SCAFFOLDS Fruit Journal, Geneva, NY Volume 4 Update on Pest Management and Crop Development June 5, 1995
43F 50F Current DD accumulations (Geneva 1/1-6/5): 766 423 (Highland 3/1-6/5): 818 444 Coming Events: Ranges: Spotted tentiform leafminer 1st flight subsides 489-978 270-575 American plum borer 1st flight peak 535-962 273-601 Codling moth 1st flight peak 547-1326 307-824 Obliquebanded leafroller 1st catch 686-1059 392-681 San Jose scale 1st flight subsides 768-1058 434-648 European red mite summer egg hatch 773-938 442-582 Dogwood borer 1st catch 798-1182 456-718 TRAP CATCHES (Number/trap/day) Geneva: 5/22 5/25 5/30 6/1 6/5 Redbanded Leafroller 1.3 1.0 0.2 1.0 0 Spotted Tentiform Leafminer 202 108 63 42 29 Oriental Fruit Moth (apple) 10.9 9.5 2.1 3.5 0.8 Lesser Appleworm 12.2 15.0 6.9 6.3 1.9 Codling Moth 2.3 3.7 1.9 21.8 5.9 San Jose Scale 0.1 1.0 0 3.5 2.3 American Plum Borer (cherry) 0.4 1.8 0.8 4.5 2.4 Lesser Peachtree Borer (peach) 0 0.3* 1.1 2.5 2.9 Lesser Peachtree Borer (cherry) 0 0 0.6* 3.3 3.0 Peachtree Borer 0 0 0 1.3* 4.0 Highland (Dick Straub, Peter Jentsch) 5/15 5/22 5/29 6/5 Redbanded Leafroller 0.7 0.6 <0.1 0 Spotted Tentiform Leafminer 8.2 2.6 0.5 0.9 Oriental Fruit Moth 1.0 0 0.5 1.1 Fruittree Leafroller 0.2 0 0 0 White Apple Leafhopper nymphs <0.1 - <0.1 <1.0 Codling Moth <0.1* 1.9 4.6 4.9 Lesser Appleworm - 1.0* <0.1 0 Sparganothis Fruitworm - 0 0 0.1* Tufted Apple Budmoth - <0.1* 1.1 1.4 * = 1st catch PEST FOCUS Geneva: Peachtree Borer 1st catch, 6/1. Highland: Sparganothis Fruitworm 1st catch, 6/5; 1st Rose Leafhopper adult on apple, 6/1. Albion: Obliquebanded Leafroller pupae present, 5/31. Lockport: Spotted Tentiform Leafminer sapfeeding mines present.
Peach leaf curl has been unusually severe in the Hudson Valley this spring. Contributing factors were that orchards were left unsprayed last year when we had no crop, and we had an unusually mild winter. In some cases, leaf curl was showing on more than 50% of the leaf canopy as of last week.
Larvae of the first OBLR summer brood cause two kinds of damage -- foliar feeding injury and rolling of the leaves, and more importantly, injury caused by feeding on the surface of the developing fruits. This fruit damage is usually more serious than the spring feeding by overwintered larvae, because more of the fruit injured late in the season remains on the tree at harvest. Despite the rather extreme measures some growers wage in the spring against the early generation larvae, you should remember that even an excellent control program against the overwintered brood does not eliminate the possibility of a problem summer population. To maximize the effectiveness of any sprays against the first summer generation OBLR infestation, you should sample leaf and fruit clusters at the proper time. You will need to know the date of the first adult flight in your area; the value of knowing the precise date of this event on your own farm cannot be emphasized too strongly, and maintaining a few pheromone traps is not very difficult or time consuming. Check traps two or three times a week until the first adult is caught. Wait for 600 degree-days (43 F base) after this date. Degree-day (DD) values can be obtained for some locations from CENET (from the "CLIMOD" Menu) or from Cooperative Extension personnel. You can also just look them up on the DD Charts that appeared in the March 20 Scaffolds, or else estimate them each day by using the following formula:
Degree Days for 1 Day = 1/2 x [Daily Maximum Temp. + Daily Minimum Temp.] - 43.If you do not have access to any of this information, use July 5 as an estimated best sample date in a "normal" year.
Guidelines for sampling can be found on pp. 77-78, 85-86, 89 and 94 of the 1995 Recommends. Sample from random trees that are representative of the entire block, examining 10 expanding leaf terminals per tree. It is not necessary to pick the terminals. Record the number of samples infested with live larvae; do not count actual numbers of larvae in an infested terminal, and do not count damaged terminals that have no OBLR in them, or those containing only dead OBLR. To minimize bias, choose half of your samples from inside the tree canopy, including some watersprouts, and the other half from near the outside of the canopy. If the tree is more than 10 ft tall, try to include some clusters from the mid- to upper canopy area. Use the 3% infestation threshold for fresh fruit, and 10% for processing fruit. A "Stop Sampling and Treat" decision means that a spray to control OBLR is recommended at this time. A "Stop Sampling, Don't Treat" decision indicates that you should return in 3-5 days, after 100 more degree-days have accumulated, and repeat the sample. A second "Below Threshold" decision indicates that no treatment against this generation of OBLR is recommended. Recommended materials include a B.t. product (such as Dipel, Biobit or MVP), Lorsban, Lannate, or possibly Asana or Penncap-M, depending on the population pressure in your orchards and the considerations discussed in the 5/30 article. We have a 2(ee) recommendation for Dipel plus a 1/10 rate of Asana, but please note that this strategy tends to be variable in its success rate from block to block. More on this pest in the next issue.
Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:
Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX:315-787-2326
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