What causes empty shells in walnuts? Causes and prevention methods
Walnuts are one of our common nuts and are deeply loved by consumers, but during walnut production, the phenomenon of empty shells often occurs. The so-called empty shell phenomenon refers to some walnut fruits having no kernel. This phenomenon seriously affects walnut yield, so what causes it? Is there a solution? Let's take a look together with Qinong Web.
1. Unsuitable environment
Walnut is a warmth-loving plant. If it is planted in an environment with abnormal climate, or under sustained high-temperature climate, it will affect the growth of its kernel, especially when the temperature remains continuously above 40 degrees, the fruit is prone to sunburn, leading to a higher probability of empty shells. In addition, walnuts are relatively sensitive to water. If the planting environment has little rainfall and is relatively dry, and there is no timely watering, it is easy to cause empty shells.
Prevention method: The planting environment must be selected to be suitable for walnut growth. The suitable temperature for walnuts is 27-29 degrees, and they should not grow in temperatures that exceed 40 degrees for several days. In addition, in areas with less rainfall, timely artificial water supplementation is needed so that the fruit receives sufficient water during growth.
2. Poor pollination
Walnut is a monoecious tree species with separate male and female flowers. Their flowering is not synchronized. The fact that male and female flowers do not open at the same time leads to a low self-fruiting rate in walnuts. Some fruits cannot grow and develop normally due to insufficient pollination, so the empty shell phenomenon occurs. In addition, walnuts are pollinated by wind. If rainy weather occurs during the pollination period, the pollination effect will be poor, resulting in empty shells.
Prevention method: The phenomenon of poor pollination is relatively easy to solve. Since its self-pollination is poor, we can assist it with artificial pollination. When planting, plant according to the ratio of female and male so as to ensure sufficient pollen sources. During the rainy season, artificial pollination can be used to help: remove male flowers and apply them to female flowers to complete pollination.
3. Lack of nutrients
During the growth period of walnut fruits, a large amount of nutrients is consumed. If the nutrients in the plant and soil are insufficient, the tree body will show a kind of starvation phenomenon, causing the fruit to fail to grow due to lack of nutrients, thus forming the empty shell phenomenon.
Prevention method: During fruiting and fruit growth periods, the supply of nutrients must be ensured. During this period, strengthen fertilizer management, improve soil fertility, and ensure nutrient supply. But when fertilizing, pay attention to the reasonable combination of nitrogen, phosphorus, and potassium fertilizers to prevent nutrient imbalance. The amount of fertilizer applied should depend on the growth condition of the plant and be controlled flexibly, so as to increase yield and reduce the empty shell rate.
4. Too many fruits set
If a walnut tree is managed properly, it usually sets many fruits, generally with female flowers setting double fruits, and sometimes clusters or spike-like fruiting also occurs. Once the number of fruits set is large, competition among fruits will occur, competing for nutrients, and some fruits whose nutritional needs are not met will develop empty shells.
Prevention method: Carry out fruit thinning reasonably. When the fruit set is large, nutrient consumption is fast. To avoid this situation, we must thin the fruits in a timely manner. For fruits that are too densely grown and growing in clusters, select the larger ones and cut off some of the smaller and deformed ones, preserving enough nutrients for the remaining fruits so that they grow robustly.
The above are the causes of empty shells in walnuts and prevention methods brought to you by Qinong Web. We hope it can help you. If you want to learn more, please stay tuned to Qinong Web.