Key Points of Water Chestnut Cultivation Techniques
I. Variety Selection: From high-yield, disease-free water chestnut fields, select water chestnuts with intact appearance, no disease or insect wounds, plump corms, and thick sturdy buds as seeds, sized within 30 per jin, requiring 120-150 jin of seed per mu. II. Seedling Raising: Before raising seedlings, soak seeds in 800x diluted Haolaisi for 10 hours to prevent stem blight. The seedbed...
I. Variety Selection
From high-yield, disease-free water chestnut fields, select water chestnuts with intact appearance, no disease or insect wounds, plump corms, and thick sturdy buds as seeds, sized within 30 per jin, requiring 120-150 jin of seed per mu.
II. Seedling Raising
Before raising seedlings, soak seeds in 800x diluted Haolaisi for 10 hours to prevent stem blight. Choose a seedbed with no waterlogging, in loose fertile sandy loam or vegetable garden soil. Before raising seedlings, apply sufficient base fertilizer to the seedbed. Arrange seed corms on the seedbed at 4-5 cm spacing with the terminal bud facing upward, cover with soil, and water thoroughly. After complete emergence, if seedling leaves are yellow, apply manure water or 0.5% urea. Before transplanting, spray with "send-off medicine" using Haolaisi plus Regent to prevent stem blight and white stem borer. Seedling raising takes 25-30 days.
III. Base Fertilizer
Apply 20-30 loads of decomposed farmyard manure per mu, 50 kg calcium magnesium phosphate fertilizer, 5 kg boron-zinc-magnesium-iron fertilizer, 25 kg potassium sulfate compound fertilizer.
IV. Timely Transplanting, Reasonable Close Planting
Generally transplant before mid-to-late July. Transplanting density: lean fields should be dense, fertile fields should be sparse. Generally plant spacing is 40 x 50-60 cm, planting 2500-3300 plants per mu, with a planting depth of 5-6 cm. When transplanting, roots can be dipped in Rooting Powder No. 5.
V. Water Management
From the greening-back stage to the tillering stage of water chestnut, maintain a shallow water layer to promote tillering. After heavy application of corm-setting fertilizer, maintain a deep water layer to avoid fertilizer toxicity to water chestnut.
VI. Fertilization
Water chestnut fertilization is applied in four rounds:
1. Greening-back fertilizer: 5-7 days after planting water chestnut, apply 3.5-5 kg urea per mu as spot application at the base of plants.
2. Tillering fertilizer: Fertilizer needed for water chestnut tillering, 15-20 days after planting, broadcast 10 kg urea plus 10 kg potassium sulfate compound fertilizer per mu.
3. Corm-setting fertilizer: Apply heavy corm-setting fertilizer in mid-September, with 50-75 kg rapeseed cake and 25 kg potassium sulfate compound fertilizer per mu. At the end of September, apply 10-15 kg seedling-strengthening agent and 20 kg potassium sulfate per mu.
4. Corm enlargement fertilizer: Applied in mid-October, this is an important fertilizer for water chestnut enlargement. Apply 20 kg of Water Chestnut Root-Enlarging Super Potassium Fertilizer per mu. Fertilization note: Do not apply compound fertilizers containing chlorine.
VII. Clever Use of Hormones
Apply at the end of September depending on seedling condition. If seedlings are vigorous, apply paclobutrazol (100-150 g per mu) plus Rooting Powder No. 5 (4 packets per mu each time, used 2-3 times consecutively). Rooting powder should be dissolved with a co-solvent. If seedlings are poor, apply only rooting powder.
VIII. Pest and Disease Control
1. White stem borer (stem borer): Spray Regent once before transplanting. In mid-September, combined with fertilization, use Shachongshuang powder or Shabaichong powder for sealed killing.
2. For water chestnut stem blight, powdery mildew, and moldy base, choose Xianggeli, Senmei, or Tianguan for spraying, once a week. Adding a spreader when spraying improves effectiveness, and pay attention to supplementing foliar fertilizer.
3. Physiological red tail is caused by deficiency of boron, zinc, magnesium, and other trace elements. Apply 3-5 kg of boron, zinc, magnesium, iron fertilizer per mu.
Spraying note: Do not apply Jinggangmycin or medications containing Jinggangmycin.