Tree Fruit Phenology:
Tree fruit phenology is advanced in southern counties based on historical observations. In southern counties some early blooming varieties are at pink to 5% bloom. Most peach blocks are at bud swell to pre-pink. Redhaven was at bud swell on March 13, about 10 days earlier than the median observation date. Red Delicious was at silver tip on March 14, about 11 days earlier than the median observation date. Some apples are at green tip, and pears are about ½” green. Plums are nearing or coming into bloom. Cooler weather forecast for next week should help slow development.
Peach:
Brown Rot: Blossom infections from the brown rot fungus can occur whenever pistils are exposed and a favorable climate exists. Infections can occur during any wetting period when temperatures are between 41 and 86 °F. However, optimum conditions for infection occur with wetting and temperatures in the mid 70’s. During long wetting periods (several days or more) blossoms can be infected regardless of temperature. Generally infections that occur when conditions are sub optimal are less severe. Blossoms and fruitlets will remain susceptible until the pistil dessicates (sometime between petal fall and shuck split). Initiate coverage for blossom blight starting at pink for short petaled varieties and 5-10% bloom for showy flowers. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.
Scale Insects: Oil applications may be safely applied up to pink on peach. Other options include Centaur, Sivanto Prime, Esteem, and Venerate. These products can be combined with oil or applied alone. See the NJ Commercial Tree Fruit Production Guide and the apple section below for more information.
Apple:
Diseases: Fire blight is the main target at this stage. Copper formulations applied for fire blight suppression should be adequate for scab control at green tip to 1/4″ green, unless scab was not controlled in 2022. If your orchard had scab last year, include a protectant such as vangard or syllit (see caution below) at 1/4″ green tip. Copper should not be applied after 1/4″ green where fruit russet is a concern. Beginning at 1/2″ green highly effective scab materials should be used. Primary apple scab spores are released during any substantial infection period. At tight cluster include products effective for powdery mildew and cedar apple rust. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.
European Red Mite; San Jose Scale; and Rosy Apple Aphid: Oil applications for mite suppression and scale control should start at 1/4” green. Apply 2% dilute or 4-6 gals oil/acre concentrate at 1/4”green to tight cluster; 1% dilute or 2-3 gals/acre concentrate at tight cluster to pink. Oil should not be applied if temperatures are expected to dip into the mid 30’s within 48 hours of application, and captan or sulfur should not be applied within 14 days of any applications of oil or oil based formulations. Check the product labels for additional phytoxicity precautions. One sees many recommendations for mixing materials efficacious for scale such as the insect growth regulators (Centaur; Esteem) with delayed dormant oil applications. The general consensus from data review seems to be that the addition of scale insecticides to oil do not significantly improve control over oil applied alone. The key to scale suppression with delayed dormant sprays is coverage regardless of the materials applied. Recent tests performed by Dr. Neilsen’s lab indicate that both Sivanto Prime and Centaur and Venerate when applied alone in the pre-bloom period are comparable to dormant oil for scale control. Esteem has good efficacy for scale when applied up to to 1/2″ green. Closer has some efficacy against scale, however it has not been evaluated for control of overwintering scale. Esteem, Closer, Sivanto Prime, and Versys, applied either alone or with oil at 1/4″ to 1/2″ green all have good to excellent ratings for rosy apple aphids. See the NJ Commercial Tree Fruit Production Guide for more information. Note that the Virginia Spray Bulletin for Commercial Tree Fruit Growers lists syllit as incompatible with centaur.
Pear:
Pear Psylla: Dormant oil applications should have already been started to deter psylla egg laying. At the green cluster stage a pyrethroid is generally included with oil to knock down adults migrating into the orchard. In lieu of oil, Surround may also be applied starting at swollen bud and continued through bloom. If using Esteem for psylla control make one application delayed dormant through popcorn or two applications; one at delayed dormant through popcorn and one at petal fall. Centaur is also effective and one application may be made pre-bloom or at petal fall. Sivanto Prime is also labeled for early season applications and should be combined with oil.
Pear Diseases: It’s not too late to apply copper for fire blight suppression, but copper should not be applied past the green tip stage if fruit russet is a concern. Include effective materials such as Ziram or EBDC formulations for Pear Scab and beginning at the cluster bud stage. At white bud use products effective for rust, pear scab, and fabrea leaf spot. Particular attention should be paid to rust on aisan varieties. Start planning for blossom sprays using antibiotics. For both apples and pears, consider using Kasumin at bloom. Kasumin is an antibiotic like Streptomycin and Oxytetratracycline. It contains Kasugamycin which is a different chemistry. Kasumin is only labeled for bloom and petal fall applications while strep and oxytet are labeled for post bloom use. Using 3 different chemistries in rotation allows for resistance management while extending the protection into the post bloom period when late blossoms typically appear. Whichever material you use, the addition of Actigar, Lifeguard or other plant defense elicitors during bloom may improve control.
