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Factors Contributing To The 2019 Hudson Valley Insect Pest Management Anomalies

Factors Contributing To The 2019 Hudson Valley Tree Fruit Crop

Observations on Hudson Valley Tree Fruit this season.

This season the apple crop will pick out a just slightly below a full crop for the Hudson Valley.
*Empires are off in production volume this season.
*Gala, HC and Macs were all less firm (around 1 lb) with slightly reduced Brix, a day or two behind in maturity from last season.
*Excellent coloring weather
*Rain at just the right times, minimal interference with harvest
*Bitter Pit / Honeycrisp prediction models suggest below average incidence for fruit out of storage (beta testing the models)
*Soft scald risk may be higher this season than in recent years for Honeycrisp, especially lots that are stored at 33F and not pre-conditioned.
*Some russeting with cold injury suspected as the culprit. Maybe from last November, or this March.
*To date, have not heard of any labor issues.

Insect Pest Management Anomalies: Peter Jentsch

Rainfall accumulations & temperature events: The start of the 2019 season began relatively cool and dry in March remaining below the average rainfall through April with rainfall accumulations of 2.01” in March (3.6” Ave.), 2.01” in April (3.8” Ave.), and above average of 5.52” in May (4.4” Ave.). The month of June saw a below average rain events totaling 3.00” (4.4” Ave.), with ample rain to produce moderate levels of apple scab and fire blight infection, especially in newly planted blocks. July had relatively consistent weekly levels of rain with 8 days above 90oF requiring weekly irrigation and sunburn protection in UV sensitive fruiting varieties. August also experienced below average rainfall with accumulations of 3.30” (4.2” Ave.). Total rainfall for the March 1st through September 1st growing season totaled 19.21”, significantly lower then 2018 of 26.74” of rain, and well below the seasonal average of 25.1”. Rain events over the region were relatively lackluster in lower Ulster and Dutchess County, with no visible impact on fruit or tree architecture support systems.

Tree phenology: Bud development was again hampered in 2019 by lingering cold temperatures. The season began 10-days later then the average. However, by petal-fall, the season was one-week later then the latest day of the 38-year phenology mean, 10 days earlier then the latest recorded date.

McIntosh green tip (10 April) occurred 10 days later than the 38-year historical mid-range (see McIntosh phenology. King bloom on McIntosh began on the 28th of April. Day length and predominately cool temperatures prevailed, ranging between 34.0oF and 72.2oF, and setting the stage for a very long bloom period lasting 17 days, 7 days longer then the mean of 9.4 days with > 80% PF in McIntosh occurred on 15th May.

Degree-day accumulations of 533.143 and 257.250 were mid-range relative to the 38-year average up to PF. A moderate temperature range of 39 oF to 84.7oF followed 15-days after PF.

There was ample sunlight and temperature for pollinators yielding strong pollination with may varieties showing strong fruit set, requiring significant thinning for a marketable crop. Yet, very cold temperatures hampered a few varieties in November 2018 as retained leaves and high water tables present from 2018 during record rain events exacerbated the damage. Trees suffered from significant bud injury on the morning of Nov. 23rd prior to complete leaf drop and hardening off. Temperatures fell from 43oF to 6oF over a two-day period, speculated to have caused bud injury and reduced flower development of varieties in compromised locations.

Early water stress was a concern for tree fruit growers during early the early season with ample rain fall and ground moisture available during most the season. By 20th May, 100% of McIntosh fruit had set with king fruit sized > 5 mm, with 3% plum curculio injury noted in the untreated Ginger Gold control plots on that date.

Tarnished Plant Bug (TPB) presence and fruit injury was slightly above average this season, requiring timely applications for management in orchards with historical fruit damage. Significant injury occurred during the post bloom period this season as cool temperatures prior to bloom were not conducive for TPB activity. Injury from this pest at fruit set was recorded to be below 0.5%, yet injury one week later was observed to be at 8.0% by the 21st of May in the UTC Ginger Gold this season. Relatively dry conditions during the pre-bloom period favor TPB activity, often requiring insecticide applications at both TC and P that, in many years, show numeric reduction in fruit injury. Low levels of injury in higher valued fruit such as Sweetango, Honeycrisp, Gala and Fuji typically require TPB management if culls from this insect exceed economic threshold. We observed TPB injury at 12.0% in Ginger Gold on 28 May 4 June in untreated plots with lower damage levels noted in these plots in early July.

Plum Curculio (PC) damage levels were moderately high with development with first observation of ovipositional injury on 20th June (3.0% at 5 days post PF in Ginger Gold; 25% PC injury in Red Delicious) in early varieties and moderate later into the season (25% by the 28th May in Red Del. and 32% by the 3rd of June). The predictive model using 308DD50 calculated the completion of PC migration and need for residual insecticide until the 9th June using the HVRL NEWA station.

This season PC management required two applications in most orchards beginning at 80% PF to control PC based on reapplications if a 14d interval was used. Significant rain events occurred at the end of the PF -1st cover for most mid to late varieties. Rains after PF through the 27th-29th May (1.50” @ 14 days post PF), required reapplication on the 30th of May. A June applications (0.67” post 9-days post 1C) may have been needed in cooler sites to maintain residue through the 9th of June or 308DD PC migration completion model. Very light PC migration likely began during bloom with temperatures exceeding 70oF on consecutive days. However, overall high pressure was observed this season just prior to McIntosh with low damage levels to Ginger Gold at >5mm fruit set and moderate PC injury observations prior to June Drop exceeding 30% in Ginger Gold and Red Delicious. In early harvest assessments after ‘June Drop’ damage was assessed at 50% in untreated Ginger Gold.

Lepidopteran complex: Overwintering larvae of the spotted green fruit worm (SGFW), red banded leafroller (RBLR) and OBLR larva during the pre-bloom period through fruit set remain a concern for most Hudson Valley and Lake Champlain pome fruit growers. The tools for use against the Lepidoptera complex are diverse in mode of action, very effective with excellent residual activity. Relatively low levels of infestation was observed in the pre bloom and early season leafroller complex.

The codling moth (CM) 1st generation sustained adult flight occurred on 17th May with larval emergence predicted for 3rd June using 220 DD50 from CM biofix. The internal lepidopteran complex, lesser apple worm (LAW), oriental fruit moth (OFM) and CM showed moderate levels of damage to apple, with frass produced by the internal lep. complex appearing during mid-late June through early July. Damage from 1st generation evaluated in late June on untreated Ginger Gold and Red Delicious showed 15.9% and 22.7% injured fruit respectively. 1st generation internal worm composition of 60 untreated McIntosh fruit exhibiting either calex end frass or larval site entry hole infested with 36 larva. Upon dissection, 45 fruit (75%) had direct seed feeding and 30 live larva without anal comb, with the remaining 17 fruit (15%) had feeding on the flesh and 6 live larva with anal comb. The 2nd generation adult sustained catch for the CM biofix occurred on 12th of July with management for larval emergence prediction using 250 DD50 to occur on July 22nd.

Obliquebanded leafroller (OBLR) monitoring and management by tree fruit growers continues to be a high priority, albeit significantly lower levels of fruit injury is attributed to the leafroller complex in fruit pack-out assessments. Targeting up to three seasonal application windows while employing a single mode of action for each period, growers can achieve successful management of the OBLR larva. These include the pre-bloom through Petal Fall period for the overwintering generation, often using IGR’s such as Proclaim and Intrepid, the Summer generation using either Altacor or Delegate, and later in August applying either Delegate or Altacor in rotation for resistance management. Recommendations for applications were made using insect phenology predictions for early emergence, using 340 DD50 from biofix to manage emergence of larvae, predicted to occur on mid June. In general, low-levels of leafroller feeding was observed on developing foliage and fruitlets this spring. Trap captures began on 3rd June were moderate for 1st generation OBLR averaging 3.25 / day during the peak periods (27th June). The 340 DD43 emergence date of 1st summer OBLR generation was 22nd June. The 2nd generation flight began on the 22nd of July with larval emergence predicted for the 1st of August. OBLR trap numbers were very low during August at just above 0.5 adults per day.

European apple sawfly (EAS) activity occurred in very low numbers again this season with early varieties showing a range from 0.5% to 1.1% injury in Ginger Gold and McIntosh cluster fruit evaluations with early harvest assessments at < 1.0%. This was the fifth year in which EAS populations were at very low fruit damage levels. Spotted Tentiform Leafminer (STLM) ) populations remain at very high levels in seasonal pheromone trapping with two distinct flights. Since the planting of our semi-dwarf test plots that correlate with the onset and use of the neonicotinoid class of insecticides employed in apple and reduced broad spectrum OP use, the STLM has not been observed to cause injury to foliage to a degree requiring insecticide management. Parasitism of early larval stages continue to be observed during the season.

San Jose scale (SJS) crawler emergence was predicted to occur during the second week of June (8th June) based on the 1st adult capture on the 20th of May using a 260-360 DD50, model. Nymphs were observed on fruit on the 17th of June, 9 days after the predicted emergence date. In general SJS scale levels were moderate in infested trees. The infestation means ranged from 0.5% to 3.0% injury observed in HVRL research plots on 8th July representing 1st generation infestation levels. In conventionally treated orchards, the SJS has become a major insect pest to manage in apple, requiring targeted applications for multiple generations. In 2015 we observed a 3rd generation in late September.

We are seeing a trend of increasingly high levels of red banded leafroller (RBLR) with mixed populations of tufted apple bud moth (TABM) and sparganothis fruitworm (SFW) during the season, likely contributing to the overall leafroller leaf and fruit damage damage occurring yearly.

Apple maggot (AM) emergence was earlier this season (24th June) compared with first emergence on 2nd July in 2018. Threshold of 5 flies per trap per block was observed on the 1st of July. Yet AM density was very low to moderate throughout the region with reduced emergence and subsequent trap captures through August. Highest populations occurred late in the season on 12th August under ideal emergence conditions for the adult fly. However, in our untreated orchard, we had a peak of only 20 flies per trap. Very low levels of AM injury were observed to early and mid season varieties.

The brown marmorated stink bug (BMSB), Halyomorpha halys, has been observed throughout the southern Hudson Valley since December 2008. Populations have been documented on the increase in urban environments and have been found on many farms throughout the season in the lower to mid-Hudson Valley region since 2011. We have observed intermittent second generation development over the past few years, developing in mid-late August in HVRL voltinism studies. In 2019 we again found adult egg laying from mid-August through September, indicating a 2nd generation and in some location with populations exceeding the action threshold.

Although there appears to be stink bug feeding in apple this season, both BMSB and the green stink bug, Acrosternum hilare were found from mid-season through harvest on pome fruit in lower to mid-Hudson Valley. We have been seeing increasing northern populations and fruit injury occurring in Columbia County beginning in 2013.

BMSB has been found reproducing in deciduous trees such as Sugar Maple, White Ash, Tree of Heaven, Ailanthus altissima, and eastern black walnut in high numbers with lower numbers observed in Staghorn Sumac and wild grape. Late season nymphs and adult trap captures of BMSB using Tedders traps, duel pheromone comprised of #10 lure and the Plaudi stali aggregation pheromone lure, methyl (E,E,Z)-2,4,6-decatrienoate, was observed along the orchard edges in Orange, Ulster, Dutchess and Columbia Counties throughout the season. In 2019 we monitored the population throughout NYS in 14 tree fruit orchard sites, employing a trap threshold of 10 total BMSB adults per trap to recommend management timing for tree fruit production. We are presently recommending that growers access https://www.eddmaps.org/bmsbny/ for weekly updates on BMSB monitoring of adults and fruit injury requiring management.

Spotted wing drosophila (SWD), Drosophila suzukii, (Matsumura) (Diptera: Drosophilae) were first observed in NY late August of 2011. As in years past, EDDMaps was used to record trapping data with Erie County finding the first SWD on 22nd of May, which is the earliest recorded capture date in NYS. In 2019 SWD were monitored in two counties in the the mid-Hudson Valley this season using baited Trece traps across small fruit, grape and tree fruit.

SWD trap captures were found in Columbia County on the 1st of July, 5th of June at the HVRL in Ulster County, on the 13th June in Suffolk County. Populations were generally slow to build in commercial berry crops, showing less damage to berry then in previous 5 years. Growers who harvested frequently and kept to a 3-7 day spray program were able to maintain low infestations levels this season. We are presently recommending that growers access http://www.eddmaps.org/project/project.cfm?proj=9 for weekly updates on BMSB monitoring of adults and fruit injury for early season management.

Major Problems/Successes this Year: Codling moth fruit infestation continues to be a severe problem in orchards.

Contributing factors include rain events reducing insecticide efficacy, lax re-application spray schedules, delayed timing during the early emergence, reduced rates or use of less effective insecticides.

Unusual events: Fall Webworm, (Lepidoptera: Erebidae) Hyphantria cunea Drury, was observed in both research and commercial orchards again this season.