Vegetable greenhouses are now very common, and one of the essential fruits and vegetables for greenhouse vegetables is cucumber. In the process of planting cucumbers, it is often found that greenhouse cucumbers show symptoms of wilting, and sometimes cause plant death. With the increase of cucumber planting area in greenhouses, this wilting disease is increasing year by year, which seriously affects the yield of cucumber. Xiaobian below introduces the symptoms and prevention strategies of cucumber wilting disease in greenhouse.
Identification of the symptoms of cucumber wilt disease in greenhouse
1. The physiological disease caused by the water loss caused by the water loss of cucumber leaves caused by cucumber leaves. The acute wilting of cucumber leaves means that in a short time, the whole cucumbers suddenly wilted and lost the ability to make cucumbers. For example, the disease occurred in the cucumber planting area of ​​Laiyang greenhouse in the winter solstice of 2006. The leaves of the light disease plants gradually wilted from bottom to top, but the top leaves were not wilted, and the vascular bundles at the base of the stem were not discolored or slightly yellowish. , the disease-free Fusarium wilt was not isolated, and it was physiologically wilting.
The main reason is that the greenhouse cucumbers planted in autumn or early spring are more likely to encounter rainy and snowy days, especially the low temperature lasts for a long time, and the ground temperature is low. When the root system is underdeveloped or the plants are weak, the plants are in a sunny day, and the temperature in the greenhouse is high during the day. The transpiration is strong, and the roots do not absorb enough water and nutrients, resulting in a sudden wilting of the leaves and severe death of the whole plant.
2, grafted cucumber root rot grafted cucumber in a month of normal development, after the heart picking to the harvest period began to occur, the cucumber cucumber disease progress is slow, the initial leaves lose vitality, sunny at noon leaves wilting, morning and evening or cloudy return to the original state, the number After the day, the lower leaves began to yellow, and gradually expanded upward, inhibiting the growth of lateral branches to cucumber dysplasia. The base of the stem of the black seed pumpkin used as a rootstock is water-soaked and becomes black and spoiled until the whole plant is dead.
The external symptoms of mild disease are not obvious, but the rootstock and scion are not visible. If the fine roots become black and rot, part of the main root and lateral roots will become light brown or brown. If it is serious, then the roots will all change. It is brown and dark brown, and the diseased plant has a longitudinal split at the base and a grayish black banded hyphae in the middle of the irregular longitudinal crack. The dense black spots are visible on the root bark, ie the pathogen spores . The disease is a fungal disease caused by Phomopsis spp., and the pathogen is overwintered in the soil with the diseased body. The grafting of cucumber is easy to occur in the next year, and the ground temperature can be 15 to 30 °C, and the incidence is 20 to 25 °C.
3, cucumber blight Cucumber can occur in the whole growth period, which is the most serious in the flowering period. In the early stage of its onset, the symptoms are that the leaves gradually wilted from the bottom to the top, similar to lack of water, it will be more obvious at noon, but it will return to normal in the morning and evening. After a few days, the whole leaves are withered and no longer return to normal, and in a humid environment, the diseased part will show a white or pink mildew layer.
The disease is a fungal disease caused by Fusarium. The bacteria survives in the soil for at least 5 to 6 years. The bacteria invade from the root wound and root hair cells of the cucumber, and grow rapidly in the vascular bundle duct, secreting and decomposing. Enzymes and toxins cause the plants to wilting and the catheter to brown.
4, cucumber root knot nematode disease The upper part of the symptoms are short stigma, dysplasia, when the soil drought and water supply is insufficient, there may be symptoms of wilting around noon, the root symptoms are on the fibrous roots and lateral roots, can form a tumor of different sizes In the root section, the root section begins to be milky white, and later turns into a light brown color. The root section is cut open and there is a small milky white nematode inside.
The disease is a root disease caused by root knot nematodes. Nematodes overwinter in the soil with eggs or 2nd instar larvae and survive for 3 to 4 years in the soil. The nematode invades from the root tip of the cucumber, settles in the growth cone, and secretes stimulants to form giant cells and nodules. The suitable temperature for nematode survival is 25-30 °C, and the sandy soil is generally harmful.
Control measures for cucumber wilt disease in greenhouse
1 Selection of resistant varieties Nowadays, the resistant varieties are strictly resistant to moderate disease. Such as Jinza 2, Jizao 1, Zhongnong 5, Changchun Mia, Xintai Mickey and so on.
2 Soil disinfection The dough was treated with 50% carbendazim WP 8g/m2. Before planting, use 50% carbendazim WP 2kg per 667 square meters, mix 30kg of fine dry soil, mix well and evenly spread into the colonization hole.
3 It is best not to practice crop rotation for cucumber for more than 3 years, and the interval between rotations is 3 to 4 years.
4 Grafting and rooting with black seed pumpkin as a rootstock for grafting, not only disease prevention, but also obvious yield increase effect.
5 control methods for the acute wilting of leaves caused by low temperature barrier of cucumber, pay attention to increase the ground temperature, especially the nighttime ground temperature should be maintained at 12 ~ 15 ° C or above, if the ground temperature in the night shed is 8 ~ 10 ° C for a long time, when the day is sunny, the shed The temperature will rise quickly and slow heating measures should be adopted. For example, after the sunrise, the temperature of the shed rises above 30 °C, and the grass curtain is used to block the shading, so that the physiological function of the cucumber can be slowly recovered to avoid the sudden wilting of the leaves.
6 Control root rot can be rooted with 70% methyl thiophanate WP (Japan Soda Co., Ltd.) 800 times or 40% DuPont Fuxing emulsifiable concentrate (DuPont).
7 control of wilt disease can be rooted with 2% agricultural anti-120 water agent (Wuhan Kono Biological Pesticide Co., Ltd.) 250 times liquid, 50% of carbendazim WP (Yantai Xinrun Fine Chemical Co., Ltd.) 3000 times solution Rooting.
8 Prevention and control of root-knot nematode disease, before the planting with 1.5 billion / g of Afro Streptomyces and its actives (commercial name line treasure) granules (Qingdao Jiaonan Luzhou Development Zone production), every 667 square meters ditch 2 ~3kg, in the growing season, 1.8% avermectin EC (Shijiazhuang pesticide chemical plant) can be used to irrigate 1500 times.
The above liquids should be used alternately. Generally, 0.25 kg of each liquid is filled once every 10 to 15 days, and even 2 to 3 times can reduce the incidence.
The above is about the introduction of cucumber wilting disease in greenhouses. Greenhouse cucumbers are used as anti-seasonal cultivation, and more attention should be paid to various disease prevention and control, which is also to ensure the interests of the growers themselves.
Zhejiang Industrial Group Co., Ltd. , https://www.xingyeseafood.com