Sunburned pumpkins by handle. Note even handle is burned on one side.

This title should seem familiar as a slight twist on the famous John Denver tune from 1971. With temperatures in the low to mid 90’s for at least three days last week across most of the state, fruit that were not properly covered in the canopy were placed at a higher risk for getting sunburned.

Downy mildew infested field with no leaf canopy.

Based on observations over several years, fruit that are cut off the vine tend to burn more readily than those that remain on the vine, likely a function of being able to evapotranpirate enough moisture to stave off burning. As clade 2 downy mildew was reported on August 13 (active on pumpkin/squash), fields that were not protected suffered almost 100% defoliation with 10-14 days. Amazingly this photo with near total canopy loss had nearly no detectable sun burned fruit despite several fruit actually being desiccated to the point where they were shriveling in the sun! If these fruit were cut off the vine, I would have expected significant rind burning to occur.

While there are a few “white washing” products on the market to spray on fruit in the field to prevent burning, they have not been investigated at OSU. The best prevention is a good canopy through harvest. The next best strategies though more labor intensive would be to cut and move fruit to a shaded location to cure naturally. If fruit are in a u-pick patch, moving them to distinct piles and covering with shade cloth may also be a possible solution.

Another pest that we are actively monitoring using clear sticky traps and pheromone lures is the Brown Marmorated Stink Bug. This stink bug is known to feed on vegetables, grain crops, small fruit and tree fruit.

BMSB adults on sticky trap

While we are actively monitoring for this pest in eight counties, Adams, Athens, Greene, Seneca and Wayne counties are seeing trap catch increases, mostly related to adults. Late stage nymphs and adults pose the biggest threat to tree crops like apples, with their damage resembling several other types of injury such as hail injury or bitter pit (stink bug surface injury (L), internal injury (R); Celeste Welty).

Stink bug injury on apple, courtesy of Celeste Welty

Soon these adults will migrate from the fields to structures to seek refuge from the cold temperatures as they attempt to over-winter. If you have lived in Ohio for the past few years, you are no doubt familiar with these large brown stink bugs that invade your home or office in the fall.

While we only have established thresholds for this pest in apples, these were established in the mid-Atlantic and have not been vetted in Ohio yet. We would expect these thresholds to work well in Ohio but research has not been conducted to confirm the results. Monitoring strategies for vegetables, grapes and small fruit can be found here: https://www.stopbmsb.org/managing-bmsb/management-by-crop/

The monitoring system in apples requires two traps, one placed at the edge of an apple block and one placed in the interior. When the cumulative weekly total of both trap catches exceeds 10 stink bugs, an alternate row middle spray for BMSB may be justified. The details are outlined in this article: https://www.stopbmsb.org/stopBMSB/assets/File/BMSB-in-Orchard-Crops-English.pdf

Although we are moving toward the end of the season for most small fruit producers, keep in mind that spotted-wing Drosophila populations remain high across the state where traps have been placed on farms. Because of their short life cycle and abundance of ripe fruit, expect these populations to increase up until the first significant frost/freeze event.

SWD larvae in fruit

For growers who have abandoned their small fruit plantings for this year, SWD adults can easily be seen buzzing around ripe fruit as they oviposit eggs beneath the soft skin. Evidence of infestation can be readily seen as soft juicy fruit are filled with white SWD larvae. Even for growers who have maintained a regular spray schedule to control this insect, SWD adults can still be detected flying around bramble and blueberry patches albeit in lower numbers.

Since the threshold for this pest is only one adult per trap, it is necessary to maintain a spray schedule as long as the farm intends to harvest fruit. Once the decision has been made to end harvest, the sprays can be halted.