Summary of Pesticide Use Experience in Pollution-Free Strawberry Production

I. Strictly select pesticides and strictly implement pesticide safety intervals

In pollution-free strawberry production, biological pesticides should be given priority, and highly efficient, low-toxicity, low-residue chemical pesticides should be used selectively. These pesticides mainly include: (1) Insecticides, such as the Bt series, avermectin series, pyrethroids, plant extracts (such as tebuconazole and capsaicin, etc.), insect hormones (Mimic, Cascade, IKI-7899), a small number of organophosphorus pesticides (trichlorfon, chlorpyrifos, Lorsban) and other pesticides such as imidacloprid, etc. (2) Fungicides, such as Bordeaux mixture, polyoxin, thiophanate-methyl, Score, Nustar, Kocide, chlorothalonil, triflumizole, Bellkute, pyrimethanil, etc. (3) Herbicides, such as quizalofop, haloxyfop, etc. (4) Smoke agents, such as sulfur fumigants, procymidone, aphid-killing smoke agents, etc. Throughout the entire strawberry production process, it is strictly forbidden to use highly toxic and high-residue pesticides such as methamidophos, carbofuran, chlordimeform, omethoate, dicofol, methyl parathion, sodium pentachlorophenate, fosthiazate, chloropicrin, nitrofen, etc.

The pesticide residue level in fresh strawberries is closely related to the length of time between the last application and harvest. The shorter the interval, the higher the pesticide residue; conversely, the lower it is. Therefore, producers must strictly observe the safety interval for each pesticide. Generally, strawberries can only be harvested and marketed about 10 days after the last application or before harvest; for pesticides with long residual activity such as imidacloprid, fresh fruit should only be harvested and marketed more than 15 days after application.

II. Emphasize control strategies and accurately grasp the appropriate control timing

For the control of noctuid pests such as the tobacco cutworm, the principle of "control the first generation to suppress the second" should be followed, that is, controlling one generation to reduce the pest population base of the next generation, and control should be carried out in the evening. Control of red spider mites should be carried out at the stage of patchy, localized occurrence. The occurrence of strawberry viral diseases is closely related to aphids; as long as aphids are well controlled, the incidence of viral diseases can be significantly reduced. At the same time, according to the occurrence of pests and diseases in the field, it is very important to accurately choose the method of application. For example, if spot treatment is possible, never treat the whole field; if local treatment is possible, never apply pesticides universally.

III. Apply pesticides in appropriate amounts, alternately, and scientifically

Some producers have misconceptions about pesticide use; they believe that the larger the dose, the better the insecticidal or disease-control effect. In fact, this not only increases costs but also easily causes phytotoxicity. Therefore, what pesticide to use and what dosage to use should be strictly controlled. In addition, one of the effective methods to overcome and delay pesticide resistance is to alternately use two or more pesticides with different mechanisms of action, and care should be taken to alternately select agents without cross-resistance. If a mixed pesticide is needed, it should be prepared and used on the spot.