Investigation on the effect of shelter cultivation on the control effect of main diseases and fruit quality of grape

Investigation on the effect of shelter cultivation on the control effect of main diseases and fruit quality of grape

Chencang District is located at the western end of Guanzhong Plain in Shaanxi Province, with mountains, rivers and plateaus, which is suitable for the growth of apple, kiwifruit, grape, cherry, peach and other fruit trees. Especially in recent years, with the promotion of the construction of Chencang national modern agricultural demonstration zone, a large number of table grape demonstration gardens dominated by new operators have developed vigorously in the Weibei plateau area, which has become a model for leading the transformation and upgrading of Chencang fruit industry. However, due to the continental warm temperate monsoon climate in Chencang district, which is often dry in spring, hot in summer and waterlogged in autumn, and uneven rain and heat, more than 75% of the annual rainfall is concentrated from June to September every year, and the rainy season overlaps with the grape growth and ripening seasons. it often leads to outbreaks of diseases such as grape downy mildew, white rot and gray mold, which pose a serious threat to grape production. Drawing lessons from the successful experience of some forerunners of rain shelter cultivation in the south and the province, we chose the Jinxiang species breeding professional cooperative grape base in Weibei plateau area of our region for shelter cultivation demonstration, and focused on the detailed investigation and summary of the occurrence of main diseases and fruit growth and ripening of grape under the rain shelter cultivation mode, in order to provide guidance for the cultivation and disease prevention and control of table grape in rainy areas in summer and autumn.

I. Materials and methods

1. Basic situation of the demonstration site

The demonstration site is located in the fresh grape base of Jinxiang breeding Cooperative, a village in Zhouyuan Town, Weibei Plateau, Chencang District, with an elevation of 735m, flat terrain and deep soil layer, with an average annual temperature of 13 ℃, annual rainfall of 650mm and sunshine hours of 2100 hours. In January 2017, we selected two grape varieties, Red Barado and Sunshine Rose, in the base for shelter cultivation demonstration, with a total area of 20 mu, with a double cross "V" frame shaping, with a planting density of 2.8 meters × 0.8 meters and 300 plants per mu. Both the demonstration garden and the open field cultivation garden are managed by conventional management methods.

two。 Design of rain shelter

The rain shelter is made of steel and bamboo. The arch shed is 2.4 meters wide and 1 meter high (the height and width of the shed can be adjusted according to the grape frame cultivation specifications). The arch shed is covered with 2.5 meters wide plastic film. When setting up the shed, each prefabricated stainless steel pipe arch beam with bottom crossbar is fixed on the cement bar, and then one iron wire is tightly pulled at each end, middle and top of the stainless steel pipe arch beam. Five bamboo arch beams are uniformly fixed between the stainless steel arch beams in the row through these five iron wires to form a small steel bamboo arch shed covered along the grape line, and then covered with film (after bagging, about June 25). Drains were built on both sides of the plants outside the shed, and Rain Water flowed directly into the gutters from the side.

3. Disease investigation

The day before plastic film mulching in the arch shed, the base number of main diseases (grape downy mildew, white rot, gray mold) of grape in shelter cultivation and open field was investigated uniformly. From August 14, the incidence of leaves and ears of treated and control orchards were investigated every 20 days (10 grape varieties were randomly selected, 4 new shoots per plant were randomly fixed, 10 leaves were investigated from top to bottom, and then the diseased leaf rate was calculated. At the same time, the ear incidence of the selected plant was investigated, and the ear incidence was calculated, until the ear was ripe and defoliated, a total of 5 times were investigated, and finally the occurrence of the disease was statistically analyzed.

4. Determination of the effect on the growth and quality of grape

After the ear was ripe, 10 grape plants were randomly selected from each plot, and 3 ears were randomly selected on each plant. The ear weight, grain weight and the content of soluble solids in each variety were measured, and the grain color and powder integrity of the fruit were observed. 30 clusters of ears of each variety were weighed by balance, 100 grains (uniform size and maturity) were randomly selected from 30 clusters of ears, 100 grains were weighed by balance, and the content of soluble solids was determined by hand-held sugar meter after juice extraction and mixing. The leaf shedding rates of plants in rain shelter and open field cultivation gardens were measured in early November.

II. Results and analysis

1. Control effect of shelter cultivation on grape diseases

According to the results of the demonstration investigation in Table 1, no matter Red Barado or Sunshine Rose Grape, shelter cultivation has a good control effect on leaf and fruit diseases such as downy mildew, white rot and gray mold, and with the increase of rainy days, the effect of disease prevention and control is becoming more and more obvious. Among them, the results of two surveys on August 14 and September 4 showed that there was no significant difference in disease control effect due to very few rainfall days and rainfall, but with the increase of rain days and rainfall in the later stage, the effect of rain shelter on the prevention and control of grape diseases was prominent. the results of the last survey on November 3, 2017 showed that the incidence of leaves and fruits cultivated in rain shelter was only 11.3% and 12.7% respectively. The open field cultivation gardens were as high as 98.7% and 97.2% respectively. The incidence rates of leaves and fruits of sunny rose grapes cultivated in rain shelter were 10.5% and 9.5%, respectively, while those in open field cultivation gardens were 26.8% and 24.8%, respectively, which were 255% and 261% of those cultivated in rain shelter.

Table 1 investigation on the control effect of shelter cultivation on main diseases of grape

Table 2 determination results of grape fruit characters in shelter cultivation model

two。 Effect of shelter cultivation on growth and quality of grape

The investigation results in Table 2 showed that there was no significant difference in fruit size, color and grain weight between the two grape varieties cultivated in the rain shelter and the open field, but because of the serious diseases of leaves and ears in the open field, the ear weight and soluble solids in the open field cultivation garden were significantly lower than those in rain shelter cultivation, while the leaf shedding rate (in early November) was significantly higher than that in rain shelter cultivation. At the same time, after rain shelter cultivation, due to plastic film mulching and bagging, the light is relatively weak in open field cultivation, which can delay harvest, and after maturity is not affected by climatic factors such as rainfall, the fruit can continue to hang on trees for about 60 days without loss, which is conducive to flexible grasp of market demand and increase the price of grapes.