What are the causes of fruit cracking in Jufeng grapes
An introduction to the maintenance of fruit trees, focusing on Jufeng grapes, what are the causes of fruit cracking in Jufeng grapes, the details are as follows:
Fruit cracking in Jufeng grapes has several causes, 1, weak tree vigor, caused by overload. 2, excessive soil moisture changes, causing fruit cracking. 3, improper use of hormones, causing fruit cracking. 4, last year's use of girdling technique, causing fruit cracking this year. Fertilizer is also very good. After the fruit ferments, it can be used to water flowers, or buried in the soil.
The sparse fruit in the picture should be due to weak tree vigor. Jufeng grapes naturally set fruit, and this situation is prone to occur when the front is controlled and the back is promoted.
Jufeng grape cracking has physiological and pathological cracking types.
1, physiological cracking. It often occurs during the harvest period. There are two symptoms: one is the top cracking, and the other is the peduncle cracking. Physiological cracking generally has deep cracks, with both the peel and flesh splitting, and the juice flowing out. The main causes of physiological cracking are as follows.
① Drought and lack of rain in the early stage. Insufficient groundwater supply causes severe water deficiency in the plants, and from mid-July to late August, which is the fruit coloring period, sudden high temperatures and dryness after consecutive rainy days can easily cause fruit cracking, especially after the heavy rain from August 18th to 19th, 2001, more than 80% of the vineyards in the county had severe fruit cracking, with less than 20% good fruit rate and less than 10% good cluster rate.
② Soil compaction. Poorly drained clay soil, which is prone to drought and flood, causes severe fruit cracking.
③ Young fruiting trees with strong vigor and less fruit retention have less cracking, while mature fruiting trees with weak vigor and high fruit retention have severe cracking.
④ Unreasonable fertilization. Too much nitrogen fertilizer, less phosphorus, potassium, and calcium fertilizers; more inorganic fertilizers, less organic fertilizers, causing severe fruit cracking in vineyards.
⑤ Unreasonable pruning. The traditional pinching method, leaving only 8-10 old leaves on each fruiting branch, removing all new leaves, many fruit farmers have continued to use this method, resulting in fewer leaves, reduced ability to regulate water, and easy fruit cracking after rain.
⑥ High temperature during the young fruit stage. Abnormal high temperatures in North China from mid-May to late June inhibit cell division, resulting in insufficient cell numbers. At the same time, severe sunscald disease caused by high temperatures also causes severe grape cracking.
2, pathological cracking. Mainly caused by (T-J) disease and powdery mildew. Fruit cracking can occur at any time as long as there is disease damage. The symptoms are fruit peel cracking, shallow cracks, no flesh flowing out, and after disease control, the cracked area can form a dry spot.
II, Preventive measures
1, Change open-air cultivation to protected cultivation. Sunlight greenhouses and simple cold greenhouses can effectively control fruit cracking.
2, Reasonable fertilization, soil improvement. Apply nitrogen fertilizers in moderation, increase phosphorus, potassium, and calcium fertilizers, and apply more organic fertilizers. For heavy soil, the amount of calcium fertilizer should be increased. It is best to apply base fertilizers in furrows. For soil with poor aeration and poor drainage, methods such as deep tillage and strengthening drainage facilities should be used to improve soil physical properties and reduce soil moisture changes.
3, Mulch the ground. Covering the vineyard with mulch can prevent the roots from absorbing too much rainwater, inhibit the evaporation of surface moisture, and reduce soil moisture changes. Mulching combined with irrigation during dry periods can effectively prevent fruit cracking.
4, Adjust the fruiting quantity. Excessive fruiting in Jufeng grapes can lead to poor fruit coloring and more cracking. Therefore, it is necessary to adjust the fruiting quantity through thinning clusters and berries, and also to determine the yield based on fertilization to reduce cracking.
5, Reasonable pruning. Change the traditional pinching method, leave more leaves, with all sub-branches above the fruit clusters retaining 2 leaves and removing all axillary buds. Achieve more than 25-26 normal leaves per fruiting branch to enhance the leaves' ability to regulate moisture.
6, Tillage to loosen the soil. After rain or irrigation, tillage should be carried out to make the soil loose and increase soil aeration.
7, Timely spraying. Prevent (T-J) disease and powdery mildew. At the same time, vineyards that often crack should avoid spraying ethephon, coloring and sugar-increasing agents, etc., to prevent premature coloring, to avoid exacerbating fruit cracking.
This article shares the full content of the causes of fruit cracking in Jufeng grapes for your comprehensive understanding and reference!