Balsam pear can mature prematurely in greenhouse.

Balsam pear, also known as cold gourd, is a plant of the family Cucurbitaceae and is an annual climbing herb. Stems, branches, petioles and pedicels pilose, axillary tendrils. Leaves 3 to 12 cm in diameter, 5 to 7 palmately parted, lobes oval, outer margin serrated. Blossoms at the turn of spring and summer, monoecious and yellow. The fruit is long oval, with most irregular tumor-like protuberances on the surface. The seeds are hidden in fleshy fruit and are wrapped in red sacs when ripe. Balsam pear is a favorite vegetable, the origin is not clear, but it is generally believed to be native to the tropics. It is widely cultivated in South Asia, Southeast Asia, China, and the Caribbean Islands.

Balsam pear likes temperature, more heat-resistant, not cold-resistant. The seed germination is suitable for 30-35 ℃. When the temperature is below 20 ℃, the germination is slow, but it is difficult to germinate below 13 ℃. The seedlings with 4-5 true leaves can be bred in about 15 days at about 25 ℃, and 20-30 days at about 15 ℃. Balsam pear plants grew slowly at 10-15 ℃, but grew poorly when the temperature was below 10 ℃. When the temperature was below 5 ℃, the plants were significantly damaged. However, with slightly lower temperature and short sunshine, the node of the first female flower occurred earlier. The flowering and fruiting period is more than 20 ℃, and the suitable period is about 25 ℃. The higher the temperature in the range of 15-30 ℃, the more beneficial to the growth of balsam pear-early fruit, high yield and good quality. However, more than 30 ℃ and less than 15 ℃ were disadvantageous to the growth and fruit of balsam pear.

Balsam pear can only be listed in open field for about 7 months, and it can be put on the market more than one month earlier in greenhouse. So how to use greenhouse cultivation to achieve early maturity of balsam pear? Next, let's introduce how to do it.

1) the excellent balsam pear varieties suitable for greenhouse cultivation are: Sichuan Changbai balsam pear, Hunan Lanshan balsam pear, Jiangxi Yangzizhou balsam pear, Ji'an white balsam pear and so on.

2) cultivate strong seedlings in the first and middle of January, raise seedlings in the electric hotbed in the greenhouse, and protect the roots with nutrition bowl. Balsam pear seeds have a tortoise shell, need to be washed with boiling water or warm water, stir until not hot, soak at room temperature (about 25 ℃) for 24 ℃ for 28 hours, remove, wash, wrap, and sprout in 30 ℃ 35 ℃ for 10 days. About 200 grams are needed for every 667 square meters (1 mu) of greenhouse.

3) when the seedlings in the middle and last ten days of February had 5 leaves, they were planted in the high border of 1.2m wide in Liangou, planting one row with a distance of 0.5m, and 1100 plants were planted every 667m2.

4) Management after planting

① greenhouse controls temperature and humidity. After planting, the seedling stage was closed to raise the temperature and promote the slow seedling. Keep warm and freeze-proof before the end of March, and be properly ventilated during the day. Before the end of April, pay attention to heat preservation at night and ventilation and dampness during the day. After May, ventilation is mainly used to cool and dehumidify. Ventilation begins when the noon temperature reaches 30 ℃, and stops when the temperature in the shed drops to 25 ℃ in the afternoon. In June, the apron membrane at the bottom of the greenhouse was removed and the roof film was retained to protect against rain.

② fertilizer and water management. Balsam pear likes fertilizer and dampness. under the condition of sufficient water and fertilizer, the yield is high and the quality is good. On the basis of applying sufficient base fertilizer, fertilizer and water management must be strengthened. Although balsam pear is tolerant to fertilizer, it is weak at seedling stage, and slightly thicker fertilizer will burn the seedlings, so topdressing should be light in front and heavy in back. After planting, 10% dilute dung water can be used at the slow seedling stage. During the vigorous growth period of stems and leaves and the flowering and fruiting period, heavy fertilizer should be applied twice, each time 25 Mel 30 kg of compound fertilizer per 667 square meters, and after each harvest, 0.2% urea and 0.3% potassium dihydrogen phosphate mixture should be used to top fertilizer. The characteristic of water management is that the moisture can be properly controlled and the soil can be kept moist in the early stage of slow seedling growth. Ditches should be cleared and drained in time in the rainy season.

③ pruning and scaffolding. Balsam pear has strong branching and high cultivation density in greenhouse, which is more likely to produce overdense vine leaves, poor ventilation and light transmission, empty consumption of nutrients, affecting yield and commerciality. Therefore, it is necessary to strengthen pruning and cultivate it with stents. When drawing long tendrils, build a herringbone frame or arch or trapezoid frame in time to draw the vine on the shelf. Balsam pear is mainly composed of main vines, and lateral vines should be removed. Under the condition of sufficient fertilizer and water, several lateral vines can also be left in the later stage to increase yield in the later stage. At the same time, the old and diseased leaves should be removed at any time in the middle and later stage of production to facilitate ventilation.

④ artificial pollination. Due to the low temperature of early maturing cultivation of balsam pear, less door opening, small air flow in the shed, and few insect pollination, it is difficult to pollinate naturally, so it is necessary to pollinate artificially and smear female pedicel or young gourd with 20Mel 40mg / L 2min 4Mel D to increase the fruit setting rate of balsam pear, overcome melons, promote melon expansion and increase yield.

5) the balsam pear should be harvested as tender melon for consumption, and it should be harvested in time 15 days after flowering. Generally speaking, when the fruit grows fully and the Corolla begins to dry up, it is the right time for harvest. Early-maturing cultivation in greenhouse began to appear on the market in mid-late April, with a yield of 2500 kg per 667m2, with considerable benefits.