What causes leaf curling in passion fruit? A detailed guide to prevention and control methods
Passion fruit is one of the more popular fruits on the market today, with relatively high economic returns, but during passion fruit cultivation, leaf curling often occurs, seriously affecting passion fruit yield and reducing growing profits. So what causes passion fruit leaf curling? How should it be prevented? Let's find out together.
1. High temperature effects
When the temperature rises above 30 degrees, it affects the growth of passion fruit. If high temperatures above 35 degrees persist, it intensifies leaf transpiration, causing the transpiration rate of the leaves to exceed the rate at which the roots absorb water, making it very easy for the plant to lose water. The leaf stomata are forced to close, and the leaves appear dehydrated and curled.
Prevention and control methods: Take good care of the roots to improve the root system's absorption capacity, and water and fertilize reasonably to avoid the soil becoming too dry. It is not advisable to water and fertilize at midday, as this will worsen the leaf curling. When leaf curling becomes severe, brassinolide can be sprayed to relieve the symptoms.
2. Rainy season effects
After the plants are transplanted, if the soil is too dry, and then when the rainy season arrives with excessive rain, the root system remains soaked for a long time. This inhibits leaf transpiration, and the leaves curl backward as a self-protection mechanism. If the rainy season lasts too long, the branches and leaves become dense and closed, photosynthesis weakens, and this can also cause nutrient imbalance in the stems and leaves, leading to leaf curling.
Prevention and control methods: During the seedling stage, irrigate reasonably when there is drought, do a good job of water retention and harvesting, and avoid excessive soil dryness after transplanting. After a drought, do not use flood irrigation. In addition, during the rainy season, do a good job of drainage and take good care of the root system to reduce the occurrence of leaf curling.
3. Pesticide damage
In summer, when temperatures are too high, if the concentration of pesticides is not paid attention to during use, pesticide damage can occur, causing discoloration or small spots on the leaf surface, and the leaves will also curl upward. In addition, when herbicides are used on nearby fields for weed control, they can easily drift with air currents, causing pesticide damage to passion fruit and triggering upward leaf curling.
Prevention and control methods: When spraying pesticides in high summer temperatures, reduce the concentration. Once pesticide damage occurs, promptly spray water or brassinolide to relieve it. Generally, for leaf curling symptoms, the growing tips can be pinched off in time or the affected branches and leaves can be cut off, or Bihu can be sprayed and organic fertilizer applied to achieve better results.
4. Fertilizer damage
Fertilization can achieve higher yields, but improper fertilization can cause root burn and leaf curling and withering. Too much nitrogen fertilizer, especially excessive application of nitrate nitrogen, raises the concentration of the soil solution, causing passion fruit leaves to flip and curl upward. When there is too much ammoniacal nitrogen fertilizer in the soil, the leaves bulge and the small leaves take on a reversed boat-bottom shape.
Prevention and control methods: Fertilize reasonably, especially controlling the application of nitrogen fertilizer, pay attention to fertilizer and water management and the reasonable combination of fertilizers. Especially during the rainy season, to prevent the plants from growing excessively, nitrogen fertilizer application should be controlled even more. Various micro-fertilizers can be used, mixed with other fertilizers, to ensure sufficient fertilizer and water supply during the flowering and fruiting period of passion fruit.
The above is an introduction to the causes of passion fruit leaf curling and prevention and control methods. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.