Change is Upon Us

The team and I are very pleased to announce that Heather Kase will be joining the ENYCH team as an Extension Associate Berry Specialist starting July 1. Heather brings a wealth of knowledge and experience working with growers across the Northeast as a technical sales rep for BioBee. She has a master’s in plant health management from Ohio State University and a bachelor’s degree in environmental biology from SUNY ESF. Through her work at BioBee, experience working on and managing a farm, and her master’s work, she is a well-rounded agriculturalist who is eager to start working with growers in our region.  I know you will put her to the test with your questions!  You can reach her via email at hjk77@cornell.edu.

This edition of the Berry E-News will be my last as editor, as I will retire officially on July 27th.   It is a bittersweet time for me as it’s been a true pleasure to work with berry growers in eastern NY and throughout the state.  I’ll be spending my last remaining days helping Heather meet some of you and giving her an overview of some of the biggest challenges that you face.  I hope the 2024 season treats you well.

Best to you all,

Laura

Berry ‘To-Do’ list:

• Spotted Wing Drosophila populations continue to grow. Several evaluations of raspberries using the salt water flotation method revealed infestation levels that are unacceptable.  Growers need to shore up their spray program, and try to do floation tests on a regular basis.   The 2024 SWD Pesticide Quick Guide of all effective insecticides – organic and conventional – is available on our website.
• Another reminder to make time to conduct Foliar tissue testing (leaf analysis) this season. This fertility evaluation is much more helpful than soil testing to manage fruit in season and beyond.  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 has mostly ended. Malwina remains the only variety in the Capital District that is still fruiting.  Day Neutral varieties are already beginning to fruit in earnest.  Both of these summer fruiters are extremely vulnerable to Tarnished Plant Bug, so don’t let your guard down – keep examining flower and fruit clusters and spray as needed.  The economic threshold is quite low.  Tarnished plant bug has been worse than I’ve seen in recent years.

• 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.

• 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.  For more information on renovation, keep reading this newsletter.

Blueberries

• Harvest has commenced in the Hudson Valley. The crop looks awesome!  Keep an eye on SWD and other maggot pests.
• Plenty of Stem Canker flagging in the region. 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.
• Several calls about Exobasidium this year. This is not one of our ‘normal’ diseases, but it’s being seen from Clinton County to Orange County.   Exobasidium leaf and fruit spot is a fungal disease that affects both leaves and berries, and historically has been seen in the southeast US.  The fungus overwinters on the surface of stems, and in spring releases spores that infect emerging leaves and flowers. Leaf symptoms appear as pale green spots on the upper surface with pure white fungal growth on the underside. Infected spots on berries remain green and do not ripen. Spots become sunken and distorted over time and berries may drop prematurely. This disease is likely worse this season due to the wet year in 2023 and then the warm temperatures so far this season.

• Cultural Control — To reduce disease, encourage air flow and reduce humidity in the blueberry field. Use drip irrigation instead of overhead irrigation, eliminate standing water, and remove trees on the perimeter that block air movement. Prune bushes to create an open canopy with good air flow.
• Chemical Control — A single application of lime sulfur (calcium polysulfide) at the delayed dormant stage (about two weeks before bud break) will provide significant control.

Brambles:

• Red and black raspberries are ripening quickly. Harvest will begin in earnest in most locations this weekend.  The crop looks good, but I’m quite concerned about SWD levels.  The populations are high already, and cane berries are so vulnerable.  Continue to monitor fruit using the saltwater flotation method.  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.  Aggressive harvesting is often one of the best ways to control SWD in raspberries.  Harvest then refrigerate fruit immediately.
• Another reminder about Tarnished Plant Bug. It can become a major pest in raspberry plantings.  TPB feed through buds, in open blooms, or on developing fruits and results in stunted 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.

Tips for renovating strawberries in plasticulture systems

Gordon Johnson, Retired Extension Vegetable & Fruit Specialist, University of Delaware

With the strawberry season winding down in our annual strawberry production on plastic mulch, many growers may consider carrying the beds over for a second year’s harvest. These are some guidelines for the renovation of plasticulture strawberries:

1) Evaluate disease pressure. If the planting had significant anthracnose, botrytis crown rot, phytophthora, or identified viruses do not carry over the planting. Do not carry over anthracnose-susceptible varieties

2) Evaluate plastic mulch and drip lines. Do not carry over beds with deteriorated mulch or plugged drip systems.

3) If relatively disease-free, mow the tops with a rotary mower (in smaller plantings this can be done with a line trimmer or with hand clippers). You want to leave some leaves. Do not damage the crown.

4) Remove any runners that are left after mowing by hand. Make any plastic mulch repairs and drip system repairs as necessary. Treat and flush drip lines as necessary.

5) Remove all dead plant material around the crowns. This can be done by hand or with a leaf blower.

6) Evaluate crown thickness (number of crown plants). If over 5, crowns must be thinned out. This can be done by breaking of part of the crown by hand or by using an asparagus knife to cut away part of the crown. Leave a minimum of 3 crown plants.

7) Apply additional herbicides to row middles using a shielded sprayer to control weeds during the summer months. Hand weed holes during the summer if weeds emerge.

8) Maintain plant health by controlling diseases, insects, and mites throughout the summer months and irrigate regularly. A small amount of nitrogen fertilizer (20 lbs. N per acre) can be applied at this time if needed to maintain plant health. Take leaf tissue samples to evaluate plant nutritional status.

9) In late August or early September, apply 60-60-60 (N, P2O5, K2O) through the drip system.

10) Replant any holes with missing plants by the middle of September.

Research has shown that with proper renovation and care, second year yields will be higher than the first year, but berry size will be smaller.

Renovating day neutral plantings

Fall planted day neutral (repeat blooming) varieties such as Albion, Seascape, or San Andreas will often stop blooming in the heat of the summer. To extend bloom period, manage irrigation so plants have enough water (do not drop lower than 60 % of field capacity) in the hot period and apply 5-7 lbs. of nitrogen per acre every week, and add other nutrients as indicated by tissue testing. Remove any runners that form. If crowns are crowded, thin as described above.

If production has ceased in day-neutral fields (flowering often stops in mid-July), then renovate as described above but fertilize to stimulate new growth in early August to fruit again in the fall.

 

Renovation in perennial strawberry fields

Benjamin Phillips and Cheyenne Sloan, Michigan State University Extension – July 11, 2023

Renovation is a key step after harvest to ensure maximum yields next summer.

This article was synthesized and updated from several previous articles written by Eric Hanson, Mark Longstroth, Bob Tritten, Bernard Zandstra, and Sushila Chaudhari.

Matted-row strawberry beds destined to be carried over for another harvest season need to be renovated annually. As strawberry fields age, yields and berry size decline while weeds and disease problems increase. Deciding whether to renovate or remove a bed differs with every grower’s circumstance, such as market demand, land availability, and production costs. Growers with high market demand, but limited available acreage, tend to retain beds longer.

If one does decide to renovate, start as soon as possible after harvest. This will give the plants plenty of time to grow. The earlier runner-plants develop, the higher they yield the following year, so delaying renovation will reduce yields next year.

There are four main steps when renovating matted-row strawberries: mowing, narrowing, weeding and maintenance.

1. Mow off the leaves

Mow off the leaves just above crown height if the plants are healthy. Mowing may not be desired if the plants are stressed by drought or root diseases because weak plants have difficulty developing new leaves. Also, do not mow the leaves if renovation is delayed for more than a few weeks after the end of harvest.

2. Narrow the rows

Narrow the rows to 8 to 10 inches by cultivating with a rototiller or disk. Rototillers with tines removed above the row work very well because they toss some soil on top of the remaining plants, encouraging additional rooting. More than an inch of soil may smother the plants.

Some growers have success narrowing rows by treating the row middles with directed or shielded sprays of Gramoxone (paraquat). Gramoxone is a contact weed killer that is not mobile in plants, so it only kills treated tissues. This effectively narrows the plant row and does not expose new weed seeds by disturbing the soil. One problem with this approach is that it does not provide loosely tilled soil for the rooting of runner plants. It also does not throw soil back over crowns.

3. Weed control

Weed control at renovation will enable strong growth and rooting area for daughter plants to establish for fall bud formation and next year’s fruiting. At renovation, preharvest intervals aren’t generally a concern, and it can be a key point for weed control in a matted-row system. This is a great time to focus on perennial broadleaves and grasses with contact and residual herbicides to burn them down at renovation and help keep weeds down into the fall.

If there are many broadleaf weeds, especially perennial weeds (dandelion, field bindweed, wild carrot, horsenettle, vetches, and common milkweed), in the field, it may be necessary to apply 2,4-D (Formula 40 or Embed Extra) immediately after the last harvest. In fields with dominating composite weeds (e.g., Canada thistle, dandelion, mayweed, ragweed, groundsel), clopyralid (Stinger) may be used instead of 2,4-D. Stinger has a Michigan 24c label. Do not include an adjuvant if Stinger is included in the spray mix. However, if the field has mainly annual broadleaved weeds, the herbicide application can wait until after tillage and mowing.

After tillage, apply residual herbicides to control weeds for the rest of the summer. For broad-spectrum, full-season weed control, include two residual herbicides in the post-renovation application. Effective mixes include a primarily grass herbicide (Dual Magnum, Prowl H2O) and a primarily broadleaf herbicide (Spartan, Ultra Blazer). See the table below for recommendations on common herbicides used in strawberries as well as when they can be applied in a matted-row system and weeds they’re effective against. As always, read the label before applying anything and if there are any questions, reach out to a local agricultural Extension educator.

Herbicide	Weeds of concern	Application timing
		Renovation	Fall	Spring
2,4-D amine or choline	Smartweeds, velvetleaf, pigweeds, mustards, dandelion*, bindweed, Canada thistle, plantains*	X
Chateau** (flumioxazin)	Chickweed, common lambsquarters, mustards, pigweeds*, foxtail, dandelion, mallow	X	X	X
Devrinol (napropamide)	Chickweed, common lambsquarters, pigweed, sowthistle, barnyardgrass*, crabgrass*, fall panicum*, foxtail*, witchgrass*		X	X
Dual Magnum (S-metolachlor)	Barnyardgrass*, crabgrass*, fall panicum, foxtail*, witchgrass*, pigweeds, nutsedge	X		X
Fusilade (fluazifop-P)	Barnyardgrass*, crabgrass, fall panicum, foxtail*, sandbur, witchgrass*, quackgrass*	X	X	X
Gramoxone** (paraquat)	Chickweed*, common lambsquarters*, mustards, pigweeds*, ragweed, smartweeds*, barnyardgrass*, bromegrass*, crabgrass*, fall panicum*, foxtail*, witchgrass*	X
Poast (sethoxydim)	Barnyardgrass*, crabgrass, fall panicum*, foxtail*, witchgrass	X	X	X
Prowl H2O (pendimethalin)	Common lambsquarters, pigweeds, barnyardgrass*, crabgrass*, fall panicum, foxtail, sandbur, witchgrass*	X	X	X
Select Max (clethodim)	Barnyardgrass*, bromegrass, crabgrass, fall panicum, foxtail*, sandbur, witchgrass*	X	X	X
Sinbar (terbacil)	Chickweed*, common lambsquarters*, horseweed, mustards*, smartweeds*, velvetleaf, barnyardgrass*, bromegrass*, crabgrass, fall panicum*, foxtail*, witchgrass*, horsenettle, plantains, quackgrass, sowthistle	X	X
Stinger (clopyralid)	Horseweed, pigweeds, clover, groundcherry, knotweed, plantains, Canada thistle, dandelion, sowthistle, vetch*	X	X	X

* Weeds are rated as “excellent” control while all others are rated as “good.”
**Apply as a directed spray to row middles for preemergence control of annual broadleaves. Contact with strawberry plants will cause severe crop injury.

4. Maintenance – fertilizing and irrigation

The final step in renovation is to fertilize and irrigate the planting to encourage new growth and runnering. On heavier loamy soils, apply enough fertilizer to supply 50 pounds of nitrogen per acre. On sandy soils, apply 30 to 40 pounds of nitrogen at renovation and again in early August.

Do not neglect to water the field during renovation and during the remainder of summer. Plants need water to grow and all other efforts are wasted if the renovated plants do not get off to a strong start. Runner plants that develop during July and August need adequate moisture to root and maintain a healthy leaf canopy to store food reserves for next year’s crop. With summers becoming drier, this will often necessitate irrigation on many sites.