Since there is mulch, the planting of crops is not divided into seasons, and melons, fruits and vegetables that should not appear have also appeared, in short, an early word. Watermelon, for example, was originally eaten in the summer, but it can be eaten in early summer. So for ordinary growers (except for solar greenhouses), when can these early-harvested watermelons be planted early? This article will talk about the planting time of watermelon in spring and the issues that should be paid attention to.
1. The basic requirements for temperature for watermelon growth.
During the germination period, the suitable temperature for growth is about 28-30. The initial temperature of seed germination is about 16-17, and when the temperature is lower than 16 or higher than 40, the germination rate is extremely low.
At the seedling stage, the suitable temperature for growth is about 22-25. The minimum temperature of watermelon root growth is about 8-10, the lowest temperature of root hair growth is about 13-14, and the maximum temperature of root growth and root hair growth is about 38-40.
During the vine extension stage, the suitable temperature for growth is about 25-28.
During the fruiting period, the suitable temperature for growth is about 30-35, and generally should not be lower than 18. It has been observed that the flowering time can be advanced or delayed by about 30 minutes for every 1 rise or fall in temperature at night. If the temperature stays above 18 at night, flowering can be as early as 6 a.m.
In the whole growth and development period of watermelon, the required activity accumulated temperature is about 2500-3000, of which the accumulated temperature required from the opening of female flowers to fruit maturity is about 800-1000, of which the accumulated temperature required for early-maturing varieties and small varieties is 800-900, and the accumulated temperature required for late-maturing varieties and large varieties is 900-1000.
The above introduction of so much about the influence of temperature on the growth of watermelon is to let you find out when the most suitable watermelon planting time is.
2. Pay attention to choosing the appropriate planting time.
Planting is generally divided into open land planting and small arch planting. First of all, open field planting, to avoid the late frost period, the general area is Qingming frost, that is to say, watermelon planting should be in early April, this planting does not need additional investment facilities, the use of natural light and heat resources, although compared with the facility planting a few days later on the market, but this method of melon quality is good, high sweetness, good market sales and high price, compared with the facility planting economic income will not be low.
In addition, facility planting, a kind of watermelon, using the method of mulch film and arch shed, the planting time should be about 30 days earlier than the open field, and the general area is planted in early or mid-March. It will be available by early to mid-June.
3. Pay attention to seedling training.
In order to increase the stress resistance of melon seedlings, it is necessary to ventilate and cool the melon seedlings about a week before they are ready to plant, and the seedlings need to be trained with water control. In order to thicken the protective tissue on the surface of the stem and leaf of the seedlings, and increase the concentration of cell fluid, so as to improve the adaptability and stress resistance of the seedlings. The practice is to choose a sunny day with a high temperature to water the seedbed, increase the ventilation of the seedbed, keep the temperature of the seedbed at 20 22, when the temperature is above 25 degrees, the seedbed cover can be uncovered for seedling. Open the seedbed on both sides of ventilation at night, so that the bed temperature is kept at 18 20, when the night temperature is stable above 18, the seedbed cover can also be completely uncovered at night. During the seedling refining period, if there is a cold snap, strong wind, rainfall and other conditions, it is still necessary to cover the seedbed, and do not let the seedbed get rained.
Fourth, pay attention to the application of plantar fertilizer on the transplanting site.
Before planting watermelon, it is necessary to do a good job of land preparation, deep ploughing and cultivation during land preparation, combined with base fertilizer. The base fertilizer can be either well-rotted farmyard manure or poultry manure, but whatever the fertilizer is, it needs to be fully decomposed before application. Because the unrotted fertilizer will produce great heat, the temperature is too high and it is easy to burn the seedlings, affecting the growth. Generally, 3 5 square meters of organic fertilizer are applied per mu, including 100 kg of cake fertilizer, and cake fertilizer is applied to increase the content of soil organic matter and increase the sweetness of watermelon. In addition, low-nitrogen compound fertilizer should be applied 80 100 kg per mu, and trace elements should be added appropriately. This measure should be completed 10 days before planting, so that the fertile soil is fully integrated. I prevent planting while preparing the land and prevent manure from burning a root.
5. Pay attention to temperature control.
In early spring, the temperature is unstable, and the special facilities planted may encounter a cold wave, and the temperature in the shed should be controlled at 22 25 degrees during the day and not lower than 18 degrees at night.
The period of planting to the open field should be after the local final frost, the soil temperature should not be lower than 15, and the air temperature should not be lower than 18.
Whether it is an open field or a facility planting, it is best to choose a sunny and warm day with high soil temperature, which is conducive to slowing down seedlings and germinating new roots. Try to make good use of the cold tail and warm head, and choose the appropriate setting time.
Sixth, pay attention to a few specific matters.
1. When using a plastic nutrient bowl for planting, attention should be paid to avoiding the nutrient soil in the bowl being broken and hurting the roots, and the paper at the bottom of the bowl and around the bowl should be torn off when the paper nutrient bowl is planted.
2. The planting hole should be larger and deeper than the nutrient bowl, and fill the hole with some fine soil, so that the seedling soil and the field soil can be closely combined to avoid overhead nutrient bowl.
3. The planting depth should be buried in the field soil 1cm on the surface of the bowl soil, which affects the soil heating and ventilation if it is too deep, and it is not easy to moisturize if it is too shallow, which affects the root development of melon seedlings.
4. The sequence of transplanting and planting is to open holes, place seedlings, cover soil, water, and then cover the soil, and then water.