From flowering to young fruit expansion is a very important stage of grape growth. Whether the management at this stage is in place directly affects the yield and quality of grapes in that year. The main points of this management are:

In the grape production cycle, from the beginning of flowering to the end of flowering, normal years generally last about 4- 14 days, and most of them last 7- 12 days. The main factors affecting the flowering and fruiting of grapes are temperature, humidity, drought and wind. The flowering period needs high temperature. When the temperature reaches above 25℃, grapes bloom in large quantities, and the optimum temperature is 27.5℃. When the temperature is lower than 15℃, grapes can't bloom normally, and fertilization is inhibited. The suitable relative humidity at flowering stage is 56%. If it is rainy and dry, it will affect flowering and pollination. The higher the soil moisture, the earlier the flowering time, and the later the flowering. Wind is also an important factor affecting flowering. Strong winds are not conducive to flowering, but will aggravate falling flowers. During the flowering period of grapes, the flowering peak is at 6- 1 1 every morning, and the peak is at 7-9. The first physiological fruit drop period is 3-5 days after flowering. During the flowering period of grapes, a lot of nutrients are consumed due to flowering, flower bud differentiation and branch growth. During this period, the competition between vegetative growth and reproductive growth for nutrients is very fierce. If the growth of new shoots consumes a lot of nutrients and the nutrients for reproductive growth are not satisfied, a large number of buds will fall before flowering and will continue to fall after flowering, thus reducing the fruit setting rate. If the soil moisture is too much and the root system is not well ventilated during flowering, it will affect nutrient absorption and lead to flowering. According to the conditions and physiological characteristics of grape flowering, the production management of grape flowering period should focus on the following aspects:

First, topdressing

In order to alleviate the competition between vegetative growth and reproductive growth at flowering stage and meet the needs of flowering and fruit setting, topdressing must be carried out before and after flowering, and 0.2%-0.3% boric acid or borax solution should be sprayed before flowering to promote pollen tube elongation and improve fruit setting rate. At the same time, do a good job in vine management and improve the ventilation and light transmission conditions of the park. During the flowering period of grapes, in order to save nutrient consumption, it is necessary to tie vines, remove secondary branches, pick cores, pinch ears and remove secondary ears in time.

Second, strengthen temperature and humidity control.

Grapes cultivated in greenhouse must pay attention to the control of temperature and humidity in greenhouse. In order to improve the germination rate of pollen and ensure the smooth progress of pollination and fertilization. Temperature management index in the shed: keep it around 28℃ during the day and 16- 18℃ at night. Humidity control: When flowering begins, stop irrigation, control the air humidity in the shed at about 50%, and pay attention to frequent ventilation. It is difficult to control the temperature of grapes cultivated in the open field, but it is necessary to loosen and reduce the soil humidity so that the humidity in the garden is conducive to flowering and fruit setting.

Third, do a good job in finishing and finishing the flower heads.

This is an important measure to control the yield reasonably and keep the ear even and tidy, so we must do a good job.

Fourthly, the female flower varieties are artificially pollinated.

Most varieties of grapes are bisexual flowers, which can be naturally fertilized. However, due to the degeneration of male nucleus, female flower varieties need pollination to obtain higher yield. Therefore, we must pay attention to artificial pollination.

Five, the need for nuclear-free varieties should be timely use of plant growth regulators.

For example, Kyoho varieties were treated with GA3 for the first time in full bloom, and the ear was treated for the second time after 10- 15 days.

Six, pest control.

2-4 days before the grapes bloom, preventive drugs must be used well. Focus on the prevention and control of gray mold, black pox, anthracnose, downy mildew, ear stalk brown blight, winged moth and scarab.