Influence of foliar applied benzoic acid on growth, yield and nutrients uptake in heat stressed cotton (Gossypium hirsutum L.)

A field and a pot experiment was conducted to study the influence of foliar applied benzoic acid on growth, yield and nutrients' uptake in heat stressed cotton (Gossypium hirsutum L.). Field experiment was conducted at Agronomic Research Area while the pot experiment was conducted at Glass house of Faculty of Agriculture, University of Agriculture, Faisalabad, during Kharif 2014. Field experiment was laid out in Randomized Complete Block design (RCBD) with split plot arrangement in three replications with net plot size of 3 x 4.5 m. The pot experiment was conducted in glass house using completely randomized design with split arrangement in three replications. Treatments included; (A) Two levels of heat stress; plots without polythene sheet (control), plots covered with polythene sheet at square initiation for one week (heat stress), (B) Six benzoic acid levels; viz. control (no spray), control (water spray), benzoic acid spray at 0.25, 0.50, 0.75 and 1.00 mM. The crop in field was sown on 75 cm apart ridges and plant to plant distance was maintained at 30 cm whereas in pots there was one plant/pot. All other agronomic practices were kept normal and uniform. The standard procedures were adopted for recording the data on various cotton parameters. The data were statistically analyzed using Fisher's analysis of variance technique by using statistix software and the treatments' means were compared by using Turkey's HSD (Honestly significant difference) test at 5% probability. The results of this study showed that days to first floral bud initiation, appearance of first flower, first boll splition, boll maturation period, number of monopodial branches, number of sympodial branches, number of infested bolls, number of CLCuV affected plants, aborted sites per plant, number of nodes up to first fruiting branch, height up to first fruiting branch, earliness index, seed cotton yield per plant average boll weight, plant height and seed cotton yield per hectare were affected by heat stress (H) and benzoic acid spray. Increase in benzoic acid spray concentration increased all above parameters but up to some extent and then started decline. While seed index, fiber uniformity, fiber elongation, fiber length and fiber strength were affected by benzoic acid but not by heat stress. It was concluded from both field and pot experiment that application of 0.75 mM benzoic acid spray improved cotton performance under both, no heat and heat induced environments. Similarly, economic analysis also showed that application of 0.75 mM benzoic acid on cotton crop gave maximum net income and benefit cost ratio.