Effect of Vermicompost and Organic and Inorganic Fertilizers on Growth, Yield Components and Sucking Insect Pest Populations of Cotton (Gossypium Hirsutum L.)

A field experiment was conducted at the Cotton Research Institute (CRI), Multan, Punjab, Pakistan, during Kharif 2026 to assess the effects of vermicompost and other organic and inorganic fertilizers on cotton growth, yield, and sucking insect pest populations. Cotton cultivar MNH-1050 was evaluated in a randomized complete block design (RCBD) with three replications and six treatments: T1, unfertilized control; T2, recommended NPK (150-75-75 kg ha⁻¹); T3, farmyard manure (FYM) at 10 t ha⁻¹; T4, vermicompost at 5 t ha⁻¹; T5, vermicompost at 5 t ha⁻¹ plus 50% recommended NPK; and T6, FYM at 10 t ha⁻¹ plus 50% recommended NPK. Data were recorded for plant growth, yield components, and seed cotton yield. Populations of whitefly (Bemisia tabaci), jassid (Amrasca devastans), and thrips (Thrips tabaci) were monitored fortnightly. The integrated FYM-based treatment (T6) produced the highest seed cotton yield (2,512 kg ha⁻¹), 73.0% greater than the control (1,452 kg ha⁻¹). This advantage was associated with the highest average boll weight (3.58 g). In comparison, T5 recorded the maximum fresh leaf weight (214.5 g plant⁻¹), dry leaf weight (67.9 g plant⁻¹), dry fruit weight (118.2 g plant⁻¹), number of branches (18.4 plant⁻¹), and bolls per plant (34.7). The highest combined sucking-pest population occurred under sole chemical fertilization (T2), at 26.2 insects per three leaves, whereas T5 had the lowest population (15.8), a 39.7% reduction compared with T2. Whitefly and jassid populations responded more strongly to fertilizer treatments than thrips, and pest populations peaked at 75 days after sowing. Overall, integrating organic amendments with 50% of the recommended NPK rate improved cotton performance and reduced sucking-pest populations relative to sole chemical fertilization. FYM combined with reduced NPK was most effective for maximizing seed cotton yield, whereas vermicompost combined with reduced NPK promoted vegetative and reproductive growth and was associated with lower pest pressure. These findings demonstrate the potential of integrated nutrient management to support productive and sustainable cotton cultivation under the agro-climatic conditions of Multan.