Summer disease pressures have advanced at a relatively steady pace over the past two weeks, with several extended wetting periods and continued accumulation of wetting hours. As of Monday, July 18, we were more than 2 weeks past the 250-hr accumulated wetting hour threshold (ACW) for all of the wetness sensors at our AREC, Winchester and for Tyro, VA.
Wetting hour accumulation (ACW) at Winchester: at 909 ft elevation, 555 hr (with the 250-hr threshold reached June 5); at 952 ft elevation, 419 hr (near the threshold); and at the 983 ft elevation, 341 hr ACW. At Tyro, VA as of July 18, a sensor placed at the 941 ft elevation had accumulated 529 hr (with the 250-hr threshold reached June 6); the one at 1165 ft. elevation had accumulated 309 wetting hours, and the one 1465 ft. elevation had accumulated 341 .
At Winchester in the past two weeks we had three significant extended wetting events favorable for SBFS and fruit rot development: July 4-5: 20 hr at 71-67°, with 0.74 in. rain, July 12-13: 13 hr at 77-66° with 0.04 in. rain, and July 16-17: 15 hr at 77-65° with 0.34 in. rain. Bitter rot was observed on apple fruit at Winchester as early as June 22, and all of these recent wetting periods were at temperatures favorable for bitter rot. Specific treatment against the SBFS fungal complex and rot diseases is advised.
We have installed a new, publicly accessible weather station at our AREC in Winchester. The station, which updates hourly, is located near the laboratory building at an elevation of 933 feet. This station is part of the NEWA system, so to access it one can either click on the NEWA weather station locator map, or go to:
http://newa.cornell.edu/index.php?page=weather-station-page&WeatherStation=va_win
A caution about the station is that because it was install after the beginning of this year's wetting hour accumulation period (May 14), it will not be up to date for predictions in the sooty blotch/flyspeck model.
Wednesday, July 20, 2016
Continued summer disease pressures
Summer disease pressures have advanced at a relatively steady pace over the past two weeks, with several extended wetting periods and continued accumulation of wetting hours. As of Monday, July 18, we were more than 2 weeks past the 250-hr accumulated wetting hour threshold (ACW) for all of the wetness sensors at our AREC, Winchester and for Tyro, VA. Altough the volume of rainfall has not been excessive, shower activity has favored spread of fungal spores for fruit rots such as bitter rot on apples and brown rot on peaches and other stone fruits.
Wetting hour accumulation (ACW) at Winchester: at 909 ft elevation, 555 hr (with the 250-hr threshold reached June 5); at 952 ft elevation, 419 hr (near the threshold); and at the 983 ft elevation, 341 hr ACW. At Tyro, VA as of July 18, a sensor placed at the 941 ft elevation had accumulated 529 hr (with the 250-hr threshold reached June 6); the one at 1165 ft. elevation had accumulated 309 wetting hours, and the one 1465 ft. elevation had accumulated 341 .
At Winchester in the past two weeks we had three significant extended wetting events favorable for SBFS and fruit rot development: July 4-5: 20 hr at 71-67°, with 0.74 in. rain, July 12-13: 13 hr at 77-66° with 0.04 in. rain, and July 16-17: 15 hr at 77-65° with 0.34 in. rain. Bitter rot was observed on apple fruit at Winchester as early as June 22, and all of these recent wetting periods were at temperatures favorable for bitter rot. Specific treatment against the SBFS fungal complex and rot diseases is advised.
We have installed a new, publicly accessible weather station at our AREC in Winchester. The station, which updates hourly, is located near the labooratory building at an elevation of 933 feet. This station is part of the NEWA system, so to access it one can either click on the NEWA weather station locator map, or go directly to:
http://newa.cornell.edu/index.php?page=weather-station-page&WeatherStation=va_win
A caution about the station is that because it was installed after the beginning of this year's wetting hour accumulation period (May 14), it will not be up to date for predictions in the sooty blotch/flyspeck model.
Wetting hour accumulation (ACW) at Winchester: at 909 ft elevation, 555 hr (with the 250-hr threshold reached June 5); at 952 ft elevation, 419 hr (near the threshold); and at the 983 ft elevation, 341 hr ACW. At Tyro, VA as of July 18, a sensor placed at the 941 ft elevation had accumulated 529 hr (with the 250-hr threshold reached June 6); the one at 1165 ft. elevation had accumulated 309 wetting hours, and the one 1465 ft. elevation had accumulated 341 .
At Winchester in the past two weeks we had three significant extended wetting events favorable for SBFS and fruit rot development: July 4-5: 20 hr at 71-67°, with 0.74 in. rain, July 12-13: 13 hr at 77-66° with 0.04 in. rain, and July 16-17: 15 hr at 77-65° with 0.34 in. rain. Bitter rot was observed on apple fruit at Winchester as early as June 22, and all of these recent wetting periods were at temperatures favorable for bitter rot. Specific treatment against the SBFS fungal complex and rot diseases is advised.
We have installed a new, publicly accessible weather station at our AREC in Winchester. The station, which updates hourly, is located near the labooratory building at an elevation of 933 feet. This station is part of the NEWA system, so to access it one can either click on the NEWA weather station locator map, or go directly to:
http://newa.cornell.edu/index.php?page=weather-station-page&WeatherStation=va_win
A caution about the station is that because it was installed after the beginning of this year's wetting hour accumulation period (May 14), it will not be up to date for predictions in the sooty blotch/flyspeck model.
Wednesday, July 6, 2016
Bitter rot observed at Winchester; Sooty blotch and flyspeck thresholds reached at Winchester and Tyro, VA.
For predicting the development of the sooty blotch and flyspeck (SBFS) fungal complex, we record accumulated wetting hours from rainfall or dew, starting 10 days after petal fall. This year we began wetting hour accumulation at Winchester from May 14. As of Monday, July 4, the 250-hr accumulated wetting hour threshold (ACW) has been surpassed at all of the wetness sensors at our AREC and at Tyro, VA.
At Winchester ACW: at 909 ft elevation, 442 hr (with the 250-hr threshold reached June 5); at 952 ft elevation, 341 hr (near the threshold); and at the 983 ft elevation, 280 hr ACW. At Tyro, VA we started wetting hour accumulation May 4, and as of July 4, a sensor placed at the 941 ft elevation had accumulated 426 hr (with the 250-hr threshold reached June 6); the one at 1165 ft. elevation had accumulated 264 wetting hours, and the one 1465 ft. elevation had accumulated 280 wetting hours.
At Winchester in the past two weeks we had three significant extended wetting events favorable for SBFS and fruit rot development: June 23: 9 hr at 66°, with 0.55 in. rain, and June 27-28: 14 hr at 80-72° with 0.08 in. rain, and July 3-4: 17 hr at 68° with 0.02 in. rain. Bitter rot was observed in Honeycrisp apples at Winchester as early as June 22. Specific treatment against the SBFS fungal complex and rot diseases is advised.
Summer disease management should be directed toward the array of potential problems in specific orchard blocks, utilizing protective fungicides for general purposes, but supplementing them with more specifically active fungicides directed at higher disease pressures and special control problems. Expect higher fruit rot pressures where fire blight killed shoots and fruit mummies are present in the trees. For more information on the effectiveness of apple fungicides for management of sooty blotch/flyspeck, Brooks fruit spot, black rot, white rot and bitter rot consult Table 6 (pp. 53-54) in the 2016 Spray Bulletin for Commercial Tree Fruit Growers.
At Winchester ACW: at 909 ft elevation, 442 hr (with the 250-hr threshold reached June 5); at 952 ft elevation, 341 hr (near the threshold); and at the 983 ft elevation, 280 hr ACW. At Tyro, VA we started wetting hour accumulation May 4, and as of July 4, a sensor placed at the 941 ft elevation had accumulated 426 hr (with the 250-hr threshold reached June 6); the one at 1165 ft. elevation had accumulated 264 wetting hours, and the one 1465 ft. elevation had accumulated 280 wetting hours.
At Winchester in the past two weeks we had three significant extended wetting events favorable for SBFS and fruit rot development: June 23: 9 hr at 66°, with 0.55 in. rain, and June 27-28: 14 hr at 80-72° with 0.08 in. rain, and July 3-4: 17 hr at 68° with 0.02 in. rain. Bitter rot was observed in Honeycrisp apples at Winchester as early as June 22. Specific treatment against the SBFS fungal complex and rot diseases is advised.
Summer disease management should be directed toward the array of potential problems in specific orchard blocks, utilizing protective fungicides for general purposes, but supplementing them with more specifically active fungicides directed at higher disease pressures and special control problems. Expect higher fruit rot pressures where fire blight killed shoots and fruit mummies are present in the trees. For more information on the effectiveness of apple fungicides for management of sooty blotch/flyspeck, Brooks fruit spot, black rot, white rot and bitter rot consult Table 6 (pp. 53-54) in the 2016 Spray Bulletin for Commercial Tree Fruit Growers.
Subscribe to:
Posts (Atom)