Performance of summer maize (Zea mays) under varying irrigation levels and agro-chemicals in sub-humid southern plains of Rajasthan

A field experiment was conducted during summer season of 2010 and 2011 at Rajasthan college of Agriculture, Udaipur, to evaluate the impact of irrigation levels and agro-chemicals on yield and water-use efficiency (WUE) of maize (Zea mays L.). The application of 8 irrigations significantly improved crop-growth rate (CGR) at 25–50 days after sowing (DAS) and 50–75 DAS, relative water and chlorophyll contents. The maximum grain weight/cob (63.6 g), cob length (15.9 cm), 1000-seed weight (176.9 g) and shelling% (76.7) were recorded with 8 irrigations. Similarly, application of 8 irrigations also resulted in significantly higher grain and stover yields, and the highest consumptive use (279.1 ha-mm) and water-use efficiency (9.52 kg/ha-mm). Among the agro-chemicals, application of brassinolide resulted in the maximum CGR at 25–50 (7.06 g/m/day) and 50–75 (19.5 g/m/day) DAS, respectively. Likewise, brassinolide also superior most with respect to all the yield attributes, yields and shelling % as compared to the other chemicals. Brassinolide application also resulted in the highest consumptive use (244.7 ha-mm) and water-use efficiency (9.35 kg/ha-mm) among all the agrochemicals.