Cucumber has a high mortality rate. What is the cause of cucumber death?

Cucumber greenhouses were planted in many areas of China, but many farmers found that all the cucumbers planted in the greenhouses died. What is the reason? Let's introduce the causes of cucumber death and preventive measures.

malnutrition

1. Cucumber grows rapidly in high temperature season. Many vegetable farmers unilaterally pursue yield for a short time, leaving too many melons. The photosynthetic products of the main stem can't meet the needs of cucumber growth.

2. Insufficient sunlight (for example, the awning is always blocked), the photosynthesis of plants is weak, and the organic chemical nutrients in the main stems are not made enough.

The main symptoms of nutrient deficiency in the aboveground part of the main stem are aging and melon topping. However, the root system lacks organic chemical nutrients, which leads to slow root growth and few roots.

Poor air permeability of soil

Soil permeability is an important criterion for the growth and development of cucumber roots. However, many farmers irrigate too much in open field cultivation, and their roots can't carry out all normal photosynthesis, which leads to root death, especially in greenhouses with heavy soil. This situation is particularly serious.

Overwatering

Excessive watering at one time leads to the decrease of soil temperature and insufficient air coefficient of root system, which leads to the root system retting, which is the key cause of cucumber tree death.

According to the detection, the low PH value of soil is also the cause of the death of cucumber trees. For example, in some areas, the ph value of soil is only about 5.8, and the main reasons for soil alkalization are as follows: (1) Excessive consumption of potassium and nutrients in soil makes the soil develop towards alkalization; ② Long-term excessive application of organic fertilizer.

Continuous cropping every year leads to high pathogenic bacteria composition and unbalanced nutrient content in the soil, which is easy to cause crop root rot and other pests and diseases.

The suitable temperature for root growth is 20-25℃, but in summer, the temperature is above 30℃ in many cases. This high temperature natural environment is not conducive to the growth and embrittlement of cucumber roots.

Because of the high price of cucumber, farmers will apply a lot of fertilizer to improve efficiency, but that will lead to a large accumulation of soil salt.

Causes of death of cucumber trees and its control countermeasures

In addition, farmers' friends don't understand the characteristics of fertilizer demand of crops, and the proportion of nitrogen, phosphorus and potassium in specific fertilizers is extremely uncoordinated, which also leads to the accumulation of salt in the soil.

Therefore, the collapse of stem tip caused by excessive salt accumulation in soil is also a key factor leading to tree death. The main manifestation of tree death caused by salt damage is that the roots of crops are asymptomatic, but the parts near the soil become shriveled, resulting in poor nutrition supply of the main stems above ground and death.

root rot

① Root rot of cucumber (Fusarium oxysporum): It is a common root rot. The main stem and stem are immersed in water at first, and then rot. The rotten part of the affected part becomes dark brown and flocculent. The leaves wither in the early afternoon, and will repair themselves sooner or later, and will wither in severe cases.

Causes of death of cucumber trees and its control measures

② Rhizoctonia mycorrhiza rot of grafted cucumber: This disease is a common disease of grafted cucumber. Generally, everything grows normally after emergence and develops gradually after entering the fruiting stage. The early leaves lose their vitality, wither in sunny afternoon, return to normal in rainy day or sooner or later, and wither in a few days. According to the observation, the main reason is the atrophy, looseness and decline of the stem tip of black-spotted wax gourd, but it does not rot, and the conducting tissue at the root mouth does not fade, followed by pedantic Fusarium mycorrhizal rot and leaf blight.

The above two root diseases are both soil-borne diseases and insect pests. Pathogens remain in soil or disabled people, spread with water flow, and invade from roots and wounds. The temperature is conducive to the disease, and the diseases of continuous cropping, depressions, sticky land resources and wetlands are aggravated.

Root-knot nematodes harm roots to form tumors, leading to dead trees, leading to long roots tumors and dead trees.

Correct preventive measures for cucumber tree death;

1. Raise melons properly and balance the nutritional components of the main stems. Keep 1 melon every 2-3 leaves for large cucumber and 1 melon every 2 leaves or 2 melons for small cucumber.

2. When surfing with a sunshade net, it is recommended to shade from 10 to 3 pm every morning (which can be effectively adjusted according to the temperature and weather conditions of the day) and prevent shading for 24 hours.

3. Irrigate with small water frequently, that is, to prevent high temperature and drought damage caused by insufficient water, and at the same time to ventilate the soil immediately to ensure all normal photosynthesis of roots.

Causes of Cucumber Tree Death and Preventive Measures

4. Sprinkle long-root water-soluble fertilizers, especially long-root water-soluble fertilizers that improve soil and promote the growth of porous roots, such as water-soluble fertilizers that are exposed everywhere.

5. Scrape off the agricultural film on one side of cucumber root system, weed to disperse water, improve the air permeability of soil, and promote the growth and development of cucumber root system, so as to alleviate the root system retting caused by excessive irrigation, but we must pay attention to weeding without damaging the root system.

6. In view of the root damage and tree death caused by excessive fertilization, farmers should reduce the amount of fertilizer and apply water-soluble fertilizer, 1 mu 6 ~ 10 kg.