Precision orientation herbicide spraying against weeds in plastic-mulched fields of spring hybrid millet

Abstract

Foxtail millet (Setaria italic [L.] P. Beauv.) is an important food and fodder crop that is cultivated worldwide. However, weeds severely inhibit the growth of spring foxtail millet, and no suitable herbicide or method is available for weed control in foxtail millet fields. Field experiments were conducted to evaluate the efficacy of various herbicides and their safety toward hybrid foxtail millet, that is, ‘Zhangzagu 10’. The present study was conducted using seven herbicides applied by precision orientation spraying between plastic mulches in a foxtail millet field. All herbicide treatments exhibited no significant difference on foxtail millet shoot and root biomass. No difference in grain yield was observed among herbicide treatments, including MCPA (2-methyl-4-chlorophenoxyacetic acid), mesotrione, acetochlor, trifluralin, and pendimethalin, at the recommended dosage in field efficacy evaluation trial. For the same herbicide, the tendency of weed control increased with the increase in herbicide concentration. Following this finding, all herbicides applied at the highest dosage controlled weeds by 92.06% compared with the other treatments utilizing lower concentration. At the same concentration level, mesotrione controlled all weed populations was the highest observed among all herbicides, followed by prometryne and MCPA. Mesotrione controlled all weeds by at least 76.85%, exhibiting the highest weed injury among the herbicides and satisfying the requirement for weed species control. Finally, comprehensive analyses showed that mesotrione at 0.8 L ha-1, yielded the highest comprehensive evaluation value in foxtail millet field. Thus, this herbicide can be a good option in controlling weeds in foxtail millet field. This new model can aid in protecting hybrid ‘Zhangzagu 10’ foxtail millet seeds or seedlings against herbicide damage and is a good option in expanding the application range of herbicide in foxtail millet.