Key techniques of delaying Leaf Senescence in delayed cultivation of Red Globe Grape

Key techniques of delaying Leaf Senescence in delayed cultivation of "Red Globe" Grape

The delayed cultivation of "Red Globe" grape is a new form of grape facility cultivation with Chinese characteristics, which is opposite to promoting cultivation. It aims to cover and prevent cold in the later growth stage, delay and prolong the grape fruit growth period as far as possible, delay the ripening and harvest period of grapes, thus harvest fresh grapes to supply the market in the middle of winter, and use delayed harvest instead of fresh storage, forming good economic and social benefits. Zhangye City has a typical continental temperate arid climate, with little rain and rich "cold resources". It is one of the best areas to use greenhouse and other facilities to produce delayed red grapes in China. Since 2007, Zhangye City has introduced the achievements of Professor Chang Yongyi's "Research on delayed cultivation techniques of American hard Meat late ripening Grape in short accumulated temperature area", giving full play to the advantages of natural resources and making use of facilities to cultivate "Red Globe" grapes listed in deep winter. and continue to summarize and integrate delayed cultivation techniques, through several years of development, facility grape industry has become a sunrise industry and Huimin industry for farmers in this area to increase income and become rich. From 2009 to 2016, we summarized the core technologies of delayed cultivation of Red Globe grape facilities, such as how to delay ripening, defoliation and market time, in order to better and guide the practice. to provide technical reference for the healthy development of the industry in the region.

1 materials and methods

1.1 Overview of the experimental site

The experimental site is located in Nuanquan Village, Xinba Township, Gaotai County, with a geographical location of 99 °18 mi 99 °56 'east longitude and 39 °08 mi 39 °42' north latitude. The geology belongs to the corridor transition zone of the Qilian fold system, the topography is tilted from south to north, and the elevation is 2 500m, which belongs to the alluvial and alluvial plain at the northern foot of the Qilian Mountains. The climate belongs to the continental desert arid climate, with abundant sunshine, rich heat, cold and dry winter, dry and hot summer, windy spring, average annual temperature of 4.6 ℃, frost-free period of 120 days, annual precipitation of 219.2mm, evaporation of about 2 000mm, and annual sunshine hours of 2683 hours. Transportation and electric power are well developed, 312 National Highway and Lanxin Railway run through the whole territory, and post and telecommunications are convenient.

1.2 tested varieties and cultivation conditions

The tested variety is 4-year-old "Red Globe" grape, the row spacing is 0.8m × 1.8m, and the tree shape is in the shape of single-stem and double-arm hedgerow; the facility condition is the second-generation solar greenhouse without support, which is built according to the standard of "Construction Technology (trial) of Zhangye Grape Solar greenhouse", with a height of 3.8m, span of 7.5m, length of 50m and covers an area of 373.5m2. The soil of the experimental site is sandy loam with medium fertility, rich organic matter content and high level of fertilizer, water and management.

1.3 Test materials

Amino acid liquid fertilizer (amino acid ≥ 8%, K2O ≥ 5%) produced by Gansu Lueneng Ruiqi Biotechnology Co., Ltd.; biogas liquid produced by biogas digester used by local farmers; gibberellin produced by Jiangsu Fengyuan Bioengineering Co., Ltd.; "Biwei" made in Germany.

1.4 Experimental design

The main results are as follows: (1) through the production practice, several key factors of delayed cultivation of "Red Globe" grape in Zhangye area were summarized.

(2) the leaves were sprayed with GA3 and "Bibou" in greenhouse No. 32 of the experimental area on October 15, 2016. after spraying, the leaves with the same node on the new shoots of different treatments were taken on the 7th, 14th and 22th day after spraying, and the chlorophyll content was determined immediately by spectrophotometry, with spraying water as control.

(3) on October 10, 2016, a topdressing gun was used to topdressing the roots of grape with amino acid active fertilizer and biogas liquid in shed 31 of the experimental area. the leaves with the same position on the new shoots of different treatments were taken at 7, 14 and 22 days after root application, and the chlorophyll content was immediately determined by spectrophotometry, with clear water as the control.

2 results and analysis

The main results are as follows: (1) the key to the delayed cultivation of "Red Globe" grape is to delay the germination, flowering and ripening as far as possible in the early stage, and to postpone the harvest period in the later stage [Jishan Huayao]. In production practice, the main measure to delay grape germination is to cover the greenhouse with grass curtain from the harvest of the grape in that year to the germination of the grape in the following year, so that the grapes in the greenhouse can not see the sun and delay their germination. This measure can delay the germination of the "Red Globe" grape for about 30 days. At the end of March and the beginning of April, when the local temperature gradually rises and the temperature in the shed reaches more than 10 ℃, the method of covering the grass curtain during the day and opening the curtain and opening the vent at night can be adopted to let the cold air into the shed. This measure can delay the germination time of the "Red Earth" grape for about 10 days.

(2) temperature control is one of the core techniques of delayed cultivation of "Red Globe" grape facilities. It is necessary to buckle the greenhouse in time before the local early frost comes. Generally, due to the different range of temperature drop in autumn, the greenhouse film should be put on when the temperature drops to 8 ℃ at night. When there is no frost, the upper and lower vents are opened during the day and night, the maximum temperature during the day is about 30 ℃, and the temperature at night is kept at 12: 15 ℃. When the outside temperature drops to 7: 8 ℃ at night, pay attention to close the vents at night. During the period from the initial stage of withholding the greenhouse to the middle of October, the air can be released appropriately during the day to keep the temperature and humidity in the greenhouse not too high, while in the middle and late October, as the external temperature drops, we must pay attention to cold protection and heat preservation. Generally, the temperature in the greenhouse should be kept at 20: 25 ℃ during the day, 7: 10 ℃ at night, and the air relative humidity should be kept between 70% and 80%. From mid-late December to January, we should pay more attention to strengthening cold protection and heat preservation, keeping the temperature at about 20 ℃ during the day and 8 ℃ at night, and the lowest should not be less than 5 ℃.

(3) the senescence of leaves is mainly reflected in the degradation of chlorophyll, and there is the same rule in grape leaves. In the delayed cultivation of grape, it can be seen from Table 1 that the chlorophyll content of grape leaves treated with GA3 and spray green treatment increased at first and then decreased, while that of the control leaves showed a downward trend. On the other hand, the control leaves showed a downward trend. After 22 days of treatment, the decline rate of chlorophyll content in leaves of each treatment was lower than that of the control, in which the chlorophyll content of leaves treated with GA3 decreased by 6.01%, that of leaves treated with green protection decreased by 8.10%, and that of the control decreased by 32.27%, indicating that spraying GA3 and green protection on grape trees during delayed cultivation could effectively control the degradation of chlorophyll. Delay the senescence of leaves.

Table 1 effects of plant growth regulators on chlorophyll content of grape

(4) it can be seen from Table 2 that the chlorophyll content of grape roots with amino acid active fertilizer and biogas slurry increased at first and then decreased, while the control leaves showed a downward trend. After 22 days of treatment, the decline rate of chlorophyll content in leaves of each treatment was lower than that of the control, in which the chlorophyll content of leaves topdressing with amino acid active fertilizer and biogas liquid decreased by 6.25% and 7.10% respectively. On the other hand, the chlorophyll content of the control leaves decreased by 33.52%, indicating that the application of amino acid active fertilizer and biogas liquid in the roots of grape could delay the leaf aging rate to a certain extent, and the leaf defoliation time could be delayed in the delayed cultivation.

Table 2 effects of different root topdressing on chlorophyll content of grape

Table 3 comparison of the growth period of "Red Globe" grape cultivated inside and outside the greenhouse (month / day)

(5) it can be seen from Table 3 that through the application of various comprehensive techniques, the sprouting period of "Red Globe" grape can be delayed by about 30 days and the picking period can be delayed by 90 days.

3 summary and discussion

The main results are as follows: (1) the core technology of delaying defoliation in delayed cultivation of "Red Globe" grape is to delay germination time and defoliation time.

(2) the main technology for delaying grape germination in the facility is to cover the greenhouse with grass curtain from the harvest of the grape in the same year to the germination of the grape in the following year, so as to keep the grapes in the greenhouse from sunlight as far as possible. This measure can delay the germination of red ball grape for about 30 days.

(3) when the temperature dropped to 8 ℃ at night before the local early frost, the plastic film should be put on the greenhouse in time to ensure the temperature needed for the growth of seedlings.

(4) the regulation of temperature and humidity in autumn and winter is one of the core techniques of delayed cultivation of grape in facility. After the shed has just been buckled, the maximum temperature during the day is controlled at about 30 ℃, and the night temperature is kept at 12: 15 ℃. When the external temperature drops to 7: 8 ℃ at night, the vents should be closed at night. The temperature in the shed should be kept at 20: 25 ℃ during the day and 7: 10 ℃ at night, and the air relative humidity should be kept between 70% and 80% from mid-late October to early December. From mid-late December to January, the temperature is about 20 ℃ during the day and 8 ℃ at night, and the lowest temperature should not be lower than 5 ℃.

(5) spraying GA3 and "Bibao" on grape leaves and applying biogas liquid and amino acid active fertilizer on roots can effectively control the degradation of chlorophyll and delay the time of leaf senescence, which should be popularized in production practice.

(6) through the application of various comprehensive techniques, cultivating "Red Globe" grape in the facility can postpone the sprouting period of grape about 30 days and the picking time about 90 days.