direct application of phosphates to plantation tree crops in Malaysia. Workshop on Direct Application of Phosphate Rocks and Appropriate Technology Fertilisers in Asia: What Hinder Acceptance and Growth. IFDC, Kandy, Sri Lanka: 59-76.Goh K.J., Teo C.B. and Chew P.S. 1996. Fertiliser requirements of oil palms on Kumansi Family soil in Sabah. In: Ooi L.H. and Chew P.S. (eds). Proc. Seminar and Field Daysat Kalumpang Development Corporation, Tawau. Applied Agricultural Research Sdn. Bhd., Selangor : 81-87.
Goh K.J., Chew P.S. and Teoh K.C. 1996. Effects of manuring on canopy biomass and leaf K distribution in mature oil palm (Elaeis guineensis Jacq.) in Malaysia. Presented as poster in 2nd International Crop Science Congress, New Delhi, India.
Goh K.J., Chew P.S. and Gan H.H. 1997. Quantitative land evaluation for sustainability of oil palm plantations. In: Pushparajah E. (ed). Proc. International Planters’ Conference on Plantation Management for the 21st Century. Incorporated Society of Planters, Kuala Lumpur : 311-322.
Goh K.J. and Teo C.B. 1997. Yield potentials and agronomic limitations of oil palms in Tawau-Semporna region, Sabah, Malaysia. Soil Familiarisation Tour 2/97, Tawau-Semporna, Sabah, Malaysian Society of Soil Science, Kuala Lumpur: 16 pp
Goh K.J., Chew P.S. and Teoh K.C. 1999. Ground magnesium limestone as a source of magnesium for mature oil palm on sandy soil in Malaysia. In: Jatmika A., Bangun D., Asmono D., Sutarta E.S., Kabul P., Guritno P., Prawirosukarto S., Wahyono T., Herawan T., Hutomo T., Darmosarkoro W., Adiwiganda Y.T. and Poeloengan Z. (eds). Proc. 1998 International Oil Palm Conference On Commodity of the Past, Today and Future. International Oil Palm Research Institute, Bali, Indonesia : 347-362.
Goh K.J. 2000. Climatic requirements of oil palm for high yields. Proc. Seminar on Managing Oil Palm For High Yields : Agronomic Principles. Malaysian Society of Soil Science/Param Agric. Surveys, Kuala Lumpur : 1-17.
Goh K.J. and Chew P.S. 2000. A lecture note on agronomic requirements and management of oil palm for high yields in Malaysia. Proc. Seminar on Managing Oil Palm For High Yields : Agronomic Principles. Malaysian Society of Soil Science, Kuala Lumpur : 39-73.
Goh K.J. and Kee K.K. 2000. The oil palm sector in Southeast Asia : Changing requirements for fertilizers, particularly P and K. Workshop on Improving Soil Fertility Management in Southeast Asia held from 21-23 November 2000, Bogor, Indonesia. IBSRAM, Thailand. Preprint.
Goh K.J., Tee B.H. and Anuar A.R. 2000. Applicability of precision farming for oil palm plantations in Malaysia. Seminar on Precision Farming held on 16/10/2000 organised by Universiti Pertanian Malaysia and Agricultural Institute of Malaysia, Serdang. Preprint
Goh K.J., Tee B.H., Anuar A.R. and Woo C.Y. 2000. Spatial yield variation of oil palm in a fertiliser response trial in Malaysia. Soil Science Conference of Malaysia 2000, Malaysian Society of Soil Science, Kuala Lumpur. Poster.
Goh K.J., Teo C.B., Chew P.S. and Chiu S.B. 2000. Fertiliser management in oil palm : agronomic principles and field practices. Proc. Seminar on managing oil palm for high yields : agronomic principles. Malaysian Society of Soil Science and Param Agricultural Services : 98-135.
Goh K.J., Kee K.K., Chew P.S., Gan H.H., Heng Y.C. and Ng H.C.P. 2002. Concept of site yield potential and its applications in oil palm plantations. Presented at Oils and Fats International Congress 2000. Bulletin Malaysian Oil Science and Technology Vol.11 No. 2 : 57-63. Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:319-337.
Goh K.J. 2002. Two recent options for oil palm to oil palm replant. Annual Report 2001. Johore Planters Association : 21-26
Goh K.J.,Gan H.H. and Soh A.C. 2002. Oil palm productivity: Commercial FFB yield analysis (Revised version). Seminar On Managing Oil Palms For Maximum Yield. Incorporated Society of Planters, North East Branch, Sabah. Preprint.
Goh K.J., Hardter R. and Fairhurst T. 2003. General Oil Palm Nutrition. In : Thomas Fairhurst and Rolf Hardter (eds). Oil Palm : Management for large and sustainable yields. Potash &Phosphate Institute (PPI), Potash & Phosphate Institute, Canada (PPIC) and International Potash Institute (IPI), Singapore : 191-230.
Goh K.J., Hardter R. and Fairhurst T. 2003. Fertilizing for maximum returns. In : Thomas Fairhurst and Rolf Hardter (eds). Oil Palm : Management for large and sustainable yields. Potash & Phosphate Institute (PPI), Potash & Phosphate Institute, Canada (PPIC) and International Potash Institute (IPI), Singapore : 279-306.
Goh K.J. 2004. Fertiliser recommendation systems for oil palm : estimating the fertiliser rates. In : Chew P.S. and Tan Y.P. (eds). Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 235-268.
Goh K.J., Chew P.S. and Teoh K.C. 2004. Vegetative growth, resource optimization and N productivity of oil palm (Elaeis guineensis jacq.) as influenced by soils and fertilization. Proc. 4th International Crop Science Congress.Brisbane, Australia. Published on CDROM. Website : www.regional.org.au/au/cs
Goh K.J., Gan H.H. and Heng Y.C. 2005. Yield targeting and yield gap analysis in oil palm plantations. Proc. MOSTA Best Practices Workshops – Agronomy & Crop Management. Malaysian Oil Scientists and Technologies Association, Kuala Lumpur : 381-403
Goh K.J., Gan H.H., Kee K.K., Chew P.S. and Teoh K.C. 2005. K cycling in mature oil palm on an Oxisol in Malaysia. In : Li C.J., Oenema O., Zhang F.S., Peng S.B., Dobermann A., Rengel Z., Hinsinger P., Shen Q.R., Lambers H., Welch R., Li X.L. von Wiren N., Marschner P., Yan X.L., Maene L., Zhu Y.G. and McGarth S.(eds). Proc. XV International Plant Nutrition Colloquium on Plant Nutrition for Food Security, Human Health and Environmental Protection. TsinghuaUniversity Press, Beijing, China : 1126-1127.
Goh K.J., Gan H.H, Kee K.K., Chew P.S. and Teoh K.C. 2005. Boron requirement and distribution in the oil palm (Elaeis guineensis Jacq.) and some implications on manuring practices. Proc. International Symposium on all aspects of plant and animal boron nutrition. Wuhan, China : 79.
Goh K.J. 2005. Fertilizer recommendation systems for oil palm: estimating the fertiliser rates. In: Chew P.S. and Tan Y.P. (eds). Proc. MOSTA Best Practices Workshops – Agronomy and Crop Management. Malaysian Oil Scientists’ and Technologists, Kuala Lumpur : 235-268.Also published in Goh K.J., Chiu S.B. and Paramananthan S. (eds). 2011. Agronomic Principles and Practices of Oil Palm Cultivation. Agricultural Crop Trust:338-388.
Goh K.J. 2006. The cultivation of Mucuna bracteata – A pictorial guide. In: Goh, K.J. and Chui, S.B. (eds). Mucuna bracteata: A cover crop and living green manure. Agricultural Crop Trust (ACT), Kuala Lumpur: 165 – 170.
Goh K.J. 2006. Fertilizer recommendation systems for oil palm: Estimating the fertilizer rates. Presented at Workshop on Nutrient Needs in Oil Palm, 17 – 18 October, Potash and Phosphate Institute (PPI) Southeast Asia Program, Singapore. Preprint.
Goh K.J. 2006. Nitrogen. Presented at Workshop on Nutrient Needs in Oil Palm, 17 – 18 October, Potash and Phosphate Institute (PPI) Southeast Asia Program, Singapore. Preprint.
Goh K.J. 2006. Potassium. Presented at Workshop on Nutrient Needs in Oil Palm, 17 – 18 October, Potash and Phosphate Institute (PPI) Southeast Asia Program, Singapore. Preprint.
Goh K.J. 2006. Magnesium. Presented at Workshop on Nutrient Needs in Oil Palm, 17 – 18 October, Potash and Phosphate Institute (PPI) Southeast Asia Program, Singapore. Preprint.
Goh K.J. and Chui S.B. (eds). 2006. Mucuna bracteata: A cover crop and living green manure. Agricultural Crop Trust (ACT), Kuala Lumpur: 183 pp.
Goh K.J., Gan H.H. and Patrick Ng, H.C. 2006. Agronomy of Mucuna bracteata under oil palm. In: Goh K.J. and Chui S.B. (eds). Mucuna bracteata: a cover crop and living green manure. Agricultural Crop Trust (ACT), Kuala Lumpur: 45-83.
Records 31 to 60 of 136