Spotted Wing Drosophila: Fall Update – Jim Jasinski, Celeste Welty

Several Extension educators, specialists, and growers have been diligently trapping for spotted wing Drosophila (SWD) in berry crops at multiple sites across 20 counties in Ohio since June. In general, SWD populations at most locations have peaked at this point, but they can remain abundant for several weeks longer. Even after the first frost, some SWD adults are usually active in the field.

At some monitoring sites where growers have been spraying through the season, we are still able to trap SWD adults. Adults are also being trapped at sites where fruit is no longer being produced. While this is concerning to growers with fruit still in the field, there doesn’t seem to be any significant fruit infestation or damage, which is good news.  If you haven’t kept up on your spray schedule and still have fruit out in the field, it is strongly recommended that you check your fruit with a simple salt water test to see if you have any infested fruit. Here are the directions from an OSU factsheet (https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2017/04/SWD-salttesthandout-updated-pnd335.pdf) or via an OSU IPM YouTube video (https://www.youtube.com/watch?v=MtMXHxqcSVs).

Our closing message is that if there is still fruit on your farm worth harvesting, keep up on your spray schedule in order to protect those fruit from infestation.  If you deem it necessary to spray for another few weeks, it is important to keep an eye on the PHI of products used.  Most PHI’s range between 0-7 days, but some products labeled for grapes have a 30-day PHI. Here is the complete list of insecticide PHIs and maximum number of applications allowed: https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2017/02/SWD_insecticideOptions2018-1ppr7m8.pdf.

Spotted wing drosophila baited Scentry trap.

Spotted Wing Drosophila Exclusion Netting Workshop- Jim Jasinski, Celeste Welty & Ashley Kulhanek

While most growers manage spotted wing Drosophila (SWD) with insecticide sprays once this pest is detected on their farm, there are other non-chemical ways to successfully grow cane berry and blueberry fruit using finely woven insect proof netting.

A workshop will be held on Oct. 13th to demonstrate the basics of designing and building an enclosure around susceptible small fruit plants and then covering it with insect proof netting to prevent SWD adults from attacking the fruit. The workshop will be co-taught by Jay Cooper (grower), Celeste Welty (Extension entomologist), Jim Jasinski and Ashley Kulhanek (Extension educators).

Topics covered in the workshop will include a review of other exclusion netting projects, plant and pollination considerations, a tour of an existing exclusion netting structure on-site, and then a hands-on session to experience the process of building a second exclusion netting structure.

The workshop will run from 10am to 2pm on Oct. 13th, located at 7010 Chatham Road, Medina, OH, 44256. Registration is $20 per person and includes handouts and lunch, but must be completed by Oct. 8th. For more information on the workshop and registration details, visit https://medina.osu.edu/events/managing-spotted-wing-drosophila.

Please note this workshop is limited to only 15 participants. For additional questions about registration contact Ashley Kulhanek (kulhanek.5@osu.edu) or for questions about the program contact Jim Jasinski (jasinski.4@osu.edu).

Designing and building insect exclusion structures and netting like this will be the focus of the workshop.

Downy Mildew Confirmed in Pumpkins in Clark County, OH

A severe outbreak of downy mildew was confirmed on pumpkins from a field trial at OSU-OARDC Western Agricultural Research Station. This is the first confirmed outbreak of downy mildew on pumpkins in Ohio, although it is likely elsewhere in central Ohio, if not even more widespread.  Symptoms on pumpkins are somewhat different than on cucumber – the lesions on pumpkins are smaller than on cucumber, although both are angular, look watersoaked on the underside of leaves (upper right photo) and yellow on the upperside  (upper left photo) initially. On pumpkins the older lesions appear bronze-brown in color (lower right photo). Pumpkin leaves can be completely destroyed if not treated with effective fungicides.

With cooler temperatures expected for the rest of this week, as well as rain showers and storms, downy mildew risk is high for most of Ohio and all cucurbits should be protected with fungicides that are effective against downy mildew. Although the season is winding down, if pumpkins still need some time to reach maturity, the foliage should be protected. Information on fungicides can be found in the Midwest Vegetable Production Guide for Commercial Growers 2018; in addition, fungicide efficacy rankings from our 2017 bioassays can be found here. Control of downy mildew requires preventative fungicide application – inadequate control is often observed when fungicides are applied after infection, even if symptoms have not started to appear.

Growing Spinach Over Winter Using Low Tunnels and Row Cover

Ohio is a FOUR season growing environment.  Winter is often under utilized by the backyard grower, community gardener and urban farmer  as viable production time.  Using inexpensive equipment with a little planning allows for production of spinach over the winter under row cover with surprising success.

Site selection and preparation is very important for over wintered crops.  These crops will be challenged by weather and sunlight issues.  Areas with shade from deciduous trees in the summer can often be used as an over wintered production location when the leaves fall.  Soil enriched with organic matter will hold on to water and nutrients better as both of those inputs are not easily added over the winter season.

Spinach is an excellent choice for over winter production as it is extremely cold hardy.  As the temperature decreases the plant increases the sugar content in its vasculature.  This essentially acts as an “anti-freeze” to protect the plant.  Growth is greatly slowed by temperature and lack of sunlight.  Growth will pick back up with the arrival of spring.  Seed can be difficult to source in fall if none is left from spring planting.  Make sure to plan to have extra seed for next fall’s crop.

Planting  needs to be completed prior to Mid-October in most years to allow for decent germination and root growth.  Follow the weather prediction models carefully as this can affect timing of planting by several weeks in either direction.

Prior to planting:

  • Remove any prior season plant material
  • Amend the bed with compost and fertilizer based on prior season crop use
  • Observe crop rotation
  • Create a seed bed to ensure adequate germination

 

 

Row cover was applied immediately after planting.  This may or may not need to be done depending on location and security.  This row cover was applied as the location will be checked infrequently and deer pressure is a constant concern.  Row cover is fairly effective at preventing this predator.

 

Germination of spinach seed typically takes about 7-10 days.  Water as needed to maintain enough moisture for good germination.

 

 

If the weather allows, the row cover can be carefully lifted off,  making sure not to drop soil or debris onto the leaves, to inspect the planting.

 

 

Carefully monitor the weather predictions so that you know when to add or remove additional layers of row cover.  The ten day weather prediction showed that the weather would drop from a high in the 50’s to lows in the teens.

 

A second layer of frost blanket was added to ensure that the micro-climate under the row cover would be adequate to protect the spinach plants.  Spinach is extremely cold hardy and will make it through intense cold with proper protection in most cases.  Deep cold may terminate less cold hardy crops like lettuce if the temperatures drop very low for any period of time.

 

 

Extreme cold, wind, ice and snow were experienced over the end of December 2017 and through the beginning of 2018.  Snow is actually helpful to over wintered plantings, providing an extra layer of insulation.

 

Picture taken on January 16th. Note that the video shown next was taken approximately one week later showing the extremes that are common in Ohio weather. Removing the row cover inappropriately, even for a short time, can interfere with the micro-climate under the row cover and cause damage to the spinach plants.

 

As the weather allows, once temperatures have risen to at least the 40’s or higher, the row cover can be lifted to inspect the plantings and take a small to moderate harvest.  Make sure to replace the row cover with enough time to allow the temperature under the cover to rise prior to any over night cold periods.

 

 

Growth will be rapid once spring warmth and sunlight return.  The grower will be able to take many harvests during warm days at any point after February in most cases.

 

 

As long as harvest is taken before flowering and temperatures have not risen too high, harvest can continue.  A large volume of spinach can be harvested from a small area using this method.

Fruit Yield and Quality in a Strip-Till Tomato System as Influenced by Grafted Plants and Crop Biostimulants

Fruit yield in systems relying on tilled strips or some other form of reduced tillage tends to be lower and delayed compared to systems containing standard plastic-covered raised beds. Still, reduced tillage offers other benefits. If the productivity of reduced till (e.g., strip till) systems could be increased, their use and overall value may also increase.

We have experimented with various approaches to strip-till tomato and pepper production at the OARDC in Wooster consistently since 2014 and during previous years. Excellent work on the same topic has also been completed at other universities (e.g., Iowa State Univ., Michigan State Univ.). With support from the USDA SCRI and ORG programs, SARE, and industry, the current approach by the OSU VPSL is to ask if strip-till systems can be made more productive by including grafted plants and/or crop biostimulants; both may help address the ‘tight’ soils and other limitations associated with some strip-till experiences. At the same time, folks interested in grafted plants and/or crop biostimulants on their own merits — but questioning their returns on investment — may find that returns are beneficial if either technology helps make it more feasible to adopt reduced tillage approaches. The thirteen panels below outline the experiment underway at the OARDC in Wooster. Contact Matt Kleinhenz (kleinhenz.1@osu.edu or 330.263.3810) for more information. Special thanks to Sonia Walker, Nicole Wright, Mark Spigos, Dana Hilfinger, the OARDC Farm Crew, Stephanie Short, and others for contributing to this effort.