What to Pay Attention to Before Grapevines Bloom
Let me share with you some small experiences in green plant maintenance about what to pay attention to before grapevines bloom. Next, the editor will introduce to the netizens.
What to Pay Attention to Before Grapevines Bloom
Many grape growers often overlook a management stage in the grape growing process, which is the management before grapevines bloom. It is important to know that the period before grapevines bloom is the basic stage for the vines to utilize the stored nutrients in the trunk for sprouting, branching, flower bud differentiation, blooming, fruit setting, and physiological differentiation of the flower buds for the next year. It is also an important period when some diseases and pests begin to cause harm and multiply. Therefore, management before grapevines bloom is very important. There are four key points: water and fertilizer management, flower and fruit management, branch management, and disease and pest control. Let’s take a look together.
Fertilization and Water Management
10-15 days before blooming, apply 30 kg of compound fertilizer (nitrogen, phosphorus, potassium) per mu, water the fertilizer for blooming, timely loosen the soil to retain moisture, and raise the low temperature. Fertilization (irrigation) is prohibited within one week before blooming to reduce flower and fruit drop. Foliar application: Apply a mixture of 0.3% borax, 0.3% urea, and 0.3% potassium dihydrogen phosphate solution 1-2 times before blooming. Spraying potassium dihydrogen phosphate solution promotes flower bud differentiation, and borax increases fruit setting rate.
Flower and Fruit Management
Thinning of Cluster: Thinning of clusters is usually carried out when there are 4-6 leaves. The selection and retention index of fruiting branches with clusters is 2 clusters per new shoot or 3 clusters per new shoot for strong and vigorous fruiting branches; one new shoot and one ear in the middle; weak branches have no clusters, 2-3 branches without clusters.
Formation of Cluster: One week after blooming, first remove the small clusters that affect the inflorescence, cutting off the top 1/4-1/5 of the inflorescence from 1-2 small clusters at the shoulder of the inflorescence. Remove diseased fruit, malformed fruit, seedless fruit, and dense fruit, leaving about 50-70 berries per cluster.
Branch Management
7-10 days before blooming, remove dense branches based on the number of flower buds, leaving a 15-20 cm long strip between the same-side branches, 10-12 new shoots per square meter of trellis area, and 3000-4000 new shoots per mu. For varieties with a low fruit setting rate, such as the欧美株巨峰, more branches can be retained. Last winter, if the pruning was excessive and the fruiting mother branches were too long, the grapevines should be appropriately pruned back during the germination period to ensure normal germination of the buds at the bottom of the mother branches. If not pruned back in time, the upper sprouting branches should be cleaned to prevent the fruit from shifting upwards.
Main Branch Thinning: The multi-vine fan-shaped fruit branches often use the single-branch renewal method, renewing every two years. When the one-year-old branches are about 50 cm away from the root, they should be pinched to promote maturation for the fruiting branches of the next year. The巨峰 variety has strong growth and low fruit setting rate, and pinching before blooming gives better results. The heavier the pinch, the lighter the drop of flowers and fruits. Pinch 2-4 leaves on the inflorescence to control the apical dominance of the new shoot, increase fruit setting rate, then pinch leaves on the secondary shoot to supplement leaf nutrition; other varieties of fruit branches are pinched to the third wire (about 1.8 meters), and 3-4 leaves are pinched after the wire.
Secondary Branch Management: Do not retain secondary branches below the ear, and remove all secondary branches. Retain 3-4 leaves next to the ear and above the ear to prevent sunburn. Leave one leaf on the top of the cluster permanently, and pinch the top two elongated secondary branches repeatedly when they reach 4-6 leaves.
Disease and Pest Control
Green blind bugs are pests that must be controlled. When the grape bud scales swell and green tissue is visible, spray 10% imidacloprid wettable powder 2000 times or 5% berberine 5000 times. For orchards with severe green blind bugs, the pesticide can be applied again 6 days after application (2-3 leaf stage). When more than 90% of the inflorescences are in the branching stage, spray 70% methytobuzin 800 times, Antaisen 800 times, and Redan 1500 times.
Before blooming, due to many diseases, it is recommended to use protective fungicides and systemic fungicides in combination with miticides to control red spiders, ensuring safe blooming. 2-3 days before blooming, spray 50%bensulfuron-methyl 500 times, 1500 times, 50% cyprodinil 1000 times, 1.5% polyoxin 500 times, 50% chlorpyrifos wettable powder 800 times, 15% cypermethrin emulsifiable oil 2000-2500 times, 1.8% abamectin 2000-2500 times.
The above is the full content about what to pay attention to before grapevines bloom, hoping it helps green plant enthusiasts!