Plant & Pest Advisory» All Fruit Articles


Apple IPM Report - April 17

  • Coddling Moth
  • Apple Scab, Powdery Mildew, Cedar Apple Rust
  • Fire Blight
  • Plum Curculio
Dean Polk, Fruit IPM Agent and
David Schmitt, Eugene Rizio and Atanas Atanassov,
Program Associates, Tree Fruit IPM

    Codling Moth (CM): A Biofix for CM was set in southern counties on Sunday 4/15. This is about 2 weeks earlier than last year.

    Timing for the first of 2 sprays for the 1st generation is set at 250 to 350DD50 and again at 14 to 21 days later or around 550DD for the standard insecticides - OPs, carbamates, pyrethroids, neonicotinoids, spinosyns and Delegate, and granulosis virus. Granulosis virus is a biorational control marketed under the names Carpovirusine, Cyd-x and others. These products are useful as a supplement to mating disruption, or for resistance management. The timings for the IGR Rimon is at 75- 100DD, and the IGR’s Intrepid, and Esteem are at 100-150DD and again at 450DD. The newer rynaxypyr chemistries (Altacor, Voliam Flexi, Belt, and Tourismo) are another option at these timings. These materials have long residuals and are highly effective. They are better used for the summer generation which typically spreads out over a longer time period. The 2nd complete spray timing for CM often coincides with timings for tufted apple bud moth.

    Apple Scab, Powdery Mildew (PM) and Cedar Apple Rust (CAR): Overwintering ascospores are now 91% mature in Cream Ridge. Little moisture has occurred to release spores, and the fact that wetting periods are predicted starting this weekend through the middle of next week, all means that we could have some very severe scab infection periods with the next rains. Growers should be well covered with protective materials before the wetting periods occur.

    Fire Blight: Blossom sprays using antibiotics should be applied anytime temperatures are 65° F or above and the relative humidity is 60% or above even where most bloom is over. In southern counties, blocks of particular concern are Rome, Gala and other cultivars that have a propensity to produce “rat-tail” blooms. Refer to the production guide for recommended materials and rates. The NEWA site discussed in previous newsletters offers predictions of potential fire blight infection periods. Fire Blight is not modeled in the same way as scab. Heat units, tree phenology, dews, leaf wetness, cultivar, rootstock, and short or severe storms and/or hail all play a roll. Check the NEWA site for a more up to date prediction. In general, severe fire blight conditions are possible from 4/17-19.

    Note: Instructions on how to use NEWA in NJ can be found on the NJAES Snyder Farm Website.

    Plum Curculio (PC): PC adults usually begin egg laying sometime in late April or early May. Where control is poor fresh egg scars can be found on border rows, especially near wooded or trashy areas. This season, egg laying is occurring now, and will continue for the next several weeks. Preferred materials that offer PC control now are Actara, Avaunt, and Imidan. If using high rates of a neonicotinoid (i.e. Actara, Belay, Assail), be aware that there is a synergistic effect when used in tank mixes with DMI materials (i.e. Rally) with regard to bee toxicity. If pyrethroids are being used, then high rates are advisable, since low rates often do not control this insect, especially in hot weather. Growers should rotate away from pyrethroid insecticides if possible.