First, the problem of falling flowers and fruits of grapes
In grape planting, if the phenomenon of falling seeds, flowers and fruits is within the range of 10%, the fruit farmers need not take management measures, but if the phenomenon of falling flowers and fruits exceeds 10%, attention should be paid to it. In order to prevent grapes from falling flowers and fruits, it is necessary to understand the reasons for falling flowers and fruits, and then take effective preventive measures. Next, the reasons and preventive measures of grape falling flowers and fruits are introduced in detail.
1, Causes of Grape Flowering and Fruit Falling
There are many reasons for the falling flowers and fruits of grapes, which are nothing more than the following aspects:
(1) variety reason
Some kinds of reproductive organs are born with defects. For example, the abnormal ovule rate of Kyoho grape will reach 48%, and the filaments will still roll back, which is not conducive to pollination; The female flower structure of some varieties is defective; The organs of some male flowers degenerate, and if the pollination trees are not properly configured, it will cause the phenomenon of falling flowers and fruits.
(2) improper site management measures
Excessive application of nitrogen fertilizer before flowering, excessive watering during flowering, improper field management measures such as shaping and pruning, tying new shoots, removing kernels, heading, spraying drugs during flowering and burning stigma will all lead to the phenomenon of falling flowers and fruits.
(3) climatic factors
Unstable flowering temperature: the optimum flowering temperature is 20℃~25℃ during grape growth. If the temperature before flowering is lower than 10℃ for a long time, it will affect the differentiation of flower buds. If the flowering temperature is lower than 14℃, poor flowering will easily lead to shedding. If the flowering temperature exceeds 35℃, it is easy to cause wilting and necrosis of flowering organs.
Continuous rainfall at flowering stage: If it happens to rain at flowering stage, the corolla will be difficult to fall off and the anther will not be loose normally.
Insufficient light: insufficient light before flowering will reduce the assimilation of new shoots, and the nutrient supply of ear will not keep up during flowering.
Pests and diseases: Downy mildew, gray mold and anthracnose are all high-incidence diseases of grapes. If flowers and fruits are infected with these diseases, it is easy to cause the phenomenon of falling flowers and fruits.
Physiological factors: when the grape fruit grows to 3~4 mm, it is easy to fall off due to insufficient nutrient supply.
2. Measures to prevent falling flowers and fruits
Scientific selection of varieties: when planting, try to choose resistant grape varieties with well-developed floral organs, and pay attention to the rational allocation of pollination trees for female varieties.
Rational fertilization: If the base fertilizer is sufficiently fertilized, there is no need to apply germination accelerating fertilizer, and topdressing should be applied as far as possible before germination accelerating, especially before germination accelerating, after physiological fruit dropping and fruit coloring. Nitrogen, phosphorus and potassium are the main topdressing in the first two stages, and phosphorus and potassium are the main topdressing in the coloring stage. Nitrogen fertilizer is not applied before flowering, and it is only applied after the young fruit is harvested in autumn.
Supplementing tree nutrition: After the grape is harvested, it is necessary to replenish tree nutrition in time, especially to grasp the fertilization time, generally before and after the harvest, and at the latest in the first ten days of 10. Fertilization is mainly based on compost and manure, with two-thirds of nitrogen fertilizer consumption and half of total phosphorus and potassium fertilizer applied as base fertilizer every year.
Spraying foliar fertilizer: spraying 0.3% boric acid solution +0.3% potassium dihydrogen phosphate solution at grape bud stage, initial flowering stage and full flowering stage.
Scientific pruning: do a good job in scientific pruning of vines, such as budding, thinning branches and straight inflorescences.
Wipe the bud: wipe the weak tree and gently wipe the strong tree. The first time is after the bud unfolds, and the second time is when the leaves unfold. Sparse the tip: grasp the principle of removing the small and retaining the big, and removing the weak and retaining the strong. The first time is when the new shoot length is 10 cm, and the second time is when the new shoot length is 20 cm. Loose inflorescence: strong branches leave two inflorescences, normal branches leave one inflorescence and weak branches leave no inflorescence. Picking: strong fruit branches are picked, and medium fruit branches are picked weakly. Pick the core 7~ 10 days before flowering, and take the fruiting branches 5~6 days before flowering. Girder girdling: generally, girdling time is 5-6 days before flowering, and girdling position should be selected at 75px or before heading of fruiting branch. Circumcision is only suitable for vigorous plants and branches, and is limited to fruiting branches, and should not be carried out on main vines. Do a good job in pest control: in the high temperature and high humidity season, we should master the occurrence law of grape pests and diseases and take targeted measures to prevent and control them.
Second, the measures for grapes to bear fruit twice a year
Grapes bear fruit twice a year in a row, which is an effective remedial measure in production and the main way to increase income in normal years. So what can be done to make grapes bear fruit twice a year?
1, variety selection
The selection of varieties is very important for the second result. For example, varieties with good flower bud differentiation, strong fruiting ability and long fruit ear are suitable for secondary fruiting, such as Xiahei and Jufeng.
2. Control the amount of fruit left after one result.
In order to have good quality after the second pass, it is necessary to properly control the amount of fruit left over from the first pass. Generally, the yield per mu is controlled at around 1000 kg, which is too high. The growth of the first fruit consumes a lot of nutrients in the tree, and the second fruit will have malnutrition symptoms, easily infected with diseases, unable to achieve the goal of high quality and high yield, and the fruit's commercialization is not good.
3, timely coring to cultivate excellent secondary buds.
Timely coring can promote the growth and development of collateral branches, and different varieties have different coring measures. 0~2 days before the first-season fruit of "65438+ Kyoho" grape blooms, the second spike is picked, the spike tip is pinched off, and 4~6 leaves are left before the spike for coring; Six leaves can be left after fruit setting and before heading, and the seeds can be picked in time. After core removal, in the 65,438+0 week, it germinated and sprouted 65,438+0 times, leaving 5-6 leaves on the top 65,438+0 times for core removal. After that, it left two leaves for multiple secondary buds to pick up the core repeatedly, and all other secondary buds were erased.
4, deputy prompt timely processing
After the first fruit coring, it should be managed as usual, but when spraying foliar fertilizer and insecticide, potassium dihydrogen phosphate can be added 500~ 1000 times to inhibit the growth of new shoots and promote the flower bud differentiation of secondary shoots. After the young fruit expands in one season, from the hard core stage to the initial coloring stage, the secondary branches turn yellow and green, and when the semi-lignified axillary buds are full, 3-4 leaves are left for coring. After coring, the plant was applied with 5 kg of liquid nitrogen, phosphorus and potassium fertilizer, which promoted the orderly germination of 1-2 buds on the cutting mouth, and the axillary buds on the cutting mouth sprouted new buds with flowers.
The above are the causes and preventive measures of grape flowering and fruit dropping, as well as the measures of grape secondary fruit. If you have any problems in the process of grape planting, you can leave a message in the comment area, and we will discuss the problems encountered in the process of grape planting.