INFLUENCE ON WATER STATUS, PHOTOSYNTHESIS RATE AND PLANT-GROWTH OF DIFFERENT TEMPERATURES AND WATER REGIMES DURING POD FORMATION PHASE OF MUNGBEAN

Effects of different temperatures and water regimes on soil and leaf w ater potential, photosynthesis, growth and dry matter production of mu ngbean during pod formation were examined in the phytotron growth cham bers of the Kyushu University, Japan. Temperatures were 15, 20, 25 and 30 degrees C and water regimes were well irrigation and light irrigat ion. Almost all parameters (except root dry weight) of mungbean were m uch reduced in the light irrigated pots than those in the well irrigat ed pots irrespective of temperature gradients except 15 degrees C. Eff ects of different temperature gradients were more pronounced in photos ynthesis, plant height, number of pods per plant, total dry matter and dry matter accumulation in pods in the well irrigated pots; and soil water potential, leaf water potential, leaf area per plant and root dr y matter in the light irrigated pots. In the well irrigated condition, 25 degrees C was found to be the most favorable for growth and develo pment of mungbean, but in the light irrigated condition no definite te mperature was found to be most favorable in all cases. It may be sugge sted that for getting higher photosynthesis, growth and dry matter pro duction in mungbean an adequate soil moisture accompanied with 25 degr ees C is the best environment for the plant.