Articles from 2017

99 articles found.

Summer rots continue to rear their ugly heads (Fig. 1). This year, we are even seeing them on late season apples like Evercrisp    (Fig 2) and GoldRush. On the plus side, we are seeing some level of control with all fungicides in our trials (data will be presented at the Indiana Hort Congress); unfortunately, on highly susceptible varieties like Honeycrisp, we need to do more research to figure out how to better control these pathogens. Treatments that provided reasonable control in Golden Delicious suffered 10 times more infections on Honeycrisp. Future research will examine the role of timing and fungicide choice on infection. As always, please contact me if you are seeing new problems, increasing severity of problems, or you can surprise me and tell me what a great year you had! As you can see, Jojen loved the harvest, and has decided like most children, that Honeycrisp and[Read More…]

Strawberry production in Indiana primarily utilizes the matted row system in which bare root strawberry plants are set in the spring, fruit is first harvested in the second year and plants are maintained for a few seasons. Strawberry production using an annual plasticulture system is popular in the southern states, where strawberries are planted in the fall and harvested in the next spring. In the annual plasticulture system, strawberries have a longer harvest period and produce fruit with better quality. Growing strawberries as an annual crop is a challenge in Indiana. This is because our short fall makes it difficult for plants to reach the desirable size that leads to a sufficient yield in the following spring. This situation can be changed with the use of high tunnels that provide additional heat units and moderate frost protection. In a trial conducted in a 30 ×96 high tunnel at Southwest Purdue[Read More…]

Apple harvest is winding down with late varieties such as GoldRush and Pink Lady being harvested. Quality has continued to be good, although some stem-end cracking has shown up on some cultivars. We have continued to run about a week early throughout the season.

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Powdery and downy mildew can develop on grapes in the late season, post harvest. It is important to keep vines as healthy as possible going into winter. With the long fall we are experiencing, downy and powdery mildew are both becoming prevalent in many vineyards. Growers should consider a late season application of fungicides to keep these diseases under control to protect the foliage and assure adequate cold acclimation. Downy can be controlled with phosphorous acid products, mancozeb, or captan. However, none of those fungicides will control powdery mildew. So a tank mix including one of the above with a sterol inhibitor such as Rally or Tebuzol would be a good approach.  

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Crown gall is a common disease of many perennial plants. It causes fleshy tumors to develop on the plant and usually results in plant death. Grapes are among the most sensitive fruit crop to crown gall. The disease is caused by the bacterium Agrobacterium tumefaciens. This is the same bacterium that is used to genetically modify important crops. There are at least three biovars of A. tumefaciens that cause crown gall. The particular strain that infects grapes is biovar 3. This strain was renamed Agrobacterium vitis since it only infects grape vines and close relatives. The life cycle of Agrobacterium is interesting. The bacterial cells infect the plant through wounds. These can be caused by insects, mechanical damage, or in the case of grape vines, cold injury. Once the tissue is damaged, the bacterial cells can attach to the plant cells. However, rather than causing a canker or rot by[Read More…]

There are a number of common grape pathogens that can cause fruit rots each year in the region. Black rot and Phomopsis cane and leaf spot are by far the most common fruit pathogens. We also see Botrytis gray mold on some cultivars in cooler regions and years. Another common rot is Sour rot, but it is actually caused by yeasts and bacteria, not filamentous fungi and is spread by fruit flies. It occurs most often when heavy rains near harvest cause berry splitting. I wrote about it in a recent issue. In the past few years we’ve had a troubling rot on a new cultivar to the region, Marquette. This early ripening red has excellent wine quality and is one of the new “super cold hardy” cultivars from Minnesota. That makes it a great choice for northern Indiana vineyards. However, Marquette is not without disease problems. While only moderately[Read More…]