After the Start of Autumn, don't relax on Welsh onion management - keep these key points in mind

Summer goes and autumn comes, and Welsh onion growth enters its vigorous stage. At this time, the main management goal is to promote more leaves and rapid growth, elongate, thicken and increase the weight of the leaf sheaths (the white stalk), and keep the root system strong and firmly established. The field management technical measures can be summarized in four farming proverbs: After the Start of Autumn, don't relax on Welsh onion care, four fertilizers and seven waterings attack in succession, three hoeings and two earthings drain rain and waterlogging, and prevent and control three diseases and six insects.

1. Four fertilizers and seven waterings attack in succession. The four fertilizers refer to the tillering fertilizer (early August), applying 2000-2500 kg of high-quality decomposed barnyard manure, 10 kg of urea or 20-25 kg of ammonium bicarbonate per mu; the leaf-promoting fertilizer (late August), applying 20 kg of urea or 40-45 kg of ammonium bicarbonate and 25 kg of potassium carbonate per mu; the sheath-promoting fertilizer (to thicken the white stalk) (early September), applying 15 kg of urea or 30-35 kg of ammonium bicarbonate and 20 kg of potassium sulfate per mu; the heavy sheath fertilizer (to increase the weight of the white stalk) (late September), applying 20-25 kg of urea or 40-45 kg of ammonium bicarbonate per mu, and if intercropped with @#@245@#@, add 30-35 kg of superphosphate per mu. The seven waterings are one watering with each of the four topdressings, plus one watering each in early, middle and late October to ensure water for Welsh onion grain filling. Water thoroughly and deeply, keeping the soil surface moist. At that time, the number of waterings can be appropriately increased or decreased according to drought or waterlogging conditions.

2. Three hoeings and two earthings drain rain and waterlogging. The three hoeings are intertillage and loosening the soil in mid-August to eliminate weeds; deep hoeing and ridging at the end of August, filling ditches and leveling ridges; and shallow hoeing in early September to remove weeds after the dog days. The two earthings are carried out in mid-September and at the end of September respectively. When earthing up, be sure not to damage the leaves or bury the heart leaves, so as to help the white stalk elongate and prevent lodging. In the autumn rainy season, pay attention to moisture prevention and drainage. Do not let water accumulate in the onion furrows. In hot, sunny weather after rain, water to lower the soil temperature. When the soil surface is slightly dry, immediately loosen the soil to reduce moisture and ventilate to lower the temperature, so as to prevent "onion rot" (rotting of the white stalk).

3. Prevent and control three diseases and six insects. The three diseases are downy mildew: spray 80% phosethyl-Al wettable powder at 400 times dilution or 72% Previcur aqueous solution at 600 times dilution. Gray mold: spray 70% mancozeb wettable powder at 400 times dilution or 50% procymidone wettable powder at 1000 times dilution. Purple blotch: spray 75% chlorothalonil wettable powder at 500 times dilution or 64% oxadixyl wettable powder at 400 times dilution. The six insects are leafminer, American serpentine leafminer and thrips: spray 40.8% chlorpyrifos EC at 1000 times dilution or 75% methomyl EC at 1500 times dilution; cabbage caterpillar (cabbage white butterfly): spray 0.5% abamectin EC at 1500 times dilution; beet armyworm: spray 5% tebufenozide EC at 2500 times dilution or a mixture of 5% cypermethrin at 3000 times dilution and 90% methomyl powder at 3000 times dilution; onion maggot (onion fly): use onion maggot solution (250 mL of 50% phoxim EC + 250 mL of 40.8% chlorpyrifos EC) at 1500 times dilution or 20% soluble concentrate Confidor at 7000 times dilution and pour along the rows where the damage occurs.