Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, India during the summer (January – April) and kharif (June – September) seasons of 1994 and 1995 in a split plot design. The main plot consisted of three levels of irrigation, with irrigation water/cumulative pan evaporation (IW/CPE) ratios of 0.40, 0.60 and 0.80, and three levels of plant population (0.33, 0.44 and 0.66 million plants ha –1). The subplot treatments consisted of three levels of phosphorus (80, 100 and 120 kg P2O5 ha –1). The results revealed that irrigation at IW/CPE 0.80 with a plant population of 0.66 million plants ha –1 and a P level of 100 kg P2O5 ha –1 is promising in obtaining maximum yield in soybean. Under an irrigation regime of IW/CPE 0.80, the total water consumption varied from 450 to 533 mm, while it varied from 350 to 438 mm at IW/CPE 0.60 and from 250 to 393 mm at IW/CPE 0.40.
Field experiments were conducted during the summer (February-May) and south west monsoon (June-September) seasons of 1996 and 1997 at the Aliyarnagar Agricultural Research Station of Tamil Nadu Agricultural University, India, to study the growth and yield of soybean in response to irrigation, composted coir pith, time of N, P, K application and use of a nutrient mixture spray. The results revealed that irrigation at 0.90 IW/CPE [ratio of Irrigation Water Depth (IW) to Cumulative Pan Evaporation (CPE)], the application of composted coir pith and the split application of N, P and K in conjunction with a nutrient mixture spray significantly increased the plant height, leaf area index, dry matter production and grain yield of soybean. However, the root length of soybean was significantly reduced by irrigating at 0.90 IW/CPE (compared to irrigation at 0.70 IW/CPE and 0.50 IW/CPE) and by the application of composted coir pith.
Authors:M. Vijayakumar, P. Subbian, A. C. Lourduraj, and R. Selvaraju
Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, India during the North East Monsoon (October-December) seasons of 1997 and 1998 in a split plot design to study the effect of planting pattern and N splits on the yield attributes, yield and quality of rainfed sunflower. The main plot consisted of three plant populations (133,333 plants ha-1, 111,111 plants ha-1 and 88,888 plants ha-1) and the sub-plot treatments of six N split levels. The results revealed that the yield attributes of sunflower were higher at the closest spacing of 30 × 25 cm than at the widest spacing of 30 × 37.5 cm. The seed yield was higher at closer (30 × 25 cm) spacing in 1997 and at wider spacing (30 × 37.5 cm) in 1998. In both years the split application of nitrogen resulted in higher growth, yield attributes, seed yield and quality parameters when compared to full basal application.