Planting techniques of grafted watermelon seedlings

The growth rate and fruit setting rate of grafted watermelon seedlings are relatively high, and the border can be divided into a large border with border width 2cm and groove width 45cm, when the grafted scion grows 3-4 true leaves, it can be transplanted to the middle of the large border according to plant spacing 140cm, and about 200 plants per mu can be planted, and appropriate amount of urea, biogas liquid and potassium sulfate compound fertilizer can be applied during growth. Watering follows the principles of no watering in cloudy days, no watering in the afternoon, no watering in the morning, small delayed watering of seedlings, and early watering of large and weak seedlings.

I. steps and methods of grafting

1. Grafting tools

Grafting tools can choose to use a blade and bamboo stick, the blade should be sharp and durable, the Jack can choose a bamboo stick, the length is 6-7 cm, cut one end into an elliptical oblique plane with a length of 0.5-0.7 cm, similar to the thick oblique section of the scion, and then burn it gently with fire to make the front end of the bamboo stick hard and smooth.

2. Grafting technology

The main results are as follows: (1) grafting can be carried out when the cotyledons of scion seeds grow, the weather should be fine when grafting, and the temperature should be about 18-25 ℃. It is not suitable for grafting in overcast and rainy weather.

(2) the general method often used is top grafting. About 3-5 days before grafting, proper coring can be carried out before the rootstock seedlings grow to the second true leaf, and the grafting work needs to be carried out in the plastic greenhouse. If the light is too strong, the straw curtain can be covered on the plastic greenhouse to avoid direct sunlight.

(3) then use a flat bamboo stick with thickness of 0.1cm, width of 0.2cm and length of 12cm, insert it diagonally between the two cotyledons of the rootstock, take out the bamboo stick, and insert the cut scion into the rootstock.

3. Management of grafted seedlings

(1) it takes about 10 days for watermelon seedlings to survive from grafting to survival. under the condition of good humidity, temperature, shading and pest control, it is helpful to ensure the effect of planting. Generally, the temperature in the greenhouse needs to be stabilized at 20-35 ℃, while the humidity in the greenhouse needs to be stabilized at more than 85%. If the humidity is not enough, a sprayer can be used to supplement it.

(2) within 2 days after watermelon grafting, closed shading measures should be taken, 30 minutes of light can be given every morning and evening from the third day, and two heads of the plastic film can be opened for a change of air, and the lighting time can be appropriately prolonged in the later stage. And increase the number of ventilation.

(3) after waiting for one day, when the grafted seedlings basically survive, the mulch can be opened for routine management, and the broken and inverted disease at the seedling stage should be controlled in time in the later stage.

2. Planting techniques of grafted watermelon seedlings

1. Large beds and sparse planting

The main results are as follows: (1) the growth rate and fruit setting rate of grafted watermelon seedlings are relatively high, and the weight of single melon can be as high as 6 kg after the second fruiting. During this period, the land preparation method of "deep ditch turtle back type high border" can be adopted to make the border into a large border with a width of 2cm and a width of 45cm.

(2) when the grafted scion grows to 3-4 true leaves, it can be transplanted to the middle of the large border according to the plant distance of about 140cm. Generally, the planting density per mu is about 200. when there are more lateral branches in the later stage of growth, the vine should be trimmed in time.

2. Water and fertilizer management

The main results are as follows: (1) in the first ten days of May, you can choose to water once on a sunny day. 5-7 kg of urea can be applied per mu. Watering and fertilization should not be applied during flowering. Watermelons can be watered and fertilized according to weather conditions when the eggs are big. 20kg potassium sulfate compound fertilizer or 500kg biogas slurry can be applied per mu.

(2) watering watermelons should be carried out according to the growth and weather conditions of watermelons, following the principles of no watering in cloudy days, no watering in the afternoon, watering in the morning, small delayed watering of prosperous melons, and early watering of large and weak seedlings. Watermelon can be re-watered and fertilized once during the expansion period, fertilizing should be carried out for each watering in the later stage, and watermelon watering and fertilization should be stopped one week before watermelon ripening.

(3) during the watermelon expansion period, the temperature needs to be controlled at 25-35 ℃ in the daytime and 15-20 ℃ at night, and the temperature difference can be enlarged appropriately in the later stage. 0.2% potassium dihydrogen phosphate or 1:12-15 biogas slurry is mainly used for foliar topdressing.

3. prevention and control of diseases and insect pests

The common diseases during the growth of watermelon are anthracnose, powdery mildew, leaf blight and so on. Generally, biological control and agricultural control can be combined. Aphids are common pests. During this period, 25% imidacloprid wettable powder can be used to control.