1. High temperature affects fruit setting. Excessive temperature in bud stage will affect physiological metabolism, lead to imperfect flower development and contraction of pollen tube, and affect flower pollination, fertilization and fruit setting. On the day of flowering, the higher the temperature, the lower the fruit setting rate, and the temperature was negatively correlated with the fruit setting rate.
2. Measures to build a flat-topped frame can cover branches and leaves well, usually reaching a coverage rate of about 80%. It can reduce the solar radiation heat of the ground soil, reduce the heating rate in the field to a certain extent, and increase the air humidity, thus improving the fruit setting rate of passion fruit.
3. Pay attention to fertilization. Fertilization is the main way to obtain the growth nutrition of passion fruit. Pay attention to the proportion of nutrients in the fertilizer when topdressing, ensure the diversity of fertilizers, and provide sufficient growth nutrition for passion fruit. Because in the flowering period of passion fruit, if the temperature is higher than 30 degrees, then the pollination and fertilization of passion fruit will be very unfavorable. Therefore, in the flowering period, if the temperature is too high, it is necessary to spray water in time to cool down. Artificial pollination can be carried out at flowering stage to improve fruit setting rate.
Artificial water spraying: when the daily temperature of passion fruit is above 30℃ during flowering, it will seriously affect the pollination of passion fruit. At this time, the weather is hot, and the passion fruit orchard can be cooled and humidified by spraying water at 9: 30- 10: 30 in the morning. If the atomization effect is good, artificial pollination at flowering stage can greatly improve the fruit setting rate.
5. High temperature will accelerate breathing and consume more nutrition. The roots need to be supplemented with organic water-soluble fertilizers such as humic acid or alginic acid, and the roots need to be drenched for 500 times. To promote flowering, it is necessary to increase phosphorus, potassium, calcium and magnesium fertilizers, and to supplement leaves with trace elements such as zinc and boron.
6. After the ground of passion fruit orchard is irradiated by the sun, the temperature will be high and the heat dissipation will be slow. You can plant some grass properly. It can reduce soil temperature, reduce soil water evaporation and ensure water supply to a certain extent, thus avoiding the influence of passion fruit water shortage on fruit setting rate. Let the leaves cover the surface of the fruit properly. Passion flower is usually cultivated on the shelf during the planting process. A certain number of leaves can block flowers and fruits, avoid direct sunlight and protect flowers and young fruits. Use a sunshade net. Where the temperature is too high, you can directly block the scorching sun with a sunshade net while maintaining good ventilation conditions. Fruit bagging. Bagging is often used on many fruits, which can not only keep out the scorching sun, but also prevent pests and diseases.