INFLUENCE OF PLANTING BED WIDTH AND IRRIGATION METHODS ON APHID POPULATION INCIDENCE AND CROP WATER PRODUCTIVITY IN WHEAT

Abstract

Water scarcity and declining irrigation resources have intensified the need for efficient wheat production systems in Pakistan. A field experiment was conducted during the Rabi season at the Water Management Research Farm, Renala Khurd, Okara, to evaluate the influence of different bed widths on wheat productivity and water use efficiency under loamy soil conditions. The experiment was laid out in a Randomized Complete Block Design with four treatments: flat sowing (control), 45 cm bed, 60 cm bed, and 75 cm bed widths, each replicated three times. Growth, yield, irrigation water application, crop water productivity (CWP), and water-saving percentage were recorded. Results showed that bed planting significantly improved wheat performance compared with conventional flat sowing. The 75 cm bed width produced the highest number of tillers (270 m⁻²), grains per spike (42.89), 1000-grain weight (35.36 g), grain yield (3483 kg ha⁻¹), and crop water productivity (1.427 kg m⁻³). In contrast, flat sowing resulted in the lowest grain yield (2765 kg ha⁻¹) and CWP (1.047 kg m⁻³). Total irrigation water applied was highest under flat sowing (264 mm), whereas the 45 cm bed required the least irrigation (221 mm), resulting in the greatest water saving (16.29%). The 60 cm and 75 cm beds saved 10.98% and 7.58% irrigation water, respectively. In case of aphid incidence, comparatively greater incidence was recorded on wheat plants under flat sowing under conventional flood irrigation compared with bed-planted wheat under furrow irrigation. Overall, raised-bed planting enhanced water-use efficiency and wheat productivity under loamy soil conditions. Although the 45 cm bed provided maximum water savings, the 75 cm bed width was the most effective in achieving higher grain yield and crop water productivity. Therefore, a 75 cm raised bed can be recommended for sustainable wheat production where both yield maximization and efficient water utilization are desired.