During the rainy season maize is infested by a variety of weeds, leading to losses ranging from 34% to 67% or sometimes even more. A field experiment with different integrated weed management (IWM) practices was conducted during 2004, 2005 and 2006 with the objective of identifying appropriate IWM for enhancing productivity of maize-based cropping systems under rainfed conditions. Pooled results for the three years showed that IWM markedly reduced weed density and weed dry matter at 35 DAS and 50 days after sowing (DAS). Manual or mechanical weeding at 20 DAS and 35 DAS gave a weed control efficiency (WCE) of 44.24% and 49.91%, respectively, compared to 86.97% under weed-free control. Similarly, PE atrazine @ 0.75 kg ha-1 for a pure stand of maize gave a WCE of 62.61%. Inclusion of soybean as an intercrop in paired maize rows in a 2:2 row ratio (30/90 cm) and treatment with PE Pendimethalin @ 1.0 kg ha-1 followed by one hand weeding at 35 DAS resulted in a significant reduction in weed count, which in turn produced the least weed dry matter (41.46 gm m-2) against 115.87 gm m-2 obtained under nonweeded control at 50 DAS. Further, this system showed significant superiority in terms of WCE (64.20%), giving rise to significant improvement in yield attributes and yield of the crops in the cropping system and producing the highest maize equivalent yield of 3211 kg ha-1 with a B:C ratio of 1.98. This was significantly superior to the other IWM practices. Decreased weed counts and weed dry matter in this IWM system seem to have been the result of relatively less space being available for growth of weeds, leading to weed smothering up to the critical crop stage. Thus, maize intercropped with soybean in a 2:2 row ratio (30/90 cm) with PE Pendimethalin @ 1.0 kg ha-1 followed by one hand weeding at 35 DAS can be the appropriate IWM system for enhancing productivity of maize-based cropping systems under rainfed conditions.

Global Maize Program

Text in English

INT2823