In This Issue:
Calendar
Honeycrisp Harvest Recommendations
FireBlight Cankers, An Important Inoculum Source
Quick Guide to Chokecherry ID fro X-Disease Management
Fruit Observations & Trap Reports
Terminal Market Wholesale Fruit Prices
Many growers have planted Honeycrisp in response to market demand and the (mostly) desirable and unique characteristics of the apple. Although not all the bugs have been worked out, considerable effort by researchers in New York, Michigan, and Massachusetts over the past few years has gone into developing preliminary harvest and storage regimes for Honeycrisp.
At this point, our best recommendations for harvesting and storing Honeycrisp are as follows:
Fire blight cankers are an important inoculum source. The fire blight bacterium, Erwinia amylovora (Ea), overwinters in cankers, and these cankers can be sites of further fire blight spread both in the tree and in the orchard. As temperatures warm in the spring, cankers begin to ooze; the ooze is a sign of increased bacterial activity and marks the beginning of fire blight's recolonization of the orchard in the spring. The ooze is a source of Ea that can be rapidly and easily spread by wind and rain. Orchard blocks with fire blight cankers are under a tremendous infection risk.
The earlier that warm daytime temperatures (70-80F) occur in the growing season, the risk of fire blight symptom occurrence increases. If these temperatures occur during bloom, extensive blossom colonization followed by blossom blight will most likely occur. Blossom infections can be initiated by inoculum from cankers. In the early stages of canker activation, insects are attracted to slightly gooey cankers and can pick up enough fire blight bacteria to spread the disease to highly susceptible blossoms. Newly opened flowers are attractive to the insects when temperatures rise above approximately 55F and the stigma (pollen receptors) exude sticky substance.
If warm temperatures do not occur until later (as happened in 2003), blossom blight won't be a problem, but shoot blight will. The presence of cankers does not guarantee that extensive shoot blight infection will occur, and some growers may have gotten lucky this year. However, in the long-term, cankers raise the overall infection risk and are a consistent source of disease-causing Ea.
The annual removal of fire blight cankers in the dormant season greatly reduces the amount of fire blight in the orchard in the spring. Removing cankers is an important risk reduction measure for future fire blight infection. By actively removing cankers, especially after there has been only a little fire blight, you greatly reduce the inoculum in your orchards. Removing all the cankers in an orchard is easier to do when the number of cankers is small. In years such as 2000, with extensive long-range spread of the pathogen, a good canker removal program does not prevent fire blight epidemics if your neighbor does not have similar pruning practices. However, in years like 2003 with a delayed epidemic and little orchard-to-orchard spread, a thorough canker removal program really pays off.
Scout orchards for fire blight cankers this fall. Prune those limbs at least 1 to 2 feet below the canker margin, and burn that wood. You should also scout the orchard in the spring, looking for and cutting out any cankers that the pruning crew missed. It is easier to see the blackened and sunken cankers when the sun is behind you, so scout one side of the tree in the morning and the other side in the afternoon.
Mark Longstroth will be adding a new page entitled Annual Cycle of Fire Blight in Michigan Apples to his extensive web site devoted to fire blight. This page will include several photos of fire blight cankers. The URL will be: http://www.msue.msu.edu/vanburen/fbyear.htm.
X-disease is a sometimes severe phytoplasma-type disease of peaches and cherries in Michigan and other northern states. X-disease is commonly spread from infected chokecherry into Michigan peach and cherry orchards by specific leafhoppers. One of the best strategies for controlling X-disease is to remove chokecherry bushes from the vicinity of stone fruit orchards. This article provides a brief summary of key points for identifying chokecherry, in part from the excellent guide for identifying chokecherry written in 1977 by Alan Jones and David Rosenberger, X-Disease of Peach and Cherry: A Guide to Chokecherry Identification, Michigan State University Extension Bulletin E-842.
Chokecherry (Prunus virgininiana L.) can be confused with wild black cherry (P. serotina Ehrh) and pin cherry (P. pennsylvanica L., also called fire cherry). Wild black cherry is very common in woods along orchards and can grow to heights of 80 feet or more, whereas chokecherry and pin cherry rarely reach more than 30 feet tall and tend to be more bush-like in appearance.
Pin cherry produce fruit in clusters, with stems arising from the same point, whereas chokecherry and wild black cherry bear fruit on a central axis, raceme (Figure 1) Note Figures 1-3 can be found at http://www.ipm.msu.edu/CAT03_frt/F09-23-03.cherry.htm. Wild black cherry can be easily distinguished from chokecherry by examining fruit. Wild black cherry retains a calyx cup remnant on fruit (on the stem end of the fruit) and chokecherry has no remnant.
The leaves of common chokecherry and wild black cherry are distinctly different. The underside of wild black cherry leaves has a brown hairy midvein at the base, adjacent to the petiole (Figure 2), whereas chokecherry has a smooth midvein. The leaf shapes of the two cherry species are much different. Wild black cherry leaves are longer and narrower than common chokecherry (Figure 3), whereas leaves of the common chokecherry tend to be wider toward the tip. Remember to take time to examine several leaves and fruit per plant to avoid being misled by an atypical specimen.
Site: Waterman Lab, Columbus
Dr. Celeste Welty, OSU Extension Entomologist
Apples | ||
| Terminal Market | |
| NY 80s 26-27.00 MI 96s 21-23.00 NY 100s 24.00, 120s 21.00 NY 100s 25.50 NY 100s 17.75-19, 120s 16.50 |
Chicago Detroit Detroit Pittsburgh Pittsburgh | |
| ||
| MI 125s & 138s 16.50 NY 100s 17.50 |
Pittsburgh Pittsburgh | |
| ||
| MI 2 ½" min 15-15.50 MI 2 ½" min 12-14.50 MI 2 ½" min 12-13.50 MI 2 ¼" min 11.75 MI 2 ½" min 12.00 MI 2 ½" min 12.00 MI 2 ½" min 14-14.50 MI 2 ½" min 12-15.50 MI 2 ¼" min 11.75 MI 2 ½" min 12-13.00 MI 2 ¼" min 11.75 MI 2 ½" min 12-14.50 MI 2 ¼" min 13.00 MI 2 ½" min 12.00 MI 2 ¼" min 12.00 MI 2 ½" min 12.00 NY 2 ¼" min 12.75-13 |
Detroit Detroit Detroit Detroit Pittsburgh Detroit Detroit Detroit Detroit Pittsburgh Detroit Pittsburgh Detroit Pittsburgh Detroit Detroit Detroit | |
| ||
| MI 2 ½" up 12.00 MI 2 ¾" up 12-15.00 MI 2 ¾" up 12.00 MI 3" min 14-15, 2 ½" up 12.00 MI 2 ¾" up 15.00 MI 3" min 12.00 MI 3" min 12.00, 2 ½" up 10.00 |
Detroit Detroit Detroit Detroit Detroit Detroit Detroit | |
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|
MI lge 23-26.00, med 23-24.00 MI med 20.00-23.00 MI med 13-15 MI med 12-16.50 MI med 12.00 |
Chicago Detroit Chicago Detroit Pittsburgh | |
| Nectarines | ||
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|
MI 2 ¾" up 12-12.50 MI 2 ¾" up 19-20.00 NJ 2 ½" up 17.50, 2 ¼" up 12.75 |
Detroit Detroit Pittsburgh |
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| Peaches | ||
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| NJ 2 ¾" up 9.00, NJ 2 ½" up 7.00, 2 ¼" up 5.00 WV 2 ½" up 10.00, 2 ¼" up 8.00 |
Chicago Chicago Chicago | |
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|
MI 2 ¾" up 14.50-15 MI 2 ½" up 11.50-12.00 NJ 2 ½" up 12.00 |
Detroit Detroit Pittsburgh |
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|
NJ 2 ¾" up 8.00-10.00 NJ 2 ½" up 6.00-8.00 NJ 2 ¼" up 4.00-5.00 |
Detroit Detroit Detroit | |
| Pears | ||
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| NY 1 ¼" min 17.50 | Pittsburgh | |
| Prune Plums | ||
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MI 1 ¼" min 13.50-14.00 MI 1 ¼" min 12.50-15.00 MI 1 ¼" min 13-14.50 MI 1 ¼" min 15.00 |
Chicago Detroit Pittsburgh Detroit |
The intent of listing terminal market prices is to provide information available in the public domain. It is not intended for price setting, only to assist growers in evaluating the value of their crops. Producers need to remember that the prices listed are gross, and consideration must be given to marketing costs, including commission, handling charge, gate fees, and possible lumper
Ted W. Gastier
Extension Agent, Agriculture
Tree Fruit Team Coordinator
Ohio State University Extension Huron County
180 Milan Avenue
Norwalk, OH 44857
Phone: (419)668-8210
FAX: (419)663-4233
E-mail: gastier.1@osu.edu
Copyright © The Ohio State University 2003
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Keith L. Smith, Associate Vice President for Ag. Adm. and Director,
OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868