Ascospore release is timed to optimize infection, which happens around tight cluster through petal fall. This is when all the fun really begins: Ascospores are at their peak and ejecting, and apple tissue is expanding, providing a larger, susceptible canopy that spores can hit. That excellent timing is the poetry of evolution in motion. Other[Read More…]
Crop Management
There has been some talk about the use of promalin to help overcome the damaging effects of freezing temperatures. Only a small amount of research has been conducted on this. Dr Steve McArtney showed that promalin applied after damaging freeze events could increase parthenocarpic (seedless) fruit development. Keep in mind this was only shown to[Read More…]
As the spray season approaches, it is good to remember the profound impact water quality has on the performance of pesticides used by fruit growers. Purdue Pesticides Program recently published a guide, The Impact of Water Quality on Pesticide Performance PPP-86, available at the Education Store, 1-888-EXT-INFO or www.extension.purdue.edu/store/. I highly recommend this guide to[Read More…]
There are some potential pest and disease problems that require early season sprays. Phomopsis is a major problem on many grape varieties in the Midwest. Mancozeb should be applied starting at 1-3 inch shoots and repeated each 7-10 days, especially prior to a predicted rain event. Colleagues in Michigan and Ohio have been conducting evaluations[Read More…]
What is the best way to assess bud damage from cold temperatures? Drs. Tara Baugher and Jim Schupp at Penn. State University have put together a nice page with some excellent photos explaining how to assess fruit bud survival: http://extension.psu.edu/plants/tree-fruit/news/2016/assessing-fruit-bud-survival-and-crop-potential I would add that unless you find that more than 90% of your buds have[Read More…]
Frost and freeze damage was minor in small fruits and grapes. Below is a review of general guidelines for when we expect damage to buds, flowers and fruit. Developmental stage 10% kill (°F) 90% kill (°F) Apples Silver tip 15 2 Green tip 18 10 Half-inch green 23 15 Tight cluster 27 21 Pink 28[Read More…]
Early spring is a good time to make the first herbicide application of the year. There are several options for grapes, brambles and blueberries including both pre and post-emergent herbicides. In most situations, there will be some emerged weeds present in the planting at this time of the year. That means a post-emergent herbicide will[Read More…]
The proper time to remove straw from matted row strawberries is when the bare-soil temperature at 4 inches averages about 40-43˚F. This usually coincides with mid to late March in central Indiana. This year is earlier than average with temperatures well into the 50s already by March 15. Plants will begin pushing new leaves as[Read More…]
Spring freeze damage can be a significant economic problem for Midwest grape growers. Widespread damage occurred in 2007 and 2012 when warm temperatures in March were followed by freezing temperatures in April. Obviously this year we have had a warm February and March so it is very possible that we will have early bud break[Read More…]