Recent Blog Posts
By: Maria Smith, HCS-OSU
With the frost risks largely in the rear-view of April, we are starting to see new shoot growth bolt ahead under warming temperatures of the past week (Figure 1). Keep in mind, if you did have damage from those late-April freeze events, you may just be starting to see the emergence of secondary and tertiary shoots (Figure 2).
Figure 1. Shoot growth Chardonnay 4-May 2023 (top) at E-L stages 3-4 and 16-May 2023 (bottom) at E-L stages 11-12.
Figure 2. Primary and secondary shoot emergence from single node position
Weather
Cumulative GDD in Wooster is near the historic average for this time of year (Figure 3) as warm early- and mid-April temperaturs have been buffered with a cool down in late-April through early-May. As mentioned in the last post, we saw two late spring frost events that contributed to wide-spread injury to many vineyards in the northern portions of the state.
April precipitation (4.0”) was 0.6” above the 10-year average rainfall (3.4”), but we are currently on track for a drier than average May, with only 1.3” of accumulated rainfall in the first 2 weeks of the month.
Figure 3. Wooster, OH cumulative GDD (base 50F) as of May 16 = 372, historic GDD for May 16 = 383. Chart from CFAES Weather System (https://weather.cfaes.osu.edu)
Timely vineyard management:
Below are some considerations for cultural management of your vines at this early stage of the growing season:
- New vineyard plantings: Now through early June is when we need to get our new vineyard plantings completed. If dry weather persists, new vines should be irrigated. 1 and 2-yr-old vines should receive around 0.5” to 1” of water per week through rainfall and irrigation while root systems are being established.
- 2 and 3-yr-old vines: retain the 2-3 shoots required for continued trunk and/or cordon establishment and remove the remaining shoots from the trunk. Remove inflorescences (flower clusters) from the remaining shoots. The goal of these tasks is to encourgage robust vegetative growth of young vines.
- Mature vines: Shoot thin vines when shoots are between 6-12” in growth. For details on shoot thinning and suckering mature vines, visit our blog post from May 2022 and review our video on canopy management here. *Note: shoot thinning for vines that were adjusted for bud counts following winter injury is critical, as canopies will be denser with greater bud retention.
- The process of de-hilling soil around grafted vines should be completed to prevent scion rooting
Disease management
With the rapid rate of shoot growth along with the increase of average daily temperatures, it’s important to ensure your shoots stay protected against early season diseases, including Phomopsis, Anthracnose, Black Rot, Downy Mildew, and Powdery Mildew. Remember that disease management should be preventative beginning around 1” of shoot growth and combined with best canopy management practices.
For successful control, it’s important to understand the disease, cultivar susceptibility, and management options. There are several resources available for disease management such as the Midwest Fruit Pest Management Guide, Developing an Effective Fungicide Spray Program for Grapes in Ohio, and NY/PA Pest Management Guide. Fact sheets on important grape diseases can be found here. Read and follow all label guidelines and ensure proper fungicide rotation and sprayer coverage/calibration to reduce risks for fungicide resistance.
Vineyard insects
During the warm stretch of April, I was hearing from several growers about the prevalence of grape flea beetles in vineyards seen brazenly snacking on swollen buds. Adult beetle damage to newly developing buds can be economically damaging to yield if not adequately controlled. Flea beetles tend to be most concentrated along vineyard boarders in proximity to wood lines, so treatment may only need to be targeted in certain portions of the vineyard. Thresholds for spraying flea beetle have been suggested at 2 to 4% (or 2 to 4 injured buds per 100 buds checked), and broad-spectrum insecticides work well against flea beetles if necessary to use. Be aware that flea beetles go through one lifecycle per season and that their larvae can cause damage and skeletonization to leaves through June (though rarely in sufficient quantity to be considered economically important), and control of larvae may help reduce future populations of this insect.
Herbicide drift injury
Rapid shoot growth in vineyards generally coincides with planting time for row crops, and with that comes the risk for herbicide drift injury. The most effective way to reduce the risk for herbicide drift injury is to develop relationships with neighboring farmers and applicators and inform them about the proximity of your vineyard. However, drift injury may still happen, and it’s best to be prepared since drift events are sporadic and difficult to predict.
An early, subtle symptom of auxinic herbicide (2,4-D, dicamba, etc.) injury is shoot epinasty, which can be mistaken for other abiotic stresses like drought (Figure 4). Other symptoms including leaf cupping, curling, and chlorosis (leaf yellowing) may take additional time to develop and depend on the amount of herbicide exposure (Figure 5).
If you suspect your vineyard has experienced an herbicide drift event, document your evidence as soon as possible and consider taking action by contacting the Ohio Department of Agriculture to file a complaint.
Figure 4. Shoot epinasty, or the downward growth of shoot tips. 48-hrs following low-concentration herbicide exposure.
Figure 5. Leaf cupping patterns 48-hrs following high-concentration dicamba exposure.
By: Imed Dami and Maria Smith, HCS-OSU
Statewide frost events occurred on April 24-27 (Table 1). Early budding varieties had already broken buds or were at a more advanced shoot development, and thus sustained frost damage. At the OSU research vineyard in Wooster, temperatures in a shielded logger at 5ft high measured 32F on April 25 and 34F on April 27. However, when we measured the temperatures in proximity to the fruiting spurs, we recorded temperature between 27.5 °F and 30.2 °F, i.e., below freezing. As a result, frost injury was minimal, causing only burning of leaf margins (Figure 1).
Table 1. Ohio regional minimum temperatures (°F) from 25 April and 27 April. Weather data from CFAES Weather System and NEWA
|
Weather Station |
25 April min temps (°F) |
27 April min temps (°F) |
|
Ashtabula (Northeast) |
31.6 |
29.6 |
|
Avon Lake (North Central) |
32.5 |
30.9 |
|
Caldwell (Southeast) |
27.7 |
35.7 |
|
Cincinnati (Southwest) |
31.0 |
44.0 |
|
Columbus (Central) |
31.5 |
36.9 |
|
Fremont (Northwest) |
30.7 |
29.4 |
|
Piketon (Southcentral) |
25.5 |
35.7 |
|
Wooster (Northeast) |
26.1 |
27.2 |
Figure 1. Leaf margins burned after a frost event, bus the shoot is still alive (photo by Dami).
Factors affecting frost injury:
Phenological (developmental) stage: During deacclimation (March-April), grapevines become increasingly sensitive to temperature below freezing (32 oF) and critical temperatures (CT) vary with the stage of bud development. That is, buds become more sensitive as they grow in early spring. CT of buds or young shoots is defined as the air temperature that causes 50% damage after exposure for 30 minutes. The following is an example of CT of Pinot noir at different stages of bud/shoot development:
|
Stage of development |
Critical Temperature (CT) |
|
|
|
°F |
°C |
|
Dormant bud |
6.8 |
-14 |
|
Swollen bud stage |
25.9 |
-3.4 |
|
Bud burst (break) |
28.0 |
-2.2 |
|
First unfolded leaf |
28.4 |
-2.0 |
|
Second unfolded leaf |
28.9 |
-1.7 |
|
Fourth unfolded leaf |
29.8 |
-1.2 |
Weather conditions: CT also varies with weather conditions including air relative humidity and corresponding dew point. Dew point (DP) is the temperature at which water condenses out of the air as dew or the temperature that corresponds to 100% relative humidity. Condensation releases heat and slows the drop of air temperature. Thus, if DP is higher than CT, heat will be released before reaching damaging temperatures and may provide some protection. If the air is dry, DP is low and temperature will drop rapidly and may reach CT and thus cause more damage.
Early budding varieties are also more susceptible to spring frost. For example, Marquette, La Crescent, Concord, Chardonnay break buds early in Ohio and thus tend to be sensitive to spring frost. Late budding varieties such as Vidal rarely sustain frost damage. Further, varieties bear fruit on shoots originated from primary buds. Some bear fruit from secondary and base buds. Secondary and base buds of Vinifera and Native grapes are not as fruitful and thus may sustain more crop loss than Hybrids. Secondary buds may produce 30-50% of the crop potential. Tertiary buds typically are not fruitful regardless of variety.
Figure 2. Frosted shoot and new shoot emergence from spur base bud (Archive photo by Dami)
What to do after a frost event?
- First, do not give up! Grapevines have an amazing way of recovering and compensating for yield. Also, the percent of damage does not equate the percent of crop loss.
- Whether the damage is severe or not, you should not discontinue your disease and insect management program. You need to keep the vine canopy healthy.
- Fertilization: if the damage is severe and only fruitless shoots recovered, this situation may lead to excessive shoot growth and vigor. You should avoid nitrogen fertilization. If the damage is minimum and a normal crop is expected, continue a normal fertilizer program. If you practice split application of nitrogen (N), skip the first one and then, based on the fruit to shoot growth, decide whether to apply the post-fruit set N application.
- Canopy management: due to excessive foliage and resulting shading you may need to be more aggressive with your canopy management practices. This practice will vary with the level of frost damage and variety. Like any other vineyard operation, it comes down to practice cost and the “well-being” of the grapevine. Sometime, the two factors do not go together. It is up to the grower to decide which way to proceed. Since there are many scenarios to consider that are dependent on the type of frost damage (partial or complete) and variety.
- Provided below are two specific examples of canopy management based on reported research in Indiana and California.
- Our colleague, Dr. Bruce Bordelon at Purdue University, conducted a trial to manage several hybrids after a frost event that caused partial frost damage. Damaged shoots were either pruned (shoot or spur) or left intact (untreated control). With Marquette, pruning damaged shoots resulted in increased yield and better cane quality (size) the following year.
- Glenn McGourty, past OGWC speaker and viticulturist at UC Davis, conducted a similar trial with Chardonnay. He also found that removal of damaged shoots resulted in higher yield. Fruit ripening was delayed, but fruit quality was unaffected. In both situations, there was added labor to remove damaged shoots (20 to 30 hrs/acre). However, the extra cost in the year of frost damage was justified with less labor for pruning the following season and better cane quality. Basically, a severe frost year was a good year to “clean up” old cordons for new spur development. If you have a specific situation and undecided how to proceed, please do not hesitate to contact me.
- Disaster Assistance: Contact your local USDA-FSA (Farm Service Agency) and report your crop loss. It is important that you record the extent of damage you have, in case some assistance program becomes available.
By: Maria Smith, HCS-OSU
It sure does feel like March Madness, especially with the recent arrival of Ohio’s infamous “second winter”. Thankfully, the cooldown from February’s warm, spring-inspired weather will help us keep the vines asleep a little bit longer. This cooldown should help us complete this most important dormant-season activity: pruning. As a follow up to last week's pruning workshop, let’s go down the reminders of when, what, and whys of pruning.
Why prune?
In young vines (< 3yo), pruning is intended to build the vine to conform to the intended training system. This means, selecting healthy wood for trunk and/or cordon establishment.
For mature vines (>3 yo), the main goal of pruning is to adjust the vine size and yield potential to produce a healthy crop in the upcoming season (i.e., create a balanced vine). For new grape growers, this seems dramatic, but in “normal” years, this means removing more than 90% of the 1 yo wood that is on the vine (Fig 1).
Figure 1. Vine before pruning (left) and after pruning (right). High wire, bilateral cordon-trained Vitis hybrid.
What to prune? Or how many buds to retain?
Normally, we suggest a method called “balanced pruning”, or retaining bud numbers according to vine size based on the pruning weight of 1-year-old canes.
Table 1. Balanced pruning formulas for different grape types. Adapted from Midwest Grape Production Guide. The formula follows the number of buds to leave for the 1 lb of pruning weight + the number for each additional lb of pruning weight.
|
Grape Type |
Pruning Formula |
Cluster Thinning |
|
American |
30 + 10 |
No |
|
French Hybrids |
20 + 10 |
Yes |
|
New Hybrids |
20 + 20 |
No |
|
Seedless Table |
30 + 10 |
Yes |
|
Vinifera |
20 + 20 |
Yes / No |
A general rule of thumb: this should equate to approximately 4-6 buds per foot of vine spacing (e.g., if the vine spacing is 5-8’, retain 20-50 buds per vine). *Note, buds on hybrid and Vinifera wine grape varieties are typically more fruitful on the basal nodes. Therefore, when retaining buds, it is often best to leave more 2-3 bud spurs instead of fewer, longer spurs. This is not the case with Concord, Niagara, and other American varieties where the most fruitful buds are nodes 3-6.
But winter 2022-2023 wasn’t “normal”. The Christmas Eve polar vortex may have caused significant bud injury to your vines, especially in the most cold-sensitive varieties or in the colder locations in the state (see: Pre-Christmas Freeze and Impact on Grapevines). In Ohio where we have a propensity for winter injury, it’s important to check your bud injury and adjust pruning accordingly to maintain cropping levels (Fig. 2, Table 2). At Wooster, we assess bud injury as a % of 100 buds (10-bud canes). This is performed by variety.
Figure 2. Assessing bud mortality by cross-sectioning buds using a sharp razor blade. Notice the alive (left) vs. dead (right) status of the primary buds in the figure above.
Table 2: Adjusted pruning based on % bud mortality.
|
% Primary bud injury |
Adjustment |
|
0 to 14% |
No adjustment needed |
|
15 to 34% |
Retain an extra 35% buds |
|
35 to 50% |
Retain an extra 50% buds |
|
>50% |
Minimal prune to 5-bud spurs |
|
80 to 100% |
Likely trunk damage, renew trunk by retraining suckers |
Why minimal prune? Yes, it’s a pain to shoot thin, but what we have noticed is that hedge pruning can aid in maintaining yield levels despite extensive (70-80%) primary bud injury. We have observed in the past that the rates of bud injury tend to be higher on node positions in the middle and end of canes vs. towards the base of canes. This means that buds retained from minimal hedge-styled pruning tend to be more alive than leaving more buds through cane pruning modifications (e.g., double-wrapping canes, quad-cane pruning).
Wood quality. Healthy, sun-exposed, reddish-brown wood that is approximately ¼ to ½” in diameter is optimal (think: Sharpie™, Pencil, Pen; Figure 3). This wood will contain buds with better cold hardiness, higher fruitfulness, and have the carbohydrate availability to support the development of 2-3 shoots. AVOID: bull wood (large, vegetive wood > ½” in diameter) and weak (< ¼” diameter).
Figure 3. Healthy, optimal wood selection for spurs and trunk and cordon training
When to prune? We acknowledge that larger vineyards are time-constrained and likely begin pruning earlier in the winter. However, if possible, small vineyards should wait as long as possible into spring. This is to allow compensation in case of winter injury, but can also help stave off early bud break by suppressing the development of the most basal buds on the cane (explained in our 2019 OGEN article: Grapevine Dormant Pruning). If waiting is not possible, begin with the most cold hardy varieties first, then proceed to the most cold sensitive varieties last (note* If you’re growing cold hardy MN hybrids, prioritize the later breaking varieties like Frontenac to prune first and prune the most early bud break varieties prone to spring freeze like Marquette and La Crescent last).
Pruning should be completed by the beginning of bud swell. Although bud break timing depends on numerous factors, we typically see signs of bud swell in mid to late-April in Wooster (may be 2-3 weeks different in southern and northern parts of Ohio). If you are double or delayed pruning as a spring frost avoidance strategy, final pruning needs to be completed no later than 1” in apical shoot growth. This is to avoid potential yield losses associated with basal bud break delays.
The Wine Production Guide from Todd Steiner in collaboration between OSU and OGIC is now available for purchase through OSU Extension.
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Order Today: At $51.50 for a printed publication and $33.50 for a PDF version, this publication is a great investment to learn about wine production and includes a digital cash flow spreadsheet that can be customized with the specifics of anyone looking to start and operate a successful winery. Visit extensionpubs.osu.edu to view sample pages. If you work at a state Extension office ask about our partner pricing.
***All current Ohio A2 permit holders can receive a complementary print copy through The Ohio Grape Industries Committee (OGIC). Also, all commercial Ohio A2 permit holders receive access to a free digital (PDF) version through their OGIC industry login***
Learn More: Looking for more resources on grape production, visit The Ohio State University Department of Horticulture and Crop Science at hcs.osu.edu; Buckeye Appellation at go.osu.edu/grapes; or search for “grapes” at OSU Extension’s Ohioline at ohioline.osu.edu.
By: Imed Dami, HCS-OSU
On December 23-24, Ohio experienced the coldest temperatures of the year 2022. Temperature lows ranged between 3F and -13F (see map). Statewide, the lowest temperatures occurred in West central Ohio and ranged between -9 F and -13F. In central Ohio, minimum temperatures ranged between -5F and -10F. In southwest, temperature dropped to -7F to -12F. In southeast, 3F to -6F were recorded. In Northwest, temperatures ranged between -3F and -11F. Northeast (majority of vinifera grape acreage) experienced the mildest temperatures ranging between -2F and -6F. At our research vineyard in Wooster, we recorded -7F on December 23, 2022.
To have a preliminary assessment of cold injury, we collected canes from our most cold sensitive vinifera varieties. We also collected a cold hardy hybrid, Frontenac blanc for comparison. Our findings were disappointing with higher-than-expected cold damage across the board. Table 1 summarizes cold injury of primary and secondary buds from 8 varieties. In vinifera primary bud injury ranged between 87% and 100%. Frontenac blanc sustained only 5% primary bud injury. Our results suggest that cold damage of vinifera varieties could be more severe than expected across the state. Hybrids (with LT50 of -13F or lower) should have minimum to no injury from this cold event.
The extensive cold damage of vinifera varieties is puzzling. In late November, buds showed a good level of cold hardiness. For example, Chardonnay had LT50 = -7.7F. In December, low temperature of -7F was recorded in that vineyard in Wooster. So, at that temperature, we should have 50% or more bud survival. But, that was not the case and we had 10% primary bud survival (see Table 1). One way to explain this discrepancy is that vines lost cold hardiness in December. This is possible since we had a mild December with mean temperature 3F above the 30-year average (Figure 2).
We still have a few weeks to go with winter weather and potential damaging temperatures are still possible. Growers should be mindful of that and bud assessment, before pruning, is recommended. Pruning adjustment is definitely needed this year.
Figure 1. Minimum temperatures on December 23-24, 2022. Note that minimum temperatures ranged between 3F and -13F. Source: Dr. Aaron Wilson, OSU state climatologist.
Table 1. Bud injury of 8 grape varieties exposed to -7F on December 23, 2022. Wooster, OH.
|
Species |
Variety |
Clone |
Primary bud injury (%) |
Secondary bud injury (%) |
|
V. vinifera |
Arneis |
FPS 01 |
100 |
100 |
|
|
Cabernet franc |
FPS 11 |
90 |
82 |
|
|
Chardonnay |
FPS 37 |
90 |
50 |
|
|
Dolcetto |
FPS 02 |
100 |
100 |
|
|
Malvasia |
FPS 03 |
100 |
100 |
|
|
Sauvignon blanc |
FPS 27 |
87 |
67 |
|
|
|
|
|
|
|
Hybrids |
Frontenac blanc |
|
5 |
2 |
|
|
Regent |
|
94 |
67 |
Figure 2. Monthly mean temperature deviation from the 30-year average in 2022 in Wooster. Bars above 0F means temperature was above the 30-year average. Bars below 0F means temperature was below the 30-year average.
By: Imed Dami and Diane Kinney, HCS-OSU
This article summarizes the 2022 dormant and growing seasons and the impact of weather on grape varieties grown on the research vineyard at the OSU-OARDC in Wooster, Ohio.
Weather: Temperature
The Wooster weather through the month of November has been nearly identical as 2021 with the averages being within 2 degrees each month. Once again, our winter low was within the tolerance level for all of our grape varieties, which had achieved maximum cold hardiness despite the fact we had a mild December when our lowest recorded temperature of -4.4 o F occurred on January 22nd. Although our average temperatures for March and April were on track, we had a wide swing hitting 70+ oF a couple of days in early March, as well as lows of 11 oF later in the month. These low temperatures held off bud break due to low GDD’s. The last week of April the temperatures finally warmed and induced bud break. Although many areas of the state were hit hard by a spring frost, in Wooster, damaging temperatures were avoided due to limited or no bud break of most varieties. The early ripening period during August and September remained largely on pace with not only 2021 but our 30 year-long term average while temperature dropped in October averaging 51 oF in comparison to 60 oF in 2021. Our first hard freeze occurred on November 17th resulting in a growing season length of 201 frost-free-days.
Weather: GDD
We were very slow to gain GDD’s this year only hitting 100 in the later part of April but May roared ahead gaining over 300 GDD’s during the month putting us ahead of both 2021 and the long-term average. We then settled down into normal gains until October were things just abruptly stopped, including fruit ripening. Cumulatively, that averages out overtime, but we were well below our 2021 number of 3283 vs 3104 (thru November) in 2022.
Weather: Precipitation
2021 ended the year with a total cumulative rainfall of only 30.99”. We exceeded that amount in August of 2022. By the end of November, we have recorded 39.62” which is 10” over the long-term average. This is a change over the past 4 years where rainfall declined each year over the long term. 2022 has been very wet keeping us above the long-term averages every month up until October.
Vineyard Notes:
2022 Spring freeze injury: In Wooster we were fortunate to avoid a spring freeze event which wreaked havoc on a majority of the state the end of April. We would have likely faired a bit better as our buds were in early developmental stages at this point versus southern regions of the state.
Diseases and insects: Regular cover sprays were a must as we had consistent rains which resulted in sour rot. Other diseases such as botrytis, downy mildew were seen in smaller amounts which caused minimal damage in our vineyard. Our typical bird and other wildlife pressure was low while yellow jackets caused a fair amount of damage thereby helping encourage the spread of sour rot.
Fruit quality: Sour rot caused a real challenge in fruit quality. Our first harvest occurred on August 17th for Brianna and our final harvest occurred on October 25th for Chambourcin. Overall, fruit maturity was not as ideal as in 2021. In 2022, we recorded lower pH and higher TA as compared to 2021.
Table: 2022 Harvest fruit composition of selected grape varieties at the Wooster research vineyard:
|
Variety |
Harvest Date |
100 Berry wt (g) |
SS (%) |
pH |
T.A. (g/L) |
FMI |
|
Brianna |
17-Aug |
268 |
17.1 |
3.00 |
8.9 |
19 |
|
Cabernet franc |
11-Oct |
141 |
20.9 |
3.13 |
8.1 |
26 |
|
Chambourcin |
25-Oct |
232 |
22.0 |
3.20 |
11.4 |
19 |
|
Chardonnay |
27-Sep |
186 |
21.2 |
3.14 |
8.5 |
25 |
|
Crimson Pearl |
21-Sep |
206 |
20.7 |
3.35 |
8.4 |
25 |
|
Einset |
31-Aug |
252 |
19.3 |
3.12 |
5.4 |
36 |
|
Frontenac |
21-Sep |
120 |
22.0 |
3.24 |
16.3 |
14 |
|
Frontenac blanc |
21-Sep |
125 |
23.7 |
3.11 |
14.7 |
16 |
|
Itasca |
7-Sep |
152 |
22.9 |
3.50 |
8.6 |
27 |
|
La Crescent |
22-Sep |
138 |
20.9 |
3.02 |
15.1 |
14 |
|
Marquette |
14-Sep |
142 |
21.6 |
2.87 |
13.3 |
17 |
|
Marquis |
9-Sep |
502 |
13.9 |
2.88 |
5.1 |
27 |
|
Regent |
15-Sep |
251 |
19.8 |
3.07 |
7.2 |
28 |
|
Sauvignon blanc 27 |
29-Sep |
203 |
20.5 |
3.09 |
9.0 |
23 |
|
Vanessa |
1-Sep |
274 |
18.0 |
3.21 |
4.8 |
37 |
By: Doug Jackson-Smith, SENR OSU
The Ohio Grape Industries Committee (OGIC) recently asked researchers at the Ohio State University (OSU) to carry out a full census survey of growers who grew grapes in Ohio in 2021. This report was designed to capture the acres and estimated production of various grape varieties in Ohio, and updates a report last issued by the USDA in 2017. The survey was completed by 148 farms (an 83% response rate), and documents 112 varieties raised on 1,222 acres across 55 counties (including 95 acres of newly planted vines). The results are interesting and can help grape growers and processors plan for the future. To see a copy of the full report in PDF – click here. A copy of this report and the technical appendix will be hosted under the Grape Growers tab of the Buckeye Appellation website. Questions regarding the survey and results can be directed towards Doug Jackson-Smith at jackson-smith.1@osu.edu.
By: Tom deHaas, AGNR Extension Educator Erie County, intro by Maria Smith, HCS-OSU
The following are republished updates from Tom deHaas on scouting and treatment efforts for the invasive Spotted Lanternfly (SLF) in northeast Ohio from June through August 2022. Currently, SLF infestations have been identified in 3 Ohio counties: Lorain, Cuyahoga, and Jefferson (Fig 1). However, individual SLFs have been found in other Ohio counties, and SLF infestations have been identified in Indiana and Michigan. Our collective goal continues to be limiting spread and minimizing population sizes by immediately reporting any suspected finds to the Ohio Department of Agriculture.
Fig 1. Distribution of SLF updated August 24, 2022. Image from New York State IPM
You'll see a recurring theme in this post, and it's SCOUT! SLF's appearance is most easily identifiable now that we are entering the time of year when SLF adults are emerging. In general, SLF are being found first on its main host, Ailanthus altissima (tree-of-heaven), but in some areas, as reported by Tom below, are also being found in grapes. Because of SLF's high affinity for grapes, it's important to add SLF into your routine vineyard scouting, since many Ohio vineyards are near rail corridors that may carry SLF and receive visitors from areas with known infestations. To aid scouting efforts ODA has provided a downloadable PDF checklist of common items to inspect, especially if those items are coming from or going to counties with infestations. If you have further questions on the information provided below, please feel free to reach out to Tom deHaas at dehaas.2@osu.edu.
--
Scouting and Spraying for Spotted Lanternfly in late June 2022 (Jul 6, 2022)
Multiple partners from Ohio Department of Agriculture, United States Department of Agriculture-Division of Forestry, The Ohio State University, Cleveland Metroparks, and USDA – APHIS (Animal and Plant Health Inspection Service) assemble to scout for Spotted Lanternfly in potentially infested areas in and around Cleveland – Cuyahoga County including Mill Creek Metropark, Paramelt, and St Joseph Cemetery. Additionally, and area in Amherst located in Lorain County was inspected and sprayed.
The group assembled on Tuesday, June 28th and 29th. Agency participation included from ODA, Dave Adkins and Scott Chelsa, USDA Division of Forestry Zoe Crist, Joe Ball, Ivich Fraser, and Taylor Dawes, USDA-Aphis Avi Eitam and Mark Hitchcox, Cleveland Metroparks Connie Hausman and Sarah Eysenbach, The Ohio State University Jim Jasinski, Ashley Leach, and Thomas deHaas. Scouting occurred on Tuesday and Wednesday.
The group surveyed Mill Creek Park on Tuesday morning. Visual inspections and trapping were used. A small number of 2nd instar nymphs were found at the site.
Next some of the group inspected Paramelt, a processing plant near West 117 in Cleveland. A number of nymphs were discovered including several 4th instar nymphs. Most numphs were found feeding on Tree of Heaven, but some were found on grapevines. Honeydew was present on several grape leaves
Next Saint Joseph Cemetery on the near east side of Cleveland was searched. A large population of nymphs was detected. The majority were found feeding on Tree of Heaven. They seemed to congregate in groups on the central leader as well as on the midvein of the leaves.
Finally, Amherst was scouted, and several nymphs were detected,
The sites at Paramelt, St Joseph and Amherst were all sprayed to help control the spread.
Please continue to look for Spotted Lanternfly and contact Ohio Department of Agriculture if you detect it. Remember to take a picture and mark the location.
The following is a short video showing scouting and spraying:
https://www.youtube.com/watch?v=W3FhyJulLHU
We need your help. Keep Scouting!!!
--
City of Cleveland trains staff to scout for Spotted Lanternfly (Aug 11, 2022)
Cleveland Urban Forestry, Cleveland Division of Park Maintenance, Cleveland Metroparks, and The Ohio State University Extension Team Up to Teach employees to ‘SPOT’ Spotted Lanternfly.
Field Operation Forman, Arborists, Park Maintenance Staff, Unit Leaders and Managers from Cleveland spent Thursday afternoon, learning how to scout for Spotted Lanternfly at an active infestation at Mohican Park in Cleveland.
Jennifer Kipp-Cleveland Urban Forestry, Perrin Verzi-Cleveland Division of Park Maintenance, Connie Hausman and Megan Powell-Cleveland Metroparks, and Thomas deHaas-The Ohio State University Extension, led a tour of the infestation. Over 20 staff attended which is a credit to the leadership of the group.
Staff saw up close Adults and 4th instar nymphs on Tree of Heaven and on Grapevines and were able to see where they were feeding.
The goal was to teach how to scout and identify Spotted Lanternfly and favored host plants.
The insect will not bite but has been known to negatively impact vineyards in Pennsylvania.
Staff was provided ID cards with a QR code to send reports to the Ohio Department of Agriculture.
Many scouts will help identify locations of infestations.
SCOUT!
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Treating Spotted Lanternfly in Cleveland (Aug 25, 2022)
Ohio Department of Agriculture sprayed an infestation of Spotted Lanternfly on the West Side of Cleveland at Mohican Park.
An infestation was detected several weeks ago and the City of Cleveland – Division of Forestry, granted permission to spray the invasive pest.
Several hot spots were detected and treated to help control the spread of Spotted Lanternfly.
Scouting for the pest continues with help from the Ohio Department of Agriculture, Cleveland Metroparks, City of Cleveland, and The Ohio State University Extension.
Adults were found on Tree of Heaven and on Wild Grape vines. The pest continues to spread and threatens grape growers and orchards.
The insect will not hurt people but sucks the life out of fruit trees and vines.
Continue to look for the insect and report findings to ODA at 614-728-6400.
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By: Imed Dami, HCS-OSU
In early June, members of the OSU Grape Team, Andy Kirk, AARS manager and Andrew Holden, Extension educator, visited vineyards in Lake and Ashtabula counties (NE-OH) and reported extensive cold injury ranging from bud to trunk injury (Figure 1). The cold events (temperature in low to high-20s) at the end of April were initially to blame. Even though these temperatures are lethal to young emerging shoots as it was observed in central and southern Ohio, this was not the case in northern Ohio since most buds were still closed. Therefore, we suspect that previous and successive cold events since January through March were the culprit for the extensive damage. The warm spells in late February and early March accelerated the timing and magnitude of deacclimation (loss of cold hardiness). Figure 2 shows the minimum temperatures in January that ranged between 0 and -11F. I doubt those temperatures had caused extensive damage in most varieties (except the most tender vinifera). So the extensive damage is unlikely from the January events. Figure 4 shows the lowest temperatures in late April that occurred mostly in NE-OH. Those temperatures may be lethal to early bud-breaking varieties, but most varieties did not break buds yet in late April. Figure 3 shows the lowest temperatures in March that ranged between 13.6 and 20.6F. Those temperatures likely caused the extensive damage. Figure 5 shows daily minimum and maximum temperatures of 2021 and 2022 at the AARS in Kingsville. Note warmer February in 2022 than 2021, and peaks of maximum temperatures (70s) in mid-March followed by sudden drop to 15.2F then 18.3F at the end of the month. Even though we don’t know the level of deacclimation in each variety, the low temperatures in the mid-teens were likely lethal. Furthermore, there was a large swing of temperature from 85.3F on April 24th to 28.2F on April 29th, which could have been damaging to buds in the early stages of development. Maria Smith and Andy Kirk also observed more damage in low lying vineyards and those with southern aspects (exposure), which tend to intensify deacclimation (due to excess heat accumulation) and hence exacerbate cold damage.
Regardless of the origin of the damaging cold events, vines sustained shoot damage, bud damage, or damage to the vascular tissues (cane, cordon, trunk). The following section describes the steps to take to address each type of cold damage.
Managing cold damage of frosted shoots: recommendations for managing the vineyard in the event of frost damage can be found in the APRIL 2020 OGEN.
Managing trunk damage: It is an ideal time now to assess trunk damage. The abundance of sucker growth is an indication of trunk damage. In 2014-2015, we experienced one of the worst cold damages to vineyards across Ohio. We conducted several trials to determine the best management practices after cold injury. The following are highlight of our findings and recommendations:
- Train all suckers (Figure 6) produced by each vine. Do not keep 2 suckers per vine as this would promote bull growth in mature vines which is undesirable.
- Fan training (Figure 7): suckers can be trained vertically and onto a fan shape. Shoots can be kept straight by tucking them between the catch wires. This training promotes good exposure of shoots to sunlight and good penetration of fungicides. Labor is also minimized with this training as vines do the training by themselves.
- Dead trunks and cordons can be removed with loppers during this season. Cut back trunks to 6-8” stumps to avoid fungal disease infection caused by Eutypa and other pathogens. Stumps can be removed later in the summer.
- No need to train shoots to horizontal position to establish cordons for next season. It is best to save this job for next season when pruning.
- Next year when pruning, you could select the best two canes as your new trunks. These canes will have medium size diameter, fully hardened-off, and disease-free. Remove bull canes. The optimum-sized canes can be laid down on the fruiting wires to establish the new cordons. Once laid down, cut back each cane to about 24” (or 10-12 buds, whichever is the shortest) in each side. This practice would avoid apical dominance growth.
Finally, make sure you contact your local FSA representative and report damage. You need to document the damage. In 2014, we developed a factsheet that shows different types of vine damage. Please visit this link Assessing cold damage in early summer to read or download. It is also used by FSA reps to assess freeze damage.
As always, please do not hesitate to contact our Grape Team (Gary Gao, Andy Kirk, Maria Smith and Imed Dami) if you have any questions regarding managing vines after cold damage.
Figure 1. Cold damage of Cabernet franc grapevine grown in NE-OH. Note growth of suckers at the vine base. Photo by: Maria Smith.
January 2022 Minimums
Figure 2. Minimum temperatures in January 2022 and corresponding dates of occurrence in parentheses. Note that minimum temperatures ranged between 0 and -11F with lowest in northern Ohio (west to east). Source: Dr. Aaron Wilson, OSU state climatologist.
Figure 3. Minimum temperatures in late March 2022 and corresponding dates of occurrence in parentheses. Note that minimum temperatures ranged between 13.6 and 20.6F with lowest in NE-OH. Source: Dr. Aaron Wilson, OSU state climatologist.
Figure 4. Minimum temperatures in late April 2022 and corresponding dates of occurrence in parentheses. Note that minimum temperatures ranged between 24.7 and 34F with lowest in NE-OH. Source: Dr. Aaron Wilson, OSU state climatologist.
Figure 5. Daily minimum and maximum temperatures in 2021 and 2022 at the AARS in Kingsville.
Figure 6. Sucker growth is an indication of trunk injury. Keep all suckers when retraining new trunks for following season.
Figure 7. Suckers of Cabernet franc trained on fan shape system during summer after trunk cold injury.
By: Maria Smith, HCS-OSU
This past week, I have received several questions on when, where, and what to shoot thin (ST), so now is the perfect time to highlight the importance of this practice. In 2017, I co-authored an in-depth article on shoot thinning with Dr. Michela Centinari at Penn State that can be used as a cited companion resource to this blog post.
Shoot thinning is the first important canopy management practice following dormant pruning, especially throughout Ohio and the Eastern US where high humidity, temperatures, and precipitation pose significant challenges to vigor control and disease management. This practice reduces the density of the canopy through the selective removal of excess shoots, in turn opening the canopy to increased sunlight exposure and airflow. The main benefits of ST include:
- Reduce excess yield and decrease fruit shading, thus improving fruit composition at harvest
- Improved winter bud cold hardiness through increased sunlight exposure during bud development
- Lower disease pressure due to a less humid, faster drying canopy environment and, again, more sunlight penetration through the canopy
Timing ST:
ST is best performed when shoots are between approximately 6-12” in length and, if possible, following the last date of frost. However, as Hickey, 2021 noted, constraints for timing ST may be dependent on labor availability. Also, hybrid varieties can be thinned before Vinifera due to the highly fruitful nature of secondary and latent/basal buds in the event of a spring frost. Very early ST (< 4”) can reduce the practice benefits by inducing emergence of secondary and latent buds, while late ST (> 12”) can be difficult due to the lignification of the shoot base. Late thinning should be performed using pruning shears to reduce injury to the vine.
As of this week (5/16/22), we are approaching the start of the window for shoot thinning at Unit 2 in Wooster (Fig 1).
Fig 1. Shoot growth at E-L stage 12 on 5/14/22 on Marquette. At this stage, shoots are about 5 leaves unfolded and 4” in growth.
Density of shoots:
For the sake of speed, keep in mind that these are estimates and visual inspections are sufficient as you are thinning. Only in academia will we stand around precisely counting shoots!
- Vinifera: 3 to 5 shoots per foot of cordon (= 18 to 30 shoots per vine at 6’ spacing)
- Hybrids: 4 to 6 shoots per foot of cordon (= 24 to 36 shoots per vine at 6’ spacing)
- Native or Labrusca varieties: up to 15 shoots per foot of cordon (= up to 90 shoots per vine at 6’ spacing)
As Dr. Patty Skinkis mentioned at the OGWC in February, spur vs. cane pruning tends to shift labor demands in the vineyard: spur pruning, while quicker to perform during dormancy, often requires more labor for ST than cane pruning. This is because spurs from older cordons tend to produce latent shoots that require removal, while cane pruning will typically produce one, or occasionally two shoots depending on secondary bud break, at each node position along the cane (Fig 2, Fig 3).
Fig 2. Shoot density of 2-bud spur (left) vs. canes (right). Note: increased density often arises from latent buds of older cordon wood or on vines with excessive bud retention in spur-pruned vines. Photos from Unit 2, Wooster. 5/14/22
Fig 3. Ideal shoot density, representing approximately 4 shoots per 1’ of space in V. vinifera Chardonnay. Photo from Unit 2, Wooster. 5/14/22
What shoots to keep/remove?
In a spur-pruned vine, the fruitful primary shoots from count nodes 1-2 on each spur should be prioritized (Fig 4). If a spur is becoming stacked, one well-positioned healthy shoot closer to the cordon may be prioritized for spur renewal. Fruitless basal and latent, diseased, weak-growing, and poorly positioned shoots should be the first to go, especially in highly dense portions of the canopy (Fig 5).
Lastly, unless retaining a shoot for potential cordon or trunk renewal, vine trunks should be suckered to prevent dense growth from shading the fruitful shoots (Fig 6). This can be accomplished easily at the 6-12” shoot growth stage by simply running a hand down the trunk of the vine to remove excess shoots.
Fig 4. Shoot emergence on a 3-bud spur on V. vinifera Cabernet Franc. 5/14/22, Unit 2, Wooster. Note: shoots that emerge on “non-count” buds are often fruitless in Vinifera and can be thinned. Fruitful shoots from nodes 1 and 2 should be prioritized for retention due to proximity to the cordon.
Fig 5. Example of a weak, fruitless latent shoot that should be removed during thinning
Fig 6. Example of a vine with dense growth on the trunk that requires suckering to remove the excess shoots and prevent canopy shading. 5/14/22, Unit 2, Wooster