The latest course on management techniques and methods of growing watermelons in greenhouse

Watermelons used to be summer fruits, but now they are all planted in greenhouses. Planting in the greenhouse artificially provides a man-made microclimate with heat and moisture, and the temperature can be adjusted, which can be separated from the external climate and used for out-of-season planting, so that the cultivation of watermelons is no longer restricted by the season. However, the environment in the greenhouse needs to be controlled by itself, losing the role of natural regulation, and everything should be cautious and meticulous. To manage the greenhouse environment by yourself, we need to pay attention to the following aspects.

1. Temperature

Watermelons like high temperature and strong light, grow well in such an environment, light and action are fully carried out, the growth quality will be better, and the yield will be improved. In general, the temperature in the shed will also be affected by the outside to a certain extent. If the temperature outside the shed is high, the temperature inside the shed will rise accordingly, and the temperature will also decrease, but the overall temperature will be higher than that of the outside world. Therefore, the temperature difference between day and night is large. It will appear that the temperature in the daytime is higher than that in the outside world, and the temperature in the night decreases, and the skylight must be opened for ventilation and cooling during the day. Add straw mats to warm up outside at night.

2. Humidity

When the temperature in the greenhouse increases, the transpiration of watermelons accelerates, and the water produced will condense on the greenhouse film, and finally drip down to the soil, which will increase soil moisture, or drop to leaves, which is prone to disease and transpiration, forming a vicious circle. So generally, when the temperature rises after irrigation, open the side door to ventilate and reduce humidity, no watering in rainy days, less watering in sunny days, to avoid excessive humidity, evaporation can not go out. It is usually ventilated at night and closed in the morning, and the water droplets can also be artificially scraped off when the water droplets are formed in the greenhouse film, and the humidity can be reduced by raising the temperature appropriately.

3. Lighting

Watermelon likes light, enough light to meet its growth, in general, the light transmittance of watermelon film will directly affect the light, for example, some films are more transparent, the light will be good, if the film transmittance is poor, the ability to accept light will also be reduced. Therefore, in general, the light absorption of monolayer film is better, and the light absorption of bilayer film will be reduced by about 40%. In addition, when setting up the greenhouse, the concrete scaffolding will block the sun more than other scaffolding. The construction site and orientation of the greenhouse have a direct impact on the lighting.

4. Air

The air in the shed belongs to a relatively closed environment, and the air must be circulated in time to ensure that the air in the shed does not accumulate toxic substances, mainly to manage the content of carbon dioxide for oxygen supply. Generally, watermelons need a lot of oxygen to grow. Watermelons release some carbon dioxide at night, and when oxygen is insufficient, windows need to be opened in time to breathe. Consumption of carbon dioxide during the day to grow, so the need to supplement carbon dioxide, you can generally use plastic containers to hold some water, and then to 1/3 of sulfuric acid. Place it all over the shed to replenish carbon dioxide.

The work of planting watermelon in greenhouse is very different from that in open field. Temperature and humidity in greenhouse is the key management object, while fertilizer and water in open field is the key management item. Therefore, when growing watermelons in the greenhouse, we must pay attention to do a good job in these aspects of management.