Integrated Fruit Production in Hood River, Oregon

The Mid-Columbia (OR) Valley tree fruit production region is a major producer of pears, cherries, and apples on 15,000 acres. Hood River Valley growers have embraced a system of Integrated Fruit Production (IFP) to economically produce high quality fruit while protecting human health and the environment. Also, they hope to distinguish themselves in the marketplace (both foreign and domestic) by promoting IFP. Basic tenets of IFP adopted by Hood River Valley growers include:

Horticulture:

• maximize production of high quality fruit
• minimize water application to reduce the possibility of leaching nutrients or other chemicals through the plant root zone
• minimize nitrogen applications to prevent potential leaching while insuring adequate tree growth
• utilize only non-persistent, contact herbicides in the herbicide strip
• utilize those practices which encourage fruit production and quality while reducing pest and disease pressure

Pest management:

• reduce use of OP and other broad-spectrum insecticides
• increase use of selective control alternatives such as IGR’s, pheromones, spray oils, etc.
• apply pesticides only when treatment thresholds are exceeded
• alternate pesticides with different modes of action to delay resistance development
• encourage biological control of pear psylla and other pests
• adjust spray volumes using the tree-row-volume concept
• employ sprayer technology which reduces pesticide runoff and drift

Although all these basics of IFP used in the Hood River Valley are not equally applicable to Massachusetts orchards, the majority should serve as a model for a system of sustainable fruit growing in the State and the Northeast.

Plum Curculio

For those who had enough insecticide residue on perimeter-row trees to protect fruit through the weekend, you can consider the PC season to be over. If you didn’t see any fresh PC egglaying scars by this past Saturday or Sunday, chances are you won’t see any for the rest of the year. During the past week, we had substantial immigration of PC from overwintering sites, as indicated by PC captures.

We believe that rather few overwintered PCs still remain in woods and hedgerows. Not enough to worry about.
PC egglaying on unmanaged trees shot up rapidly during the warm and humid nights of the past week, reaching 45% of sampled fruit damaged by PC or a 92% increase over the previous week. In commercial orchards, damage increased by 33% over the previous week, which was considerably less than the 76% increase in PC damage during this same week a year ago. This suggests that growers this year were more attentive to controlling PC through mid-June than they were a year ago.

For those who have seen substantial fresh PC egglaying scars on perimeter-row trees during the past few days, a perimeter-row spray might be a good idea because the PCs causing the damage can continue to do so for at least a couple of weeks.

Leafminers

Some second-generation adults are now emerging, though most LM are in the pupal or larval stage. Only about 10% or so of sampled commercial orchards are showing enough mines to call for a treatment against LM. If you are among those unlucky few, then next week might be the optimum time to consider a spray of Provado, Spintor, or Esteem against second-generation eggs and larvae.

Mites

Red mite eggs have begun to hatch, and this week is an ideal time to sample foliage for determining a need for miticide application. Mid-age fruit cluster leaves or older leaves of terminal shoots are the places to look. If you find 50% or more of sampled leaves having motile mites, it may be worthwhile to apply a miticide in the near future to catch the young nymphs at their maximum stage of pesticide susceptibility.

Aphids

Spirea and green apple aphids are beginning to appear on growing tips of terminal foliage. But in most orchards plenty of predators are on hand to provide very good biocontrol. So there should be little or no need to target these aphids with a spray.

Pear Psylla

First generation of summer eggs have hatched. Now is an ideal time to sample for this important pest by examining leaves on terminal shoots for the nymphs. If more than 2-3 nymphs per leaf are found, it is a good bet that trouble lies ahead if no action is taken. Pyramite and Provado are good candidate materials for use at this time, but it’s too late for effective control by Agri-Mek or Esteem.

Peach Borers

As indicated by pheromone traps, adults of both lesser PTB and PTB have emerged. Now is a good time to apply Lorsban 4 EC to trunks of peach trees to control newly laid eggs and emerging larvae of this pest. If Lorsban is applied now, residual activity in bark should last through the egglaying period of this generation. Lorsban should be restricted to peach tree trunks and limbs. Applications should not reach the fruit.

Scab Laboring

Apple scab is continuing to develop sporadically in some orchards. Lesions from infections that occurred at the beginning of June are now showing up. Ascospore production stopped about 2 weeks ago in most areas. Infections from the major primary infection period(s) in late May are now well established. If there are no infections in an orchard now, then there is little chance that any will develop. However, where there are infections, scab will continue to work. Check last week’s Healthy Fruit for eradication materials and rates.

Early Flyspeck

No, there isn’t any flyspeck in orchards yet. However, we’ve been seeing mature ascospores in the lab. This means that the fungus is now spreading and infecting new plants. These early new infections are probably restricted to wild hosts in orchard border areas, and are not very important on fruit. They do build up the inoculum that can move into the orchard later in the summer. For the next two weeks, at least, application of a fungicide against sooty blotch and flyspeck is not necessary.