Effect of zinc foliar application on productivity and quality characteristics of several cotton varieties

Zinc deficiency is a common issue in cotton cultivation that can significantly impact yield and quality, especially when the soil zinc content is unavailable due to a problem related to nutrient competition. A field experiment was conducted during the summer season of 2023, on a farmers’ field in Al-Anbar province, Iraq, to investigate the effect of zinc spraying on cotton yield and its components, as well as quality characteristics, for several cotton varieties. The experiment utilised a split-plot design that was arranged within a randomised complete block design (RCBD) with three replications. The main plots occupied by four zinc concentrations, which were 0, 75, 150 and 225 mg L-1, while the sub-plot contained four cotton varieties: Spearo888, Cocker 310, Pak-cot and Candia. The results showed that the Spearo 888 cotton variety had the highest average in terms of plant height, reaching 156.72 cm, while the Pak-Cot variety had the highest average for traits: branch per plant-1 (12.61), number of total and opened bolls per plant-1 (26.57 and 19.04), boll weight (3.97 g) and total seed cotton yield (2.95 t ha-1). The studied traits improved progressively with increasing zinc concentration, with the highest concentration yielding the best results. The integration of zinc with the varieties led to the best results. The cotton fibre characteristics were not significantly affected by zinc concentrations; rather, variety had the greatest influence, indicating that these characteristics are more influenced by gene action than by environmental conditions.