Recently, the reporter visited some sheds and learned that the current thrips are seriously harmful. Whether it is peppers, eggplants or cucumbers, there are traces of thrips activity and harm on their flowers, leaves and fruits. Whenever it comes to the discovery and prevention of thrips, vegetable farmers are mostly helpless. But in the interview, experienced vegetable farmers said that the thrips are getting bigger and bigger, how can this be explained?
Thrips are harmful to fruit symptoms
Thrips are difficult to prevent the cause
The reason why thrips are difficult to prevent and treat, analyze it, there are roughly three: first of all, the thrips are small in size, 0.5 mm - 2 mm in length, not easy to detect, when a small number of thrips in the shed are harmed, vegetable farmers are difficult to find. When the number is large and the harm is obvious, the difficulty of prevention and control increases. Then there is the strong concealment of thrips, the eggs overlap generations, mostly in the flower, the back of the leaf activity, nymphs eat on the back of the leaf to the end of the advanced age to stop feeding, falling into the topsoil pupa. It is difficult to be meticulous when spraying. There is also the repeated use of the drug, and the resistance of thrips is enhanced. These are the root causes of the harm thrips.
Thrips are harmful symptoms
Thrips are harmful leaf front picture
Let's take a look at the symptoms of thrips. At present, the main force of planting greenhouses is older, and the eyes will have different degrees of presbyopia symptoms, if you do not use tools such as magnifying glasses, it is indeed difficult to identify thistle. Taking cucumber as an example, thrips are harmed by young leaves in the upper part of the plant, and after the damage, the leaves have yellow spots on the front of the leaves, which spread from the near petiole to the surrounding areas, and the damaged area on the back of the leaves is shiny; the symptoms are difficult to show when the flowers are damaged, but the fruit and the stalk will leave obvious marks, and there is a "bright skin" on the fruit surface, which is different from the symptoms of wood embolization caused by boron deficiency, and the former looks smoother.
Picture of the back of the leaf where the thrips are harmed
Multiple measures are taken to prevent and control thrips
Correctly understand the symptoms of thrips, and then look for thrips in turn, the problem will become simple. Compared with the tiny size of the thrips, the area of harm is much larger, and the symptoms are also obvious. But it takes a familiar process. According to the symptoms of thrips, find the active thrips, combined with the life habits of the thrips, in most cases, the thrips will hide in the flowers, the back of the leaves or the surface of the young melon, so that vegetable farmers can easily find the presence and harm of thrips in actual production. Of course, there is also a way, combined with the blue characteristics of thrips, hanging blue armyworm boards in the shed, the armyworm board is located in the upper middle of the plant, hanging 30-40 pieces per acre. The armyworm board can play a role in pest warning and reduce the number of insect populations. In this way, the more the thrips look bigger and bigger, it is very reasonable.
Then the key is to do a good job in the prevention and control of thrips. The first is to do a good job in the comprehensive protection of the shed. Insect nets should be installed at the air outlet, front face and entrance of the roof, and checked in time to avoid the situation that the insect net and the shed film are not tightly sealed. The second is early prevention, it is best to spray prevention before flowering to reduce the harm of thrips entering the flowers. Then pay attention to the method of medication, once the shed is found to be harmful to thrips, it should be used in time, pay attention to the walking speed when spraying, be comprehensive and meticulous, and ensure that the liquid accurately reaches the growth point of young leaves, flowers, the back of the leaves and the surface. At the same time, if there are weeds or other vegetables planted on the front of the face, the medicine should also be used. It should be reminded that ensuring that the liquid is sufficient here does not mean increasing the dosage of the drug. Then choose the right combination of agents. It is recommended to use insecticides in parallel with ovulents, and to choose a combination of fast-acting and long-acting agents. Finally, pay attention to the alternating drug use, which refers to the different composition of the agent, and can not simply be considered to be the replacement of three agents, so that sometimes there are cases where the trade names are different but the ingredients are the same.
In addition, after pollination of the flowers infested by thrips, there will be different degrees of scars on the surface of the fruit and the stalk of the fruit, which has a greater impact on the commerciality of the fruit. In this regard, vegetable farmers can remove the affected flowers as soon as possible, and then take them out of the shed to concentrate on treatment.