Enhancing Broccoli (Brassica oleracea var. italica) Growth, Yield and Water Productivity through Irrigation and Mulching Techniques in Local Climate

Abstract

Introduction: Broccoli's efficient irrigation management is critical with changing climatic patterns and increasing water scarcity. The study aimed to assess the impacts of various irrigation methods and mulching techniques on broccoli cultivation. Methodology: A randomized complete block design with three replications was used, considering two factors: irrigation methods (drip and surface) and mulching materials (black polythene, white polythene, grass straw, and no mulching). Results: Drip irrigation, combined with black polythene mulching (I1MBP), consistently demonstrated its superiority that significantly improved multiple aspects of plant growth, yield and water productivity. In particular, I1MBP resulted in the highest plant heights at different growth stages, with the tallest plants at harvest (43.87 cm). However, surface irrigation with the same mulching (I2MBP) also showed higher plant heights but slightly shorter than drip irrigation. A similar trend was observed for the number of leaves per plant, with the I1MBP treatment having the most leaves. In curd development, the treatment (I1MBP) produced curds with larger diameters and lengths at harvest. In contrast, surface irrigation with the same mulching (I2MBP) also showed a larger curd size but, again, slightly lower than drip irrigation. In terms of curd initiation time, the I1MBP treatment had a longer duration, while the I1MN treatment had a shorter duration. Surface irrigation treatments followed a similar trend. With respect to yield, the I1MBP consistently had the highest unit weight of curd (423.14 g plant-1), yield per plot (25.39 Kg plot-1), and total yield (16.93 t ha-1), regardless of the mulching condition. However, surface irrigation with the same mulching (I2MBP) also showed higher yields (15.93 t ha-1) but slightly less than drip irrigation. On the other hand, the I1MBP demonstrated superior water use efficiencies (74.68 kg/ha-mm) and productivity (7.47 Kg m-3) compared to other treatments. Still, surface irrigation with the same mulching (I2MBP) also exhibited better water use efficiency (64.98 kg/ha-mm) and productivity (6.50 Kg m-3) than treatments with no mulch. Environmental factors, including temperature, humidity, wind speed, sunshine hours, and evaporation, were found to correlate with broccoli growth stages, emphasizing their influence on crop development. Conclusion: Finally, drip irrigation and black polythene mulching are pivotal for improved growth, yield, and water management, contributing to sustainable agriculture practices.