A recent question from a raspberry grower in North Jersey asked about treatments for SWD on raspberries. The following table is from Cornell University – Greg Loeb, Laura McDermott, Peter Jentsch, Tess Grasswitz and Juliet Carroll, and published in the New York State Berry Growers Association newsletter: [Read more…]
Fruit Crops Edition
Seasonal updates on diseases, insects, weeds impacting tree fruit and small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
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Getting the Upper Hand on Virginia creeper
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/07/vacreeper8-1-300x202.jpg)
Picture 1 – Virginia creeper vine
Virginia creeper (Parthenocissus quinquefolia) is a perennial woody vine that climbs on other objects or trails along the ground. It is a common weed of orchards, vineyards and blueberry plantation. It is best identified by the typical palmate leaf with 5 leaflets that originate from the same point (picture 1). Virginia creeper will produce many tendrils with adhesive disks at their tips that will allow the vine to climb upward and to attach to any support. It can grow under a wide range of conditions including dry sandy or moist organic soils, sunny or shady sites, and is tolerant to high salinity. Plants will often establish through seeds dropped by birds who consumed the small blue berries in fall, but also by the spread of crawling stems that will produce new roots in contact with soil (picture 2). Virginia creeper is often confused with Poison-Ivy (Toxicodendron radicans). However, poison-ivy has 3 leaflets instead of 5 for Virginia creeper and lacks the tendrils and adhesive disks.
As a perennial weed, Virginia creeper will be tough to control as it can easily regrow after foliar injury from its extensive underground root system. When established, Virginia creeper will most often not be controlled with a single herbicide application, and multiple applications will be necessary to achieve acceptable control. Only nonselective postemergence herbicide (glyphosate) must be used to suppress or control this weed. In order to increase the efficiency of postemergence applications during the growing season, remove the vine from their support during winter pruning and lay it on the ground or plan a “cut stump” treatment during the growing season. Do NOT “prune out” the vine during the dormant season.
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/07/20170703_124109-300x225.jpg)
Picture 2 – Virginia creeper rooting stem
Spot treatment. Glyphosate may be applied in mid- to late summer after vine flowers in early July until the first signs of fall color appear in the foliage. Good growth and maximum leaf area is needed at the time of herbicide application during the summer. Wet a minimum of 50 percent of the weed foliage with a 1% glyphosate solution (1.25 oz of 4.5lb acid material per gallon of water) for effective control. For best control, don’t apply on stressed/wilted weeds.
Cut stump treatment. Best results are often obtained in late summer and early fall, but before fall color is observed in the foliage. Apply a 1% glyphosate solution to the cambial areas (inner bark area) of the stump of woody plants IMMEDIATELY after cutting. Cut and treat stumps only when the Virginia creeper is actively growing and not under stress.
WARNING. Injury due to root grafting may occur in adjacent plants. Do not treat cut stumps if there is a possibility of root grafting to desirable vegetation. Do NOT allow contact with green bark, trunk wounds, leaves, or root suckers of blueberry bushes.
The mention of trade names and rates is for educational purposes and does not imply endorsement by the author or the New Jersey Agricultural Experiment Station. Always defer to the product label for instructions on properly applying an herbicide.
Fruit IPM for 7/7/17
Peach:
Oriental Fruit Moth (OFM): The next and 3rd flight for OFM has begun in southern counties. This will produce the 3rd brood of larvae. First generation eggs are laid primarily on leaf petioles and larvae mine down the petiole into new shoot growth, causing the flagging on terminal growth. The second generation has a similar behavior, but also lays eggs on the fruit, producing fruit infestations. This generation lays eggs primarily on the fruit, and can cause considerable fruit infestation or ‘wormy fruit’ if left uncontrolled or improperly sprayed.
Sparganothis Fruitworm Degree-Day Update: as of July 05, 2017
Based on our degree-day (DD) model for Sparganothis fruitworm, first eggs hatched at about 900 DD (see chart). As of July 05, Sparganothis has accumulated 1,358 DD (using March 1 as biofix) or 1,318 DD (using April 1 as biofix). This indicates that most eggs should have hatched by now and fruit is susceptible to infestation. Most beds are out of bloom (early varieties) or should be coming out of bloom. Thus, if trap counts have been high, then a post-bloom application might be necessary. Growers should consider treatment in the next few days (as soon as bees are removed) to prevent damage to berries. Your best post-bloom options are Diazinon, Altacor, or Delegate.
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/07/DD-Sparg-300x225.jpg)
Sparganothis fruitworm degree-day benchmarks
Fruit IPM for 06/27/17
Blueberry:
Spotted Wing Drosophila (SWD): Adult trap captures have remained close to the averages seen the previous week, but maximum trap captures increased in Atlantic County to 30 males per trap on 1 farm. Weekly applications are still required on both Duke and Bluecrop. The same type of program should also include late varieties like Elliott. No infested harvested fruit have been found on any commercial farms as of this date.
Sparganothis Fruitworm Degree-Day Update: as of June 25, 2017
Based on our degree-day (DD) model for Sparganothis fruitworm, peak flight is expected at around 884 DD and first eggs hatched expected at 895 DD (see chart). As of June 25, Sparganothis has accumulated 1,118 DD (using March 1 as biofix) or 1,078 DD (using April 1 as biofix). This indicates that we have passed peak flight and eggs have started to hatch. I will keep you updated as the season progresses.
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/06/DD-Sparg-2-300x225.jpg)
Sparganothis fruitworm degree-day benchmarks
Cranberry beds are in bloom. If insects have been effectively managed prior to bloom, we recommend no sprays at this time. A reminder: when bees are present your only choices of insecticides are insect growth regulators (IGRs) such as Intrepid 2F or Bt products such as DiPel. During bloom we recommend monitoring insect populations using pheromone traps. Pheromone traps should be used particularly to monitor activity of Sparganothis fruitworm and blackheaded fireworm, two key pests in New Jersey.
Sparganothis fruitworm- Damage by the second generation larvae begins after the eggs hatch, usually 9-12 days after they are laid. Based on our DD model, eggs have started to hatch (see above). These larvae will feed on foliage and fruit. Larvae will partially feed on berries, causes scarring of the fruit. However, particularly on Ben Lear, larvae may feed inside the fruit. Insecticide treatment should target small larvae. Pheromone traps can be utilized to time insecticides sprays. If treatment is required, sprays should be applied two weeks after peak moth flight and/or earlier if using an IGR. If trap counts indicate a low population that requires management, a single insecticide application may be made post-bloom. If trap counts are high, then an early application of an IGR may be used when the first eggs start to hatch, i.e., at this time of the year (this is most critical for early varieties). This would be followed by a second application soon after bloom, which is approximately 1,400 DD and will most likely coincide with the 1st-2nd week in July. Your post-bloom options are Diazinon, Altacor, Delegate, or Intrepid.
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/06/Blackheaded-fireworm-Larva-200x300.jpg)
Blackheaded fireworm larva
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/06/Sparganothis-fruitworm-Larva-300x164.jpg)
Sparganothis fruitworm larva
As indicated above, controlling fruitworm populations is often very difficult and many require multiple applications depending on pest pressure. Sparganothis fruitworm populations in Massachusetts are resistant to organophosphate insecticides (e.g. Diazinon, Lorsban). Thus, organophosphates should be used with care, i.e., always rotate insecticides with different modes of action. Organophosphate insecticides will also negatively affect natural enemy populations. Delegate, Intrepid and Altacor are reduced-risk insecticides registered against fruitworms and can be used as an alternative to organophosphates post-bloom.
![](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/06/Sparg-adult-1-300x226.jpg)
Sparganothis fruitworm adult