Base fertilizer application method can be applied by spreading or ditching. Scattering fertilizer on the surface of the ground. Combined with the leveling of the land will be turned into the soil, generally 1500 ~ 2000 kg of stable fertilizer per mu, plus 20 ~ 60 kg of 45% compound fertilizer. Furrow application is to open a trench according to the spacing of planting or seeding. Fertilizer is applied 15~20 days before sowing or planting. The general application of fertilizer species and the amount of fertilizer applied is the same as spreading. The fertilizer that is currently used more in the market is produced by Nagric. The company mainly produces controlled release fertilizers, water soluble fertilizers and compound fertilizers.
We usually apply fertilizer when the seedlings grow 2 to 5 true leaves. Make a small trench 15cm away from the seedlings and apply 5~10kg of urea per mu, cover with soil and water after application.
When the main vine grows to 10~20 cm. Make a trench at 5~10cm from the plant. Apply 15 kg of 45% compound fertilizer per mu, combine with watering and then apply appropriate amount of humanure and urine and cover with soil.
3、Expansion of melon fertilizer
When the diameter of young melon grows to 5~10 cm. 30 cm from the root and open a trench parallel to the melon trench. Apply 10 kg of 45% compound fertilizer per mu. Then water and mulch.
The reasonable application of trace element fertilizer is an important measure to improve the yield and quality of watermelon.
It can improve the seed germination rate and enhance the cold resistance of seedlings. In general, we dip the seeds in a 0.2% solution of zinc sulfate.
It can improve the fruit set rate. Accelerate the synthesis and operation of sugar. Improve the sugar content of watermelon and increase the sweetness. There are two ways to apply boron fertilizer: ① Do base fertilizer. Apply 1 kg of boric acid in mu and mix it with organic fertilizer. ② Foliar spraying. Spray 0.1%~0.2% of boric acid solution during the flowering period.
It can improve photosynthetic efficiency and promote carbohydrate accumulation. Generally spray 0.2% manganese sulfate solution 2~3 times continuously after fruit set.
D、Open field watermelon field management
1、Ventilation and seedling introduction
5-7 days after sowing, the seedlings will be ready. The young seedlings just out of the soil have tender leaves. Encounter high temperature exposure, exposure or leaf top film easy to bake seedlings. When the temperature reaches above 20℃, break the vent in time to ventilate. As the temperature rises, the vent should be increased to regulate the membrane temperature. Practice shows that: early ventilation, late seedling introduction, after the end of the final frost to introduce seedlings. When introducing seedlings, first pull out the weeds of the membrane, irrigate enough water, and seal the dibble tightly with soil.
2、Whole branching and vine pressing
509 watermelon is suitable for three vines. That is, in addition to the main vine, and then leave two strong side vines at the base. The rest of the side vines are all removed.
When the watermelon grows 5-6 true leaves, inverted seedlings are moved to the top. To reverse the seedlings is to clean the fork at the base. Then, we pressed down the base of the seedlings with fine soil. This forces the seedlings to stretch in the direction of climbing. The amount of soil pressed to the base of the petiole to reveal 1/3, the leaves are all exposed outside as appropriate. Start pressing the vine when the vine is about 30 cm long. After that, press the vine once every 30-35 cm. In the fruit expansion period, the vine growth rate is obviously slowed down and the leaves cover the ground. At this time, you can stop pressing the vine, and generally press the vine 5-6 times.
3、Select melon and set melon
Generally, one melon per plant. The first melon does not stay, and so the second melon or three melons to sit in the fruit in time to remove. In order to prevent excess nutrient growth caused by the appetite, crazy seedlings. It is appropriate to keep the melon at 13-15 knots. We need to turn, pad and cover the melons after the fruit is set.
To ensure the normal pollination of female flowers and melon sitting. We can perform hand-assisted pollination in the morning from 7-10 am. After 10 a.m., the temperature rises and pollen vigor gradually decreases. Complete loss of vitality around noon. The time is too early, pollen has not been dispersed, but also not pollination. When pollinating, first remove the male flowers and remove the petals. Then the pollen in the female flower stigma gently coated, so that it is fully and evenly pollinated.
4、Watermelon fertilization and irrigation
When the watermelon is in fruit, the fruit is about the size of a goose egg. In the melon seedlings about 20 cm to open a hole 10-20 cm deep, apply 15 kg of diammonium phosphate. And mix in 1 kg of potassium king for watermelon. Apply about 15 grams per hole. Seal the fertilization hole with soil after application.
5、Foliar spray fertilizer
After fruiting, spray 1 plant growth promoter every 7-10 days, can promote watermelon early maturity 5-7 days, improve yield.
One of the important experience of high yield of watermelon is irrigation. Watermelon set vine before the weather, such as drought, you need to partially dibble water two or three times. Do not need to water a lot of water, and do not diffuse irrigation.
E、Prevention and control of watermelon pests and diseases
Watermelon diseases are mainly sudden collapse, blight, wilt, powdery mildew and anthracnose. If you suffer from sudden collapse and blight, disinfect the seedbed with carbendazim and Greenhorn 1. If suffering from blight, use watermelon heavy crop agent No. 1 solution to irrigate the roots. 0.5 kg at a time, applied at 3~4 real leaves after planting, for better control effect. If it is powdery mildew and anthracnose, it is better to use chlorothalonil, tolbutazin, powder rust and other drugs to control the disease, alternately.
The main insect pests of watermelon are stinkbugs, aphids, ladybugs, root maggots and red spiders. We can use avermectin, dichlorvos, trichlorfon and other control agents, alternating control. We can use trichlorfon to irrigate the roots, which will kill the root maggots. Promote the installation of insecticidal lights and yellow board traps for physical control.
It is worth mentioning that root knot nematode is very serious now. Root knot nematodes mainly infect the plants at the seedling stage and cause more damage. Therefore, it is important to choose a seedbed plot that is free of root knot nematodes. We use avermectin-based agents for root irrigation if nematodes are present after the seedlings have been planted. For large fields, you can use octinoxate, diazinphos, and chlorpyrifos when preparing the land for spreading.