Diagnostic Methods and Prevention and Control Measures for Herbicide Damage
1. Soil residual herbicide damage: Farmland where long-residual herbicides such as triazines, sulfonylureas, and imidazolinones have been used cannot be planted with Schisandra chinensis within two years. If, due to a lack of understanding of the herbicide use on the planting plot in the previous two years, the herbicide damage to Schisandra chinensis is relatively severe, it cannot be remedied, because in current agricultural production there is still...
In recent years, the area treated with herbicides and the amount applied have increased year by year, saving farmers time in controlling weeds. However, due to human factors, improper application of herbicides has also brought adverse effects on production. 1. Improper storage and blind misuse. Due to improper storage of herbicides, packaging labels fall off or are corroded and become illegible, and herbicides are mistakenly applied as insecticides or fungicides, or are applied without following the herbicide label instructions, causing herbicide damage. Prevention method: Store herbicides properly to prevent packaging labels from falling off. If a label is found to be lost, a new label should immediately be attached indicating the herbicide name and application method.
2. Excessive dosage and overly high concentration. The application rate and concentration of herbicides are stricter than those of insecticides and fungicides. Each herbicide has a prescribed dosage; for example, excessive dosage of tribenuron-methyl can cause damage to wheat. Prevention method: Strictly control the herbicide dosage and concentration.
3. Improper application method. Once a herbicide is applied improperly, it will cause herbicide damage. For example, when many herbicides are applied, if they contaminate the seeds, damage is easily caused; when herbicides are sprayed near sensitive crops and under windy conditions, a large amount of droplets drift onto sensitive crops and cause damage. Prevention method: According to the weeds, herbicide, and environmental conditions, choose different application methods and master the technical points for safe and efficient herbicide application.
4. Blind mixing of pesticides. Mixing herbicides can improve the weed control effect, control diseases, insects, and weeds at the same time, save pesticide use, and has advantages such as saving labor, time, and money. However, if mixed blindly, it not only has no synergistic effect but instead reduces efficacy and causes herbicide damage. Prevention method: Prohibit arbitrary and indiscriminate mixing of herbicides. Before mixing pesticides, conduct compatibility observation, efficacy, and phytotoxicity tests first. According to tests, common varieties that can reduce efficacy and cause herbicide damage after mixing include: propanil mixed with organophosphorus and carbamate pesticides; quizalofop mixed with bentazone; MCPA mixed with acidic pesticides; and fluazifop-P-butyl mixed with bentazone, all of which can lead to herbicide damage.