Evaluating Variation among Selected Cotton Genotypes for Growth, Yield and Boron-Use-Efficiency

Abstract

Boron (B) plays significant roles in the growth, development, yield and quality of cotton. However, there exists a very narrow gap between plant deficiency and toxicity limits of B. We conducted this field study, following a thrice replicated randomized complete block split-plot design (main: B levels and sub: genotypes), to evaluate the growth, yield, and boron-use-efficiency of five cotton genotypes (Sohni, Chandi, Reshmi, Qalandri and CRIS-443) of Sindh under deficient (0 kg B ha^-1) and adequate (2.0 kg B ha^-1) levels of soil applied B (Borax, 11.5% B). The crop also received a blanket dose of 120-60-60 kg NPK ha^-1. The soil used was clay loam, alkaline in nature (pH: 8.2), slightly saline (EC: 1.7dS m^-1), while low in organic matter (0.79%) and diluted HCl-B (0.42 mg kg^-1). Both the sources of variance (B and cotton genotypes) (G) significantly (p <0.001) affected all the traits. Cotton genotypes significantly differed for their B accumulation. Boron × genotypes interaction significantly (p <0.05) affected the number of bolls and seed cotton yield. Qalandari produced maximum number of sympodia, bolls, seed cotton yield, and accumulated maximum B concentration under both the levels of B. Sohni had maximum ginning out turns and B accumulation under both the B levels. Reshmi produced maximum boll weight under both the B conditions. Qalandari appeared to be a potential genotype to perform both under low and high B input agriculture, being most efficient-responsive genotype. We concluded that the adequate B nutrition significantly affect most of the growth traits and seed yield of cotton genotypes, though independent of boron accumulation. Hence, a wide range of cotton genotypes may be involved to exploit their variation for B accumulation in quest of identifying B-use-efficient cotton genotypes.