What causes empty watermelon vines? Here's how to prevent it
During watermelon cultivation, it is common to see empty vines that fail to set fruit. Many growers mistakenly blame the variety for the failure to set fruit, but in fact the variety has very little to do with it. So what causes empty watermelon vines? Let's find out together.
1. Poor climate
Watermelon is a warmth-loving crop, with an optimum growing temperature of 15-33°C. Below 15°C or above 40°C growth is inhibited, causing poor development of female flowers and ovaries, which leads to fruit drop and fruit abortion, and thus causes “empty vines” in watermelon. For example, low temperatures at flowering, high-temperature drought, rainy weather at flowering and intense direct sunlight can all produce empty vines.
Prevention methods: For empty vines caused by various adverse climates, targeted preventive measures are needed. For low temperatures at flowering, artificial pollination can be used to artificially promote fruit set; for high-temperature drought, phosphorus fertilizer water can be used to irrigate the roots or heavy irrigation can be used to change the air and soil humidity, promoting pollen development and fertilization; for rainy weather at flowering, rain-proof measures can be taken in advance according to weather forecasts, such as putting rain-proof paper caps on female flowers, or collecting opened male flowers in advance and carrying out artificial pollination after the rain; and for intense direct sunlight, weeds or the stems and vines cut off during pruning can be used to cover young fruits to prevent sunscald.
2. Improper cultivation techniques
Improper sowing can cause empty vines. The later the sowing time, the higher the node position where female flowers are borne, and insufficient supply of nutrients and water causes flower drop or fruit abortion, resulting in empty vines. If the sowing density is too high, the peak vegetative growth period coincides with the hot, rainy season; at this time the plants are densely closed in the field, with poor aeration and insufficient light, producing empty vines.
Prevention methods: Sowing should be done at the right time, with early seedling raising and early cultivation, aiming to cultivate strong seedlings, avoiding the high-temperature period of flower bud differentiation, lowering the node position where female flowers are borne, and preventing empty vines. The cultivation density of watermelon should be determined according to the variety and soil fertility, so as to avoid too low a density causing plants to become densely closed. Generally, mid- and late-maturing varieties are planted at 600-800 plants per mu, while extra-large watermelons are planted at 350-400 plants per mu, and early-maturing small-fruited types are planted at 1000-1300 plants per mu.
3. Improper cultivation management
Improper management at the seedling stage can cause weak seedling growth and lead to empty vines; if field management cannot keep up in the early vine-extension stage, vegetative growth becomes excessive, light penetration and ventilation between plants decrease, causing flower and fruit drop and leading to empty vines; if pruning and vine pressing are unreasonable, vegetative growth cannot normally shift to reproductive growth, affecting the fruit-setting rate and causing empty vines. Improper fertilizer and water management, with an unreasonable ratio of nitrogen, phosphorus, potassium and trace elements. Insufficient nutrient supply or uncoordinated nutrients cause excessive vegetative growth of the plants, and previously empty vines.
Prevention methods: At the seedling stage, intertillage, fertilization and strong seedlings can promote flower bud differentiation; during vine extension, pruning and vine pressing can inhibit vegetative growth, coordinate the contradiction between vegetative growth and reproductive growth, and improve the fruit-setting rate; fertilizer and water management should be strengthened, with reasonable formula fertilization to prevent excessive nitrogen fertilizer, which causes rampant vine growth and running vines.
The above is an introduction to the causes of empty watermelon vines and prevention methods. We hope it can help you. To learn more related knowledge, please stay tuned to us.