Grape management methods in February

February is a critical period for grape management. Management measures at this time are crucial to the growth of grapes, and any carelessness may affect the yield and quality of the entire year. So, what are the main management tasks of the vineyard in February?

1. Bud removal and shoot determination

1. Remove the buds

After the grapes sprout, bud removal is required. Usually, when there are multiple buds sprouting on a fruiting branch, leave a bud every 15 to 20 cm, leave 2 to 5 new shoots on each fruiting branch, and remove the rest from the base. When removing buds, generally remove the buds without flower spikes and weak buds among the double buds, leaving only one tip for one bud eye. To ensure yield, you can also decide whether to keep or remove the new shoots when they grow 4 to 5 leaves, depending on whether the first silk roll has a flower spike.

2. Fix the shoot

The inflorescence can be seen when the new shoots grow to about 15 to 20 cm. At this time, the shoots should be fixed and the overgrown shoots, weak shoots and excess preparatory branches should be removed. The density of shoots should be 8 to 12 per square meter for trellis grapes, with a spacing of about 20 cm between new shoots. The rule of determining the shoots follows the principle of "total quantity control, five to keep and five not to keep":

① Keep the middle ones, not the early or late ones (meaning do not keep the buds that sprout too early or too late).

② Leave the late ones and not the weak ones (referring to leaving the fat buds and thick new shoots).

③ Leave flowers and not empty spaces (referring to leaving new shoots with inflorescences).

④ Leave the new shoots but not the upper ones (referring to leaving the new shoots close to the base of the mother branch).

⑤ Leave the outside and not the inside (referring to leaving new shoots with space to grow).

2. Binding vines

The vines should be tied in time according to their growth. Generally, the new shoots should be tied when they are about 40 cm long to ensure that the new shoots grow in an orderly manner and avoid entanglement and shading.

3. Pinching

For fruiting shoots with strong growth potential, twist the upper part of the inflorescence 7 to 10 days before flowering, and pinch off 5 to 6 large leaves on the upper part of the inflorescence, which can significantly increase the fruit setting rate (such as varieties such as Kyoho). However, it should be noted that watering during the flowering period and pinching after fruit setting will significantly reduce the fruit setting rate (such as red grape varieties).

4. Fertilizer and water management

1. Fertilizer and water management for open-air grape cultivation

Bud strengthening water: depends on the moisture conditions of the garden soil. Vineyards in arid areas should be irrigated with germination water, while vineyards with better soil moisture conditions can be irrigated less or without water.

Bud fertilizer: It is mainly used to supplement the insufficient amount of fertilizer in winter and some trace elements to promote rapid growth of branches. It is recommended to use high-nitrogen compound fertilizer + trace element fertilizers such as calcium, magnesium and zinc + rooting fertilizer or humic acid fertilizer to promote absorption.

Note:

The application of germination fertilizer should be determined according to the fertility of the garden soil and the variety. In gardens with good soil fertility, no fertilizer is required or an appropriate amount is applied; in gardens with vigorous growth or severe flower and fruit drop, no fertilizer is required.

The time for using germination water and germination fertilizer is generally 10 to 20 days before the grapes sprout.

2. Fertilizer and water management from the growth period of new shoots to the flowering period to promote early cultivation

Fertilization: About 20 days after germination, use quick-acting nitrogen and phosphorus fertilizers as the main fertilizers, and add potassium fertilizers in appropriate amounts. At this time, new shoots grow rapidly, inflorescences grow rapidly, and the plant has a great demand for nutrients. However, for varieties that are prone to flower and fruit drop, it is not advisable to apply nitrogen fertilizer 10 days before flowering to avoid aggravating flower and fruit drop. Nitrogen fertilizer should be applied after flowering.

Watering: Generally, watering should be done one week before flowering to create good moisture conditions for grape flowering and fruit setting, and to alleviate the contradiction between the water demand for flowering and new shoot growth. In the rainy areas in the south, attention should be paid to field drainage, to prevent root rot and to reduce field humidity; in the arid areas in the south, water supply should be ensured at this time to promote the formation of leaves and inflorescences. Orchards with poor growth should be careful not to flood with water after germination, so as to avoid causing the soil temperature to be too low and the root absorption capacity to decrease.

Note: For varieties that are prone to flower and fruit drop, such as Kyoho and Hutai No. 8, you can water them appropriately during germination, and pay attention to controlling fertilizer and water before and after flowering to prevent serious flower and fruit drop caused by excessive growth.

5. Pest and disease control

Before and after flowering, special attention should be paid to the occurrence of diseases and pests such as gray mold, brown blight of the spike axis, downy mildew, and green stink bug.

1. Botrytis cinerea

Symptoms: Mainly harms the corolla, inflorescence and fruit, causing flower and fruit falling and fruit rot. After the disease occurs, the inflorescence becomes soft and wilts, and even the entire inflorescence becomes necrotic; when the disease occurs, brown faded spots appear on the fruit, the skin of the affected fruit is prone to cracking, and the skin is easily separated from the flesh and falls off. The disease occurs when light yellow-brown "V"-shaped spots appear at the tip of the leaves, then expand inward, and the color changes from yellow-brown to dark brown. When young stems are attacked by gray mold, small water-soaked spots appear, which later develop into oval spots with gray-brown mold on them.

Prevention and control measures: For prevention before flowering, optional pesticides (such as procymidone, cypermethrin, mancozeb, etc.) should be sprayed 1 to 2 times; for prevention at the early stage of the disease, optional pesticides (such as pyrimethanil, fenpropimorph, propiconazole, pyrimethanil, thiabendazole, etc.) should be sprayed 2 to 3 times every 10 to 15 days.

Downy mildew: Please refer to relevant prevention and control measures.

2. Brown blight of spike

Symptoms: Initially, brown water-soaked spots appear on the branches and spikes of young ears, which quickly expand and cause the spikes to turn brown and die; the fruits lose water, wilt and fall off, and sometimes black mold appears on the diseased parts; young fruits become infected and produce small round dark brown spots, which become scab-like on the surface as the fruits continue to swell; when the fruits grow to medium size, the scabs fall off and the ears shrink and dry up.

Prevention and control measures: Pay attention to inspect the orchard. When the disease just starts to occur, use 1000 times of pyrimethanil (Sephadrol) to spray the flower spikes to control it.

3. Green Lygus

Symptoms: Adults and nymphs pierce and suck the epidermal cells of grape shoots, tender leaves, flower buds and young fruits, branches and leaves, causing pinhole-like holes to appear at the feeding sites. After the tender buds are pierced and sucked, reddish-brown needle-sized necrotic spots are formed, and they cannot sprout and expand leaves normally; after the tender leaves are damaged, small dead spots appear first, and as the leaves grow, countless holes are formed, and severely the leaves are broken, deformed and wrinkled; after the flower buds are damaged, small black spots appear, development stops, and they begin to wither and fall off; the young fruit initially shows inconspicuous small black spots on the surface, and then as the fruit expands, the black spots turn brown and dark brown, forming irregular scabs, which inhibit the expansion of the fruit.

Prevention and control measures: The key periods for prevention and control are the bud sprouting and greening stage, the green leaf showing stage, the flower catkin separation stage and the small young fruit stage. The recommended control agent combinations are high-efficiency cypermethrin + imidacloprid, high-efficiency cypermethrin + acetamiprid, fluphenazine, and cypermethrin + thiamethoxam. Apply the medicine in the afternoon on a warm sunny day or after rain, focusing on the front part of the branches and leaves where the green stink bug hides.

In short, February is a critical period for grape management. Doing a good job in bud removal, tip determination, vine tying, pinching, fertilizer and water management, and disease and pest control can lay a solid foundation for the healthy growth and high harvest of grapes.