EFFECT OF PLANTING DATES AND STORAGE ON YIELD AND QUALITY OF INDIGENOUS LAND RACES AND IMPROVED VARIETIES OF SOYABEAN

Production of edible oil in the country is only one third of the total requirements. Soybean yield is very low, due to poor plant stand and seed viability. The objective of this study was to explore the production potential and seed viability of indigenous land races and improved varieties under different planting dates and storage conditions. Two experiments were conducted during 2004 and 2005 at New Developmental Farm, NWFP Agricultural University, Peshawar, Pakistan. In experiment I, three soybean land races, (Kulat brown, Kulat white and Mothi) and two improved varieties (NARC-II and Swat 84) were planted at four planting dates (April, May, June and July) in randomized complete block design with split plot arrangement replicated four times. Planting dates were allotted to main plots and varieties to subplots. In experiment II, the seed of four varieties (Kulat brown, Kulat white, NARC-II and Swat-84) harvested from four planting dates (April, May, June and July) were stored in three storage materials (plastic jar, cloth bag and pod) under two storage conditions (room and refrigerator) for different storage durations (2-12 months) in a randomized complete block design with four replications. Planting dates significantly affected agronomic plant characteristics, nutritional values, physiological parameters, seed quality and vigour values. Maximum days to emergence (6), flower initiation (86), bloom (88), pod initiation (90), pod elongation (105), seed initiation (117), full seed formation (127), physiological maturity initiation (172) and full maturity (187) were recorded for April planted crop. Similarly maximum pods plantl (74.2), seeds pod-1 (2.1), seed yield (1459 kg ha-I), protein content (321 g kg-I), protein yield (467.7 kg ha-1), leaf area planr1 (2735 cm2), leaf area index (LAI) (11), specific leaf area (SLA) (391.6 cm2 g-l), field emergence (60%), emergence index (79) and viable seeds (75 %) determined by tetrazolium test was recorded for the crop planted in April. However, maximum plant height (91.4 em), hundred seed weight (11.4 g), biological yield (12598 kg ha-I), nodules plane1 (24), nodule weight plane-I (53.3 mg), oil content (169 g kg-I) and oil yield (244 kg ha-I), standard germination (74.6%) and accelerated aging germination (73.9%) was exhibited by May planting. When planting was advanced from April to July, days to various reproductive stages, agronomic plant characteristics, seed viability and vigour values gradually declined but specific leaf weight, crop growth rate (CGR) and relative growth rate (RGR) at early vegetative stage and electrical conductivity values increased. Varieties significantly affected days to 50% emergence, days to various reproductive stages and maturity, yield components, CGR and RGR, seed viability and vigour. Land races took maximum days to flower initiation (85), bloom (87), pod initiation (99), pod elongation (106), seed initiation (117), full seed formation (130), physiological maturity initiation (160) and maturity (169). Similarly maximum plant height (93.2 cm), pods planr1 (62.4), biological yield (12353 kg ha-1), leaf area planr1 (1871 cm2), LAI (7.1), SLA (214.7 cm2 g-l), standard germination (77.1 %), accelerated aging germination (71.2%), field emergence (61.8%), emergence index (79.2) and tetrazolium test values (80.6 %) were recorded for land races. Improved varieties produced maximum seeds pod-1 (2), hundred seed weight (15.3 g), seed yield (1306 kg ha-1), oil and protein content (17.1 and 31.9 g kg-I), oil yield (227 kg ha-1), protein yield (415 kg ha-1), seedling dry weight (15.7 mg) and electrical conductivity values (0.49 dsm-2). Moisture content and germination of stored seeds was significantly affected by planting dates, varieties, storage material, storage condition and storage duration. Maximum moisture was recorded in seeds stored in cloth bag, in refrigerator for the first four months. Maximum germination was recorded in seeds stored in plastic jars, in refrigerator during the first two months of storage. Germination decreased with storage duration. Seeds from April planting gave maximum germination. It is concluded that early planting (April, May) produced good quality highest seed yield. Land races produced equal seed yield of superior quality and storability. Download Full Thesis 2324.53 KB