Arthropod Management Tests

Asquith, Dean; Hull, Larry A.; Travis, James W.; Mowery, Paul D.

1977 Arthropod Management Tests

doi: 10.1093/iat/2.1.13

Experimental sprays were applied to run-off to single-tree plots in a complete randomized block design with 4 replicates of Golden Delicious except GCP-5126 which was applied to 4 York Imperial trees, a better host of the white apple leafhopper. Treated single-frees were separated by others not sprayed with insecticides. Experimental sprays were applied with a John Bean sprayer, 35 gpm pump, equipped with a spray mast carrying 7 spray guns arranged to wet the uniformly trimmed trees. Spray dates for the test insecticides were: Apr 27, May 7, Aug 3 and Aug 18 only for GCP-5126. Guthion was applied to these same trees on May 25, June 8 and June 23. Other test insecticides were applied on May 6 and 7, May 25, June 8, June 23, Aug 3 and 4, and Aug 18 and 19. The split dates indicate interruption of spraying by weather. Both dosages of Sumithion were discontinued after June 23. During May, general sprays involving Cyprex, Polyram, sulfur, and calcium chloride were applied as 6X concentrates with an airblast sprayer to the whole experimental block. From June 1 to July 6, the general sprays involved captan, sulfur, and calcium chloride. Late season general sprays were of captan and zineb. Average temperatures weTe: May 57.74° F, June 71.30° F, July 70.09° F, August 67.92° F, and September 62.78° F. Rainfall in inches averaged: May 5.68, June 2.63, July 4.86, August 2.62, September 4.49. Effectiveness of the test chemicals on the European red mite and the twospotted spider mite was evaluated by counting the mites several times during the season on samples of 20 leaves/tree, 80 leaves/treatment. The effect of sprays on the predator S. punctum was evaluated by 3-min counts of adults and larvae around the periphery of the test trees. Effectiveness of chemicals on fruit feeders was assessed by scoring for injury all drops after July 1 and two picked samples, Aug 16 and 30. Apple samples averaged 121 fruits/replicate, 484/treatment002E

Forsythe, H. Y.

1977 Arthropod Management Tests

doi: 10.1093/iat/2.1.15

Test materials were applied to 11-year-old apple trees at Monmouth, Maine, as dilute sprays with a hand gun from a hydraulic sprayer operating at 300 psi and at a rate of ca 500 gal per acre. Spray dates were April 23 (half-inch green). May 10 (pink), June 2-3 (petal fall), June 10 (first cover), and June 24 (second cover). The standard pesticide program consisted of captan 80W.(1.25 lb/100 gal) on 14 dates, Epsom salts (15 lb) and Marlate 50W (3 lb) on June 3, 11, and 24, and Sevin 80W (1.25 lb) on July 8 and 22. There were no tank-mixtures of acaricides with other pesticides. There were 4 single-tree replications per treatment. A randomized complete block design was utilized with 2 Cortland and 2 Early Mcintosh cultivars per treatment in Test 1, 4 Red Delicious per treatment in Test 2, and 2 Mcintosh and 2 Golden Delicious per treatment in Test 3. From each tree, 25 leaves were collected mostly at chest-height around the periphery of the tree, brought into the laboratory, and brushed onto glass plates coated with a Tween 20-alcohol mixture; mites were counted the same day. Mite population pressure was not very severe. Following hot and dry weather the first half of June, there was abundant rainfall through July.