Fruit IPM for 06/30/20

Peach:

Oriental Fruit Moth: We are between generations 1 and 2, with the first insecticide applications having been just applied in southern counties, and in northern counties due by the weekend. The second application will be due the following week.

See timings below:

Tarnished Plant Bugs and Other Catfacing Insects:  Catfacing insect pressure has begun to increase in southern counties where groundcover management is poor. In addition BMSB was noted in several southern and northern orchards. Populations are very low but this demonstrates that adults are present in orchard environments. BMSB was noted this week primarily in blocks being harvested. Where traps are placed, we have seen up to 5 bugs per trap. Nymphs are present and can be found in some locations.

Bacterial Spot and Cold Injury: Foliar infections continue to increase. Fruit damage levels remain very low. Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. Where infections are still evident, continue copper use up to 3 weeks pre harvest.

Brown Rot and Anthracnose: Implement a Pre-harvest Brown rot management program starting about 3 weeks before harvest. An effective program might start with Captan, followed by Pristine or Merivon 7 days later and ending with a DMI such as Tilt. In varieties susceptible to Anthracnose begin with Captan or QoI chemistry (Abound, Flint Extra) 4 weeks prior to harvest. A word of caution – Some growers still change over to the more effective brown rot materials 7 days before picking. This is not adequate, and can produce brown rot infected fruit under high humidity and rainfall.

Western Flower Thrips and Flower Thrips: Thrips were found in the groundcover while looking for catfacing insects. This is another reason to not have flower weeds present in the groundcover.

Apple:

Codling Moth (CM): On average, trap captures are low, but we should start to see an increase as the second flight starts to emerge. Given how this insect can be problematic on some farms, it is very important to hit the second emergence on time. Approximate timings for the initial 2^nd generation treatments are outlined below:

European Red Mite: Mites are beginning to be seen at threshold numbers in only a few orchards. Effective materials at this time of the year include Zeal (low populations only); Nealta; Portal; Fujimite; and Nexter. See the NJ Commercial Tree fruit Production Guide.

Tufted Apple Budmoth (TABM): A biofix was set statewide on May 6. In southern counties, we are in the middle of insecticide timing for TABM, with the last treatment timings just past in all areas of the state.

Scouting Calendar Tree Fruit Southern Counties

The following table is intended as an aid for orchard scouting. It should not be used to time pesticide applications. Median dates for pest events and crop phenology are displayed. These dates are compiled from observations made since 1995 in Gloucester County. Events in northern New Jersey should occur 7-10 days later.

Tree  Fruit Trap Counts – Southern Counties

Tree  Fruit Trap Counts – Northern Counties

Blueberry:

Blueberry Maggot (BBM): The first adult fly was captured on Monday 6/29. This marks the start of the 1 generation per year of this insect. Growers who are exporting fruit to Canada need to maintain an insecticide program that adheres to the Canadian Export protocol. This means that the first insecticide application must be applied within the 5 day period after the first fly capture, or by Saturday 7/4. In most cases, treatments are being applied for SWD that also control BBM. Given this schedule, those growers exporting to Canada are OK as long as one of these treatments has fallen between 6/29 and 7/4.

Figure 1. Adult blueberry maggot fly on trap. (Photo – Carrie Denson).

Spotted Wing Drosophila (SWD): This is still the primary insect of concern at this time. Try to stay on a 7 day program if you are still picking. The best insecticide choices include any pyrethroid (Asana, Brigade/Bifenture, Danitol, Mustang, Hero), Imidan, Delegate, Lannate, Malathion ,and Exirel and Verdepryn.

Aphids: Average aphid infestation levels remained near the same levels as the previous week. We had an average of 2.5% of terminal infested with colonies, with a high of 32% on newly developing canes. Anecdotally, we observed one field that had very high aphid populations, and also had high blueberry scorch incidence.

Putnam Scale: Some scale crawlers are still present, but should decrease over the next week to 10 days. Growers concerned about this pest should target the second generation crawler stage in early to mid-August.

By the Numbers:

Grapes:

Summer Disease Management is key now. Targets in the summer are mainly Powdery Mildew and Downy Mildew.  Brian Hed at Penn State has a very good rundown of summer disease management in  recent blogpost. You can also find suggestions on Mizuho Nita’s grape blog, and in the Rutgers Grape Production Guide.

Grape Berry Moth (GRB): The biofix was set for 6/3 in southern counties. We need 810 DD₄₇ until eggs start to hatch and ‘early timed’ (insect growth regulators and diamides) insecticides are applied. These materials include Intrepid, and the diamide and diamide premixes – Altacor, Exirel, Voliam Flexi, and Verdepryn. Other materials like Imidan, Sevin and the pyrethroids can be applied 2-3 days later. The projected timing for the ‘early applied’ materials is on or about July 2-3 in southern counties.

Spotted Lanternfly (SLF): Spotted Lanternfly nymphs have been present in mid to northern county vineyards. Numbers vary quite a bit, but most populations have been controlled where insecticides were used. As a reminder the following is reprinted from the last newsletter: “There are no treatment thresholds that have been developed for this insect. We do know that once an egg mass hatches in the vineyard, the nymphs can stay around for a while. Nymphs go through 4 instars, and can leave at any time before becoming adults. There may be a prolonged period of time when, after the nymphs leave, there are no SLF in the vineyard until mid to late August. Then as the fall progresses, more SLF adults come in and feed. Penn State provisional guidelines suggest insecticide use if there are at least 15-20 nymphs per vine, or 5-10 adults per vine. Brigade, Actara, Scorpion, Danitol, malathion, and Mustang have been the materials of choice. Do not combine Danitol with Captan on grapes.” High population may appear as in the photo in Figure 2 below:

Figure 2. Spotted lanternfly nymphs in Hunterdon County vineyard, (Photo – Atanas Atanassov).

Potato Leafhopper: Potato Leafhopper is a sporadic pest of grapes. It causes damage in susceptible cultivars by damaging cells and injecting saliva when feeding. It is of most concern in new plantings as heavy feeding can stunt growth. In older plantings the damage may be limited to growing tips and won’t be as severe. Older plantings generally grow past the damage once the pest is controlled. Leafhoppers are known to transmit bacterial disease in tree fruit and viruses in grapes so it may also play a role in virus transmission. Symptoms are leaf cupping and yellowing of the leaf margins (see Fig.3). Most broad spectrum insecticides and neonicotinoids will control leafhoppers.

Figure 3. Potato leafhopper damage to grape leaves, (Photo – David Schmitt).