Avermectin B1, isazofos, and fenamiphos for control of Hoplolaimus galeatus and Tylenchorhynchus dubius infesting Poa annua

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Avermectin B1, isazofos, and fenamiphos were evaluated in greenhouse experiments for efficacy against two common turfgrass parasites. Hoplolaimus galeatus and Tylenchorhynchus dubius. Treatments in all experiments were arranged in a completely randomized design and replicated four times. In the first experiment, avermectin B1 at rates of 0.2 and 0.4 kg a.i./ha and isazofos at rates of 2.3 and 23 kg a.i./ha significantly reduced populations of both species of parasitic nematodes compared to controls at 14 and 28 days after treatment (P ≤ 0.01). In the second experiment, the greatest reductions in both nematode populations occurred at 28 and 56 days after treatment, where 23 kg a.i./ha of isazofos was applied (P ≤ 0.01). These reduction, however, were not different from reductions of H. galeatus at 28 and 56 days after treatment (P ≤ 0.01) or T. dubius at 56 days after treatment (P ≤ 0.01), where 0.2- and 0.4-kg a.i./ha rates of avermectin B1 were mixed throughout the soil. In the third experiment, the greatest population reduction of H. galeatus was observed with a 0.4-kg a.i./ha treatment of avermectin B1 at 56 days after treatment (P ≤ 0.05). T. dubius populations were reduced by the 0.4-kg a.i./ha rate of avermectin B1 at 28 (P ≤ 0.01), 56 (P ≤ 0.05), and 70 (P ≤0.01) days after treatment. In the fourth and fifth experiments, avermectin B1 at rates of 7.5 and 15.2 kg a.i./ha consistently reduced nematode populations compared to controls and performed as well or better than fenamiphos (P ≤ 0.01).

Publication Title, e.g., Journal

Journal of Nematology