The phenomenon of walnut kernels has been confused by planters, especially last year due to the continuous high temperature days, the sunburn phenomenon has occurred seriously, resulting in the harvest of the fruit is difficult to sell or low-cost hands. Now entering the grain filling stage of walnuts, from the perspective of the development of walnut fruit, the key to improving the fullness of nuts is to grasp the key period of nutrient accumulation in the early stage of July to the end of August, and prevent the disease from happening. Several steps should be taken as follows:
Fertilization should be timely and sufficient.
Walnut is a high-yield oil and wood, which requires a large amount of fertilizer and requires a small amount of water. After entering the fruit-bearing period, it is necessary to use the fertilizer as a first-class task.
It takes about 130 days for the walnut to mature from flowering to fruit ripening. From the end of April to the beginning of June, about 30 to 35 days is the long-term fruit speed. During this period, the volume and weight of the fruit increase rapidly, and the volume reaches 90% of maturity and the weight reaches 70%. In this period, the nutrient is insufficient and photosynthesis is used. Less product will result in a smaller fruit, which is the determining period of fruit size. From the beginning of June to the beginning of July, it is the hard core period of fruit. In this period, the fruit size is basically fixed, and nutrients are rapidly accumulated. In this period, if the light is insufficient, the core shell will be unrealized and the phenomenon of Luren will appear. From the beginning of July to the end of August, about 50 to 55 days is the rapid conversion period of fats and oils. During this period, the rapid increase of fruit fat, the rapid enrichment of seed kernels, the rapid growth of weight, and the rapid decline of water content are the key periods for the accumulation of nutrients in walnut kernels. From the end of August to the beginning of September, about 15 to 20 days is the fruit ripening period. The fruit weight in this period increases slightly, and the oil content still increases. Therefore, in the annual cycle, under the premise of applying the base fertilizer, it is necessary to combine the phenological period with flexible and timely fertilizer application. Phosphorus and potassium fertilizer should be added after June. Insufficient nutrient accumulation seriously affects the quality of walnut fruit.
In July, pest control should be done well