Detailed Explanation of Key Technical Points for Organic Vegetable Greenhouse Cultivation

Greenhouse Organic Vegetable Cultivation Techniques

1 Analysis of Influencing Factors in Greenhouse Vegetable Cultivation

1.1 Influence of Harmful Gases

The most fundamental difference between greenhouse vegetables and ordinary vegetables lies in the incorporation of artificial management. Greenhouse vegetables remain in a sealed environment for extended periods, so their internal environment requires manual regulation, and vegetable growth requires human control. However, artificial cultivation also has certain drawbacks. For example, failure to ventilate in time due to human negligence, or harmful gases produced by improper fertilization remaining in the greenhouse, will both lead to poor growth vigor of greenhouse vegetables. An increase in harmful gases inside the greenhouse and poor air circulation will have a major impact on vegetables, such as causing root and stem rot and leaf lesions. Harmful gases inside the greenhouse are invisible to the naked eye, and some growers even have weak awareness in this regard, failing to realize the threat that harmful gases pose to vegetables. In addition to harmful gases produced by fertilization, carbon dioxide and nitrous acid are also harmful gases affecting vegetable growth, and all of these will affect vegetable quality.

1.2 Influence of Extreme Weather

Disastrous weather easily causes disease infection and disasters, seriously affecting the growth quality of vegetables. In low-temperature weather, the invasion of strong cold air, increased wind force and rapidly dropping temperatures are very unfavorable to vegetable growth inside the greenhouse. In mild cases, they cause the temperature inside the greenhouse to drop and vegetable growth to stagnate; in severe cases, they cause damage to the greenhouse film and freezing injury. Foggy weather is also a major factor affecting vegetable production. Reduced sunlight intensity and lower crop photosynthesis rates make disease outbreaks highly likely. In addition, high humidity inside the greenhouse during foggy weather also affects vegetable production benefits. Moreover, severe high-temperature weather can cause problems such as difficulty in obtaining irrigation water. Once the temperature is too high, water loss in the greenhouse will intensify, the internal environment will become unbalanced, and large amounts of bacteria and harmful gases are highly likely to be produced, which is unfavorable to vegetable growth.

2 Greenhouse Organic Vegetable Cultivation Techniques

2.1 Selecting Suitable Vegetable Varieties

Organic, high-yield and high-efficiency vegetable varieties should be selected. Nowadays there are many genetically modified vegetables and genetically modified vegetable seedlings. These vegetable varieties have not undergone professional identification and quality testing. When selecting vegetable varieties, growers should choose non-genetically modified varieties. It is advisable to select seedlings with good appearance and relatively complete root, stem and leaf growth. To ensure that the greenhouse vegetables grown are organic, first choose seedlings that have not been treated with chemicals, and choose vegetable seeds that have passed testing by relevant institutions and succeeded in trials, so as to ensure the safety and reliability of greenhouse-grown vegetables.

2.2 Selecting a Suitable Planting Base

Greenhouse vegetable warming uses solar radiation as the main energy source, so the planting base should be selected in a place with sufficient light, so that crops can fully receive sunlight and carry out photosynthesis to promote plant growth. Avoid choosing mountain wind gaps, mountain foot areas and low-lying land as greenhouse vegetable fields. Generally, there are three requirements for the land. 1) A relatively complete plot of land should be selected, and there must be no other conventional vegetables in this plot, so as to better ensure the balanced growth of organic greenhouse vegetables. 2) Organic vegetables and ordinary vegetables should be planted separately. To distinguish the two more clearly, obvious markers should also be set up at the dividing line. 3) When planting organic vegetables, attention must be paid to the planning and management of the surrounding land. Some land around the vegetable planting area that can be converted into organic land should be set aside. This part of the land cannot be planted arbitrarily; only after passing inspection by personnel from relevant testing institutions can planting take place. Only by accomplishing the above three points can the sustainable development of organic greenhouse vegetables be better achieved.

2.3 Vegetable Cultivation Management

Vegetable cultivation management is also one of the key factors in organic greenhouse vegetable cultivation. To better improve the planting quality and planting efficiency of organic vegetables, the importance of organic vegetable cultivation management should be fully recognized. Cultivation techniques should keep pace with the times, and some advanced modern management equipment should be introduced in a timely manner. Only with complete equipment and advanced technology can the planting yield of organic greenhouse vegetables be better improved.

2.4 Reasonable Fertilization

Organic greenhouse vegetables have relatively high requirements for fertilizers, which requires fertilization personnel to strictly control the amount and types of fertilizers during use. For the selection of organic vegetable fertilizers, pure natural fertilizers should be given priority, such as animal manure and plant decay matter. Pure natural fertilizers are not only environmentally friendly, but also do not produce large amounts of toxic substances that harm human health. Scientific and reasonable fertilization is the key to improving organic greenhouse vegetable cultivation. When choosing fertilizers, the use of chemically synthesized fertilizers must be eliminated, but some special fertilizers certified by professional institutions can be selected. Only scientific fertilization can ensure the safety of organic vegetables.

3 Green Prevention and Control Techniques for Diseases and Insect Pests in Greenhouse Vegetables

3.1 Green Prevention and Control Techniques for Insect Pests

3.1.1 Light Trapping and Killing

Using the phototaxis of insects to make insect-killing lamps to trap and kill pests is a very important physical control measure for agricultural pests, and is also an important part of integrated control. At present, insect-killing lamps targeting crop pests mainly include two types: solar insect-killing lamps and electric insect-killing lamps. At night, insect-killing lamps can emit a light source to lure pests into rushing toward the light source and touching the high-voltage electric grid outside the insect-killing lamp, thereby eliminating the pests. When using insect-killing lamps, it is advisable to choose open terrain. Using insect-killing lamps to eliminate pests with phototaxis kills a large number of pests and does not pollute the environment, and this technique is easy to use on a large scale.

3.1.2 Sex Hormone Trapping and Killing

Certain chemicals secreted by pests themselves that are related to sex communication are used to trap and kill male adults, thereby achieving the purpose of controlling pest reproduction. At present, artificially synthesized sex hormone products include sex attractants, sex stimulants and sex control agents. Among them, sex attractants can trap and kill specified pest species. For example, male moths such as the tobacco cutworm and the diamondback moth have great lethality, eliminating pests in one go and controlling pest reproduction. However, because there are many pest species and relatively few types of pest sex pheromones, there are certain limitations when using this method, so research on other pests needs to be deepened.

3.1.3 Colored Board Trapping and Killing

Using the color taxis of insects, colored boards are made to trap and kill pests. At present, common colored insect-killing boards include yellow and blue types. For example, pests such as the American serpentine leafminer, aphids and whiteflies prefer yellow, so yellow boards can be selected to trap pests. It should be noted that oil should be applied to the colored boards every 7-10 d to avoid affecting the trapping and killing effect because the oil on the colored boards has dried.

3.1.4 Insect-Proof Net Trapping and Killing

Insect-proof nets are made from fine-mesh gauze and used in combination with greenhouses. The advantage of this technique is that, on the one hand, it can effectively prevent pests from entering the greenhouse and protect vegetables from insect damage. On the other hand, it also has good light and air permeability and does not affect the normal growth of vegetables.

3.2 Green Integrated Prevention and Control Techniques for Diseases

Green prevention and control of vegetable cultivation diseases includes the following points. 1) According to factors such as the soil conditions and geographical conditions of the region, selecting vegetable varieties with high disease resistance, high quality and high yield and suitable for planting in the region is the basis for preventing and controlling vegetable diseases. 2) High ridges and narrow beds, with matching ditches, aim to prevent water accumulation on the bed surface, so that accumulated water can be quickly drained even when it rains, lowering the temperature inside the greenhouse and avoiding disease occurrence. 3) After the previous round of crops is harvested, the soil should be deeply plowed and turned in time, and it is best to sun-dry the plowed soil for several days, thereby reducing diseases in the soil. 4) Implement crop rotation to prevent soil-borne diseases. 5) Strengthen field management and promptly remove plants already infected with diseases to ensure the healthy growth of vegetables.

3.3 Ecological Prevention and Control Techniques for Diseases and Insect Pests

Ecological prevention and control mainly plays a role in taking preventive measures. Many regions encounter disastrous weather such as strong winds, rainstorms and hail. When such severe weather occurs, organic vegetables in greenhouses will experience conditions such as dew on leaves and greenhouse leakage, and severe weather will also affect the air quality in the greenhouse. According to relevant research results, diseases and insect pests are more likely to occur in acidic environments, so scientific and effective measures should be taken to control the pH of the planting environment. Growers can appropriately spray alkaline substances on vegetable leaves, which can effectively reduce the probability of diseases and insect pests occurring.