Search articles from 1992 to the present.
Apple IPM Update
This article was published originally on 5/26/1993Apple scab. Orchards in central and southwest Iowa are just past petal fall. Growers who are using the IRS reduced-spray program for scab control need to apply a tank mix of a SI fungicide (e.g., Nova or Rubigan) with a contact fungicide (e.g., mancozeb, polyram, captan) at petal fall and again at first cover (a week to 10 days after petal fall). This will bring you to the end of the high-risk period for primary infection by scab.
Fire blight. Fire blight infection risk during bloom has been moderated by cool temperatures. With petal fall comes the end of the highest-risk period for the blossom blight phase of fire blight. Two things to keep in mind:
Codling moth. Most IPM cooperators have reached the biofix point (capture of a total of at least 5 male moths in pheromone traps in the orchard). Accumulation of the required 250 degree- days between biofix and the next scheduled insecticide spray for codling moth has been slow due to the unseasonably cold weather. Keep in mind that the IPM program for codling moth covers that insect only. Pink and petal fall insecticide sprays for cat-facing insects (such as tarnished plant bug) are advisable, and growers with a history of apple maggot problems may want to use the commercially available sticky sphere traps to monitor for this insect, beginning about mid-June.
Year of Publication:
IC-465(13) -- May 26, 1993