The more common physiological diseases in greenhouse vegetable cultivation
1. Cucumber flower topping (head flower) Phenomenon: The top of the cucumber plant (growth point) is born with multiple female flowers, the stem section is shortened and thinned, the leaves are obviously smaller, the plants are dwarfed and the growth is stopped. This phenomenon is called by the melon farmers. It is called "flower topping" or "head flower."
The "flower topping" phenomenon is extremely common in the cultivation of cucumber in energy-saving greenhouses. Almost all greenhouse cucumbers are difficult to avoid. Once cucumber plants form a "flower topping", due to the excessive number of female flowers and fierce nutrition competition, most female flowers do not get enough nutrients and it is difficult to grow into mature melons, which consumes a lot of nutrients and affects plants. The growth and development of the plants caused the plants to become more debilitated, and at the same time it also caused a large amount of melons, causing a sharp drop in yield and a significant reduction in production. If it cannot be adjusted in time and restore the vegetative growth potential, not only the production will not go up, but the life cycle of the plants will also be greatly shortened.
2. Magnesium deficiency in cucumber: yellowing between veins in the lower leaves of the plant, residual greenness in the veins and leaf margins, or intermittent and bleak green ring phenomenon, and the leaves gradually withered from the bottom up.
3. Iron deficiency disease in cucumber: The new leaves of the growing point lose their green color and become yellow-white. When the iron deficiency is severe, the upper leaves may become yellowish-white, and necrotic brown spots appear on the edge of the leaves.
4. Cucumber calcium deficiency disease: the upper leaves are significantly reduced, veins yellow, veins slightly sag, yellow-green, leaf-shaped mushrooms, and sometimes the upper leaves appear Phnom Penh, near the growth point of the leaf margin withered.
5. Cholera deficiency in cucumber: The growth point is significantly shortened between the nodes, leaf veins are atrophic, the leaves become smaller, leaf margins are reversed and necrotic, brown, juvenile melons are severely melonized, many thin waisted melons, and melon strips have brown spots.
6. Tomato hypocalcemia: calcium deficiency during flowering can occur top crack fruit, young fruit and around the umbilical crack, placental tissue valgus, so that the young fruit formation of seven inverted, very ugly. Calcium deficiency during the expansion of young fruit can form umbilical rot fruit, commonly known as “black plaster diseaseâ€. In the early stage of disease, yellow-brown spots appear near the umbilicus. As the lesions expand, the lesions turn brown, and the inward depression and harden. Stop expanding, redden early, fruit shape flat, fruit surface less shiny, no food value. According to the survey, the incidence of tomato Calcium deficiency disease in greenhouse cultivation is as high as 80%.
7. Tomato potassium deficiency disease: The leaves of the middle and lower leaves of tomato lose chlorosis and yellowing is limited to the leaf margin. The lack of potassium can seriously affect the development of young fruit, reduce the quality of the fruit, but also can cause rot and other diseases.
8. Tomato hypomagnesemia: The lower leaves of the tomato are generally yellow and develop from bottom to top, mostly due to lack of magnesium. In the absence of magnesium, leaves lose their green color, their chlorophyll content is low, and their photosynthesis is weak, which seriously affects the accumulation of organic nutrients, which can result in a significant reduction in production.
9. Tomato rot rot disease: also known as streak disease or strip rot, is a common occurrence of greenhouse tomatoes, and a relatively serious harm to a physiological disease. There are two types of symptoms: brown tendon rot, partial browning on the fruit surface, and even necrotic spots. The fruit surface is uneven and the flesh is stiff. The flesh can be seen by the incision of the vascular bundle with browning and necrosis. Obvious green or pale green spots. The second type is white-type rot, which occurs in the skin tissue of the fruit. The diseased part has a wax-like luster, which is hard and hard. The pulp looks like a "heart-shaped heart" and the diseased part is poorly colored.
10. Tomato empty fruit: The empty fruit is a kind of physiological disease that occurs in greenhouse tomato, especially in the cultivation of winter hoe. The symptom is that the appearance of the fruit is ribbed, the cross-section is polygonal, and a clear cavity is seen after the incision.
11. Tomato malformation: Frequently occurring malformations in greenhouses include large umbilical fruit, pointed fruit, and many carpels.
The incidence of diseases such as tomato rot, tomato empty fruit and tomato malformation are as high as 90% in greenhouse cultivation, and up to 100% in some years.
In addition, watermelons, melons and other melons lack of symptoms, spicy (sweet) pepper deciduous disease, falling flowers, stems and leaves curling, malformation, disease, eggplant malformation (stuck fruit), lack of disease, kidney beans, Legumes and other beans falling out of flowers and other diseases also occur frequently.
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