When is the right time to transplant chili peppers? Key points on pesticide use and management techniques
Transplanting provides more space for the plant to grow. It helps the plant carry out photosynthesis better.So when is it generally suitable to transplant chili peppers? What pesticides should be used? What are the key management techniques?According to Mr. Gao, a chili pepper grower in Shandong, chili peppers should preferably be transplanted on a sunny day. On sunny days the soil temperature is high, which favors root growth and survival. After planting seedlings on a sunny day, a certain degree of temporary wilting is normal. When seedlings are planted in overcast and rainy weather, although the plants do not wilt, the soil temperature is low, and because of the human activity during planting, the soil becomes sticky and compacted, which is unfavorable for root development and results in a low survival rate. Therefore, seedlings planted on sunny days recover quickly from transplanting, while those planted on overcast and rainy days recover slowly and do not grow well.
What pesticides are generally used on chili peppers?
1. Chili pepper viral disease
Field symptoms include four types: mosaic, yellowing, necrosis and malformation. It generally appears as mosaic; in severe cases several symptoms appear at the same time, causing heavy leaf drop, flower drop and fruit drop, and necrosis of the growing point.
Control method: use Virus K, Virus A, Virus Ling or Virus Jing at 400-500 times dilution at the early stage of the disease, spraying once every 7 days for 3 consecutive sprays. Spraying 0.1% potassium permanganate, or 20 mg/kg naphthaleneacetic acid, or 1% calcium superphosphate solution also has a certain preventive effect on mosaic virus.
2. Chili pepper soft rot
It mainly damages the fruit, and the disease mostly occurs on green fruits. The rind first shows water-soaked dark green spots, then turns brown and soft-rotted with a foul odor, the internal flesh rots, and the fruit becomes deformed, as if a bag were filled with muddy water; some call it “a bag of water”. In the later stage the fruit shrivels after losing water, leaving only grayish-white rind hanging on the branches, which drops off at the slightest external force.
Control method: spray promptly before and after rain with 72% agricultural streptomycin wettable powder at 4000 times dilution, 50% copper succinate wettable powder at 500 times dilution, 77% Kocide wettable powder at 500 times dilution, etc., spraying once every 6-7 days for 3-4 consecutive sprays.
3. Chili pepper anthracnose
It mainly shows brown water-soaked round or irregular lesions on the fruit surface, about 1 cm in diameter, mostly sunken, with a clear boundary between diseased and healthy tissue, and small black or orange-red dots arranged in rings on the lesion surface. When dry, such lesions tend to shrink and crack, hanging like tiger skin, hence the name “tiger skin disease”. When humid, a red sticky substance oozes from the fruit surface, and the diseased fruit rots and drops off. It often hangs on the fruit branches. It is prone to occur under high temperature and high humidity, and spreads quickly, often causing significant losses within a week.
Control method: after discovering diseased plants, promptly spray with 80% anthracnose thiram wettable powder at 800 times dilution, or 75% chlorothalonil wettable powder at 500-600 times dilution, or 70% mancozeb wettable powder at 400-500 times dilution, or 70% thiophanate-methyl wettable powder at 600-800 times dilution, spraying once every 7-10 days for 3 consecutive sprays.
4. Chili pepper phytophthora blight
When distinct black elongated lesions form, the lesions rapidly expand around the stem, 3-5 cm long or longer, with a clear boundary between diseased and healthy tissue, and the lesions are slightly sunken or constricted. On leaf tips or leaf margins, large nearly round water-soaked lesions appear, after which the whole leaf soft-rots and dies. The fruit mostly becomes diseased starting from the stem end, showing water-soaked dark green, rapidly turning brown and soft-rotted; in the later stage it shrivels after losing water but does not drop off, and when humid a sparse grayish-white mold can be seen.
Control method: after discovering the center of infection, spray with 50% metalaxyl-copper wettable powder at 500-600 times dilution, 60% DTM wettable powder at 500 times dilution, 77% Kocide wettable powder at 500 times dilution, 75% chlorothalonil wettable powder at 800 times dilution, etc., spraying once every 7-10 days for 2-3 consecutive sprays; in severe cases spray once every 5 days for 3-4 consecutive sprays.
What are the key management techniques for transplanting chili peppers?
1. Apply high-quality decomposed organic fertilizer before transplanting, which can reduce pest damage, gas damage or root and seedling burning caused by applying undecomposed organic fertilizer to the soil.
2. Apply medicated soil or biological inoculant in the planting hole at transplanting: when applying medicated soil in the planting hole, copper hydroxide plus cymoxanil-mancozeb can be chosen; prepare the medicated soil at a ratio of pesticide : soil = 1 : 10, mix evenly and apply in the hole. If a biological inoculant for preventing plant death is chosen, there is no need to mix medicated soil; by improving the soil environment and root growth, the disease resistance of the plant can be enhanced.
3. Soak the plug trays before transplanting: to ensure that peppers recover quickly after transplanting, have well-developed roots and grow vigorously, the plug trays can be soaked with 72.2% propamocarb aqueous solution at 600-800 times dilution, or 62.5% fludioxonil.metalaxyl-M at 1500 times dilution, adding 46.1% copper hydroxide water-dispersible granules at 1500 times dilution, and also 25% thiamethoxam water-dispersible granules at 2500-5000 times dilution, etc.; this can improve the plant's resistance, promote plant growth, and at the same time control seedling-stage pests.
4. Chili peppers should not be transplanted too deep or too shallow; if too shallow the root ball is exposed and the seedlings recover poorly, while if too deep the roots are prone to rot and the seedlings die.
5. When taking out seedlings for transplanting chili peppers, bring plenty of soil and be careful to reduce damage to the roots. The planting depth should be such that the cotyledons of the seedling are level with the soil, and immediately after transplanting water thoroughly to settle the roots.
6. Drench the roots after transplanting: choose one of the pesticides copper hydroxide, copper quinoline, copper calcium sulfate, copper bis(8-hydroxyquinoline) sulfate, etc., and add cymoxanil-mancozeb or metalaxyl or pyraclostrobin or oxadixyl-mancozeb, etc. for root drenching, with 100-200 grams of pesticide solution per plant being appropriate.
7. Do not hill the soil too deep: ridge cultivation is recommended. If flat-bed cultivation is used and hilling is needed, be careful not to hill too deep, and when watering, the water should preferably not exceed the hilled position; this can prevent plant death.
8. After transplanting chili peppers, pay attention to drainage and irrigation. If high temperature and drought occur, irrigation is necessary; if there is continuous overcast rain, pay attention to drainage to avoid waterlogging, root rot and seedling death. Keep timely track of and pay attention to weather changes, drain promptly when it rains, and avoid excessive rainwater causing waterlogging damage and plant death.
9. Water thoroughly at transplanting. After the seedlings recover, if the soil is dry, water once with recovery water, in a slightly larger amount, but it must not exceed the ridge surface, because chili pepper roots are not well developed, and exceeding the ridge surface easily causes waterlogging damage and death.