Summer disease control on Golden Delicious and Red Delicious, 2008.

摘要

The trial was conducted at the Central Crops Research Station, Clayton, NC in one orchard of Golden Delicious trees (14 years old) and one orchard with Golden Delicious and Delicious trees (18 years old). Fungicide treatments were applied in each orchard with an airblast sprayer calibrated to deliver 225 gpa to two 5-tree replications. Prior to the initiation of the test, Golden Delicious trees were sprayed weekly from green-tip with Nova 40W at 5.0 oz/A to control cedar apple rust. Treatment applications were begun on 1 May at first cover (1C). Subsequent sprays were made on 12 and 23 May;2, 12 and 23 Jun; 4, 14 and 25 Jul; and 4 and 14 Aug. On the day of harvest, 25 Aug, the percent fruit affected with bitter rot or bot rot was determined on Delicious and Golden Delicious trees by estimating the total number of fruit on the tree and ground and counting the number of fruit affected with bitter rot or bot rot on the ground and in the tree. On 28 Aug, 25 fruit were selected from each replication of Golden Delicious in each orchard and stored for 1-week at ambient temperatures (25-30oC) toallow rotsto develop. Following storage the incidence of rots and the incidence and severity of sooty blotch and flyspeck were determined. Fruit finish was also scored on an arbitrary sample of 10 Golden Delicious fruit from each replication by estimating the percent surface area covered with russet.