| Background Information for this page | |
| Return to radar list for Sanford ME | |
| Weather data for Sanford ME. Forecast values begin August 13, 2009 | |
Green text is for horticultural events and management activities. Red is for insect pest events. Maroon is for mite pest events. Blue is for disease events. |
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| Highest priority growing season activities are highlighted in yellow boxes. | |
| Date | Biological Events and Management Activities |
| Before
bud break |
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. |
April 18, Sat |
McIntosh trees at 50% Green Tip (observed) Where copper deficient, foliar application recommended at green tip to 1/4" green. Later application can cause leaf burn and possibly lead to fruit russetting from residue. If monitoring tarnished plant bug, traps should be set by now or as soon as possible. If using traps to monitor leafminers, traps should be set by now or as soon as possible. Cutworm defoliation of emerging buds can be a problem on young trees as early as green tip, especially where there is high ground cover growth near the trees. |
April 21, Tue |
First primary scab infection period. See Scab ratings tables and charts for details. |
April 26, Sun |
McIntosh trees at Half-Inch Green Beginning of optimum time window for oil application to smother European red mite eggs before they hatch. More than 3 thrips per fruit bud can decrease fruit set. Effective timing for Lorsban trunk application to get season-long suppression of insect borers. |
April 28, Tue |
Beginning of 1st generation Spotted tentiform leafminer flight |
April 30, Thu |
McIntosh Tight Cluster First of two foliar urea applications for possible fruit set improvement is timed for tight cluster to pink (2nd is after petal fall). Where zinc is deficient, first of two zinc chelate applications recommended at tight cluster (2nd is second cover spray after petal fall). Tarnished plant bug damage beyond this point leaves damaged fruit on tree: retail crop threshold - cumulative average 5 per trap wholesale crop threshold - cumulative average 3 per trap Leafminer thresholds: McIntosh - cumulative average 4 per trap other cultivars - cumulative average 8 per trap |
| Tight
Cluster to Pink thresholds for other pests:
Green fruit worm - 5 larvae per 100 fruit clusters. Green pug moth - 6 larvae per 100 fruit clusters. Obliquebanded leafroller - 2+ larvae in first 30 fruit clusters or vegetative terminals, 3+ in 100 (can stop looking if there are none in first 50) Rosy apple aphid - 1 or more colonies per 100 fruit clusters. Watch for Tent caterpillars on low-spray trees. Where Powdery mildew is a concern, check 100 terminals per block (10 per tree x 10 trees). Between Tight cluster and 1 week after Petal fall, threshold is 10% infected terminals. Threshold indicates need for treatment because of high risk for subsequent yield reduction and fruit infections. |
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| May 1, Fri | First primary scab infection period on or after Half Inch Green. Infection risk increases as green tissue expands. |
May 2, Sat |
McIntosh Open Cluster As good a time as any to set out shingles to establish vole monitoring stations for late summer and fall use. A few stations in border rows is better than none. A full block survey requires stations in every 4th tree in a center row, and one station per row in a diagonal line across the block. Set European apple sawfly traps. |
May 5, Tue |
1st generation European red mite egg hatch begins Prebloom oil treatment still worthwhile, but loses some efficacy as eggs hatch progresses. |
May 7, Thu |
McIntosh full extended Pink Tarnished plant bug thresholds: retail - cumulative average 8 per trap wholesale - cumulative average 5 per trap Leafminer thresholds: McIntosh - cumulative average 9 per trap other cultivars - cumulative average 21 per trap. Pink stage is control opportunity for TPB, mullein bug, rosy apple aphid, green fruitworm where these pests are over threshold. Pink insecticide application may also suppress European apple sawfly, Plum curculio, leafrollers and other caterpillars. |
May 7, Thu |
Gypsy Moth eggs hatch into larvae (rough guess) Gypsy moth feeding on buds can cause serious defoliation on young trees with no prior insecticide coverage, Bt is an option if treatment needed before petal fall. |
May 8, Fri |
McIntosh King Bloom See Fire blight tables and charts for early warning of blossom blight infection conditions. |
May 11, Mon |
McIntosh Full Bloom Apogee for vegetative growth control and reduced susceptibility to fire blight shoot infection should be applied when the most vigorous shoots are 1 to 2 inches long. This usually coincides with late bloom - petal fall. Weed competition in the tree row is most damaging to tree growth and productivity in the prebloom-bloom-early summer period. Postemergence burndown herbicides are more effective and lower end of rate range can be used when weeds are small: <6" for Gramoxone (paraquat), <8" for Rely (glufosinate), < 12" for Roundup (glyphosate). If monitoring Codling moth, set pheromone traps. Best time to find blooming wild rosaceous pest-host trees in woods within 50-100 meters of orchard and tag for later removal. |
May 13, Wed |
Peak of 1st generation Spotted tentiform leafminer flight |
May 15, Fri |
1st generation White apple leafhopper (WAL) nymphs present |
May 19, Tue |
McIntosh 95% Petal Fall (estimated or observed) European apple sawfly thresholds: block without prebloom insecticide - 4 to 5 per trap block with prebloom insecticide - 6 to 9 per trap. Monitor Plum curculio damage if delaying insecticide past petal fall. Threshold for 1st generation European red mites is an average of 1 mite per leaf, or mites present on more than 30% of middle-aged fruit cluster leaves. If ERM are over threshold, suppression is more effective if done quickly to minimize the number of 2nd generation eggs. Consider need for Calyx end rot control in fungicide selection if bloom period had prolonged wet cloudy weather. Where Powdery mildew is a concern, Petal fall is end of time window for optimum fungicide control. Continue monitoring until terminal bud set. Date for terminal bud set varies by cultivar, tree age, and nutritional status, but is generally around 6-8 weeks after Petal fall. |
May 20, Wed |
McIntosh at about 100% Petal Fall See Thinning Weather table and chart to identify optimum conditions and to help adjust rates for chemical thinning. Second of two foliar urea applications for possible fruit set improvement is timed for petal fall to 7 days after petal fall. Where magnesium deficient, foliar application is recommended for petal fall, first and second cover sprays (risk of phytotoxicity if temperature > 80F or if slow drying conditions). |
May 20, Wed |
Mullein plant bug egg hatch at 50%, best time for limb tap sampling, especially where there is block history of damage. Threshold: 8 nymphs per 20 limbs tapped over 2-foot-square dark tray. |
May 20, Wed |
White apple leafhopper threshold - 1 per leaf, lower if leafhoppers were a problem at harvest last year. Obliquebanded leafroller - Last opportunity to control spring generation of larvae. Threshold: 2+ larvae in first 30 fruit clusters or vegetative terminals, 3+ in 100 (can stop looking if there are none in first 50). Although the ideal timing may be different for each pest, insecticide application at petal fall also helps control rosy apple aphid, tarnished plant bug, codling moth, green fruitworm, leafrollers, and roundheaded apple tree borer. |
May 22, Fri |
McIntosh Fruit Set Good time to recheck that sprayer calibration is still on target after early season sprays. First cover spray is timing for manganese foliar application where deficient. One of many boron application times, boron recommendations are too complex for this table. Increased risk of Plum curculio damage. Usually best time for scouting 1st generation Spotted tentiform leafminer mines as more of the first generation mines have had time to appear, but still early enough for effective control even with systemic insecticide options that require application within two weeks after petal fall for best absorption. Where Powdery mildew is a concern, check 100 terminals per block (10 per tree x 10 trees). Finding more than 20% infected terminals between fruit set and terminal bud set indicates weakness in control program and high risk for yield reduction and fruit infection next season. Date for terminal bud set varies by variety, tree age and nutritional status, but is generally around 6-8 weeks after Petal fall. |
May 24, Sun |
1st generation Spotted tentiform leafminer sap-feeding mines start showing. Thresholds vary between states: McIntosh & stressed trees - 7 to 50 mines per 100 leaves; other cultivars and unstressed trees - 14 to 100 mines per 100 leaves |
May 24, Sun |
Date by which 50% of primary scab potential has had time to begin appearing as 1st generation foliar lesions. Good time for intensive scab scouting. Finding 5 or more infected leaves per 100 fruit cluster clusters in a commercial orchard suggests need for increased fungicide protection to suppress spore production from lesions and to protect leaves and fruit from secondary infections. It also indicates need to identify cause for breakdown in protection. Common causes are inadequate fungicide coverage, timing, or dosage. |
May 24, Sun |
Date of earliest High or Extreme fireblight infection risk where inoculum abundant |
May 27, Wed |
Best-guess date for 95% scab ascospore release (50:50 chance that true value is higher or lower). Reasonable estimate for depletion of primary scab infection risk in blocks where low scab inoculum was documented with scab index the previous fall. |
May 27, Wed |
Date of final primary scab ascosore release ('final' defined as best guess that 99+% of ascospores have been released, with high probability that at least 95% have been released.) |
June 8, Mon |
If using pheromone traps to time sampling for Obliquebanded leafroller larvae, time to set traps. First trap capture expected in 7 days. |
June 8, Mon |
Date by which 50% of primary scab potential has had time to begin appearing as 2nd generation lesions on foliage and fruit. Finding more than 5 scab-infected leaves per 100 fruit clusters or vegetative shoots in a commercial orchard suggests need for fungicide applications 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 9, Tue |
Date by which ALL primary scab infection periods have had time to begin appearing as 1st generation lesions. Finding scab infections on fewer than 5 leaves per 100 clusters/shoots suggests that primary scab control was successful. If there is doubt about primary scab control, continue sampling for 2nd generation lesions before relaxing protection against secondary scab. Light infestation of 1st generation lesions can be difficult to detect. Infections delayed but not killed by fungicide application or partial resistance of older leaves may appear later. Finding more than 5 leaves with fresh scab lesions per 100 fruit clusters and vegetative shoots in a commercial orchard at this time 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 10, Wed | First date after Petal Fall with increased sensitivity for chemical thinner application. |
June 13, Sat |
Roundheaded apple tree borers begin laying eggs. Young trees or other trees not receiving insecticide for other pests need to have protection by a physical barrier or trunk insecticide on or before this date. |
| June 14, Sun | Recommended timing to begin calcium foliar sprays at two week intervals to prevent early summer cork spot and late summer bitter pit before harvest, and to decrease senescent breakdown in storage. Increased calcium level may also decrease chance of storage scald. Where zinc is deficient, second of two zinc chelate applications recommended for 2nd cover spray after petal fall. |
| mid-June to mid-July |
Most effective timing for controlling persistent weeds (bindweed, brambles, dandelion, goldenrod, vetch etc.) with Gramoxone (paraquat) or Rely (glufosinate). Green apple aphid populations typically become more apparent at this time. Effective biocontrol in most orchards limits threat to young trees for which maximum growth is desired. Treatment threshold on established trees is if more than 50% of shoots are infested AND less than 20% of aphid colonies have predators. |
June 15, Mon |
1st generation Codling moth 3% egg hatch. Codling moth control typically provided by insecticide applications against plum curculio and apple maggot. If separate codling moth control is 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 1st 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. |
June 16, Tue |
If using pheromone traps to time sampling for 2nd generation Spotted tentiform leafminer, time to set traps. First trap capture expected in 7 days. |
June 16, Tue |
ERM threshold increases to 2.5 mites per leaf, or mites present on 59% of middle-aged fruit cluster leaves, until July 16. See ERM sampling table for optimum scouting intervals. |
June 17, Wed |
Date by which blossom blight symptoms would become obvious if Fire blight infection occurred on May 24. |
June 18, Thu |
Second generation European red mite nymphs appear. An important monitoring period is between now and June 25 to detect above threshold population before 3rd generation eggs are laid. |
June 19, Fri |
Earliest safe date for final Plum curculio insecticide spray. See Plum curculio table and charts. |
June 21, Sun |
End of Plum curculio control period |
June 23, Tue |
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 25, Thu |
1st generation Codling moth - best date for single spray (estimated 20% egg hatch) where separate control needed. No reliable threshold: Go by block history. Another risk indicator is pheromone trap capture above 5 to 14 codling moths per week. |
June 25, Thu |
Earliest 2nd generation European red mite adults begin laying 3rd generation eggs. |
June 28, Sun |
Date shoot blight symptoms would become obvious if fireblight infection occurred on May 24. |