Morphological Responses of Dimethoate, Lambda-Cyhalothrin, and their Combination on Cowpea Plant: Implications for Plant Reproduction and Development

Abstract

This study evaluates the effects of Dimethoate (A), Lambda-Cyhalothrin (B), and their combination (A+B) on cowpea germination, growth, and yield. In germination trials, Lambda-Cyhalothrin (B) at 30 mL/L showed the fastest germination rate at 3.5 days in vitro, while Dimethoate (A) at 50 mL/L took the longest at 7.5 days. In vivo, Lambda-Cyhalothrin (B) at 40 mL/L germinated in 3 days, and Dimethoate (A) at 10 mL/L took 7 days. The tallest plants (67.75 cm) were from Lambda-Cyhalothrin (B) at 50 mL/L, while the shortest (34.25 cm) were from the combination (A+B) at 50 mL/L. The highest leaf count (38.5 leaves) was noted for Lambda-Cyhalothrin (B) at 20 mL/L, and the lowest (14.75 leaves) for Dimethoate (A) at 40 mL/L. The leaf area index (LAI) was 50% for Lambda-Cyhalothrin (B) and only 1% for the combination (A+B). Dimethoate (A) at 10 mL/L produced the most flower buds (16) and the highest aborted flowers (8). The combination (A+B) at 20 mL/L had the fewest flower buds (9.25) and the lowest abortion (5). Yield-wise, both the control group and Dimethoate (A) at 10 mL/L had the highest pod count (25), while Dimethoate (A) at 50 mL/L had the lowest (4.2). Lambda-Cyhalothrin (B) at 10 mL/L had the highest seed count per pod (92.6), while at 50 mL/L it was lowest (12.5). The heaviest seeds (14.2 g) were in Lambda-Cyhalothrin (B) at 10 mL/L, and the lightest (2.20 g) were at 50 mL/L. Lambda-Cyhalothrin (B) positively influenced germination, plant height, leaf number, and yield, while Dimethoate (A) and its combination with Lambda-Cyhalothrin (A+B) negatively affected growth and productivity.

Keywords: Pesticides, Morphology, Germination, Biomass, Leaf Area Index.