A Detailed Guide to Choosing Herbicides for Corn Fields
The main weeds in corn fields include: crabgrass, green foxtail, yellow foxtail, Chloris virgata, lovegrass, goosegrass, barnyardgrass, lambsquarters, Chenopodium serotinum, Chenopodium glaucum, Chenopodium aristatum, Kochia scoparia, Salsola collina, Amaranthus lividus, Amaranthus spinosus, redroot pigweed, Amaranthus paniculatus, amaranth, Amaranthus hypochondriacus, green amaranth, Amaranthus polygonoides, Celosia argentea, purslane, Acalypha australis, velvetleaf, wild watermelon seedling, black nightshade, and other weeds. Perennial weeds include bindweed, reed, and purple nutsedge.
After Sowing, Before Emergence
1. For plots with no weeds in the field, a pre-emergence treatment can be used. Commonly used agents: 40% propisochlor · atrazine 250-300 g/mu, 40% acetochlor · atrazine 200-250 g/mu, 40% butachlor · atrazine 200-250 g/mu, 52% propisochlor · atrazine 200-250 g/mu, 60% propisochlor · atrazine 180-230 g/mu, 40% acetochlor · metolachlor · atrazine 200-250 g/mu.
2. After wheat harvest, for fields with many annual weeds, use a tank-mix technique, carrying out "one pre-emergence treatment plus one burndown": 40% propisochlor · atrazine 200-250 g + 20% paraquat 150-200 g/mu, 52% propisochlor · atrazine 150-200 g + 20% paraquat 150-200 g/mu.
3. After wheat harvest, for fields with many perennial weeds, use a tank-mix technique, carrying out "one pre-emergence treatment plus one burndown": 40% propisochlor · atrazine 200-250 g + 41% glyphosate-isopropylammonium salt 250-300 g/mu, 52% propisochlor · atrazine 150-200 g + 41% glyphosate-isopropylammonium salt 250-300 g/mu.
Corn Growth Period
1. From the 1-3 leaf stage of corn before weeds emerge to the 1-2 leaf stage of weeds, commonly used agents: 40% Yufeng (propisochlor · atrazine) 250-300 mL/mu, 40% Yuduoshou (propisochlor · atrazine) 250-300 mL/mu, 52% Xiyangyang (propisochlor · atrazine) 200-250 mL/mu, 60% Yujia (propisochlor · atrazine) 180-230 mL/mu.
2. The 3-5 leaf stage of corn is an important period for weed control in corn fields. If weeds are not controlled in time, it will directly affect the growth and yield of corn. At the 3-5 leaf stage of corn, when grass weeds are at the 2-5 leaf stage and broadleaf weeds are 3-5 cm tall. Commonly used agents: 4% nicosulfuron suspension concentrate 100-120 mL/mu, 40% Jinyufeng (nicosulfuron) suspension concentrate 100-120 mL/mu, 53% Yutian (nicosulfuron · atrazine) 90-105 g/mu.
3. At the 3-4 leaf stage of corn, for plots with many purple nutsedge in the field. Commonly used agents: 40% Xishiduo (nicosulfuron · atrazine) 80-100 mL + 56% MCPA-sodium 50-60 g/mu, 4% nicosulfuron 100 mL/mu + 56% MCPA-sodium 50-60 g/mu, 56% MCPA-sodium 60-80 g/mu, 48% bentazone 150-200 mL/mu, 4% nicosulfuron 120-150 mL/mu.
4. For plots with many weeds at the 5-6 leaf stage of corn, you can choose 40% Xishiduo (nicosulfuron · atrazine) 120-150 mL/mu, 40% Jinyufeng (nicosulfuron) 120-150 mL/mu, 40% Yuanfen (sulfentrazone · atrazine) 250-300 mL/mu, 40% Xishiduo (nicosulfuron · atrazine) 80-100 mL + 56% MCPA-sodium 50-60 g/mu, 40% Yuanfen (sulfentrazone · atrazine) 100-150 mL + 40% Xishiduo 80-100 mL/mu.
5. For plots with many weeds such as purple nutsedge, field bindweed, small thistle, and lambsquarters at the 5-7 leaf stage of corn, you can apply 56% MCPA-sodium soluble powder 80-100 g/mu, 48% bentazone 200-250 mL/mu, 40% Xishiduo (nicosulfuron · atrazine) 80-100 mL + 56% MCPA-sodium 50-60 g/mu.
6. For plots with many weeds after the 8-10 leaf stage of corn (plant height 80 cm), apply a directed spray between the rows of 20% paraquat aqueous solution 150-200 mL/mu. If the weeds in the field are sparse, a pre-emergence herbicide can be added for use together, such as 40% propisochlor · atrazine 150-200 mL + 20% paraquat 200 mL/mu.