Tree Fruit Phenology: Tree Fruit Phenology remains advanced in peach, but development is slowing. In southern counties all peach orchards are late bloom to petal fall. Redhaven and PF-17 were at approximately full bloom on April 6. Plums are at shuck split. Pears are full bloom for Asian varieties and first bloom for Europeans. Apples and cherries are coming into bloom.

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 desiccates (sometime between petal fall and shuck split). Initiate coverage for blossom blight starting at pink for short petal varieties and 5-10% bloom for showy flowers. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Bacterial Spot: Copper formulations should be used starting at petal fall to suppress bacterial spot. Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods.

Peach Scab: In addition to Rusty Spot and Bacterial Spot, Peach Scab requires protective applications starting at petal fall. Peach scab cankers (Fig. 1) begin to expand at bloom and by shuck split begin to shed spores during wetting periods. Topsin, Topsin/Captan combinations, Flint Extra, Inspire Super, and especially Quadris Top applied at petal fall are the best materials for blocks that had scab last year. Quadris Top, Flint Extra or Topsin should be used at the high rate to suppress overwintering lesions on the wood. Quadris Top contains azoxystrobin which is phytotoxic to many apple varieties. Phytotoxic residues can remain in the tank for long periods after an application is made, even if a tank cleaner is used. Do not use Quadris Top or Abound in the same sprayer used for apples. Bravo (chlorothalonil) is also a good protectant that may be applied no later than shuck split. Captan is also helpful in cover sprays after shuck split where scab was troublesome last year.

Fig. 1 Peach Scab lesions on peach twig.

Oriental Fruit Moth: A biofix point for OFM was set on 4/11 in both northern and southern counties. It is not too late to place dispensers for OFM mating disruption, however if they aren’t in place soon the first generation should be controlled with insecticides. The first insecticides for first generation Oriental Fruit Moth control should be applied at 170-200 degree days base 45 after biofix. This timing generally coincides with 100% petal fall in peaches.  Do not apply insecticides until all bloom is off regardless of degree day timing. No Insecticides for OFM should be needed needed where Mating Disruption is implemented.

Green Peach Aphid: GPA colonies begin forming sometime during bloom. Examine trees for the presence of colonies from pink to shuck split. Count the number of colonies on ten trees and use a treatment threshold of 2 colonies/tree at petal fall for peach, and 1 colony/tree for nectarine. The best way to scout for aphids during bloom is with a beating tray. Blossoms may also be collected, opened, and examined for the presence of aphids using a hand lens. This is particularly important for nectarine blocks. Check 10 trees per block with the beating tray. Collect 50 blossoms per block and examine for the presence of aphids. If more than 1 colony of aphids are found in nectarines, or 2-3 colonies are found in peaches, an insecticide for aphids will be needed when all petals are off. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates. No aphid activity has been noted on southern counties to date.

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: Plum Curculio start to move into orchards at about 88-100 degree days base 50 after January 1. Applications for PC should be initiated once all petals are off, with a second application made with ovicidal materials at 379-402 DD. Currently we have accumulated about 103 DD base 50 in southern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are starting activity but cause little damage at this time of the year. Catfacing insects will become more of an issue as temperatures warm and mowing and other ground cover activities become more common after bloom. Insecticides for catfacing insects and plum curculio are not recommended until after all petals are off.

Scale Insects: Dormant oil applications are standard recommendations for scale control, but in some years conditions are not good for oil and control is less than desired. Where scale has been recurring the application of Movento at petal fall to shuck split has “cleaned up” chronic scale outbreaks. Movento should be applied at 6-9 ozs/ac. a penetrant must be included as described on the product label. Movento will also control green peach aphid at this timing.

Lesser and Greater Peach Borer: Mating disruption dispensers for borers should be deployed in early May. See the NJ Commercial Tree Fruit Production Guide for recommended dispensers and rates.

Apples and Pears:

Diseases: Fire Blight, Apple Scab, Rust diseases, and Powdery Mildew are the main targets at this stage. The NEWA apple scab model is estimating about 40% ascospore maturity as of 4/12 in southern NJ with 38 % of cumulative ascospores discharged. Northern counties were at Green tip on or about 3/18. The model estimates about 22% ascopsore maturity for Northern Counties with only 21% ascospores released. Primary apple scab spores are released during any substantial infection period. More information can be found in this blogpost from Penn State. Between tight cluster and first cover include products effective for powdery mildew and cedar apple rust. To manage Fire Blight in 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 (note that Fireline 45 only allows for 1 postbloom application on apple). Using 3 different chemistries in rotation allows for resistance management while extending the protection into the post bloom period when late blossoms typically appear which ever material you use, the addition of Actigard or other plant defense elicitors may improve control.

Rust Diseases: The two most common rust diseases that affect pome fruit are Quince Rust and Cedar Apple Rust. In some years these diseases can be troublesome in commercial orchards. Most disease control programs for scab will also control rust. In organically managed blocks in the east options are limited for approved materials that are effective for rust. Potassium Bicarbonate products have shown good efficacy for rust diseases in trials performed in Virginia. Organic growers should seek out and plant rust resistant cultivars. Cultural controls are not practicable due to the widespread presence of alternate host Junipers both wild and cultivated. Rust disease development on junipers should now be producing large spore releases during wetting periods. See this link for pictures of rust on pome fruit and juniper.

Scale Insects: Dormant oil applications are standard recommendations for scale control, but in some years conditions are not good for oil and control is less than desired. Where scale has been recurring the application of Movento at petal fall to shuck split has “cleaned up” chronic scale outbreaks. Movento should be applied at 6-9 ozs/ac. a penetrant must be included as described on the product label. Movento should also control rosy apple aphid at this timing.

Rosy Apple Aphid:  If a pre-bloom application was not made, monitor for colonies during bloom and use a treatment threshold of 1 colony/tree at petal fall. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Pear Psylla:  Dormant oil applications should have already been started to deter psylla egg laying. At the green cluster stage a pyrethroid or Esteem is generally included with oil. Pyrethroids may knock down some of the adults migrating into the orchard, while Esteem may sterilize them.  In lieu of oil or insecticides, Surround may also be applied starting at swollen bud and continued through petal fall. If using Surround through the bloom period stop at petal fall and switch to applications of 1% summer oil @ 1gal/ac in no less than 150 gals/ac. these should be made at no more than 2 week intervals. At petal fall insecticide options for Psylla control include Actara, Assail, Belay, Movento, Sivanto Prime, and Agri-mek. See the NJ Commercial Tree Fruit Production Guide for recommended materials and rates.

Pear Diseases:  Include effective materials such as Ziram or EBDC formulations for Pear Scab and Rust diseases beginning at the cluster bud stage. At white bud use products effective for pear scab, rusts, and fabrea leaf spot. 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 Actigard or other plant defense elicitors may improve control.

Grapes: Grapes are at budbreak to the 1″ stage of development. The most important disease to manage at this time is Phomopsis. Insect pests to monitor are Grape Flea Beetle, and Climbing Cutworms. Controls for these insects are rarely needed. If control is determined to be necessary, use one of the materials recommended in the New Jersey Commercial Grape Production Guide. It’s also not too late to scout for and destroy SLF egg masses on posts and trunks.

Peach:

Borers:  Where mating disruption dispensers are used there should be no need for butt sprays. If mating disruption was not used, the only other options are pyrethroids with a label for the use. The New Jersey Commercial Tree Fruit Production Guide recommends either Asana or Pounce. Pyrethroids lack a long residual so our recommendation would be a late August/early September butt spray followed by an additional application in mid to late September. Since this would be a labor intensive practice it would be most efficient to give priority younger and most productive orchards. Remember to follow the label as to the maximum allowable amount per season of either material.

Apples and Pears

Brown Marmorated Stink Bugs: Brown Marmorated Stink bugs are nearly absent in orchards statewide, likewise native stinkbug populations have been very low. If stinkbugs are a concern for your orchard, see the NJ Tree Fruit Production guide for effective materials. If treatment is needed for orchards near harvest. Venerate has a +++ rating for stink bugs and a 0 day PHI. In tests conducted by Dr. Neilsen’s lab, Venerate always performed better when applied at half the highest labeled rate.

Codling Moth (CM): Second generation treatments according to the degree day model are now over. Additional treatments should be made if trap captures are over 5 moths/trap. Most orchards have very low CM pressure, however a few orchards have had continuing trap captures above threshold.

Summer Diseases: Disease control is over for early season apple varieties. Mid to late season varieties will need further applications on a two week schedule until mid september for sooty blotch and fly speck.

Lesser Appleworm: In 2022 some orchards in southern counties have had internal worm damage that we think was Lesser Apple Worm. This sporadic pest sometimes shows up in late summer and fall. The damage is similar to codling moth. Larvae complete their life cycle quickly and often by the time damage is seen the larvae is already gone. Typically LAW will feed in the fruit calyx and not go into the flesh, however they may also feed on fruit flesh excavating a small hole under the skin and occasionally tunneling into the fruit. Control options are the same as for codling moth. LAW can be monitored using traps baited with OFM pheromone.

Grape

Bunch Rots: Disease management continues to focus on downy and powdery mildew and also turns to bunch rot management. Refer to the NJ Commercial Grape Production Guide as well as the linked presentation from Dr. Nita in Virginia.

Grape Berry Moth: The timing for the third generation is past. In some hot summers a fourth generation may occur, however no further treatments should be needed, especially where insecticides are being applied for SLF and SWD.

Drosophila’s and Sour Rot: SWD adults are being caught in and around commercial vineyards. As the sugars start to increase in early verities like Chardonnay, be aware of Spotted Wing Drosophila combined with native fruit fly species. These populations increase at this time of year and help spread sour rot. Sour rot will only be pres ent when you also have injured fruit. Fruit splits and various insects can help cause that initial injury. It is thought that the spotted wing drosophila (SWD), because of its saw-like ovipositor, can help cause this initial injury, helping to make the fruit more attractive to native drosophilid species.  After injury the fruit serves as a food source for ethanol-producing yeasts and acetic acid producing bacteria, the causal agents of sour rot. This in turn attracts more fruit flies to lay more eggs and spread the decay. Good canopy management for air circulation is useful to reduce sour rot incidence. However, this must be combined with insecticides and antimicrobials. A treatment regime that consists of weekly applications of an insecticide (Mustang Maxx (or other pyrethroid), Malathion, Delegate/Entrust, Verdepryn).  Add Oxidate 2.0 if fruit cracking from rain or other causes is observed. Since it is important to rotate insecticide classes when treating this often, growers should use no pyrethroid or other insecticide class more that 2 times in a row. These treatments should be started before the onset of visible sour rot and fruit fly presence.

Spotted Lantern Fly: Spotted lantern fly adults are not yet appearing in vineyards, however they should be soon. When the first adults are observed, border treatments with effective materials should be adequate since most adults will be found on vineyard edges and populations will be low. As we move into September adult migration will increase and at that point growers should apply materials with long residual efficacy (refer to the table from Penn State below.) More information on biology and control can be found from Penn State.