Prevention and control measures of strawberry deformity in flat greenhouse with too thin and fat chicken crown

Greenhouse strawberries often appear too fat or too thin, chicken crown, flat and other deformed fruit. This kind of strawberry not only affects the quality, but also reduces the value. In order to reduce or even avoid abnormal fruit, the causes and prevention methods of strawberry abnormal fruit are introduced as follows:

Strawberry deformity

First, the causes of abnormal strawberries:

1. Breed difference. In strawberry varieties, most of them are normal complete flowers, while a few flowers with short stamens and long pistils are easy to appear, and the pollen grains are few, and most of them have no germinating power, which is easy to cause abnormal fruit. Generally shallow dormancy, strong cold tolerance, more and sound pollen, such as Fengxiang, Chunxiang, Baojiao early varieties have few abnormal fruits. In addition, strawberry plants will degenerate and senescence after 3-4 years of age, resulting in an increase in malformed fruit.

two。 Flower level. Lower secondary flowers are prone to male sterility; higher secondary flowers are prone to female sterility, but the former can set fruit normally as long as it has good pollen, while the latter is poor or even unable to set fruit, and is prone to deformed fruit.

3. Temperature and humidity. Low temperature, high temperature or high humidity can easily cause deformed fruit. High humidity affects anther dehiscence, causing water droplets to scour the stigma. The suitable temperature for strawberry growth is 20 ℃-25 ℃. During flowering and fruiting stage, the lowest temperature should not be less than 5 ℃. Too low or too high temperature will affect strawberry growth and pollination, and deformed fruit is easy to occur.

4. Spray at flowering stage. Anthesis spray can wash the stigma and cause abnormal fruit, especially strawberry flowers blooming on the same day. Some greenhouse strawberries, due to the abuse of pesticides during flowering, not only directly hinder pollination and fertilization, but also kill bees and flies, resulting in the outbreak of abnormal fruits.

5. Light conditions. Pollen formation begins about 2 weeks before flowering. If there is not enough light in this period, the accumulation of starch needed for pollen germination will be inhibited in cloudy and rainy days, thus reducing the pollen germination rate, which is not conducive to fertilization and lead to abnormal fruit.

6. Cultivation and management. During the period of flower bud differentiation of strawberry, such as insufficient or excessive fertilizer, too low or too high nitrogen level in seedlings, will affect the quality of flower bud differentiation and is not conducive to normal pollination. During the period of flower bud differentiation, flowering and expansion of strawberry, if the water is insufficient, the flower organ will be dysplastic, the pollination and fertilization will be imperfect, the expansion of strawberry will be blocked, and the deformed fruit will be formed easily.

II. Prevention and control measures:

In order to prevent the abnormal fruit of strawberry, in addition to selecting good varieties and planting some varieties with large amount of pollen in the main varieties, we should also do a good job:

1. Promote the full differentiation of flower buds. The full differentiation of strawberry flower buds affects the yield and quality of strawberry. If the flower bud differentiation is good, the flower will be more, the fruit will be bigger, and the abnormal fruit will be less. Generally, two weeks before strawberry planting, root cutting, shading, nitrogen control and removal of old leaves began to promote the full differentiation of flower buds.

two。 Reasonable regulation of temperature and humidity. The flower organ of strawberry is sensitive to low temperature. If it meets-2 ℃ for 1 hour, the pistil will turn black, so it is necessary to improve the heat preservation performance of the greenhouse. The greenhouse temperature is 20 ℃-25 ℃ in the daytime, 8 ℃-10 ℃ at night, and the ground temperature is 18 ℃-20 ℃. The relative humidity of strawberry anther dehiscence was 30% 50%, and the relative humidity of stigma fertilization and pollen germination was 50%, 60%. The environment in the greenhouse is airtight and not ventilated in time, which will make the humidity too high and produce abnormal fruit. In production, it can be covered with non-dripping film and high ridge plastic film to reduce soil water evaporation, vent for a short time at noon and adjust temperature and humidity.

Release bees in strawberry florescence

3. Release bees at flowering stage. When the first batch of flower buds of strawberries are formed, bees are kept in the shed, and 2-3 boxes of bees are placed evenly in each standard shed, so that the pollination rate can reach 95%. Release time: 8-9 a.m. and 3-4 p.m. The use of bee-assisted pollination can reduce deformed fruit.

4. It is strictly forbidden to apply pesticides during flowering. During the flowering period of strawberries, it is strictly forbidden to use drugs to prevent abnormal fruits caused by reducing the germination rate of pollen. Therefore, diseases should be thoroughly prevented before strawberries bloom; after flowering, diseased plants and leaves and inflorescences should be pulled out in time to control the spread of the disease.

5. Timely thinning of flowers and fruits. Timely thinning of secondary flowers, malformed small fruits, diseased leaves, old leaves and yellow leaves will help to increase light, reduce the rate of abnormal fruits, help concentrated supply of nutrients, and improve the weight and quality of strawberries.

6. Strengthen the management of fertilizer and water. The soil in the greenhouse is too dry, too wet, lack of fertilizer or improper fertilization, which will cause the imbalance of water and nutrient supply and demand, lead to strawberry dysplasia and produce deformed fruit. Lack of soil moisture, to timely watering small water, such as lack of fertilizer, should be combined with watering topdressing, increase phosphorus and potassium fertilizer, about 15 kg per mu, with hydration, hole topdressing, the effect is better. After fertilization, the soil moisture is insufficient, so it is necessary to water strawberries in time to meet the needs of normal flowering and fruiting of strawberries and to prevent deformed fruits.