PERTUMBUHAN DAN HASIL DUA VARIETAS TANAMAN KEDELAI (Glycine max (L.) Merril) DIBAWAH KONDISI CEKAMAN KEKERINGAN PADA BERBAGAI STADIA TUMBUH

Abstract

Soybean is categorized as a plant which sensitive to water deficit or surplus in its life cycle. If water requirement is not sufficient for the growth and development, the soybean will be subjected to stress. Water stress, such deficiency or excess of water in the plant environment is a condition that disrupts the balance of plant growth. Therefore, it is necessary to observe the interaction between drought stress at various growth stages and soybean varieties, and observe which growth stages that would provide the highest yield of soybean know the differences in drought stress in various stadia of plant growth on the growth and yield of two varieties of soybean crops and which currently can give the highest yield in various stadia grow. This research was carried out by using polybag in the greenhouse of Faculty of Agriculture Universitas Lambung Mangkurat Banjarbaru for 4 months from March to June 2017. The experimental design was Randomized Completely Design with Split Plot Design Factorial. The first factor is soybean varieties (V) as main plot, i.e. Grobogan (v1) and Anjasmoro (v2), and the second factor is the growth stages those subjected to drought stress (C) as subplot, i.e. c1 : vegetative stage 3 (29 DAS and 36 DAS), c2 : flowering stage (35 DAS and 46 DAS), c3 pods appearance/emergence (42 DAS and 53 DAS), and c4 : pods filling stage (68 DAS and 76 DAS). The treatment was repeated 3 times and each experiment unit consists of 5 polybags, thus there were 120 plants in total. The crop growth rate, number of main branch nodes, number of effective root nodules, shoot root ratio, the first flowering time, the harvest time, number of pods per plant, number of seed per plant, 100 seed dry weight, and the number of dry seed per plant. The result showed there was no interaction effect between drought stress in various stages and soybean varieties on all variables. Drought stress at vegetative stage 3 (c1) caused the number of main branch nodes, the number of pods per plant, the number of seed per plant, the 100 seed dry weight and the number of dry seed per plant are lower if they are compared to the plants those subjected to drought stress at pod filling stage (c4). Nevertheless, those variables were not different at drought stress at flowering stage (c2), pods appearance (c3) and pod filling stage (4). Soybean varieties observation showed that the Grobogan were faster in flowering time and higher in crop growth (26.49 DAS and 3.08 g d-1 respectively) compared to the Anjasmoro (34.08 DAS and 2.73 g d-1 respectively).