Orchard management:   Synopsis of key late season dates

Background Information for this page
Return to radar list for Sanford ME
Weather data for Sanford ME.  Forecast values begin October 17, 2008
Green text is for horticultural events or management activities.    Red is for insect pest events.    Maroon is for mite pest events.    Blue is for disease events.
Highest priority growing season activities are highlighted in yellow boxes.
Date	Biological Events and Management Activities
June 22, Sun	Date by which 2nd generation Flyspeck spores start becoming available, increasing risk of infections that will show by harvest.  In low-flyspeck-risk blocks, continuous protection may not be needed prior to this date.  See Flyspeck tables for optimum spray intervals and definition of low-risk blocks.
June 23, Mon	Start of 2nd generation Spotted tentiform leafminer flight
June 25, Wed	Japanese beetles begin showing up (rough guess).  Honeycrisp apples seem to be one of their favorite foods.
June 26, Thu	Date by which 2nd generation lesions from the final primary scab infection period have had time to begin appearing.  Finding fewer than 5 leaves with fresh lesions per 100 fruit clusters and vegetative shoots after this date indicates that scab control has been successful.    Finding more than 5 leaves with fresh scab lesions per 100 clusters/shoots at this time in a commercial orchard suggests that fungicide selection and spray intervals need to be adjusted to suppress spore production, and to protect fruit and foliage for at least 4 weeks until active scab lesions exhaust their supply of spores.
June 30, Mon	If using pheromone traps to estimate populations and time treatment for Oriental fruit moth larvae, time to set traps.  First trap capture expected in 7 days.
July 1, Tue	Where preventive control of small Obliquebanded leafroller larvae is needed, date for first application of Assail, Calypso, Intrepid, SpinTor, a Bt product, or other insecticide effective against OBLR.
July 1, Tue	European red mite threshold until July 31 is 5 mites per leaf, or mites present on 77% of middle-aged leaves.  See July ERM sampling table for optimum scouting intervals.
July 1, Tue	Apple maggot adults start appearing on traps (rough guess, rain factor not included in estimate).  Time to set traps or risk missing early emerging flies.
July 2, Wed	Early 3rd generation European red mite nymphs appear    Between now and July 9 is an important monitoring period to detect for above threshold population before 4th generation eggs are laid.
July 2, Wed	Glyphosate (Roundup) herbicide application more than 45 days after full bloom to soil around apple trees with root suckers, especially young trees, poses increased risk of damage from systemic uptake through root suckers into the trunk and root system.  Apple trees without root suckers may also become more sensitive to trunk contact by glyphosate with late season application, especially trees under drought or other stress.
July 3, Thu	Roundheaded apple tree borer peak egglaying period is approximately July 3 to July 16.  Unprotected young trees at risk of borer infestation.
July 5, Sat	Plum curculio egglaying begins natural decline.  If using Surround repellence instead of insecticide mortality to prevent PC damage, coverage should be maintained from Petal fall until at least this date.
July 6, Sun	Dogwood borer egg hatch begins.  Peak egg hatch is roughly August 7.    Trunk insecticide (chlorpyrifos offers best protection) needs to be in place by this date, especially on young trees with burr knots and not receiving insecticide for other pests.
July 9, Wed	Rough guess of terminal bud set on bearing trees, but actual date is highly variable by cultivar, tree age, tree vigor, and weather.  Vertical shoots may have new foliar growth beyond this date as they set terminal buds later.  Summer pruning to open tree canopies for better fruit color and to increase number of flower buds next year should only begin after terminal bud set.  Summer pruning before terminal bud set has undesirable effects on fruit quality and vegetative regrowth.    Lack of succulent new growth after terminal bud set slows progress of new apple scab infections, powdery mildew, and fire blight shoot blight.  But both scab and fire blight infections can spread with suitable conditions and lack of protection. In orchards with active fire blight, delay hand thinning and bud pinching until after terminal bud set.     Summer pruning also lowers canopy humidity and allows better spray coverage to suppress flyspeck, scab, and bitter rot diseases, and removes water sprouts that are favored aphid habitat.
July 9, Wed	Early 3rd generation European red mite adults begin laying 4th generation eggs.  Fourth generation is typically the peak ERM population of the year.
July 10, Thu	First sample date for late instar summer generation Obliquebanded leafroller larvae.  Threshold is 4 or more larvae per 100 shoot terminals.
July 10, Thu	Apple maggot trap captures increase as emergence from soil reaches 50% (rough guess, rain factor not included in estimate).   Thresholds:        odor-baited traps - 5 AM flies per trap since previous insecticide depleted       unbaited - 1+ per trap since previous insecticide depleted
July 14, Mon	First treatment date for 2nd generation Oriental fruit moth larvae.    Rough threshold:  6 to 14 OFM moths per pheromone trap per week.
July 14, Mon	Date by which 3rd generation Flyspeck spores start becoming available.  From this date until about 30 days before harvest is the peak risk for flyspeck infections that will show by harvest.  Good date to begin scouting for flyspeck on fruit to see if there is need for intensified suppression.    See Flyspeck tables for optimum spray intervals.
mid-July through September	Regular close mowing helps lower canopy humidity, conserves soil moisture, and can help suppress orchard vole populations.    Late-season herbicide application can prevent desirable ground cover regrowth to help protect roots from low winter temperatures.
July 18, Fri	First sample date for 2nd generation Spotted tentiform leafminer sap-feeding mines (early mines fully visible but few have reached less vulnerable tissue-feeding stage).    Thresholds:  McIntosh & stressed trees - 1 mine per leaf;         unstressed trees - 1.3 per leaf
July 26, Sat	Date to collect leaf samples for foliar nutrient analysis    (acceptable range is +/- 10 to 14 days of this date)
August 1, Fri	European red mite threshold until August 15 is 7.5 mites per leaf, or mites present on 86% of middle-aged leaves.  See August ERM sampling table for optimum scouting intervals.
August 6, Wed	2nd generation Codling moth 7% egg hatch.  If control needed, and Bt or other material requiring repeated applications for control is being used, this is best date for first application.  See Codling moth tables for follow-up spray dates to maintain protection through 2nd generation CM egg hatch.     No reliable threshold:  Go by block history.  Another risk indicator is pheromone trap capture above 5 to 14 codling moths per week.
August 16, Sat	2nd generation White apple leafhopper nymphs present.  Threshold:  2 per leaf, lower if leafhoppers were a problem at harvest last year
August 16, Sat	Rough estimate for most effective date to apply ReTain to non-spur McIntosh.
August 18, Mon	2nd generation Codling moth - best treatment date where single spray is adequate (estimated 30% egg hatch)
Preharvest	Harvest preparations to optimize fruit quality, to reduce bruising and to prevent postharvest rots:    Repair and disinfect bins; monitor fruit maturity; make arrangements for harvest management; smooth travel lanes; check rapid cooling capacity; packing shed sanitation; set criteria for determining if postharvest dip needed.
August 25, Mon	Rough guess at latest recommended date to begin starch iodine index monitoring for non-spur McIntosh.  See 'Harvest dates' and 'Other cultivar' tables for rough estimates of harvest dates.
August 31, Sun	August mean temperature more than 1 degree F below long-term average.  Observations in Western NY have associated this with increased susceptibility fruit to Low Temperature Injury during CA storage.
August and September	Most effective timing for controlling persistent weeds (bindweed, brambles, dandelion, goldenrod, vetch etc.) with carefully targetted glyphosate (Roundup).  But there is also increased risk of systemic tree damage from misdirected spray and on trees with root suckers with late-season application.  Requires extra caution for application method and wind.  Trees with root suckers removed at least one week prior to application and with trunks protected with white paint are less susceptible.  Also note preharvest interval.    Green apple aphid populations typically under biocontrol by this time.  If abundant, see threshold comments in the mid-June entry.  Also, high aphid population near harvest can result in honeydew staining of fruit.  The sticky honeydew is relatively easy to wash off, but can lead to sooty mold growth and be a problem for harvest operations and pick-your-own marketing.  Threshold stated as 10% of fruit stained, but actual threshold is farm-specific.
September 13, Sat	For long-range planning only:  Preliminary early season estimate of when non-spur McIntosh will reach starch index 4.  This begins the optimum maturity window to harvest for long term CA storage.
September 22, Mon	Preliminary early season estimate (where Champlain Valley maturity model is applicable, see Harvest Dates table for others) of when non-spur McIntosh will reach starch index 6, and end of optimum maturity window to harvest for long term CA storage.
During or soon after harvest	Record pest damage observations at harvest to improve next year's pest management program.     About 25 minutes per block for Apple scab indexing after September 15 and before leaf discoloration in October can yield more effective and less expensive scab control next spring.
October 8, Wed	End of chilling hour forecast range.  165 preharvest chilling hours  NOT accumulated by this date
Fall activities	Look for trees with foliage turning color earlier than others.  May be indication of collar rot or fire blight rootstock infection, systemic herbicide damage, vole girdling, or other damage to tree's vascular system.    Check trees with trunks less than 4 inch diameter for signs of borers and remove borers if found.
Fall activities	Check vole monitoring stations for activity .  Chances of vole damage are higher where grass alley between trees and woods or brushy border has not been regularly mowed through summer and fall weeds cover more than 40% of tree row area.  If more than 20% of apple slices placed under shingles with evidence of vole activity are chewed or entirely missing after 24 hours, this indicates potential for serious vole damage.    Mowing is effective at reducing subsequent vole immigration.  If using vole bait, remove drops as bait competition and wait for forecast of three dry sunny days in succession.     Recheck vole stations for recent activity 2-3 weeks after application to see if reapplication needed.    Check vole guards before snow season.
Fall activities	Flail mowing and/or urea application to reduce overwintering Apple scab and leafminer populations.    Painting trunks with white latex paint solution reduces freeze cracking, may reduce borer infestation and makes detection of infestation easier to see, and reduces bark exposure to misdirected herbicide spray.    Check and repair fencing before deer establish feeding habit.
Fall activities	Clean and service spray equipment, prepare them for winter storage.  Insure proper storage conditions for leftover pesticides.  Review what worked and didn't work well is pest management program this year, and why.
Winter activities	Check for vole damage, re-bait if needed and there is no snow cover.  Maintain deer fence and repellants, remove violators.  Remove wild host trees tagged earlier, remove undesirable windbreaks.
Winter activities	Consider pest management needs while pruning, i.e. open canopy and removal of cankers and fire blight-infected wood.    Burn prunings that had wood rot canker or Fire blight.    Catch up on pest management reading in Extension and trade publications, attend winter meetings.
Winter activities	Review what did and did not work well in your pest management program this year, and why.    Revise pest management plan for coming season.  Get specific.  Write it down!    Inventory pesticides.  Organize record keeping. Order pesticides, traps, etc. for next spring.
Before budbreak	Check tractor and sprayer for needed repairs.    Replace worn nozzles, weak hoses, damaged or blocked filters, and inaccurate pressure gauges.  Check for tank leaks, adequate agitation and pump function.    Check commonly used dosage calculations.  Review safety guidelines, check safety equipment.    Calibrate sprayers, test spray pattern, test pH of spray water source.