Agronomic performance and economic analysis of soybean (Glycine max) in relation to growth regulating substances in Punjab, India

A field experiment was conducted at the Punjab Agricultural University, Ludhiana (36°56' N, 75°52' E and altitude 247 m), India during rainy seasons of 2006 to 2008 in split plot design. Experiment comprised of twelve treatment combinations with four plant growth regulators application (salicylic acid @ 50 mg/l, ethrel @ 200 mg/l, cycocel @ 500 mg/l and water spray) in main plot and three stages of application time (at flower initiation, pod initiation and flower + pod initiation) in sub plot, was replicated thrice. Pods per plant in cycocel @ 500 mg/l were significantly higher than ethrel, salicylic acid and water spray. Ethrel 200 mg/l recorded seed yield statistically on par with salicylic acid 50 mg/l but significantly higher than water spray and lower than cycocel 500 mg/l. Pods per plant with plant regulators application at flower + pod initiation were significantly higher than flower and pod initiation. Application of growth regulators at flower and pod initiation gave significantly higher seed yield than flower and pod alone in 2006. On pooled mean basis growth regulators at flower + pod initiation gave 4.9 and 7.7% higher than at flower initiation and pod initiation respectively.