Pruning fruit trees is an important horticultural practice that promotes proper tree vigor and canopy architecture for optimal fruit production. Generally the best time for dormant pruning pome fruit in the northeast is January through early March. Stone fruit, with the exception of sweet cherry, may be safely pruned as late as the delayed dormant and early bloom periods.
April 27, 2020
Tree Fruit IPM Report for April 28, 2020
Disease Control in Freese Damaged Orchards: Dr. Lalancette has published his recommendations for how to protect tree fruit from diseases in freeze damaged orchards.
Tree Fruit Phenology: Tree Fruit Phenology remains advanced, but development is slowing. In southern counties peach orchards are at Shuck Split. We are now only about 5 days ahead of the median date for shuck split. Pears are late bloom/Petal Fall. Red Delicious was about Full Bloom on 4/25. Cherries are about full Bloom. [Read more…]
April 20, 2020
Tree Fruit IPM Report for April 21, 2020
Evaluating Freeze Damage in Tree Fruit: The subfreezing temperatures on the morning of April 17 Caused injury at varying levels across the state. Lows ranged from 27-30 in southern counties. Much is the damage is now visible. Any physiological damage that is not visible now will appear as the season progresses. A helpful guide for evaluating fruit damage can be in the Intermountain Tree Fruit Production Guide.
Tree Fruit Phenology: Tree Fruit Phenology remains advanced, but development is slowing. In southern counties all peach orchards are late bloom to early Shuck Split. Redhaven was at approximately full bloom on March 30, and was at Petal Fall by April 14. Peach bloom has been very long this year. Plums are past shuck fall. Pears are late bloom/Petal Fall. Red Delicious is pink to 50% bloom. Cherries are at 50% bloom. [Read more…]
April 13, 2020
Tree Fruit IPM Report for April 14, 2020
Special Announcement! : The long awaited update to the NJ Commercial Tree Fruit Production Guide is available. We have updated the pesticide tables to include new products, pesticide safety, and efficacy. We hope to have the text sections updated for 2021.
Tree Fruit Phenology:
Tree Fruit Phenology remains advanced, but development is slowing. In southern counties all peach orchards are just past full bloom to petal fall. Redhaven was at approximately full bloom on March 30, and was late bloom on 4/7. Peach bloom has been very long this year. Plums are past petal fall and Pears are in bloom. Red Delicious is pink. Cherries are in bloom. [Read more…]
April 10, 2020
What to Look for At Bloom: Cankers of Stone fruit.
Bacterial Spot is a key pest of Peach, Nectarine and Plum and in some years like 2019 can cause significant losses. It is caused by the bacterium Xanthomonas arbicola pv. pruni. During bloom overwintering cankers begin to appear. These cankers are very similar to other peach diseases and are often difficult to distinguish when they first appear. Other cankers that may appear during bloom are caused by the blossom blight phase of brown rot, and constriction canker. While scouting last week the first signs of tip die back where observed. Typical symptoms are a gradual blackening of the tip with dead tissue moving down the twig. This is typical of black tip from bacterial spot and was observed in blocks of highly susceptible cultivars (Fig. 1).
Fig. 1 Tip die back likely bacterial spot.
In some blocks the twig was healthy and the tip began growing only to die back after leafing out and flowering. This is often a symptom of late winter/early spring infections of constriction canker. Indeed this was observed in a block of old trees that has a history of constriction canker. This is often a symptom of late winter/early spring infections of constriction canker. Indeed this was observed in a block of old trees that has a history of constriction canker (Fig. 2).
Fig. 2 Tip die back possibly constriction canker.
In none of these cases were cankers observed on flower buds lower down the on the twig as is typical of blossom blight and constriction canker. Spring cankers of bacterial spot that form around flower buds are less commonly seen in our region. Only tip die back was observed suggesting the likelihood that bacterial spot cankers are forming. In cases like this its difficult to diagnose the disease early on. The only thing that can be done is to note the trouble blocks and watch to see what develops. Blossom blight and constriction canker will eventually develop unique symptoms. Bacterial spot lesions will eventually show on the leaves. If you see these cankers forming during bloom its not a bad idea to assume its bacterial spot and include copper or oxytetracycline with your blossom blight sprays.
