Over the past 7-10 days it has become clear that a bacterial spot epidemic is underway. It is eerily reminiscent of the epidemic of 1997, although so far it does not appear as widespread or affecting all cultivars as that year. Many blocks are dropping leaves this week, and fruit lesions are beginning to appear. Remember that it takes about a week for leaf infections to appear, and about 2 weeks for those infected leaves to start dropping. It takes about 3 weeks for those same infections to show up on the fruit. Looking back at weather records over at CoCoRaHs (choose your dates and local observations) it appears that the severe winds of May 23, and the rains over the weeks that followed set up a conducive environment for the bacteria in southern counties. We are seeing leaf drop in many locations regardless of treatment. The coming week will tell the story of how much fruit infection there is. [Read more…]
Tree Fruit March Checklist
- Oil for Pear Psylla and Scale Control
- Scout While Pruning
- Dormant Season Copper Sprays
- Dormant Season Urea Sprays
Oil for Pear Psylla and Scale Control: During the recent warm up pear psylla adults were active, however no egg laying has yet been observed. Growers with pears should be thinking about oil applications to deter egg laying. [Read more…]
How Cold Did it Get?
South West Injury on Peach
Integrate Sanitation Into Your Apple Scab Control Program
Apple Scab Control with Urea.
Video link: http://youtu.be/8g0WyVi68GM
This past season we saw elevated levels of apple scab in southern counties. Our IPM scouts found low levels of scab present in orchards where scab had not been detected for many years, even though these orchards had been carefully sprayed using effective materials. Most likely what we are witnessing is the result of an increasing pattern of wet seasons with periods of extreme rainfall and not resistance to DMI fungicides, although that is an area of great concern and cannot be ruled out. Regardless of the cause, high inoculum in the orchard will eventually lead to control failures with materials such as the DMI’s and other chemistries prone to resistance.
At any rate growers that had scab this year should integrate sanitation practices into their scab control program. The recommended sanitation program involves either: fall or spring applications of Urea; flail mowing fallen leaves: or preferably both.
Dr. Dan Cooley and Jon Clements at UMass have uploaded a short video explaining this approach.
Brown Rot Found in Nectarines
Last week a block of Fantasia nectarines was found to have a very small percentage of rot present. This week several more blocks were found with rotten fruit present. The common denominator between the three is that they were all mid – late season nectarines that had been just thinned or were being thinned during the severe weather pattern we just experienced. Fruit were injured or the stems knocked loose from either heavy downpours or breaking up clusters. In one orchard many of the rotten fruit were dropping so it is likely the stem had been compromised. Any type of injury in these weather conditions can lead to rot infection.
So what should you do?
- Don’t panic! Fruit should have a high degree of resistance at this point. Only fruit injured in some way should be susceptible to rot;
- Maintain good coverage with a full rate of captan during periods of unstable weather;
- If possible, remove all the rotten fruit from the orchard canopy. Rotten fruit on the ground can be removed by discing where sod middles are not maintained.
Tree Fruit Fire Blight Alert: Extreme
The Cougar Blight model at NEWA is predicting “Extreme Risk” for fire blight for the period May 10-15. The model is basing the prediction on the current weather forecast for both southern and northern regions. Keep a close eye on the weather. Apply antibiotics such as Streptomycin, Mycoshield, or Fireline. Streptomycin is the most effective of the antibiotics. The Terramycin products (Mycoshield and Fireline) should be rotated with strep for resistance management. See the New Jersey Commercial Tree Fruit Production Guide for rates. Keep in mind that these antibiotics are best applied under slow drying conditions (dilute applications), and have limited residual activity.
