Cabbage and radish are harmed by Pieris rapae, no pesticides are used to kill the insects, 4 kinds of plants are soaked in water with high efficiency and no residue

Introduction: Pieris rapae is an important pest that damages cabbage and radish.
From the perspective of food safety, if vegetable farmers do not want to use pesticides, they can use 4 kinds of plants to soak in water to prevent them.
It is easy to obtain, efficient, and has no residue, which is better than pesticides.
Used
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When it comes to the field pest of cabbage caterpillar, not only every vegetable grower is familiar with it, but ordinary farmers will be quite impressed with it, just because it is so annoying
.
The spring and autumn seasons of each year are a good time for farmers to grow vegetables, cabbage, and small or large radishes
.
Pieris caterpillars also occur heavily in spring and autumn every year.
They damage cabbage, rape, radishes planted by farmers in early spring, or vegetables such as Chinese cabbage, radishes, and cauliflower planted in autumn
.
The young larvae of Pieris rapae will gnaw off the leaf flesh of the damaged vegetables, leaving only the transparent skin
.
And Pieris rapae after the third instar will not only enter the binge eating period, but also eat the entire vegetable leaves, leaving only the veins
.
On the one hand, it will affect the packing of cabbage and the growth of green vegetables.
On the other hand, Pieris rapae will leave a large amount of insect dung on the vegetables that it eats, pollute the leaves, flower buds or bulbs of vegetables, and reduce the quality of vegetables
.
Vegetable farmers and ordinary farmers who want to kill Pieris rapae, of course, can choose to use corresponding insecticides
.
However, the use of any pesticides must pay attention to the interval between medications
.
But even in this way, it is difficult to guarantee that there will be no residues on vegetables that have been used
.
From the perspective of food safety, if vegetable farmers or ordinary farmers want to kill Pieris rapae without spraying pesticides, they can use 4 kinds of them which are easily available.
They are also effective in killing Pieris rapae, and their plant-derived insecticidal ingredients are easy to decompose.
No residual plants will be formed, and the leaves or root bark will be directly soaked in water and sprayed with a clear solution for control
.
The four plants are tobacco, ailanthus altissima, veratrum, and fish cane
.
Some people may say, what are you talking about? Tobacco and Ailanthus altissima are more common in rural areas, but these two plants, hellebore and fish cane, are not available in our local area.
Where do you start with the "easy", and where do you want us to find this "easy" What about things? I admit that the distribution of veratrum and fish cane in China is not wide, but both are Chinese medicinal materials, and you can easily buy them from local Chinese medicine stores
.
Tobacco can be used directly for killing insects.
Dried tobacco can be boiled or sprayed in water, or ground and used for dusting.
Of course, fresh tobacco can only be sprayed in water
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Tobacco can not only kill field pests such as cabbage caterpillars, plutella xylostella, leaf rollers and other chewing mouthparts, but also piercing and sucking mouthparts such as aphids, thrips, planthoppers, stink bugs, etc.
, and can also cure rice field leeches
.
Tobacco can be used to kill insects because tobacco contains an alkaloid (that is, nicotine), which has contact killing, fumigation and stomach poisoning effects on pests
.
After tobacco is used, the insecticidal speed is fast, but the effective period is relatively short
.
However, this is an advantage for vegetables that need to be harvested at any time
.
Tobacco powder is used to kill insects, and 2 to 3 kilograms of tobacco powder can be used per acre
.
If you choose spraying, you can generally use 1 kg of outer tobacco leaves per acre, or the same weight of coarsely crushed tobacco stems, tobacco ribs and 10-20 liters of water.
After soaking, filter out the tobacco residue, and use the extract to spray directly to prevent chewing mouthparts.
The cabbage caterpillar and so on
.
If you want to control piercing and sucking mouthparts pests, you should use lime water to soak tobacco
.
No matter what kind of tobacco extract, it needs to be used with the bubble, because the nicotine component is very easy to volatilize
.
Ailanthus altissima was originally called Ailanthus altissima, also known as Ailanthus altissima and wood hull.
It is a deciduous tree of the genus Ailanthus of the bitter wood family
.
It is named because the base of its leaves has glandular dots that can emit a foul smell .
Ailanthus altissima is distributed in the Yellow River basin and can be seen in most areas of the country
.
The reason why Ailanthus altissima can emit a special odor is that Ailanthus altissima contains chemical components such as Ailanthus altissima, Ailanthus altissima, acetyl Ailanthus altissima, Ailanthus altissima, new sphaerocarpus lignin, etc.
, and can pass through the touch Glandular dots of leaves exude
.
Ailanthus altissima, also known as Ailanthus altissima or Ailanthus altissima, belongs to a pentacyclic diterpene lactone compound with a variety of biological activities and a strong bactericidal and insecticidal effect
.
Using the leaves and root bark of Ailanthus altissima to soak in water can also be used to kill Pieris rapae
.
If other plant-derived insecticidal ingredients can be added, the insecticidal effect after use will be better
.
Veratrum is a perennial herb in the Liliaceae family.
It is distributed in Northeast China, Hebei, Shandong, Henan, Shanxi, Shaanxi, Inner Mongolia, Gansu, Hubei, Sichuan and Guizhou
.
The veratrine contained in veratrum has a good insecticidal effect
.
Veratrine itself can be made into biological pesticides.
After use, it has very low toxicity to humans and animals, and there are few residues, and it will not pollute the environment
.
The white root of the veratrum contains more veratrine, and it is effective to spray on radishes and cabbage after being diluted in boiled water
.
After using the liquid spray of veratrum soaked in water, the active ingredients in it will pass through the epidermis of the insects such as Pieris rapae or enter the digestive system after being eaten by the insects such as Pieris rapae, causing local irritation and causing pests.
The reflex excitement of the insect body first acts by inhibiting the sensory nerve endings of the insect body such as Pieris rapae, and then it causes its death by inhibiting the central nervous system of the insects such as Pieris rapae
.
Once sprayed, the insecticidal effect can be maintained for about 10 days
.
Fish cane is a legume perennial vine, mainly distributed in Zhejiang, Fujian, Taiwan, Guangdong, Hainan, Guangxi and other places
.
Rotenone, rotenin, gray edamame and fenuol ​​are contained in roten, all of which have insecticidal effects
.
Rotenone is an insecticidal active ingredient in the roots of the roten plant.
The rotenone cultivated in Guangxi, Guangdong, Hainan, Fujian and Taiwan in China contains 6%-7% of rotenone, and some of the highest content can reach 13%.

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The wild fish vines in the areas where fish vines are distributed are also precious resources of natural biological pesticides, which can be used directly
.
Rotenone has a strong stomach toxicity and contact effect on pests, it is easy to decompose after use, and there is no residue
.
Spray after soaking in water, it can be used to control vegetable pests such as cabbage caterpillar, diamondback moth, aphid, ape leaf insect, yellow striped beetle, twenty-eight star lady beetle, yellow melon
.
(Source: Country Firefly)