Impact of Sowing Dates and Picking Stages on Yield and Seed Maturity of Cotton (Gossypium hirsutum L.) Varieties

A field experiment was conducted to evaluate the impact of sowing dates and picking stages on yield and seed maturity of cotton varieties at Nuclear Institute of Agriculture (NIA) Tandojam, Sindh Pakistan. Three cotton varieties (Sadori, Chandi-95 and Malmal) were evaluated under four sowing dates (15th April, 1st May, 15th May and 1st June). Four pickings at various boll opening stage viz. 30%, 50%, 70% and 90% of boll opening were carried out. The varieties responded differently for opening of bolls at different timings of picking. Some varieties exhibited higher percent of boll opening, others did not show any response to different planting times. The variety Sadori exhibited higher values for most of the traits like sympodial branches plant^-1 (14.28), seed cotton yield plant^-1 (51.04g), seed cotton yield (2223kgha^-1), ginning out turn (36.8%), seed index (7.4 g), and seed germination (58.5 %) as compared to other varieties. The normal (1st May sown crop) sowing showed significantly highest values for boll weight(3.18g), seed cotton yield plant^-1 (65.2g), seed cotton yield (2711 kg ha^-1), seed index (7.7g), staple length (27.60mm), and seed oil content (20.58%). Taking boll opening (%) into consideration, it was observed that at 50% boll opening most of the traits exhibited values likewise in higher boll weight (3.17g), seed index (7.7g), staple length (27.60mm), seed oil content (20.83%) and seed germination (74.66%) as compared to other pickings.