Will short sunshine time affect the growth of watermelon? How to influence?

Watermelon can promote the growth of lateral branches by increasing sunshine time and illuminance, but it has little effect on the growth of main vines. Under higher temperature and continuous sunshine, the total leaf area increases, mainly by increasing the number of leaves, not by increasing the number of leaves. ?

Sunshine duration also affects flowering and fertilization. When the sunshine time is 32,000 lux (when the luminous flux of an object is 65,438+0 lumens in an area of 65,438+0 square meters, its illuminance is 65,438+0 lux), when the sunshine time is increased from 65,438+04 hours to 24 hours, the number of flowers per plant, the size of ovary and the number of ovules in ovary are increased. If the sunshine is reduced to 8 hours, or the luminosity is reduced from 32,000 lux to 8,000 lux, the proportion of unfertilized embryos will increase. ?

This shows that short sunshine hours and weak light not only affect the vegetative growth of watermelon, but also affect the size of ovary, pollination and fertilization process.

Watermelon is very sensitive to the light. When the weather is clear, it is characterized by compact plant type, short internode petiole, thick vines, large and thick leaves and dark green leaves; If it rains continuously and the lighting conditions are insufficient, it is characterized by long internodes and petioles, long and narrow leaves, thin and pale leaves, underdeveloped protective tissues and easy to get sick.

Insufficient light at the stage of melon setting will seriously affect nutrient accumulation and fruit growth, and the sugar content of fruit will decrease obviously.

Therefore, when planting watermelon, we should adopt reasonable planting methods, choose sunny plots and appropriate planting density to prevent overlapping leaves and shading each other and improve photosynthetic efficiency.

2. The leaves of vines are very fragile

It is characterized by thin plants, thin leaves, round and thin ovaries and early maturity of the whole plant. The main reasons are drought, chemical fertilizer removal, plant malnutrition and serious shortage of fertilizer and water during flowering and fruit setting.

It shows the phenomenon of falling flowers and fruits during flowering and fruit setting. The reason is:

Too much fertilizer and water at flowering stage, malnutrition of plants, long stems and leaves, leading to falling flowers or turning melons, reducing the rate of setting melons.

Thin plants, thin ovaries or poor development will also reduce the fruit setting rate.

Spraying pesticides at flowering stage, persecuting flower-visiting insects, and reducing the fruiting rate.

Bad weather conditions during flowering, such as too high or too low temperature, will affect fertilization, leading to a decline in melon-bearing rate; Rainstorm in flowering period causes flowers to fall, or mud droplets splashed by rain pollute flowering period, resulting in flowers falling or turning into melons.

Overcoming measures:

(1) according to different varieties, determine the appropriate sowing date and cultivate strong seedlings.

② Rational fertilization and water management. Fertilize with ... Forward, control, and weight? For principle. According to the needs of different physiological periods, it is necessary to have sufficient water from the vine-pulling period to the flowering period, increase water supply during the fruit expansion period, and properly control water during the mature period. Spraying 0.2% P-K source and sink solution on leaves during the critical period of fruit expansion can improve nutrition and fruit quality.

③ Artificial pollination. When the flowering period is rainy and cold, both male and female flowers should be bagged and artificially pollinated. Artificial pollination can also be carried out with the help of pollen from low-temperature tolerant and early-maturing varieties.

4 scientifically prune melons. Watermelon is usually pruned with double vines or three vines. Double vine pruning is to select and leave the main vine, select the strong side vine at the base of the main vine, and remove all other side vines. When the young fruit grows to the size of steamed bread, the fruit begins to expand rapidly. At this time, the fruit generally no longer falls. It is necessary to choose the fruit with good node position and positive fruit shape in time, leave one fruit and prune it with double vines or three vines.

⑤ Reduce spraying at flowering stage to avoid accidental injury to insects or phytotoxicity.