Detailed Explanation of the Key Points of Kyoho Grape Cultivation and Management Techniques
Kyoho grapes are not grapes grown on giant mountain peaks. In Japanese, Kyoho is a type of grape brand; its berries are large, with thick skin and a deep color, and it has the characteristic of being easy to peel. There have been many varieties of Kyoho grapes with different forms, but most Kyoho grapes are purple-black.
Methods for Establishing a Kyoho Grape Orchard
Two cultivation trellis systems are used: the double-hedge trellis and the shed-hedge trellis. For the double-hedge trellis, the plant and row spacing is 0.6 m x 2-3 m; for the shed-hedge trellis, the plant and row spacing is 0.6 m x 4 m. Dig planting trenches at 0.6 m x 0.6 m, with a trench depth of 60 cm. When digging the trenches, keep the topsoil and subsoil separate. Backfill in the order of topsoil first, then subsoil, mixing in 100 t of farmyard manure per hectare, along with 1.5 t of superphosphate. When the fill soil is about 10 cm from the ground surface, begin watering, and after it settles, wait to plant.
The planting period is generally spring. Select strong 1-year-old seedlings, soak the roots in ABT rooting powder, then plant. After watering, cover with plastic film. Expose 2-3 buds on the upper part of the seedlings above the plastic film, and cover firmly with soil to retain moisture and prevent drying, promoting earlier sprouting. After sprouting, select and retain 2 new shoots per plant and tie them to stakes as main vines. For the secondary and tertiary shoots growing on the main vines, pinch the tips after leaving 2 leaves. Pinch the tips of the main vines in late August to promote vine maturity and the formation of flower buds. Weed and irrigate in a timely manner, and spray half-strength Bordeaux mixture once every 10-15 d.
Pruning Methods for Kyoho Grapes
1. Medium-cane pruning, determining buds by shoots
In order to moderate tree vigor, medium-cane pruning is primary, supplemented by long-cane and short-cane pruning. Winter pruning generally begins within 2-3 weeks after leaf fall and ends before bleeding. The best time is January. At this time, the organic nutrients in the one-year-old branches have already been transported to the perennial vines and root system of the plant, so there will be no loss of nutrients.
2. Remove buds in time, select and retain strong buds
After the grapes sprout in spring, remove double buds, weak small buds and other unnecessary sprouts as early as possible, retain strong buds, and thin out excess branches and slender weak branches 2-3 times before flowering. Wherever medium-cane pruning is used with 5-7 buds retained, when removing buds and setting shoots, depending on bud quality, leave one and remove one, retaining at most 3 buds, and the finally developed new shoots should be spaced 15-20 cm apart.
3. Repeated pinching to control growth
After the inflorescence appears, when more than 6 leaves have grown before the inflorescence, pinch the tip after leaving 5-6 leaves. Pinching begins 3 d before flowering and is completed in a concentrated push over 2-3 d. At the same time, remove all secondary shoots below the flower cluster; above the flower cluster, 1-2 secondary shoots may be retained, with each secondary shoot retaining 1-3 leaves, pinching once about every 10 d, for 2-3 pinchings, to control vegetative growth and ensure that sufficient nutrients are transported to the inflorescence to supply its growth and development.
4. Thin flowers and trim clusters, retain an appropriate amount of fruit
Thinning flowers and trimming clusters can increase the fruit-setting rate, making the cluster shape compact, the berries large and uniform, and the appearance attractive, improving commercial value. The method is: after new shoots emerge, promptly thin out weak, overly dense and irregular flower clusters, retain 1-2 inflorescences per new shoot, mainly retaining inflorescences on the lower part of the shoot; about 10 d before flowering, first cut off the secondary cluster, then pinch off 1/4-1/3 of the cluster tip. After fruit set, thin the fruit: first remove seedless small fruits, deformed fruits, and diseased and insect-damaged fruits, and finally thin out overly dense fruits. Retain 35-40 berries for large clusters, 30-35 berries for medium clusters, and about 25 berries for small clusters.
Water and Fertilizer Management for Kyoho Grapes
Usually, every 100 kg of berries harvested requires 1.5 kg of pure nitrogen, 1.0 kg of phosphorus, and 1.5 kg of potassium; at the same time, during berry growth, sufficient water can increase berry size and raise yield. However, if excessive irrigation is applied from berry coloring to the ripening stage, the berries will have low sugar content, high acidity, poor coloring, fruit cracking, and susceptibility to gray mold and late rot, affecting the color, aroma and taste of Kyoho grapes and lowering their quality. Therefore, irrigation must be moderate, and watering must be stopped 15-20 days before harvest.
Nitrogen fertilizer application should be controlled, and phosphorus and potassium fertilizers should be increased, to prevent the plants from remaining vegetative and growing excessively, with dense branches and leaves, poor ventilation, and insufficient light, which would prevent the grape berries from growing and ripening normally, and result in brittle and tender fruit stems and thin skins with poor resistance to various pathogens. For this, during the berry coloring stage, spray the leaves with an 800-fold potassium dihydrogen phosphate solution, and spray again half a month later, which can improve berry quality. After leaf fall in autumn, apply 2000-3000 kg per mu of decomposed organic fertilizer with 2% phosphorus fertilizer. At this time, the soil temperature is relatively high, which is favorable for the decomposition of organic fertilizer and the absorption and utilization of nutrients by the root system.
Pest and Disease Control for Kyoho Grapes
1. Downy mildew: In spring and autumn, in areas with little wind, much fog, much dew, and much rain, the disease is relatively severe. Systemic fungicides can be selected for control, such as: Jinyishuang, metalaxyl-M, flumorph, propamocarb, phosethyl-Al, metalaxyl, etc.
2. Anthracnose: It mainly damages nearly ripe fruit, so it is also called “late rot” disease. The pathogen attacks fruit stems and cluster axes, and the berries at the tip of clusters near the ground are affected first. The pathogen mainly overwinters as mycelium in the one-year-old branches of the tree. The following spring, it spreads in large quantities with wind and rain.
3. White rot: Grape white rot is commonly known as “water rot” or “cluster rot”. It is an important pathogen that occurs frequently. Generally, high temperature and abundant rain favor the epidemic of the disease. In rainy years, it often occurs together with anthracnose and causes great losses. The occurrence of white rot is closely related to rainwater. If the rainy season comes early, the disease occurs early; if the rainy season comes late, the disease occurs late. After this disease occurs in an orchard, there is often a peak of incidence after each rain. Combine control with that for anthracnose.
4. Black pox: Abundant rain and high humidity are important conditions for the occurrence and epidemic of the disease. Abundant rain and high humidity favor conidia formation, spread, and germination and infection. Especially when the plants are young and tender, if cloudy and rainy humid weather occurs, the disease will develop severely.
5. Gray mold: Gray mold is an important disease that seriously affects grape growth and storage. In spring, it is the main disease causing flower cluster rot. During an epidemic, the flower cluster damage rate of susceptible varieties reaches more than 70%. Ripe fruit is also often rotted by this disease during storage, transportation and sales. It is a disease that must be controlled before and after flowering, especially before flowering.
6. Green plant bug: It belongs to Hemiptera, Miridae, also known as flower-leaf bug, small stink bug, etc. It damages after sprouting. In orchards with green plant bug damage (as long as it is after sprouting), the earlier the control, the better.
The cultivation and management procedures for Kyoho grapes are roughly similar to those of other grape varieties, with differences only in specific management details, because each grape variety has its own unique growth characteristics. To obtain high yields and achieve profitability, one must follow the individual characteristics of the plant.