What to Do When Crops Suffer Herbicide Damage? A Full Guide to Remedies
Phytotoxicity refers to abnormal crop growth or physiological disorders after pesticide application. Phytotoxicity comes in two types: acute and chronic. So what should you do if crops suffer phytotoxicity?
1. Symptoms of phytotoxicity
Acute phytotoxicity generally shows obvious symptoms a few hours to 3—4 days after spraying, such as burning, wilting, leaf drop, flower drop, and fruit drop; chronic phytotoxicity, on the other hand, produces obvious reactions only after a relatively long period following spraying, such as poor growth, deformed leaves, and delayed maturity. Common symptoms include spots of varying size, shape, and color on the leaf surface, localized tissue scorching, perforation or leaf drop, or leaf yellowing, chlorosis, or thickening.
2. What to do when phytotoxicity occurs
1. Rinse with clean water
Most chemical pesticides do not withstand water washing. If phytotoxicity is caused by too high a spraying concentration, fill a sprayer with clean water and repeatedly spray and rinse the crop leaves to wash away the pesticide residue left on the leaf surface.
2. Apply a quick-acting fertilizer
For cases where the above-ground part suffers only mild phytotoxicity and the root system is undamaged, a quick-acting fertilizer such as urea can be applied promptly to increase nutrients, thereby enhancing crop growth vigor, promoting early growth, and accelerating the crop's recovery capacity. For crops such as cucurbits and solanaceous vegetables that are only mildly affected before and after fruiting, the effect is still quite noticeable.
3. Suspend the use of pesticides of the same type
Before the phytotoxicity is completely resolved, minimize the use of pesticides, and in particular stop using pesticides of the same type to avoid worsening the phytotoxicity. Of course, once the phytotoxicity is resolved, consider continuing to use them depending on the actual situation; for example, with spider mite pesticides, if the phytotoxicity does not affect the normal growth of the crop, continued use can be considered.
After a pesticide enters plant tissues or cells, it can also undergo chemical reactions with some internal substances, disrupting normal physiological functions and causing pathological changes.