蔬菜大棚的发展已经有些年头了，但也发现了很多问题，害虫是一件非常困难的事情，所以安装防虫网是非常必要的，有了它的存在，可以有效地防治害虫。用防虫网覆盖后，菜青虫、小菜蛾、蚜虫等害虫基本上可以避免。如果我们不加以重视，病毒的传播将带来灾难性的后果，尤其是蚜虫传播，危害极大。
蔬菜大棚安装蚊帐可以切断害虫的传播途径，在一定程度上减少病毒的发生。还有调节温度、土壤温湿度的能力，在春秋两季，用白色的防虫网覆盖，可以达到很好的保温效果，可以有效减少霜冻的影响。夏天一般用黑色和银灰色的防虫网防晒降温。另外，防虫网能防止部分雨水落入大棚，降低田间湿度，也能减少晴天蔬菜温室的水分蒸发。最后，阴影效果很好。强光会抑制蔬菜特别是叶菜类蔬菜的正常生长，防虫网能起到一定的遮荫作用。
在使用温室防虫网的过程中，必须注意几个注意事项，以便在使用过程中发挥良好的使用效果。那么，我们应该注意哪些问题呢？让我们给你介绍一下。
1温室防虫网的选择首先要考虑网目数、网目颜色和网目宽度。如果网目数过小，网目过大，则不会起到防虫的效果；如果网目数过小，可以防虫，但通风不良，造成高温和过度遮荫，不利于农作物生长。一般选用22-24目蚊帐。春、秋季与夏季相比，气温较低，光照较弱，应选用白色防虫网；夏季，应选择黑色或银灰色防虫网，以考虑遮荫和降温；在蚜虫和病毒病发生严重的地区，应使用银灰色防虫网，以驱除蚜虫，预防病毒性疾病。
2为保证覆盖质量，防虫网应全封闭、覆土严密，并用压膜线固定牢固；大中型大棚、温室的门必须安装防虫网，进出时注意立即关闭。棚架的高度应明显高于拱形小棚内作物的高度，以防害虫在植物叶片上进食或产卵。用于密封通风口的防虫网与透明盖之间不得有空隙，以免给害虫留下通道。随时检查、修补防虫网的孔洞和缝隙。
三。种子、土壤、塑料大棚或温室骨架和框架材料可能含有虫卵。蔬菜种植前对种子、土壤、棚架骨架和骨架材料进行防虫网处理，是保证防虫网覆盖栽培效果的关键环节。
The development of vegetable greenhouses has been some years,but also found a lot of problems,pest is a very difficult thing,so the installation of insect net is very necessary,with its existence,can effectively prevent pests.After covered with insect proof net,the pests of Pieris rapae,Plutella xylostella and aphids can be basically avoided.If we do not pay attention to it,the spread of the virus will bring disastrous consequences,especially aphid transmission,which is very harmful.
The installation of insect nets in vegetable greenhouses can cut off the transmission path of pests and reduce the incidence of virus to a certain extent.There is also the ability to adjust the temperature,soil temperature and humidity,in the spring and autumn,with the white insect net cover,which can achieve good insulation effect,can effectively reduce the impact of frost.In summer,black and silver gray insect proof nets are generally used to protect the sun and cool down.In addition,the insect proof net can prevent part of the rainwater from falling into the shed,which will reduce the field humidity,and also reduce the water evaporation in the vegetable greenhouse on sunny days.Finally,the shading effect is good.The strong light will inhibit the normal growth of vegetables,especially leafy vegetables,and the insect proof net can play a certain role in shading.
In the process of using the greenhouse insect proof net,we must pay attention to several points for attention,so as to play a good use effect in the process of use.So,what problems should we pay attention to?Let's introduce it to you.
1.First of all,the mesh number,color and width of the mesh should be considered in the selection of insect proof net in greenhouse.If the mesh number is too small and the mesh is too large,it will not have the effect of pest control;if the mesh number is too small,it can prevent insects,but the ventilation is poor,resulting in high temperature and excessive shading,which is not conducive to the growth of crops.Generally,22-24 mesh insect net should be selected.In spring and autumn,compared with summer,the temperature is lower and the light is weaker,so white insect net should be selected;in summer,black or silver gray insect prevention net should be selected to give consideration to shading and cooling;in areas where aphids and virus diseases occur seriously,silver grey insect prevention net should be used in order to drive away aphids and prevent virus diseases.
2.To ensure the quality of covering,the insect proof net should be completely closed and tightly covered with soil,and firmly fixed with pressure film line;the doors of large and medium-sized sheds and greenhouses must be installed with insect proof nets,and attention should be paid to close them immediately when entering and leaving.The height of the trellis should be significantly higher than that of the crops in the small arched shed,so as to prevent the pests from eating or laying eggs on the leaves of the plants.There should be no gap between the insect proof net used for sealing the vent and the transparent cover,so as to avoid leaving passage for the pest.Check and repair the holes and gaps in the insect proof net at any time.
3.The seeds,soil,plastic shed or greenhouse skeleton and frame materials may contain pests and eggs.It is the key link to ensure the effect of insect proof net covering cultivation that the seeds,soil,shed skeleton and frame materials should be treated with insect control net before planting vegetables.
