Chinese cabbage in autumn is prone to cabbage worms, so how can you control them more effectively?

Summary: Autumn Chinese cabbage is prone to cabbage worms, and these methods leave lower pesticide residues

Chinese cabbage is one of the vegetables in greatest demand in winter, especially in the northern vegetable market. Basically, one family can eat two or three bags of Chinese cabbage over a winter. Pickled Chinese cabbage, stewed Chinese cabbage, vinegar-tossed Chinese cabbage, and so on - Chinese cabbage is truly an indispensable good vegetable on the winter dining table. But the frequent outbreak of cabbage worms also really gives vegetable growers a headache. On Chinese cabbage that had been growing well, once cabbage worms crawl over the leaves, the leaves are either covered with holes or covered with insect droppings. This not only affects appearance, but more importantly affects yield.

So besides using pesticides, what other feasible methods are there to prevent cabbage worms?

The stages in which cabbage worms occur. Cabbage worms are the larvae of the small white butterfly. They generally begin chewing the leaf flesh of Chinese cabbage after the third instar. The young larvae of the small white butterfly generally have relatively weak pesticide resistance, making this the best period for chemical control. The pesticides generally used include bacterial insecticides, insect growth regulators, antibiotic insecticides, and other high-efficiency, low-toxicity agents, and control should be chosen before the third instar.

Once they become adults, their pesticide resistance increases and it becomes very difficult to kill them with pesticides. But no matter which type of insecticide formulation is used, once the frequency of use and the dosage increase, there will be pesticide residues. Therefore, in controlling cabbage worms, besides using pesticides, other methods should also be considered.

Feasible methods for controlling cabbage worm outbreaks.

Choose Chinese cabbage varieties with strong insect resistance. Among the Chinese cabbage varieties currently bred, some have insect resistance, such as Qingza No. 3, which can effectively reduce the incidence of pests such as cabbage worms, but it cannot completely avoid the occurrence of cabbage worms, and other pest control methods must also be used together.

Prepare the land, clean the vegetable plot, and carry out reasonable crop rotation. Before sowing Chinese cabbage, after the previous crop is harvested, clean up the field debris thoroughly, especially plant residues that easily attract small white butterflies, because they may contain large numbers of eggs. When necessary, soil disinfection can be carried out with high-efficiency, low-toxicity soil insecticides or fungicides.

It is also said that Baneda Bika microbial fertilizer can be applied to improve the soil. It reduces eggs and sources of insects from the source. Severe continuous cropping of Chinese cabbage is also a trigger for cabbage worm outbreaks. Therefore, Chinese cabbage can be rotated with crops such as scallions, ginger, and garlic to avoid the harm of continuous cropping.

In the early stage or the middle and late stages of a cabbage worm outbreak, use physical insect-killing methods combined with chemical insect-killing.

The current physical insect-killing method is to use black light lamps to trap and kill cabbage worms. By trapping and killing adults, the number of eggs is reduced and a major cabbage worm outbreak is avoided. In the control of cabbage worms, relying only on physical methods is still limited and cannot completely kill them. Therefore, when there is a major cabbage worm outbreak, high-efficiency, low-toxicity insecticides must still be used together, and when using insecticides, various agents should be used alternately to avoid the worms developing pesticide resistance.

Release natural enemies of cabbage worms and use insects to control insects. The natural enemies of cabbage worms include swallowtail pteromalids, Trichogramma evanescens, and others. They can be released into the vegetable plot in appropriate amounts at the appropriate time when cabbage worms break out. Combined with black light lamps to trap and kill adults, this can also play a certain role in killing the insects.

The control of cabbage worms can only be prevention first, combined with control. Relying only on physical methods to kill insects still has limited effect, and chemical control must still be combined with it. Especially in plots with major cabbage worm outbreaks, pesticides should be sprayed as early as possible to avoid reduced yield caused by cabbage worm outbreaks and to avoid affecting the hearting growth of Chinese cabbage.

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