Detailed Explanation of the Key Techniques for Off-Season Greenhouse Vegetable Cultivation

Now we find that many vegetables and fruits can be eaten no matter what the season is. In order to meet people's needs, off-season vegetables and fruits fetch fairly good returns on the market, but whether they can really be eaten with confidence is also a question that remains to be examined. Below let us take a look together at the introduction to the key points of off-season greenhouse vegetable cultivation techniques.

I. What are off-season greenhouse vegetables?

Off-season vegetables refer to vegetables that are spring and summer types grown with a delayed autumn harvest and an advanced spring production. Cold-protection measures must be taken during cultivation to achieve the goal of an earlier market launch. Off-season vegetables are one of the effective ways to ensure a year-round supply of vegetables.

For areas producing off-season vegetables in winter, the site should be chosen in a place with a warm climate, abundant sunshine, located on plains at low altitude or in hills, with convenient water sources and suitable soil conditions, and with a wind-blocking barrier where possible (such as a high mountain barrier to the north or other buildings), to avoid direct attacks by cold winds.

II. Key techniques for off-season greenhouse vegetable cultivation

1. Building the greenhouse.

Since this is greenhouse cultivation, building the greenhouse is certainly the first step. Choose a location with relatively gentle terrain and close to a water source to build the greenhouse, as this makes subsequent vegetable planting and other work convenient. Greenhouses can generally be divided into winter warm-type greenhouses and spring-autumn greenhouses, supplying different vegetable cultivation in winter and in spring and autumn respectively. After completion, disinfection must begin. Many people overlook the disinfection step, but it is actually crucial.

High-temperature greenhouse sealing or chemical disinfection can be used, which is extremely effective for pest and disease control. Half a month before planting, spray duobai dust powder inside the greenhouse, then after sealing it, fumigate with chlorothalonil smoke agent. About one week later, spray carbendazim on the ground, which can achieve an excellent disinfection and sterilization effect.

2. Land preparation and fertilization

Before planting vegetables, the land needs to be prepared and fertilized. Apply the prepared nutrient soil and fertilizer into the soil before cultivating the vegetables, generally using a combination of organic fertilizer and inorganic fertilizer.

When fertilizing, pay attention to the timing and method. Fertilizing should be done one month before planting. When fertilizing, pay attention to the amount, spread the fertilizer over the soil, then plow it so that it mixes evenly with the soil. In addition, before fertilizing, it must undergo fermentation treatment, applying thoroughly decomposed fertilizer, so as to avoid fermentation in the soil producing toxic gases that harm vegetable growth.

3. Selecting varieties

Since this is off-season cultivation, varieties certainly must be selected; it is not the case that all vegetables can adapt to off-season cultivation techniques in a greenhouse.

Choose varieties that are cold-tolerant, strongly disease-resistant and early-maturing, so as to reduce the impact of low temperatures on the vegetables. Examples include zucchini, tomato, chili pepper, eggplant, cucumber, luffa and other vegetables. In addition, spinach, Chinese cabbage and other vegetables that can be grown in winter will have a higher yield.

4. Field management

When transplanting vegetables, hole-grasping transplanting should be used. When transplanting, apply organic fertilizer into the holes, which can increase the survival rate. In addition, after transplanting, promptly water with seedling-recovery water to maintain soil moisture. Different vegetables have different water requirements, and on this point the number of waterings must be controlled to meet the growth needs of different vegetables.

In addition, in winter the leaf surfaces of vegetables should be sprayed with nutrients for cold resistance. In winter, temperatures are low and light is weak, and root absorption capacity is weak. Spraying photosynthetic micro-fertilizer on the leaf surface can supplement the nutrient deficiency symptoms caused by insufficient nutrient absorption by the roots. Spraying rice vinegar on the leaf surface can inhibit bacteria and repel insects. Mixed with white sugar and superphosphate, it can increase the sugar content and hardness of the leaf tissue and improve cold resistance. After frost damage, the leaf surface becomes alkaline and shrunken; spraying vinegar can alleviate the degree of harm. A 100-300 times dilution should be used, and growth hormones should be used sparingly or not at all, to prevent reducing cold resistance.

On a sunny winter morning, the maximum temperature inside the greenhouse can reach above 32°C. At this time, attention should be paid to repeated ventilation, so as to narrow the temperature difference between inside and outside, allowing the plants to slowly adapt to the environment and grow robustly. Beware of sudden growth in one day and ten days of cold, which can cause seedling shock and frost damage.