Apple, Late Season Leafroller Control, 1975

Abstract

Abstract This experiment was designed to determine if one application in early August or one application late in August or two applications in August of selected insecticides would control the tufted apple budmoth and redbanded leafroller. The schedule of materials used per acre (other than the test materials) was: April 14, Difolatan, grower applied; April 25, Oil 7E cone; May 5, Captan 50W 6.0 lb + Sulfur 6.0 lb + Agri-Strep 1.5 lb; May 20, Captan 50W 6.0 lb + Kararhane 1.0 lb + Zolone 3EC 42.0 oz; June 2, Captan 50W 5.0 lb + Phosphamidon 8E 5.0 oz; June 12, Captan 50W 5.0 lb + Kararhane 2.0 lb + Zolone 25W 3.0 lb; June 24, Captan 50W 4.0 lb + Kararhane 1.0 lb + Zolone 25W 3.0 lb; July 11, Captan 50W 4.0 lb + Zolone 25W 3.0 lb; July 28, Captan 80W 2.7 lb + Zolone 3EC 32.0 oz; August 1, Omite 30W 4.0 lb; August 15, Captan 80W 4.0 lb. Two 5-tree plots of Lannate L 32.0 oz/100 gal and Phosvel 45W 1.5 lb/100 gal and one 5-tree plot of Guthion 50W 0.5 lb/100 gal were sprayed dilute with a Bean high pressure sprayer operating at 540 psi on August 1. One of the plots of Lannate L and Phosvel and the Guthion plot sprayed on August 1 were sprayed again on August 20. Also one 5-tree plot unsprayed since July 28 was sprayed with Lannate L and a similar plot was sprayed with Phosvel. The treatments were evaluated by examining 10 leafrolIs/tree (50/treafment) on August 4 and August 26 to determine larval mortality. The apples were examined for leafroller injury on August 28 (50 apples/tree, 250 apples/treatment). Fruit was examined at harvest (October 7) to ascertain the increase in number of damaged apples since the summer examination (August 28). Some apples had more than one type of damage, thus, the total number of apples damaged may be less than combined total number of apples damaged at different times of the season (early + late).