Detailed Explanation of Key Winter Management Techniques for Kyoho Grapes
As winter sets in, the leaves of Kyoho grapes fall off one after another. From the outside, it seems there is nothing to do, but in fact there is a lot that should be done at this time:
1. Quickly apply sufficient base fertilizer. The base fertilizer should be mainly decomposed farmyard manure, supplemented by chemical fertilizers. Generally, apply 7-8 thousand kg of decomposed organic fertilizer per mu, 10-20 kg of potassium chloride or potassium sulfate (potassium sulfate is best), and 50 kg of superphosphate or calcium magnesium phosphate fertilizer. Be sure not to add quick-acting nitrogen fertilizer when applying base fertilizer.
2. Winter pruning. Winter pruning of Kyoho grapes differs from that of diploid grapes such as White Banana and Campbell. Young Kyoho vines should be pruned lightly and left to grow long, otherwise they will grow excessively the following year, worsening flower and fruit drop. After pruning, the branches and vines should be promptly tied to the trellis according to the principle of shaping the tree by its form; do not wait until spring bud break to tie them.
3. Deep plowing of the soil. This can be combined with applying base fertilizer to deeply plow and mature the soil in the orchard, while also organizing the drainage system. It is best to spread some organic matter while deep plowing the soil to improve it. This is beneficial for root development and plant growth. For heavy clay yellow soil, deep plowing and improvement are even more necessary. If conditions permit, some medicinal residue, rice straw, or husk dregs can be placed in when deep plowing the soil, making the plow layer loose and breathable and suppressing weed growth.
4. Cleaning the orchard. Mainly, fallen leaves, weeds, etc. should be cleared away completely and burned in a centralized manner (fallen leaves must not be used as fertilizer). Spray the Kyoho branches and vines, trellis posts, and ground with 5 degrees Baume lime sulfur mixture. At the end of February when winter buds begin to sprout, spray again with 3 degrees Baume lime sulfur mixture. This has a disease-prevention effect that yields twice the result with half the effort.
5. Winter irrigation. For orchards with severe drought or where organic base fertilizer has been applied and the soil dries quickly, winter irrigation can be carried out. This can not only dissolve organic fertilizer and allow the fertilizer to evenly penetrate into the soil, but also keep the soil moist and increase the germination rate. Winter irrigation is best done by furrow irrigation (after water covers the bed surface evenly and then naturally seeps dry). In water-network areas with a relatively high groundwater level, winter irrigation is not necessarily needed.
6. Carry out trellis surface repair or other miscellaneous work. Huang Xinnan