Causes and Control methods of inexplicably withered Pepper trees in Summer

The manifestation of Fusarium wilt of pepper is that the plant grows slowly, the lower leaves turn yellow and develop upward gradually during the flowering and fruiting stage. The leaves wilted at noon and recovered at night. After repeated several days, the whole plant wilted and died. Sometimes half of the plant is sick, half of the plant is sound, and when the condition is serious, the whole plant wilts. The basal epidermis of the stem of pepper plant was longitudinally split, and there were yellow-brown stripes in the nodes and internodes, and rosin-like glue flowed out. When it is wet, a layer of white and pink mold grows. The vascular bundles and roots of chili peppers turn yellowish brown and rotten, making them easy to pull up from the soil. When the diseased stem is cut across, the vascular bundle is brown.

Dead chili tree

Pepper root rot in the onset period, there are waterlogged disease spots on the stem near the ground, slightly sunken, and then rot, the main and lateral roots rot and die.

Pepper stem rot starts from large seedlings and is more serious after planting. The disease spot occurred at the base of the pepper stem near the ground, which was dark brown at first, then developed around the base of the stem, the epidermis rotted, and the aboveground leaves turned yellow. Pepper wilted and died gradually due to insufficient nutrition and water supply during the expansion period. External causes: excessive moisture in soil, too high plant density, poor ventilation; due to continuous cropping, excessive accumulation of bacteria, high soil temperature and so on. Human factors: the age of pepper seedlings is getting older and older when planting, too large aboveground, people do not pay attention to planting, pepper plants shake severely, the basal stem is easy to produce wounds. In addition, the management of covering plastic film, shelving and drawing vines will cause more wounds.

The above three diseases are transmitted by fungi. The pathogen can survive in the soil for many years and occur seriously in continuous cropping.

1. Implement crop rotation: pepper and non-eggplant fruit crops have been rotated for more than 3-5 years. The seedbed should be changed for 2-3 years, or new soil should be changed.

2. Soil improvement and application of no-deep tillage soil conditioner: in serious disease or continuous cropping land, combined with soil preparation, 1200-1500kg cooked lime powder per hectare was applied to inhibit the development of bacteria. No deep tillage soil conditioner was applied, and the deep soil was also loose and permeable. by Rain Water or watering, the concentration of bacteria in the upper soil decreased and the incidence of the disease was reduced.

3. Before raising seedlings and accelerating germination, pepper seeds should be disinfected, commonly used methods: soaking seeds in warm soup and dry heat treatment, dried pepper seeds should be treated in a constant temperature of 70-75 ℃ for 5-7 days.

4. Cultivation and management: high dry fields with high terrain are selected for cultivation of hot pepper, and planted with ridge cultivation, high border and semi-high border; control of watering water, timely drainage in rainy season to prevent waterlogging; fertilization should pay attention to the combined application of nitrogen, phosphorus and potassium to prevent lack of fertilizer or excessive nitrogen fertilizer. When planting, get rid of the diseased seedlings and reduce the incidence. When planting, pepper seedlings with younger seedling age were used to reduce mechanical damage. In the process of planting, plastic film mulching, shelving and so on, handle and put lightly to hurt the pepper seedlings as far as possible. After planting, at the beginning of the disease, seed dressing double-drug soil was applied at the base of the stem of pepper. In order to reduce wounds, try not to cultivate soil during the growing period.

5, chemical control: at the initial stage of the disease, you can use 50% carbendazim wettable powder 500x liquid, or 50% methyl topiramate 400x liquid, or 10% Shuangxiaoling ⅱ water agent 200300x liquid, or 100x Nongkang 120x liquid, or 48% Rhizoctonia mollissima water agent 800x liquid, each pepper root 0.25kg solution, once every 10 days, 2-3 times in a row.