ABSTRACT Crop is commonly grown in intercrop combinations of which cereal/legumes are the most widespread in tropical countries. The availability of low light inten-sity due to shading is the critical factor in determin-ing legume yield in intercropping. The experiment searches of better soybean cultivar for intercropping. A field experiment was conducted at the experimen-tal farm of Khon Kaen University in 2005. The objec-tives of this study were to determine the influence of light regimes (30% of normal light, 50% of normal light and normal light) on the growth and yield of four soybean cultivars (early, medium and late ma-turity) under artificial shading at 35 days after seed-ing until harvest in the wet and dry seasons. The re-sults showed that grain yield was significantly (p<0.05) decreased under the low light intensity at 30% of natural light both in wet and dry season. This was mainly due to low light intensity at 30% of natural light decreasing the number of pods per plant in the dry season. For cultivars, grain yield was sig-nificantly difference (p<0.05) among cultivars both in the wet and dry seasons. The cultivar KKU 74 (me-dium maturity) gave maximum grain yield both in wet and dry season under the low light at 30% of natural light. The KKU74 cultivar is better adapted to shading environment than other cultivars. This was due to the KKU74 cultivar produced higher chlorophyll b concentration in leaves after the plant experienced to shading. This physiological character can be used for soybean breeding program in shading tolerance. Therefore, the cultivar KKU 74 had a higher potential yield advantage in intercropping systems in which low light intensity is a major limit-ing factor on grain yield.
Cite this paper
nullPolthanee, A. , Promsaena, K. and Laoken, A. (2011) Influence of low light intensity on growth and yield of four soybean cultivars during wet and dry seasons of northeast thailand. Agricultural Sciences, 2, 61-67. doi: 10.4236/as.2011.22010.
 Roy, R.P., Sharam, H.M. and Thakur, H.C. (1981) Studies on intercropping in long-duration pigeonpea on sandy loam soil of North Bihar. Indian Journal of Agronomy, 26(1), 72-82.
 Faris, M.H., Burity, H.A., Reis, D.V.D. and Mafra, R.C. (1983) Economic analysis of bean and maize system in monoculture vs. associated cropping. Field Crop Research, 1, 319-335.
 Huges, H. D. and Metcalfe, D.S. (1972) Crop production 3rd Ed. Macmillan Publishing. New York.
 Odango, J.C.W., Veresoglo, D.S. and Sfica, A.G. (1990) Effects of population density, nitrogen fertilization and inoculation of the yield of intercropped maize and soybean. Field Crop Abstract, pp. 043-055619.
 Hayder, G., Mum-raz, S. S., Khan, A. and Khan, S. (2003) Maize and soybean intercropping under various levels of soybean seed rates. Asian Journal of Plant Sciences, 2(3), 339-341.
 Ahmed, S. and Rao, M. R. (1982) Performance of maize-soybean intercrop combinations in the tropics: Results of a multi-location study. Field Crop Research, 5, 147-161.
 Nizamani, M.I.F. (1986) Yield performance of maize intercropping system with soybean under various fertility levels. M. Sc. Thesis. S.A.U. Tandojam, Pakistan.
 Panhwar, M.A., Mempn, F.H., Kalhoro, M.A. and Somro, M.I. (2004) Performance of maize in intercropping system with soybean under different planting patterns and ni-trogen levels. Journal of Applied Science, 4(2), 201-204.
 Polthanee, A. and Changsri, R. (1999) Effect of planting dates of mungbean on growth and yield in corn mung-bean relay cropping under rainfed conditions in an upland area of Northeastern Thailand. Thai Journal of Agricultural Sci-ence, 32(2), 187-196.
 Polthanee, A. and Treloges, V. (2002) Growth and yield of mungbean cultivars in mung-bean-corn relay intercropping systems. Journal of International Society for Southeast Asian Agricultural Sciences, 8(2), 1-14.
 Polthanee, A. and Treloges, V. (2003) Growth, yield and land use efficiency of corn and legumes grown under intercropping systems. Plant Production Science, 6(2), 139-146.
 Kakiuchi, J. and Kobata, T. (2004) Shading and thinning effects on seed and shoot dry matter increase in de-terminate soybean during the seed-filling period. Agronomy Journal, 96, 398-405.
 Kakiuchi, J. and Kobata, T. (2006) The relationship between dry matter increase of seed and shoot during the seed-filling period in three kinds of soybeans with different growth habits subjected to shading and thinning. Plant Production Science, 9(1), 20-27.
 Department of Agriculture, Ministry of Agriculture and Cooperative Recom-mendation (2001) Good agricultural practice for soybean. Ag-ricultural Cooperative Publishing, Bangkok.
 Moran, R. (1981) Formulae for determination of chlorophyll pigments extracted with N, N-Dimethyl formide. Plant Physiology, 69, 1376-1381.
 Singh, L. (1988) Adaptation and yield of potato under low light intensity. Indian Journal of Plant Physi-ology, 31, 114-116.
 Naidu, C. V. and Swamu, P. M. (1993) Effect of shade on growth, biomass production and associated physiological parameters in Pongamia Pinnata (Linn.) Pierre. Indian Journal of Plant Physiology, 37(4), 212-214.
 Jadhav, B.B. (1987) Effect of partial shading on the yield of rice. Indian Journal of Agricultural Science, 57(7), 515-516.
 Saito, M. and Kato, T. (1994) Effects of low temperature and shade on relationships between nodulation vesicular-arbuscular mycorrhizal infection, and shoot growth of soybean. Biology and Fertility of Soil, 17, 206-211.
 Singh, V.P., Dey, S.K. and Murthy, K.S. (1988) Effect of low light stress on growth and yield of rice. Indian Journal of Plant Physiology, 31, 84-91.
 Kurosaki, H. and Yumoto, S. (2003) Effects of low temperature and shading during flowering on the yield components in soybeans. Plant Production Science, 6(1), 17-23.
 Egli, D.B. (1977) Cultivar maturity and response of soybean to shade stress dur-ing seed filling. Field Crops Research, 52, 1-8.
 Muthuchelian, K., Paliwan, K. and Gnanam, A. (1989) Influence of shading on net photosynthesis and transpi-ration rates, stomatal diffusive resistance, nitrate reductase and biomass productivity of a woody legume tree species. The Proceedings of the Indian Academy of Sciences, 99, 539-546.
 Boardman, N. K. (1977) Comparing photosyn-thesis of sun and shade plants. Annual Review of Plant Physiology, 28, 355-377.
 Usuda, H., Ku, S. B. M. and Edwards, G.E. (1985) Influence of light intensity during growth on photosynthesis and activity of several key photo-synthetic enzymes in a C4 plant (Zea mays). Physiologia Plan-tarum, 63, 65-67.
 Barker, J. (1985) Thylakoid membrane structure and organization of electron transport components. In: J. Barker and R. Baker (Eds.) Photosynthetic Mechanisms and the Environment. Elsevier. Amsterdam. pp. 91-134.
 Zhao, D. and Oosterhuis, D. (1998) Cotton responses to shade at different growth stages: Nonstructural carbohydrate composi-tion. Crop Science, 38, 1196-1203.
 Hale, M.G. and Orcutt, M.M. (1987) Irradiation stress. In : M.G. Hale and D.M. Orcutt (Eds.) The Physiology of Plants Under Stress. John Wiley and Sons, New York. pp. 109-115.