How to increase the sugar content of muskmelon in solar greenhouse

In recent years, the area of muskmelon cultivated in solar greenhouse is getting larger and larger. Due to the one-sided pursuit of yield by growers, the sugar content of thick-skinned melon is low and the price is reduced. Therefore, how to improve the sugar content of muskmelon has become a key technical measure in cultivation.

1. Select varieties with high sugar content. The refractive sugar content of No. 1, Honeyworld, Marshal, Sharon, Israel and Holland muskmelon can reach more than 16%, and the market prospect is good. When selecting varieties, we should not only consider the characteristics of low temperature tolerance, weak light tolerance and high yield, but also pay attention to the important index of sugar content.

2. Arrange the stubble skillfully. Because the fruit development of muskmelon requires high temperature and good light. When the temperature reaches 28-32 ℃ in the daytime, 15-18 ℃ at night and the light is about 60 000 lx, it is beneficial to the expansion and sugar accumulation of the fruit. Therefore, when muskmelon is cultivated in winter warm solar greenhouse, it is best to choose winter and spring stubble. Taking Langfang 40 greenhouse as an example, the harvest time is from March to June in spring, the sowing time is in the first ten days of November of the previous year, the first stubble melon began to be harvested in March, and the second stubble melon was pulled in the middle of June.

3. The base fertilizer is mainly crude fertilizer. In the greenhouse with an effective area of 6 meters × 80 meters, the general application rate of crude fertilizer should be 8-10 tons.

4. Control up and down to promote squatting seedlings. From slow seedling to sitting melon, we should insist on ploughing frequently, generally 4-5 times, and the depth of mid-ploughing should be 2-3 cm.

5. Reasonable pruning and leaving single melon. Elizabeth generally hit the top of 25 leaves, leaving 2 vines after topping, and after sitting on the vine, choose an oblong milk melon to get rid of round melons and deformed melons. Leave melon, select melon had better be completed within 3-5 days, strive to be neat and consistent. Compared with keeping more than 2 melons, the sugar content of one melon is 1-2 percentage points higher, and the commercial performance is good.

6. Increase phosphorus and potassium in the middle and later stage. After entering the fruit expansion period, it is necessary to maintain the balance of nitrogen, phosphorus and potassium in the application of chemical fertilizer. When most of the fruit grows to half a melon, it is necessary to apply ternary compound fertilizer in time. Foliar fertilization can use 0.6% potassium dihydrogen phosphate or 0.6% Baolifeng (produced in Israel), once a week and sprayed 3-4 times.

7. Enlarge the temperature difference to increase sugar content. When the fruit is selected and retained, especially after entering the fruit expansion period, the temperature difference in the greenhouse should be widened as much as possible, keeping 30-32 ℃ for 1-2 hours during the day, 18-15 ℃ in the first midnight, and 14-12 ℃ in the latter part of the night.

8. Avoid flooding before harvest. One week before harvest, if the relative humidity of the soil is less than 60%, small water can be irrigated properly. The humidity is between 70 and 75% without watering. When the soil relative humidity is more than 85%, the sugar content of fruit will be affected.