What is the reason for the formation of abnormal strawberry fruit in greenhouse? How to prevent and cure? Can I eat it?

Strawberry is cultivated in greenhouse, which is a good way to increase its yield and income. But in practice, there are often many abnormal fruits that are too thin, too fat, curved, flat and uneven, which are called deformed fruits. What is the reason for the formation of abnormal strawberry fruit in greenhouse? How to prevent and cure? Can I eat it?

First, the selection of improved varieties is the most economical and effective measure to control the occurrence of abnormal fruits.

Under the same cultivation conditions, the abnormal fruit rate of varieties such as Zhang Ji, all-Star, Fengxiang and Tianbao was more than 30% lower than that of Shuofeng and Shuomi.

Varieties with high inflorescences tend to produce abnormal fruits because of uneven distribution of nutrients, such as Chunxiang, Jinxiang and so on.

Practice shows that cold-tolerant varieties, because of strong low-temperature resistance, the probability of abnormal fruit will be greatly reduced, such as Gerrera, Changhong and other cold-tolerant varieties, less abnormal fruit.

Varieties with poor disease resistance are susceptible to disease at flowering stage, which will lead to the increase of malformed fruit. The varieties of strawberry in greenhouse with low temperature tolerance, short dormancy period, normal flowering at low temperature, high rate of self-pollination, large fruit, good fruit shape, early maturity, disease resistance, high yield and high quality are effective measures to control the occurrence of abnormal fruit and improve economic benefits.

Second, adjust the temperature of the shed. Too low temperature is an important cause of abnormal fruit.

Strawberries like warm and cool climates. they are not resistant to cold and heat. When the temperature reached 5 ℃, it began to sprout and grew, and the optimum temperature for growth and development was 20 ℃ ~ 25 ℃, and it was disadvantageous to its growth and development when it was lower than 10 ℃ and higher than 30 ℃. The temperature requirements were different in different periods: before budding, 25 ℃ ~ 28 ℃ in the day and 15 ℃ at night; from budding to flowering, 22 ℃ ~ 26 ℃ in the day, 10 ℃ at night, 15 ℃ ~ 25 ℃ in the day after flowering and no less than 8 ℃ at night. In the flowering and fruiting period, if the temperature is too low, it will seriously affect its growth and development, resulting in poor pollination and deformed fruit.

In northern China, during the period from December to early March, the climate is very cold, and the greenhouse is often attacked by a cold current, which is the period when strawberries blossom and bear fruit, and the cold current has a great impact on the growth and development of strawberries.

If the construction of the shed is unreasonable, the lighting angle is improper, and the thermal insulation facilities are not in place, it is very easy to cause the room temperature to be lower than 5 ℃, which can easily lead to more deformed fruits.

To this end, it is necessary to thicken the thickness of the north wall of the shed as soon as possible. Before the cold spell comes, adding 4 layers of Kraft paper quilt under the grass can increase the room temperature by 4 ℃; build a small arch shed on the strawberry border, the arch shed is covered with a layer of plastic film 90 cm in width, and compacted in the soil at the lower end of the film, the temperature in the small arch shed can be increased by 3 ℃; the heating effect of installing electric stove or electric hot line in the shed is better. These heat preservation measures can ensure that the temperature of the shed is above 5 ℃ in winter.

Third, doing a good job of pollination is the key measure to reduce the production of abnormal fruits.

In the severe cold season, strawberries often bear abnormal fruit due to low temperature and poor pollination, even if the room temperature is higher than 5 ℃. In the cold season, the outdoor temperature is low, the air outlet of the shed is small, the release time is short, the indoor is in a windless state, the outside of the shed is cold, no insects enter, strawberries can not be pollinated with the help of wind and insects.

Poor pollination is another important cause of abnormal fruit. The countermeasure is to do a good job of pollination, there are three main methods of pollination: first, the allocation of pollination varieties. This is a simple and effective measure to prevent the occurrence of abnormal fruit. The method is to mix 5% to 10% of the main varieties with a large amount of pollen.

If the main variety is Baojiao Zaosheng, pollination varieties such as Chunxiang or Fengxiang can be mixed. The second is artificial pollination. The flower buds of strawberries usually take 4-5 days from flowering to falling.

During flowering, artificial pollination can be carried out with a brush after 10:00 every morning, once every other day, when there is no water on the leaves and buds. Third, bee pollination. The effect of bee pollination is good. A week before strawberries bloom, a box of bees (about 5000) is kept in a shed.

Stop spraying pesticides 15-20 days before releasing the bees. The effect of honeybee pollination is not only better than manual pollination, but also can save a lot of pollination labor.

After pollination, the flowers can fall off quickly and fall off after one day, and the rapid drop of flowers can also reduce the consumption of nutrients, concentrate the results of nutrients, rapid fruit development, large fruit growth, high yield, 7 days earlier maturity and so on. According to the author's experiment, the fruit weight of the whole inflorescence after pollination can be increased by 22% to 28%, and the probability of deformed fruit can be reduced by about 40%.

Fourth, water imbalance is another important cause of malformed fruit.

Strawberries are very sensitive to water, afraid of both drought and waterlogging. If the soil is too dry or too wet in the greenhouse, it will cause the imbalance between water and nutrient supply and demand, resulting in poor fruit development and the formation of abnormal fruit.

Because the root system of strawberry is shallow, the main part of the root system is in the 20 cm topsoil, which is not resistant to drought. In addition, due to the high room temperature and large soil water evaporation, drought is very easy to occur.

When the soil moisture is insufficient, it should be watered in time. However, due to the lack of ventilation in the shed in the cold season, the indoor moisture is not easy to lose, and it is easy to produce wet damage, so it can not be flooded with flood, but should be watered frequently with small water.

The use of hidden irrigation under plastic film can not only meet the water needs of strawberries, but also avoid excessive air humidity in the greenhouse. When the air humidity in the greenhouse is too high, it is easy to induce diseases, and it will also hinder the cracking of anthers, resulting in poor pollination and deformed fruit.

Long-life non-drop greenhouse film should be selected, which can effectively reduce water droplets and prevent water droplets from soaking the stigma and affecting pollination. After entering the flowering stage, watering should be properly controlled so as not to affect pollination and fruit setting. During the period from fruit setting to ripening, the need for water increases, and it takes 5-7 days to irrigate a small amount of water to keep the soil moist.

5. Improper fertilization is also a key factor leading to abnormal fruit.

The fruiting period of strawberry in greenhouse is long, and there is more demand for nitrogen, phosphorus and potassium. Insufficient organic fertilizer, partial application of nitrogen fertilizer or improper fertilization can easily lead to excessive growth of branches and leaves, poor ventilation and light transmission of plants, and aggravate the occurrence of abnormal fruits. On the basis of heavy application of organic fertilizer, attention should be paid to the application of phosphorus and potassium fertilizer instead of ammonium bicarbonate.

Topdressing should be carried out in accordance with the principle of "less frequent application and close combination with watering". From the closed shed to the strawberry bud, the fertilizer is usually topdressing once in 15 days, 15 kg per mu of compound fertilizer, 20 kg per mu of standard compound fertilizer every 20 days from inflorescence budding to fruit harvest, and 15 kg per mu after the first harvest peak.

After hydration and opening of ternary compound fertilizer, the method of drilling and topdressing is adopted, which has the advantages of fertilizer saving, simplicity and fast fertilizer effect, and is especially suitable for greenhouse application.

After the first batch of fruits were harvested and entered the second full flowering stage, 0.3% potassium dihydrogen phosphate solution was sprayed on the leaves, once every 5-7 days, continuously for 2-3 times, and the effect was good.

It is often said that hollow strawberries should not be eaten, because of the expansion agent, deformed strawberries are also because of hormones, can not eat, is this true?

The problem of fruit deformity is more complex, low temperature and other environmental factors will cause strawberry fruit deformity. There has been an experiment that: if the seeds on strawberries are affected by low temperature, it will lead to strawberry stunting; if it is removed during strawberry growth, strawberries will also be malformed.

In addition, during flower development, the number of growing points may increase because of temperature changes and other external factors, and combine together to form a lateral growth structure, this phenomenon is called affixation.

But these malformed fruits are edible, and some malformed fruits are sweeter.