Bio-efficacy of ethalfluralin against weeds of potato (Solanum tuberosum), its phytotoxicity and effects on productivity and profitability innorth-western Himalayan region

Grassy and broadleaf weeds are the major biotic concern in potato (Solanum tuberosum L.) crops, affecting the crop yield as well as profitability. The over-dependence on specific herbicides or herbicide with similar modes of action results in the development of herbicide resistance. Herbicide cycling is a strategic approach that alternates the herbicides to mitigate resistance. The present experiment was conducted during the winter (rabi) seasons of 2018–19 and 2019–20 at Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Palampur, Himachal Pradesh to evaluate the efficacy of a novel herbicide, ethalfluralin, against weeds and its subsequent effect on potato productivity. Bio-efficacy was evaluated with nine weed control treatments comprising five doses of ethalfluralin (540, 630, 720, 810, and 1440 g a.i./ha), sole application of metribuzin 525 g a.i./ha, sole application of oxyfluorfen 200 g a.i./ha, weed-free, and weedy-check, were laid out in a randomized complete block design (RCBD) with three replications. Application of ethalfluralin 720 g a.i./ha as pre-plant incorporation resulted in lower weed density and weed dry weight with weed control efficiency of 62.75% and 70.37% during 2018–19 and 2019–20, respectively. Additionally, ethalfluralin 720 g a.i./ha resulted in significantly higher yield attributes and tuber yield (24.83 t/ha). The higher dose of ethalfluralin (@1440 g a.i./ha) was statistically at par with ethalfluralin (@720 g a.i./ha) but delayed the germination of potato crop and reduced potato tuber yield. From the results, it can be concluded that ethalfluralin at 720 g a.i./ha can be safe and productive for application in potato crops and can be adopted as an alternative to the commercially available herbicides i.e., metribuzin 70% wp and oxyfluorfen 23.5% ec.