Efficacy of herbicides and their impact on the productivity, energy relationships and economics of wheat (Triticum aestivum) in Vertisols of Central India

Field experiment was conducted at Research Farm of Indore, Madhya Pradesh during the winter (rabi) season of 2016-17 and 2017-18, to find out the efficacy of different post-emergence herbicides (halauxifen-methyl-ester, 2, 4-D and metsulfuron methyl) alone as well as mixture with carfentrazone for the control of broad-leaf weeds in wheat (Triticum aestivum L.). Data on weed dynamics indicated that, weed density and weed dry weight for broadleaf weeds decreased significantly with these herbicides as compared to weedy check. However, the maximum reduction was observed with an application of halauxifen @ 12.76 g/ha and this treatment also recorded the highest values of weed-control efficiency and the lowest values of weed index. Application of carfentrazone as sole or in combination resulted in the phyto-toxicity while higher leaf burning was observed when applied with metsulfuron and halauxifen. The maximum grain yield (6.60 and 6.27 t/ha) and biological yield (15.24 and 14.67 t/ha) were recorded with weed-free environment, being at par with application of halauxifen and metsulfuron and these treatments were altogether significant over the weedy check. Growth and yield attributes also followed the similar trend to that of grain yield. Although the highest values of energy input (23.32 thousand MJ/ha), energy output (201.1 thousand MJ/ha), cost of cultivation (52.4 thousand/ha) and gross returns (142.4 thousand/ha) were estimated with weed-free treatment, but application of halauxifen resulted in the maximum energy ratio (8.72), energy productivity (279.8 g/MJ), net returns (92.8 thousand/ha) and benefit: cost ratio (2.99). Thus, post-emergence application of halauxifen- methyl-ester @ 12.76 g/ha or metsulfuron methyl @ 4 g/ha found effective in controlling of broad-leaf weeds and fetched higher net returns and energy productivity of wheat in Vertisols of Central India.