Northern Michigan FruitNet 2009
Weekly Update
NW Michigan Horticultural Research Station
| Nikki Rothwell District Horticulturist |
Erin Lizotte District Fruit IPM/IFP Agent |
Bill Klein Farm Mgr, NWMHRS |
| Duke Elsner Agricultural & Regional Viticulture Agent |
August 11, 2009
GROWING DEGREE DAY ACCUMULATIONS AS OF August 10th AT THE NWMHRS
Year |
2009 |
2008 |
2007 |
2006 |
2005 |
2004 |
19yr. Avg. |
GDD42 |
2163 |
2377 |
2758 |
2763 |
2805 |
2190 |
2462.5 |
GDD50 |
1300 | 1521 | 1835 | 1823 | 1901 | 1328 | 1591.0 |
Growth Stages at NWMHRS (8/10/09- 4:30 p.m.)
Apple: McIntosh – 60 mm fruit
Yellow Delicious – 58 mm fruit
Gala – 48 mm fruit
Red Delicious – 52 mm fruit
Pear: Bartlett: 40 mm fruit
Plum: 33 mm fruit
Grapes: Berry touch
Weather Report
The weather is shaping up for a warm week—meteorologists are predicting temperatures in the 80’s and sunny. Last week was a different story with cooler wetter temperatures. Thus far this season, we have accumulated 2163GDD base 42 and 1300GDD base 50. These numbers are still low compared with our 19-year average: 2463GDD base 42 and 1591 base 50. We received 0.53” of rain for the week through 1 August, 1.27” during the week of 2 August through 8 August, and 0.23” 9 August through 15 August. The total rainfall for August is 1.5”.
Crop Report
Pears are sizing and are at 40-50mm. Apples are also in the 48-58mm size range. At the station, we have harvested all sweets, Montmorency, and Balatons. However, cherry harvest continues throughout the north. As of 1 August, we harvested 61.4 million pounds of the 150 million pounds estimated. Last week, fruit quality was very good despite some color issues with ripening. However, as temperatures increase and with the recent rains, we are expecting to see more soft fruit showing up, particularly in fruit growing on heavier soils. Many growers think we will pick more fruit than was estimated. Some growers are starting to harvest earlier varieties of peaches. Raspberry harvest is winding down. Apricot harvest is finished here at the station but in full swing further north. Wine grapes are at berry touch and many growers are pruning/hedging due to significant growth with the cool, wet weather.
Pest Report
Apple: We caught our first three apple maggots at the Research Station last week and have received reports from area crop consultants of variable activity of this pest. This week, we caught no apple maggot. Spotted tentiform leafminer emergence continues in high numbers for the fourth week in a row with 100’s per trap. Codling moth numbers continue to be low with an average of three moths/trap this week. Obliquebanded leafroller (OBLR) are emerging with an average of 14 per trap in apple sites this week. Oriental fruit moth numbers average 9 per trap. Susceptible apple varieties are showing significant apple scab infections with fruit scab not uncommon around the region.
Cherry: Obliquebanded leafroller numbers remain steady in tart cherry blocks at the Station, where we have caught an average of 15 moths per trap. Lesser peachtree borer numbers are down this week with an average of 10 per trap. Greater peachtree borer continue to emerge with an average of 12 moths/trap. American plum borer averaged 14 moths per trap this week. In one unsprayed block, we caught hundreds of cherry fruit fly for the second week in a row; we also recorded a significant number of black cherry fruit fly. Much of the region’s weather stations are recording an ongoing wetting period triggering variable levels of cherry leaf spot infection potential. Cherry leaf spot symptoms are quickly becoming visible and intense in untreated tarts around the region.
Wine grapes: Grapes continue to grow, and many regional vineyards are at berry touch. Leafhopper pressure is variable around the region. Symptoms of leafroll virus have been spotted in some area vineyards. Based on a biofix of wild grape bloom on June 19th, the grape berry moth model has predicted the start of egglaying. We have heard reports of the first few Japanese beetle in the region and received our first report of powdery mildew. Growers should also be on the lookout for symptoms of anthracnose and Phylloxera as these have also been observed this past week; however, these diseases are not common in the north.
POST HARVEST SPRAYS FOR CHERRY LEAF SPOT
Nikki Rothwell, NWMHRS
George Sundin, Plant Pathology, MSU
Erin Lizotte, NWMRHS
Cherry leaf spot is the most important fungal disease of tart cherry in Michigan. The leaf spot fungus Blumeriella jaapii infects leaves with symptoms first appearing on upper leaf surfaces as small purple spots. As spots accumulate on leaves, the leaves turn yellow and fall. The amount of lesions required to cause leaf yellowing and drop is variable. Late summer (August, early September) defoliation reduces the ability of trees to store photosynthate in roots leading to an overall loss of vigor and leaving trees more susceptible to killing by winter injury. Early-defoliated trees also typically exhibit reduced flower bud formation and often set less fruit the following season.
As harvest will be winding down for cherries, many growers will be considering post-harvest applications for cherry leaf spot (CLS). Considering the considerable amount of precipitation this season, disease pressure is higher than in past seasons. We have also seen CLS lesions showing up in the region, and we have observed defoliation in some sites. For these reasons, growers may want to opt for making a post-harvest application for CLS.
Leaves typically fall from branches a few weeks after they begin to show disease symptoms. Thus, the goal of a cherry leaf spot management program is to maintain a healthy canopy on trees at least through the end of September. This recommendation would ensure an adequate amount of leaves on trees into late October and beyond. Because of the wet weather this season, most growers, particularly those with CLS symptoms already present in the orchard, should be using a post-harvest spray.
The fungicide of choice for leaf spot control after harvest is chlorothalonil (Bravo). Bravo 82.5 WDG at a rate of 3 lbs/A provides excellent leaf spot control. In addition, Bravo is a broad spectrum fungicide and thus is not subject to fungicide resistance concerns.
GUIDELINES FOR COLLECTING PLANT TISSUE SAMPLES FOR NUTRIENT ANALYSIS
Eric Hanson, Dept of Horticulture, MSU
James E. Nugent, District Horticulturist Emeritus, MSUE
Tissue analysis is the best method to assess tree, vine or bush nutrient needs. The window for collecting nutrient samples in NW Michigan is from mid-July to mid-August. We strongly encourage nutrient analysis be done at least every two to three years. It is best to combine this with soil samples taken from the same blocks. This combination allows a good analysis of nutrient and lime needs.
Plant tissue analysis can be effective in monitoring the nutrient status or trouble-shooting poor growth of a crop. The following points and sampling guides will help insure collection of a good diagnostic plant tissue sample:
- Collect sample from a minimum of 20 plants representative of the field, orchard or vineyard.
- Do not collect leaves damaged by disease or insects.
- If diagnosing a problem, collect separate samples from poor and good areas aid in the diagnosis.
- Rinse the sampled tissue in clean water to remove dust, soil or spray residue.
- Dry samples before sending to the lab by laying samples out in the air (do not oven dry).
- Send samples in paper bags (not plastic) to the MSU Soil and Plant Nutrient Laboratory or another tissue testing laboratory. Be sure to include the proper, completed information sheet. Tissue sample forms for the MSU lab are available through your county Extension office or NW Michigan Horticultural Research Station.
Tree fruits – Collect 100 leaves from the middle of the current season’s growth.
Vineyards – Collect a total of 100 leaf petioles (stems) from the most recently matured leaves near the center of the shoot. Undersides of mature leaves are generally darker than those of young leaves. Do not use leaves adjacent to fruit clusters.
Blueberries – Collect a total of 100 leaves from the middle of the current season’s growth. Do not use leaves close to fruit clusters or on one year old canes.
If you have any questions on how to collect tissue samples, call your local county Extension office or District Horticultural Agent. If sending samples to MSU, the cost per sample is $27 again this year. Include a check payable to Michigan State University with sample(s) to avoid an MSU billing fee.
The Fruit Tissue Information Sheet below is also available as a printable PDF form.
FRUIT TISSUE INFORMATION SHEET
Mail to: MSU Soil and Plant Nutrient Lab
A81 Plant and Soil Sciences Building
East Lansing, MI 48824-1325
517/355-0218
Grower Name: ________________________________________________________________
Street Address:________________________________________________________________
City:______________________ State: _______ Zip: _____________ County:_______________
Analysis desired: Complete w/N:_______ Complete w/out N:_______ N alone: _______
Paid: ______ Amount: __________ Check Number: ____________
Charge client: _______ Charge county: __________
Results are sent to a MSU Extension District Horticultural Educator to be interpreted and forwarded
to the grower.
| Sample ID | Fruit Crop | Variety | Plant Age | Lab ID |
Insect and disease predictive information is available at:
http://www.enviroweather.msu.edu/home.asp
http://www.agweather.geo.msu.edu/agwx/forecasts/fcst.asp?fileid=fous46ktvc
http://www.cherries.msu.edu/
Fruit CAT Alert Reports
http://www.ipmnews.msu.edu/fruit/
This issue and past issues of the weekly FruitNet report are posted on our website at: http://www.maes.msu.edu/nwmihort/faxnet.htm
ACTUAL
AND PREDICTED DEGREE-DAY
ACCUMULATIONS
SINCE MARCH 1, 2009
Please send any comments or suggestions regarding this site
to:
Bill Klein, kleinw@msu.edu
Last Revised: 8-11-09
