State-wide update: August 2020
By: Maria Smith, HCS-OSU
Precipitation: Much of August has followed July, with warm, dry conditions. It has only been in the past couple of weeks that we have begun seeing a reprieve from this pattern (Fig. 1). Notably, southern Ohio has had several large storms come through, alleviating previous drought conditions (Fig. 2). In contrast, northwestern and portions of central Ohio have continued remaining dry.
Here in Wooster, we had a combined total of 4.25” of rain throughout August across 8 days of measurable precipitation. Approximately 30% of that accumulated total came from a single 1.31” event on August 28 from the remnants of hurricane Laura (www.newa.cornell.edu). Despite that event, Wooster and much of northern Ohio were still at or below the 30-year average precipitation for the month (Fig. 1).
Figure 1. Accumulated precipitation during the past 30 days (left) and accumulated precipitation departure from the 30-year average (right). Figures retrieved from https://climate.osu.edu/climate-tools/climate-maps-ohio.
Figure 2. Ohio drought monitor for 1 Sep 2020. Figure retrieved from https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?OH.
Temperature: A clear delineation between eastern and western Ohio could be made for temperature trends (Fig. 3). All but the northeast corner of northern Ohio continued July’s trend of above long-term average temperatures by 1-3 °F, while southern and western Ohio tended to be closer to average temperatures.
Figure 3. Maximum, minimum, and average temperatures during the past 30 days (top), and their respective departures from the 30-year average (bottom). Figures retrieved from https://climate.osu.edu/climate-tools/climate-maps-ohio.
In the vineyard:
Harvest has begun for several of the early-season varieties over the past couple of weeks. While we were grateful to get the rain to help stave off any potential berry shrivel from the summer drought, awaiting anymore right now seems to walk a fine line between “okay, this is fine” and “harvest that fruit now”.
The ability to wait out rain events should largely be determined around your fruit’s proximity to maturity, overall fruit quality (i.e., are the berries healthy and intact or are you noticing wounding, splitting, rot, or other issues that significant rain would worsen?), and the size of the anticipated rain event. Thankfully, the season has been generous so far in limiting disease pressure and allowing us to get to this point with overall healthy fruit. If you are new to tracking your fruit maturity and deciding your harvest date, please see our resources from Dr. Imed Dami and Diane Kinney: Fruit maturity factsheet and 2020 Fruit maturity updates - OARDC Wooster.
One concern for this fall that has recently caught my attention is bird pressure. Afterall, what would 2020 be without a real-life version of Alfred Hitchcock’s The Birds, right? Several growers have reported much higher than normal bird pressure and damage over the past couple of weeks. Indeed, I observed this myself during our first harvest with ‘Marquette’ last week where robins were seen trapping themselves up and under the fastened bird netting. The concern, of course, is both in yield loss and in creating wound sites for sour rot and Botrytis development. If you are in search of options for bird control, check out this comprehensive factsheet from UNH: https://extension.unh.edu/resources/files/Resource001797_Rep2514.pdf. In general, we advocate netting as the most traditional, reliable control method. However, we recognize that different operations have different limitations, and there are various methods on the market that are worth exploring.
Lastly, if you are planning for new vineyard plantings, now through October is an ideal time to get underway with vineyard site preparation. This includes tile installation, soil decompaction, plowing, weed control, pH and some nutrient amendments, and sowing ground cover. The soil is still very warm from the summer heat, but the cooling days should bring about higher soil moisture, which makes for easier cultivation and sod establishment.