Berry ‘To-Do’ list:

• We have found Spotted Wing Drosophila for several weeks in a row in traps at all locations throughout the region. Given the warm, humid weather we anticipate this pest to be a problem for cane berries and blueberries, and possibly the late strawberry varieties.  Fruit that is ripening or ripe need to be protected.  The first spray is very important as it serves to undercut the population expansion before the adults’ lay eggs in the fruit.  Research has shown that attention to the early sprays helps enormously in the season-long management strategy.  The 2024 SWD Pesticide Quick Guide of all effective insecticides – organic and conventional – is available on our website.
• Foliar tissue testing (leaf analysis) during the season is the best way to guide fertilizer application – it lets you know what nutrient levels are in the plant so you can raise/lower N applications (strawberries), or feed other nutrients to longer termed perennials like blueberries and cane berries. You can do this several times during the season, or focus on one annual testing window which for all crops is in late July.  Blueberries and cane berries will not have started moving nutrients to the plant crown at that point.  JB strawberry leaves should be gathered when leaves fully expand after renovation.  Dairy One in Ithaca NY has a fast turnaround time for tissue tests, and the results come with Cornell guidelines for optimal ranges in small fruit. Cost is $30 per sample. Sampling instructions are on the site (collect at least 30 recently matured leaves from across the tunnel and wash if there is any residue on them).

Strawberries:

• Strawberry harvest continues. Fathers Day weekend was wonderful for U-Pick and market sales alike.  The current ‘heat dome’ is less than perfect.  Varieties are bunching up and fruit cannot withstand this heat.  Prices seem to be good and demand is strong.
• Anthracnose is still appearing on strawberries.  Three related species of the fungus, Colletotrichum, including C. acutatum, C. gloeosporioides, and C. fragariae can be associated with anthracnose. Most growers have become familiar with the black, sunken fruit lesions, and some have learned about anthracnose crown rot, but the petiole and runner lesions are just as important for diagnosis and less understood.  https://ohioline.osu.edu/factsheet/plpath-fru-16.

• Winter injury that weakens the plant which then succumbs to soil-borne disease is common throughout the region.   Plants are collapsing just as the fruit starts to size.  The plant roots are likely already dead, or almost dead, causing the plant to collapse when it’s stressed by a crop.  Wet soils last fall and into winter may be the cause of Phytophthora inoculum moving in fields.  OR excessive heavy rains in December could have caused soil to erode from plant crowns.  OR the warm February followed by cold temps in March could have caused damage.  Either way, if your field is significantly impacted, there is no recovery from this damage.  Don’t keep the field and hope for something better next season.
• Potato Leafhopper adults and nymphs may be seen on strawberries and raspberries at this time of year – especially as first cuttings of hay are happening in some areas.  The ‘hopperburn’ is most notable on young plants but can be on any age plant.     Organic (Pyganic, Molt-X) and conventional (Assail, Platinum, Malathion) insecticides labeled for leafhoppers can knock numbers down quickly but repeat applications may be needed for successive waves of migrating adults. There are no economic thresholds established in strawberries.
• LOTS of calls about slugs.  Metaldehyde or iron phosphate products work well but take time.  Make sure to reapply in September to capture emerging slugs as adults lay eggs in the fall.
• Four-lined plant bugs and tarnished plant bugs are causing a good amount of damage on late varieties of June bearers and I anticipate the pressure to continue for the day-neutral strawberries.  Be aware that weeds in and near fields harbor these insects.  Mowing weed plants will push plant bugs and leafhoppers into fields.  We usually think of four-lined plant bugs as being mostly foliar feeders that causes leaf distortion but little more damage.  But, just like tarnished plant bug, they can also pierce developing seeds on young fruit.  Use the same scouting thresholds for berry clusters as you would for berry flowers.  Two leafhoppers per 20 strawberry clusters mean that you should spray.  Using row covers to keep plant bugs out will work for June bearers with discreet flowering times, but it will be much more difficult for day-neutral varieties.

• Day-Neutral strawberries should be fertigated: Standard recommendation is 5 lbs N per acre per week once fruits are forming (UNH 2019 day-neutral guide). That’s just under 2 oz. N per 1,000 sq. ft of tunnel growing area. See the last newsletter for more specific information from Dr. Vern Grubinger at UVM.
• June bearing strawberry renovation: The best way to reduce egg laying with SWD is to remove the fruit.  Renovation after harvest offers that opportunity, plus it helps control vigor of aggressive plants and provides nutrients at a critical time. Renovation also helps with weed control and covers the berry crown with soil to improve wintering.  If it is super hot at time of renovation, you might choose to NOT mow off plants.  Mowing is stressful to plants and exposes the crown briefly.  Mowing can help drying out the remaining fruit and killing off SWD, but if it’s too hot it can weaken the plant.  This is also true of herbicides, so take care when renovating.

Blueberries

• Fruit is starting to color in many plantings south of Albany, and even as far north as Clifton Park. Lots of discussions about how to manage the over-fruiting that some varieties seem to get.  Some growers are thinning – mostly at pruning they will thin out some of the lateral branches, primarily to push larger fruit, but also to prevent over fruiting and shoot/fruit imbalances.
• Spray for cranberry fruitworm if you have had issues with these insects in the past. These moths are being caught in traps region wide.
• Blueberry maggot adult flies are being caught in traps throughout eastern NY. Again, if you have had issues with this pest, start spraying as fruit just beings to turn blue.
• Stem Canker flagging is starting. There are several different pathogens that cause canker diseases.  They will result in loss of fruiting wood and loss of vigor if unchecked.  Delayed dormant applications of lime sulfur does a great job of limiting the spread of these diseases.

Brambles:

• Fruit sizing and ripening. The crop looks great! Cane growth is robust.  SWD presence is a real threat to raspberries, so monitor fruit using the saltwater flotation method as harvest season commences.  That test will help you feel confident about the success of your management program and the status of your fruit.  Keep reading for directions for this test.
• Our friends in Long Island (Dan Gilrein) remind us that Tarnished Plant Bug can become a threat to caneberries as bloom and early fruit set get underway. TPB feeding through buds, in open blooms, or on developing fruits stunts berries. Bifenture, Assail, Danitol are labeled for TPB (Brigade used in caneberries for other labeled pests will provide incidental control). In organic production Mycotrol, Grandevo, PFR-97 and PyGanic are labeled, but emphasize good weed management. Avoid application during bloom.

Guidelines for Checking Fruit for SWD Larvae in the Field

Laura McDermott, Extension Associate, Eastern NY Commercial Horticulture Program

First published in SWD Regional Workshops – Winter 2014-2015.

These suggestions are based on techniques developed by a variety of research scientists from public institutions that are listed below.

Tips to make monitoring easier:

The size of the fruit affects the time it takes for larvae to emerge into the salt solution. Larger fruit take longer. Still – 15 minutes should be enough time to allow SWD larvae to emerge even from a large-fruited strawberry sample.

A light infestation with 1st instar larvae will be very difficult to see with the naked eye. You will likely need a magnifier if not a dissecting scope in this situation.

The better the lighting the easier it will be to see the larvae.

A video produced by Peerbolt Consulting of this process can be found at: http://www.berriesnw.com/videos/baggieTest/2010SaltBagTest.htm

Materials needed:

• Re-sealable gallon sized plastic bags
• Salt
• Water
• 9″ x 13″ dark or black-painted pan
• 1/4″ hardware cloth, cut to fit in the pan
• A weight such as a metal rod
• Hand lens (or Optivisor for the super nerdy!)
• A direct light source

Checking Fruit in the Field

• Collect a sample of fruit (strawberries: 25-30/sample, caneberries or blueberries: 75/sample)
• Put fruit in a gallon-size re-sealable plastic bag.
• Pour in salt water solution so that all fruit is covered in the bag. Salt Solution: 1 cup of salt per gallon of water.
• Mark bag with field code/date.
• For a quick check in the field (after 15 minutes), hold the bag up to light and look for larvae.
• To conduct a more thorough examination, pour the fruit and salt solution into a shallow pan. Use a piece of hardware cloth to hold the fruit down making it easier to separate the larvae from the fruit. This is the method that fruit processors or storage operators could use to examine fruit on a larger scale inside a building.

Information compiled from work done by: Caryn Michel, Washington State University and Dean Polk at Rutgers University.