COVID-19 business resources, green tip approaching in VT orchards

By Terence Bradshaw

First, UVM Extension Farm Viability Program has posted a page of resources for farm businesses related to emergency loans, grants, and other updates from state agencies: http://blog.uvm.edu/farmvia/?p=1805. Of particular interest to the framing community is the Paycheck Protection Program which provides low-interest, forgiveable loans to small businesses to cover payroll, mortgage interest, rent, and utilities. The direct link to that program is: https://www.sba.gov/funding-programs/loans/coronavirus-relief-options/paycheck-protection-program-ppp.

In walking the orchards at the UVM Hort Farm yesterday, I saw a lot of swollen, delayed-dormant buds, but only none yet at silver tip. Given the warm weather expected next week, I would expect to see at least some cultivars reach green tip in the next seven days. If you have green tissue on your farm already, please send me a note to let me know. Thus begins the disease management season.

If you’re still pruning, you should wrap up what you can and get your brush pushed to make room for sprayer access. I am a believer in using copper at green tip for disease management. The timing of this spray is very important- too soon (no green tissue showing) and you risk ‘wasting’ some of the effectiveness of the material against apple scab when susceptible tissue isn’t present. Too late (beyond ½” green tip) and you risk fruit russeting, which can be quite severe. Given that, it’s better to err a bit on the early side, but you should have green tissue showing in the orchard before applying. Copper applied at green tip will give about seven days’ protection against apple scab.

Copper’s primary benefit is in reducing overwintering populations of fire blight bacteria. Even though we saqw minimal amounts of this disease last year, fire blight has become a regular disease to manage in Vermont, and a multi-pronged approach will be needed to keep it at bay. Copper should be applied to all trees in the orchard, not just susceptible varieties, and in as dilute a spray as possible. The specific copper material is less critical than the amount of metallic copper that is applied in the spray, and copper sulfate, copper hydroxide, copper oxychloride sulfate products all will be effective when used at label rates. A good primer on spring copper applications to pome fruit by Dr. David Rosenberger can be found in the March 28, 2011 issue of Scaffolds. Addition of one quart oil per 100 gallons can help improve penetration into bark crevasses where fire blight may reside. However, this could be a good time to apply a full oil spray to manage overwintering mites, and a 2% solution is recommended at this timing. Oil and copper products are compatible for tank mixing at this time of the year, but likelihood of phytotoxicity increases as more green tissue emerges. One benefit of applying oil in your first spray is that it allows more time for it to degrade or wash off before incompatible fungicides such as Captan and sulfur may be used as primary scab season ramps up. Avoid the oil if you’re within a few days (before or after the spray) of a frost to reduce chances of damage to tree tissues.

Now that the ground is clear and firming up, it also would be a good idea to perform spring orchard sanitation to reduce overwintering scab inoculum. Leaf shredding with a flail mower is an effective practice that also may be used to reduce small pruning wood to mulch, but the mower must be kept low in order to lift and grind leaves that harbor overwintering inoculum. Alternatively, there is still time to apply urea (40 lbs/100 gal water/acre) to leaf litter which aids in decomposition and breakdown of inoculum. Leaves should be wetted thoroughly and the majority of material directed into the tree row.

Good luck with the beginning of the season and please reach out if you need anything.

-Terry

Where trade names or commercial products are used for identification,

no discrimination is intended and no endorsement is implied.

Always read the label before using any pesticide.

The label is the legal document for the product use.

Disregard any information in this message if it is in conflict with the

label.

The UVM Tree Fruit and Viticulture Program is supported by the

University of Vermont Agriculture Experiment Station, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

Pre bud break vineyard management; COVID-19 farm business resources

By Terence Bradshaw

First, UVM Extension Farm Viability Program has posted a page of resources for farm businesses related to emergency loans, grants, and other updates from state agencies: http://blog.uvm.edu/farmvia/?p=1805. Of particular interest to the framing community is the Paycheck Protection Program which provides low-interest, forgiveable loans to small businesses to cover payroll, mortgage interest, rent, and utilities. The direct link to that program is: https://www.sba.gov/funding-programs/loans/coronavirus-relief-options/paycheck-protection-program-ppp.

In the vineyard, things are holding tight now but reports from the Hudson Valley suggest an early bud break. Dr. Jim Myers continues to run his bud hardiness model, which for our region, shows vines beginning to deacclimate about 7-10 days earlier than normal. Does that mean budbreak will be 7-10 days early? Maybe, but not guaranteed. But this is a suggestion that we should get things in order for the season to begin before we know it. For those who follow this list, the rest of this message is an updated copy from this time last year- the early season details are pretty much the same year-to-year:

After a long winter, spring is here and bud break is approaching. Plan on wrapping up pruning in the coming weeks and removing brush from the rive alleys to the burn pile (and burn it, too, to reduce overwintering insects and disease inoculum). This is a good time to review your previous season’s spray records and to identify any gaps that may have led to disease issues. We have updated two disease management documents in 2017 for Vermont and area grape growers: a table of relative disease susceptibility of cold-climate cultivars and an initial IPM strategy for cold climate winegrapes. More information on general viticulture and other small fruit production can be found in the 2019 New England Small Fruit Management Guide , and the 2020 New York and Pennsylvania Pest Management Guidelines for Grapes are now available and should be used in combination with specific pesticide labels to select pesticide materials for use in your IPM program.

One pesticide spray that is often considered by growers is a late dormant application of lime sulfur (LS) which aids in inoculum reduction against many diseases, especially phomopsis and anthracnose. Growers who have had more than a passing amount of either of those diseases, especially organic growers with more limited choice of materials during the growing season may consider applying this practice, but I make that recommendation with several caveats. While LS is an organically-approved pesticide, it is one of the most acutely toxic materials I have ever used, and demands special considerations for its use. It is also a restricted-used spray material, so unlicensed applicators may not purchase or apply it. LS (active ingredient calcium polysulfide) is very caustic; spray mixtures tend to have pH around 10-11, and that characteristic is what gives it its sanitizing effect as a biocide. Contact with skin or especially eyes must be avoided, and it is pretty noxious even when smelled through a respirator. This material demands respect. While those effects will dissipate in the field after sufficient washoff and degradation by rain and other elements, I would only plan on applying after pruning is finished so not to muck around in it after application. In fact, very thorough pruning out of all dead and diseased wood is an important cultural disease control practice, and if you have a lot of such wood left in the vineyard, spraying your way around pruning it out won’t help.

LS is typically labeled for application at "15-20 gallons per acre in sufficient water for coverage" (Miller Liquid Lime Sulfur). That is a very high amount of LS, and would be difficult to apply and very costly when applied to large acreages. The key is to fully soak all woody tissues in the vineyard. This may mean aiming all nozzles at the cordons, but that would leave the trunks uncovered. Alternatively, the sprayer could be operated to cover the whole zone from the fruiting wire down, which would waste a tremendous amount of spray. The best application may come from a careful handgun application, which will take a long time and should be done with full protective gear including heavy nitrile gloves, full face shield and respirator, and Tyvek or other chemical-resistant, disposable coveralls. It is hard to say how much you would apply per acre in a directed spray, since that would be much more efficient with less wasted spray than an airblast application. My suggestion would be to apply a 10% solution (1 gallon LS to 9 gallons water) by handgun to cordons and trunks in a very thorough soaking spray. If you need to use an airblast to cover more ground, I would concentrate my nozzles toward the cordons but leave one or two directed toward the trunks, that will waste spray between vines but will allow you to cover ground much quicker. Because of the reduction in efficiency, I would calibrate to apply ten gallons of LS per acre in at least fifty gallons of water.

Remember, this stuff is caustic, stinky, and degrades just about everything it touches. It’s also quite phytotoxic- application at these rates to vines after bud break will cause leaf damage if not outright defoliation. I have used a lot of LS during the growing season in organic apple production, and don’t recommend it there unless absolutely necessary. I do not have experience using it in-season (post-bud break) on grapes, so this recommended spray must be applied during the window between pruning and bud break. The spray, if left on tractors and in sprayer plumbing, will corrode hoses, gaskets, and even stainless steel. It must be thoroughly rinsed from sprayer systems and the rinsate applied back out in the vineyard, not dumped on the ground. Some growers have applied a film of vegetable oil via backpack prayer to tractors and sprayers before an LS application to prevent it from soaking into and corroding steel and other materials on equipment. It’s that bad, and I could show you sprayer hitches, mix screens, and ceramic nozzles that have been degraded by it.

With all that said, LS is extremely effective as a preventative practice to reduce disease inoculum, and I still recommend its use in vineyards where anthracnose and/or phomopsis have gotten a bit out of control. Just be careful out there and treat it with the same (and a little more) respect that you should retreat any pesticide.”

Good luck with your vineyard activities in the coming weeks, and let’s all hope for a ‘normal’, gradual spring warm-up.

Where trade names or commercial products are used for identification,

no discrimination is intended and no endorsement is implied.

Always read the label before using any pesticide.

The label is the legal document for the product use.

Disregard any information in this message if it is in conflict with the

label.

The UVM Tree Fruit and Viticulture Program is supported by the

University of Vermont Agriculture Experiment Station, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

Webinar TODAY on COVID-19 and produce farms;

By Terence Bradshaw

I apologize for the late notice. There will be a webinar hosted by the Cornell Workforce Development, Produce Safety Alliance, and Small Farm Program today, April 3 at 10:00 am : COVID-19 and Your Produce Farm. Details at: https://events.cornell.edu/event/covid-19_and_your_produce_farm_webinar

Best,

Terry

Where trade names or commercial products are used for identification,

no discrimination is intended and no endorsement is implied.

Always read the label before using any pesticide.

The label is the legal document for the product use.

Disregard any information in this message if it is in conflict with the

label.

The UVM Tree Fruit and Viticulture Program is supported by the

University of Vermont Agriculture Experiment Station, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.