Impacts of Aminopyralid on Juvenile Tomato Plants

Herbicides based on the active substance aminopyralid are widely used to control broadleaf weeds in cereals or pastures. Their disadvantage is that the residues remain not only in the soil but also bind to the plant tissues of the treated plants. The residues of herbicides in straw or manure may damage a crop of cultivated tomatoes and reduce the economic yield. The study aimed to evaluate the response of juvenile tomato plants to herbicides. Two pot experiments with tomato plants and seeds were performed. In the first experiment, the response of tomatoes to aminopyralid at doses of 0.6, 1.5, 3, 7.5 and 15 g/ha was evaluated, and in the second experiment, extracts from straw treated with the herbicide Mustang Forte were tested. As the concentration of aminopyralid increased, seed germination was delayed by 1 to 3 days, compared to the control, and all the germinating seeds were deformed. With the increased concentration of aminopyralid, injury of tomato plants also increased, at the highest applied dose of 15 g/ha, 93.75% of tomato plants were damaged. In the case of a negative effects on the width of the root collar, height and weight of the above-ground part of the plant, a critical level of concentration of aminopyralid in the soil was determined between 3 and 7.5 g/ha. The test with straw treated with herbicide did not have as clear an effect as expected compared to straw from organic farming.