More than half the flies caught in traps this week were spotted wing drosophila rather than the usual 5% or less. As blueberry harvest finishes in the region, blackberry and grape remain the main crops currently at risk and should be kept covered with short pre-harvest interval insecticides.
Some of the commonly used developmental models seem to be overestimating the pace of development for codling moth and Oriental fruit moth populations in some orchards. Therefore, such models are not very reliable indicators of the actual pest situation. Please use on-site monitoring as the main indicator in deciding if and when pesticide application is necessary.
A number of calls have come in this year regarding blueberry plants with few leaves – though some canes often appeared nearly normal – and berries on the same plant that ranged in size from normal to very tiny.
Spotted wing drosophila (SWD) numbers are up in most Pennsylvania and Maryland locations, and late blueberries and blackberries are at risk. Commercial SWD lures are supposed to last only 4 weeks and should be changed out soon.
While in most orchards the brown marmorated stink bug numbers are still very low, at some locations we spotted the first fruit injuries caused by this pest. Populations of spotted wing drosophila might be higher than in the past this season due to tart cherry blocks that were not harvested because of a light crop and their potential as reservoirs for SWD populations to build.
Management is discussed for controlling the physiological disorder necrotic leaf blotch, which is being reported throughout the area. Managing late season bacterial spot and rot diseases on stone fruit is also discussed. Disease infection periods to date for apple scab, fire blight, cedar apple rust and cherry leaf spot are included to help growers determine where control failures may have occurred this season.
Second generation flights of tufted apple bud moth and obliquebanded leafroller are underway in South-Central PA orchards, and third generation Oriental fruit moth and second generation codling moth flights are beginning. During our weekly searches on various actual and potential BMSB hosts we are continuously finding all instars of brown marmorated stink bug.
This week the U.S. Department of Agriculture (USDA) announced Noninsured Crop Disaster Assistance Program (NAP) assistance for losses to bush or tree fruit crops due to frost or freeze during the 2012 crop year. The program, authorized by the 2014 Farm Bill, provides supplemental NAP payment to eligible producers.
Plant tissue analysis is used to directly measure the amount of nutrients in fruit trees, and for established perennial crops, is usually a better indicator of nutrient status than a soil test. Nutrient management plays an especially critical role in new high density plantings because the trees come into production earlier, have higher per acre yields and smaller root systems.
Four of 7 spotted wing drosophila found this week were in black raspberries which are finishing up in Pennsylvania and shouldn’t be an issue at this point. First captures occurred in blueberry, grape and blackberry.
According to moth captures in sex pheromone traps located in various orchards in South-central Pennsylvania the third generation of Oriental fruit moth (OFM) and the second generation of codling moth (CM) just started. The first summer Brown Marmorated Stink Bug adult generation is imminent. While in the majority of orchards the numbers are still very low, at some locations we observed the first fruit injuries caused by this pest.
Growers of raspberries (both red and black), blackberries, and blueberries in particular should be monitoring for spotted wing drosophila (check traps daily if possible), and should be prepared with effective materials for control.
The first male adults of spotted wing drosophila were observed in traps placed in nearby northern Maryland. European red mite populations are increasing in some orchards.
With the cold winter last season, we are expecting a higher than normal winter mortality, and hopefully a later than usual emergence of spotted wing drosophila. At this time, we do not believe cherries are at risk and that we probably have at least another week before the first flies will be caught.
We are collecting brown marmorated stink bug adults and nymphs (first week of capturing nymphs) in traps located in fruit orchards and baited with a combination of BMSB aggregation pheromone. Also, earlier this past week we received a notice from the Pennsylvania Department of Agriculture confirming the EPA approval for Section 18 Emergency Registration for PA of bifenthrin (pyrethroid, IRAC Group 3A). Japanese beetles are present in orchards located in southern Pennsylvania.
Today we are experiencing our fourth wave of interest in summer pruning fruit trees during the past 130 years. Summer pruning is a vague term and simply refers to the time of year pruning is performed (when trees have foliage) and does not describe the type of pruning cuts, pruning severity or the physiological stage of tree development when pruning is performed.
Conditions so far this season have been excellent for many stone and pome fruit diseases. Sooty blotch/flyspeck treatment threshold has been reached and disease control is encouraged. In addition to SBFS, management strategies are covered for fire blight, apple scab, fruit rots, bacterial spot, cherry leaf spot, and powdery mildew.
Brown marmorated stink bug nymphs are now present in orchards, which means a shift from “probable BMSB injuries” to actual nymphal feeding (and injuries) on fruit. From mid July until November, traps baited with commercially available, BMSB lures are very effective in detecting and capturing BMSB adults and nymphs. Green/spirea aphids, leafhoppers (potato, white apple and rose) and leafminers are the insects to watch for during the month of July.
I suppose I do not have to tell you that bacterial spot is a difficult disease to manage. Despite numerous bactericide applications, significant yield loss is not uncommon depending on the disease pressure and cultivar susceptibility. As a Master’s student in the department of Plant Pathology and Environmental Microbiology at Penn State, much of my research was focused on refining bacterial spot management. Specifically, I examined the epidemiology of bacterial spot, the defoliation associated with the disease, and age related resistance in fruit.
A toll-free hotline is available for growers in the region to receive seasonal updates about pest and pest management information. Laminated copies of the fungicide resistance management guidelines for scab, powdery mildew, brown rot, and peach scab are available for anyone who didn’t receive a copy during the spring twilight meetings this year.