Khwam sam phan rawang phun thi bai lae nam nak haeng thi mi to phon phalit khong thua khieo song phan.

A study on the relationship between leaf area index and dry matter production of mungbean (Vigna radiata (L.) Wilczek) when planted at different population densities was conducted. Two varieties of mungbean, i.e. U-thong 1 and local variety called Fug-Khow were used as main plot in the split plot designed experiments replicated four times. The result of the experiments revealed that yield of two mungbean varieties was not significantly different for the plant densities used. However, the increase in plant population caused the increase in yield per unit area but consequently decreased the yield per plant due to severe competition which occurred as plant population increased. Dry matter accumulation per area of both mungbean varieties increased as a result of the increase in plant density as well as leaf area index. The dry matter accumulation per area in the first experiment was higher than those of the second experiment in every planting date due to the fact that considerable damage by insects occurred in the second experiment. In both experiments, total dry matter and leaf area index of two mungbean varieties increased significantly as plant density increased. The correlation coefficient between leaf area index and dry matter production were found significant and positive. In both experiments, specific leaf weight and harvest index of mungbean were not influenced by plant population. Furthermore, specific leaf weight and harvest index among the varieties were not significantly different. Generally, growth and yield of mungbean in the second experiment were poorer than the previous one and this would explain why the value of harvest index in the second trial were slightly lower than the first experiment.