Apple Talk Conference Call Summary
Tuesday, August 13th, 2013, 8:00 – 9:00
Presenters: John Aue, Threshold IPM.
Moderator: Katherine Mumm, IPM Institute of North America; questions or  comments, .
August 13th Call download: here
Final Webinar
Tuesday, August 13th
Scaffold article John referenced about borers and brown marmorated stink bugs. http://www.scaffolds.entomology.cornell.edu/2013/SCAFFOLDS%208-12-13.pdf
Bitter pit
John has found bitter pit in Zestar, Honeycrisp, Cortland and Macintosh varieties in orchards across the state. This is not an overwhelming amount but it is important to note it is present. John spoke with Philip Schwallier, Michigan State University about the timing and effectiveness of calcium late in the season. Phil noted that it is not too late to be affective on most varieties.  The symptoms may show in the orchard but more frequently they become apparent after picking.  Bitter pit is a disorder that results from an inadequate supply of calcium to developing fruit and has been associated with dry soil conditions.
Foliar applications of calcium is absorbed and utilized by the tree within two weeks, therefore fruit two weeks from harvest would still benefit from a calcium application, even if it is the first application this season.  It is too late to apply calcium on early varieties that are being harvested now or quickly approaching harvest. John suggested that one gallon of calcium chloride liquid per acre would help preserve fruit quality while in storage.
Blister spot
In early July pictures were posted on the blog of Cortland and Macintosh apples with spots prompting discussion of blister spot. We are now seeing spots on Mutsu and Fugi varieties and is located in a different position on the apple. RedCort is another blister spot susceptible variety. It is appearing on the outside of the apple that is exposed, this is unlike what we saw in early July, which was inside of the canopy.  Unfortunately there is nothing to be done for it.
Grower Synopsis
Bob Barthel-Mequon, WI
Jimmy Thielen- Burlington, WI
Craig Schultz Chippewa Falls, WI
Sara Ecker- Galesville, WI
Diseases
Scab
Bob- Significant spring rainfalls lead to seven scab infection periods during primary scab season, Bob was concerned about the scab pressure coming from his neighbors who didn’t control it; they sprayed Syllit to eradicate but are continuing to apply protectants. Â The orchard is virtually clean with a few escapes on the older standards.
Jimmy– So far it has been a pretty straight forward year, they have been picking apples for almost three weeks and are roughly half way through early apples and moving into Jersey Macs this week.  Paula Reds and Beacons are getting close to harvest. From a yearly comparison standpoint it seems early apples are very close to average harvest times. It has been a difficult season for scab control; regular cover sprays of Captan were essential and have kept scab controlled on the susceptible varieties like the Jersey Mack.  They have noticed very minimal scab but nothing serious, roughly two apples per eighteen bushels, overall they are very pleased with the control.
Craig-Things on the orchard have been quite similar to what others have reported, in a lot of respects insect pressure has been low. Â They controlled primary scab beautifully. Â Overall it is a moderate crop that is quite variable in regard to fruit set, Regent being down significantly.
Sara– Scab pressure has been managed, there is minimal damage only seen in the State Fair and Cortland varieties.
Sooty blotch
Bob-The orchard reached 175 wetting hours on July 30th, and is currently at 223 wetting hours from petal fall. Â They have not sprayed and haven’t had a problem with it in the past so they are not planning a spray.
Jimmy– One spray of Indar was made a few weeks ago; a second spray will probably be made in a few weeks to protect the Golden Delicious and other late-ripening varieties. Â There is a 14 day pre harvest interval on Indar.
Craig-With dry weather, sooty blotch and fly speck have not been an issue.
Fire blight
Bob-There was two infection periods during bloom, the first spray of streptomycin was applied on May 21st and there have been no new signs since then.  Bob didn’t feel there was much inoculum in the orchard but he applied two half-rate sprays of Apogee for pruning and growth control. The half rate was used because he has found that a full rate affects his thinning. He has found that the Honeycrisp growth renewal shuts down if two half rate sprays are applied so he only applied one half rate to his Honeycrisp.
Jimmy– An early strike of fire blight was noticed in Golden Russet but it was caught early and cut off below the canker. Streptomycin was applied on the younger trees and the susceptible varieties.  Trees that had fire blight in the past and were stressed by last year’s drought are rapidly declining.
Sara-Streptomycin was applied on fire blight susceptible varieties because it is known to be in the area Sara will continue to use the cultural approach of management.
Insects
Codling moth
Bob-Bob is currently at 1300 degree days (DD) from biofix. At the peak of first generation he was catching ten codling moths per week in some traps near known hotspots, where they come from ornamentals off of the property.  A spray for first generation was applied and numbers had been low. Now second catches began in mid-July and dropped off, now he is catching six per week in the hot blocks.  However, in most of the orchard he still isn’t catching any and is going to apply a spot spray unless apple maggot pressure increases.  If there are late obliquebanded leafrollers (OBLR) that could change his elected control but he had very few in first generation.  It is possible that his spray of Altacor for controlling plum curculio could of impacted first generation OBLR.
Jimmy– Codling moth pressure has been random and very minimal to date.  The highest count in a week’s time this year was been three or four. John suggested these low counts indicate no outside source. Mating disruption was used in the orchard in 2012.  Codling moth damage is visible on only one apple per 18 bushel bin which demonstrates a sustainable situation.
Craig– It was a normal first generation and control seems to be good, no visible fruit with frass has been found during scouting.  Pressure would be rated at low judging from comparable years. A high count this year would be six codling moths in a trap.  He is approaching 1100 DD from his biofix which was set on June 10th.  John cautions to not neglect the late flight.
Sara-The orchard is at 1300 DD since biofix approaching peak flight and numbers have been low.
Apple maggot
Bob-Bob caught his first apple maggot on July 18th on a non-bated sticky-red sphere and has since been catching about one a week. Â He has been applying block sprays or border sprays of Imidan at a rate of one pound per acre. Â His Ginger Gold block is the worst, and it is two to three weeks from harvest.
Jimmy– Apple maggot has not really been an issue this year. Â Alias was applied four to five days ago on everything but the early varieties. Â Trap counts on the early varieties have been very low, only one or two caught this year.
Craig– There have been two maggots caught on non-bated red spheres, an Assail spray was coordinated with a codling moth spray. The low numbers may be a result of the dry weather. Craig will continue to monitor through the end of the month.
Sara-Two apple maggots have been caught, one on August 7th and one on the 10th. With the low numbers it is feasible that suppression will be achieved with an Altacor spray.
San Jose scale
Bob-The orchard has had past problems with San Jose scale and this year they applied early oil 3% at silver tip which was block specific. Another oil spray for mites at tight cluster was done at 2.5%. The fruit is looking clean, and second generation would be moving if they are out there.
Borers
Bob-Five or more years ago they has a significant problem with borers but they seem to have it under-control, they continue to monitor but no longer are trapping for a flight.
Aphids
Bob-The orchard had tremendous rosy pressure this year, the most damage Bob has ever seen. He applied Alias but he thinks the spray was too late.  Bob didn’t notice any wooly apple aphids this year. There is no economic damage from the aphids but the pressure is there for next year.
Craig– Aphid pressure was very low this year.
Plum curculio
Jimmy– Plum curculio presence was fairly slow to appear and minimal to start but then popped out of nowhere, an Assail full orchard spray seemed to have controlled it pretty well but on the perimeter there are some visible stings.
Craig– A preliminary Avaunt perimeter spray and a second Avaunt alternate row spray seem to have been effective, very little visible fruit damage on apples.
Tarnished plant bug
Craig– Tarnished plant bug is present in the orchard; visible damage is prevalent but still not reaching a level of any economic damage.
Leafrollers
Craig– Leaf roller numbers are down from prior years and there wasn’t significant damage.  The highest catch was 30 per trap and then they dropped off.  It was a flush and then slowed down rapidly.  Other traps were not as high but each of three traps had catches. Second flight has not begun.  OBLR larvae could have been controlled by a Delegate spray for codling moth.
Sara– A large OBLR flight occurred on July 3rd, the trap count was 100. A second significant flight of 80 occurred on July 12th. John reflected that these are stunning numbers.  Sara found early lepidoptera damage at petal fall. Jersey Macs had one apple with lepidoptera damage.  The State Fair variety in her organic block will be a good indicator of damage when they start picking them soon. John noted that she may have another significant flight in late August.  Generally the second flight hatches out in June or July and flies late, the final generation hits in late August to early September. This generation bores under the skin of the apple to feed then overwinters on the tree. Altacor may have some affect if they are on the fruit or terminals now.  Putting a few more traps up could be beneficial because they don’t fly that well and that could help pinpoint the issue.
Potato leafhopper
Craig– There was a flush of potato leafhopper this year that coordinated with second cutting of hay. The Assail spray seemed to knock them back.
Japanese beetle
Craig– Japanese beetles appear to be declining in presence, the second codling moth spray seemed to knock them down and numbers have since been insignificant. Lower populations may be a result of the drought last year.
Sara-Japanese beetle damage has been very evident in the organic block, leaves on the one foot of new growth is completely skelotonized. Most of the damage is found in the top of the trees.  They seem to be waning after 25 pounds of Surround applied weekly.  Sara also used a couple of doses of Pyganic applied in the early evenings for control.
Spotted wing drosophila
Sara-Male and female spotted wing drosophila were confirmed from trap catches on July 25th. Sara continues to monitor the plums, peaches, and sweet cherries and has seen them on the peaches however at this point she is not seeing any damage to the fruit.
Insect models
Bob-Several different codling moth models have been developed by Michigan State that is used by Spec-Ware® in Spectrum weather stations. It is important to note that the models differ. Model eight does not use an upper threshold limit however models ten and eleven do.
Calcium deficiency
Biter pit
Bob-Bob has battled with bitter pit in the past, he has made four applications of calcium in the Honeycrisp and has two more planned.
Irrigation and weed pressure
Bob-Leaf wetness hours have been low and evapotranspiration reports indicate they are four inches short on water so they are beginning to irrigate the young trees. The subsoil was replenished in May and June which may play a role in how adequately trees can hydrate themselves, the cooler weather also helps with transpiration.  Irrigating bearing trees is primarily for fruit size.  There was an increase in weed pressure this year on the high density block so he applied Roundup in July.
Jimmy– High-density trees planted last year is irrigated but what was planted this year hasn’t been irrigated.
Plant growth regulator use to extend harvest
Retain applied to extend harvest can be effective but Honeycrisp is a sensitive variety, Bob has had experience using Retain and suggested not to apply more than a half rate. According to the label, harvest timeframe is 30 days after application.  Bob suggested mixing up the application applied so that you can space out your harvest. He has had success using a method of not applying on some trees for early harvest and using a one third rate for mid harvest and half rate for later harvest.
