Chemical weed management effects on productivity and profitability of gladiolus (Gladiolus hybridus) in north-western Indo-Gangetic Plains

A field experiment, involving ten weed control treatments laid out in a randomized complete block design with three replications, was undertaken at the Indian Agricultural Research Institute, New Delhi during the winter seasons, 2011-12 and 2012-13. The objective was to evaluate the effects of different combinations of herbicides, particularly pre-emergence tank-mix herbicides applications on weeds, and flowering, corm yield and benefit-cost economics of gladiolus (Gladiolus hybridus Hort.). It was observed that all herbicidal treatments resulted in significantly lower density of monocot and dicot weeds, and total weed dry weight compared to weedy check, which had the highest two-year mean density of monocot (165/m(2)) and dicot (364/m(2)) weeds and total weed dry weight (171 g/m(2)). Among herbicide treatments, atrazine 1.0 kg/ha pre-emergence followed by rice residue @ 5 tonnes/ha at 2 days after atrazine application caused the greatest reduction in density and dry weight of weeds. All herbicidal treatments, except butachlor 1.0 kg/ha pre-emergence, were equally effective as this treatment against weeds. The herbicides and their doses adopted in this study did not pose any phytotoxicity to gladiolus plants. The tank-mix pre-emergence applications were usually more effective than the single herbicide application. The tank-mix pre-emergence application of pendimethalin 0.75 kg/ha + metribuzin 0.3 kg/ha resulted in significantly greater two-year mean gladiolus plant height (116 cm), cut-flower yield (172 500 spikes/ha), corm yield (3.82 tonnes/ha) and net returns ((sic) 243 100/ha) compared to weedy check and most other treatments, and was most remunerative.