Assessing the Impact of Wireworms on Stand Establishment and Yield in Cotton

Wireworms are a common pest of cotton in the Texas High Plains. Two types of wireworms feed on cotton: true wireworms and false wireworms. True wireworms, commonly called click beetles, are members of the Elateridae family, while false wireworms, or darkling beetles, are from the Tenebrionidae family. The larvae damage cotton by feeding on the root, hypocotyl, and cotyledon of plants before emerging from the soil. The most severe damage occurs when the hypocotyl is severed, killing the plant and reducing the stand. A study was conducted in a field with known history of wireworm infestation to determine wireworm impact on plant stand and cotton yield under various seeding rates. Seeding rates evaluated were 1.5 seeds/row-ft (19,600 seeds/acre), 2 seeds/row-ft (26,136 seeds/acre), 3 seeds/row-ft (39204 seeds/acre), & 4 seeds/row-ft (52,270 seeds/acre). The experiment was planted on 10 June on 40-inch row spacing using cotton variety, NG3406B2XF. The experimental design was RCBD with four replications. The plots were 4-rows wide × 36 ft in length. Plant population was estimated after the stand establishment (4 true-leaves stage). The average plant population ranged from 7,500 plants per acre to 17,700 plants per acre at seeding rates 19,600 seeds/a and 52,270 seeds/a, respectively. Percentage of seeds that established into plants ranged from 28 to 38% across treatments (P = 0.759). Yield results are still pending, and harvest is expected to occur in November.