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 |
June 30, 2009
GROWING DEGREE DAY ACCUMULATIONS AS OF June 29th AT THE NWMHRS
Year |
2009 |
2008 |
2007 |
2006 |
2005 |
2004 |
19yr. Avg. |
GDD42 |
1205 |
1201 |
1541 |
1452 |
1484 |
1132 |
1302.4 |
GDD50 |
676 | 681 | 953 | 848 | 916 | 606 | 766.5 |
Growth Stages at NWMHRS (6/29/09- 3:30 p.m.)
Apple: McIntosh – 26 mm fruit
Yellow Delicious – 23 mm fruit
Gala – 23 mm fruit
Red Delicious – 28 mm fruit
Pear: Bartlett: 21 mm fruit
Sweet Cherry: Hedelfingen: 19 mm fruit
Napoleon: 18 mm fruit
Gold: 17 mm fruit
Tart Cherry: 14 mm fruit
Balaton: 14 mm fruit
Apricot: 33 mm fruit
Plum: 19 mm fruit
Grapes: 50% bloom
Weather Report
Temperatures have gone from hot last week to cool this week and with some rain in between. Temperatures were up in the 80’s and low 90’s last week, and on Monday, we dropped into the 60’s and have minimum temperatures in the low 50’s in the forecast over the coming week. Overall, degree day accumulations are 1203 base 42 and 676 base 50. These accumulations are still behind the 19-year average of 1302 base 42 and 776 base 50. We also received rainfall throughout the region, with just under 0.5” at the NWMHRS.
Crop Report
Pears are at 21-26mm while apricots are at 33mm. Apples range from 23-28mm. Montmorency cherries are 14mm and Balatons are 14mm in size. Sweet cherries are 17-19mm in size. These sizes are not much different than last week’s readings (13mm in tart cherry and 19-25mm in apple). Strawberry harvest is in full swing, but picking has been difficult with the temperature differentials.
Pest Report
In apples, we continue to catch emerging codling moth adults with an average of 9 per trap. Spotted tentiform leafminer numbers are averaging 13 per trap. Oriental fruit moth trap catch is at 9 per trap for the second week in a row. Oblique-banded leafroller are emerging in higher numbers now with an average of 32 per trap. High numbers of rose chafer have been reported in some apple orchards. Along with the wet weather, the apple scab model is predicting a heavy infection period in association with the wetting period that started on June 27. Despite cool temperatures, apple scab infection will occur under extended wetting periods. Growers are reporting scab lesions from earlier infection periods around the region and the end of primary scab is not yet predicted.
In cherries, American plum borer emergence appears to be tapering off with only 1 per trap this week (season long catch as follows: 37-6-15-7-9-1). Lesser peach tree borer continues to emerge with trap catches of 7-18-7 over the past three weeks. Greater peachtree borer continue to emerge for the second week in a row with an average of 3 per trap this week. As in apple, oblique-banded leafroller numbers are up in cherry with an average of 27 per trap this week. Growers are beginning to report some plum curculio ovipositioning scars, but less than we would expect at this time. We have not caught cherry fruit fly. High rose chafer populations have been reported in some orchards. The cherry leaf spot model has predicted a moderate and high infection potential on June 26-27 due to the wet weather. Symptoms of bacterial canker are common on sweets and we have also seen bacterial canker on green tart cherries – giving the fruit a chocolate brown appearance. Sour cherry yellows is showing up in many area tart cherry blocks, particularly in older trees.
In grapes, we continue to catch grape berry moth in high pressure sites. Potato leafhopper are arriving in higher numbers. Some sights are experiencing high numbers of rose chafer. No reports of powdery or downy mildew yet.
PREDICTED APPLE HARVEST DATES
Phil Schwallier, District Horticulturist, MSU-E
Normal Dates |
|
|||||||||
Station |
McIntosh |
Jons |
Reds |
|
||||||
SWMREC |
10-Sep |
21-Sep |
28-Sep |
|
||||||
Deerfield |
8-Sep |
21-Sep |
2-Oct |
|
||||||
Flint |
10-Sep |
25-Sep |
2-Oct |
|
||||||
Peach Ridge |
14-Sep |
26-Sep |
4-Oct |
|
||||||
Ludington |
18-Sep |
3-Oct |
14-Oct |
|
||||||
NWMHRS |
22-Sep |
10-Oct |
23-Oct |
|
||||||
Full bloom date |
Predicted harvest date |
|||||||||
Station |
McIntosh |
Jons |
Reds |
McIntosh |
Jons |
Reds |
Observer |
|||
SWMREC |
4-May |
6-May |
6-May |
5-Sep |
26-Sep |
2-Oct |
Shane |
|||
Deerfield |
5-May |
7-May |
8-May |
6-Sep |
27-Sep |
4-Oct |
Tritten |
|||
Romeo |
9-May |
12-May |
13-May |
12-Sep |
3-Oct |
12-Oct |
Tritten |
|||
Peach Ridge |
12-May |
14-May |
14-May |
15-Sep |
6-Oct |
12-Oct |
Schwallier |
|||
Ludington |
16-May |
19-May |
19-May |
20-Sep |
11-Oct |
17-Oct |
Danilovich |
|||
NWMHRS |
20-May |
21-May |
22-May |
24-Sep |
8-Oct |
15-Oct |
Rothwell |
|||
ETHEPHON ON CHERRIES
N.L. Rothwell, District Horticulturist, MSU-E
J. Nugent, Retired District Horticulturist, MSU-E
Ethephon is a plant growth regulator, and its uses vary with plant species, chemical concentration, and time of application. Ethephon regulates phases of plant growth and development by application to various growth sites. This plant growth regulator has systemic properties where it penetrates the plant tissues and is decomposed to ethylene. This decomposition impacts the plants’ growth processes. In cherry systems, ethephon promotes fruit loosening to facilitate mechanical harvesting. Ethephon, sold under the trade name Ethrel, has been used as a common management practice in both tart and sweet cherry harvest.
Ethephon releases ethylene, which penetrates plant cells and binds to receptors that affect expression of various genes. In the case of cherries, ethephon affects the gene that controls the synthesis/activation of cell wall loosening enzymes such as polygalacturonase and pectin methylesterase, thus dissolving the pectins between cells in the abscission layer. This chain-like reaction leads to cell separation in the developmentally-programmed abscission zone between pedicel and fruit or pedicel and spur. In short, ethephon loosens the cherries from the stem, which results in a gentle ‘shaking’ of the tree to remove the fruit.
One main concern in recent years (2005-2007) has been the amount of ethephon-induced damage with the hot, dry weather conditions. Ethephon can have excessive activity under a certain set of conditions, which can result in tree injury. As mentioned last season, we remind growers that we have observed quite a bit of ethephon damage in the past few years, especially in sweet cherries and of those varieties, Golds seem the most sensitive. This damage occurred when ethephon was applied during hot and dry weather conditions during 2007, 2006 and even in many blocks in 2005. Trees under stress, particularly drought stress, become more susceptible to ethephon damage. Damaged trees exhibit excessive gumming, and branches lose their leaves. We have also noticed areas within a block may show considerably more ethephon damage than other areas. Most likely the trees that show the most damage were more stressed in some way at the time of application, and soils in a particular area can help showcase this ethephon damage.
Timing the ethephon application is an important factor. A lower rate of ethephon provides adequate loosening if given adequate time for action (10 to 14 days), while higher rates will loosen fruit to the same degree more quickly. Therefore, it is possible to substitute time for rate and obtain the same effect. Secondly, it is important that the chemical not be applied too early in the season. The fruit should be in Stage III of growth, where the fruit is growing rapidly and the grass-green color begins to yellow or take on a tinge of red. If ethephon is applied earlier than Stage III, the fruit may fail to grow further and has the potential to drop off the tree with the stems attached.
As mentioned above, both temperature and tree vigor are associated with the degree of response achieved. At higher temperatures during the 72 hours following application, the magnitude of response is increased and at lower temperatures it is decreased. Trees low in vigor or under stress respond to a greater extent, and gumming and leaf abscission may result. Do not treat such trees! Repeat, do not treat such trees!
The following recommendations should be used when applying ethephon to cherries:
- Rate: Vary the rate depending on anticipated temperatures for 72 hours after application, days before harvest, tree stress and past experience. Lower rates decrease the likelihood of tree injury.
- Light sweets -- When applied concentrate (80 gals. water/acre or less), 1 to 2 pts/acre applied 10-14 days before anticipated harvest should provide adequate loosening. Rates up to 2.5 pts/acre may be necessary for harvesting in less than 10 days. When applied dilute, use no more than ¾ pt/100 gals or 3 pts/acre.
- Dark sweets -- When applied concentrate, use 1.5 to 2.5 pts/acre applied 10-14 days prior to anticipated harvest. Rates up to 3 pts/acre may be necessary for harvesting in less than10 days. When applied dilute, use no more than 1 pt/100 gals. or 4 pts/acre.
- Tart cherries -- When applied concentrate, use 0.5 to 1 pt/acre applied 7 to 14 days prior to anticipated harvest. When applied dilute, apply no more than 1/3 pt/100 gals or 1 pt/acre.
- Time of Application: Apply approximately 7 to 14 days before anticipated harvest. Do not harvest within 7 days of application (7-day PHI).
- Temperature: Avoid application when high temperatures are expected to exceed 85° F or remain below 60° F for the 72 hour period after application. Use relatively high rates when high temperatures are expected to be in the 60's ° F and lower than normal rates when highs are expected in the lower 80's.
- Tree stress: Do not spray trees that are low in vigor or under stress conditions.
- Do not spray trees that had serious gumming the previous year.
- Crop load: Heavy crop load, ie, low leaf to fruit ratio, is more difficult to loosen so use relatively higher rates or expect a longer time to achieve desired loosening.
- Concentrate spraying: Applying ethephon with concentrate sprayers (i.e., 80 gallons of water/acre or less) achieves the same level of loosening at lower rates per acre than does dilute applications. Uniform coverage is important.
- Tree size: Suggested rates/acre are based on full-sized trees. Adjust rates downward when treating blocks with smaller trees.
Growers should pay particular attention to the temperatures. As evident from the last three seasons, hot temperatures can really do damage to cherry trees. Growers that have had problems in the past years should avoid ethephon, especially if the trees showed serious gumming and leaf loss.
EFFICACY OF TANK-MIXING INSECTICIDES AND ETHEPHON
N.L. Rothwell and K.L. Powers, Northwest Michigan Hort. Research Station
Insecticides and fungicides are pH-sensitive, and when tank-mixed with plant growth regulators, such as ethephon, could present efficacy issues. This purpose of this trial was to evaluate the impact of ethephon on pH in the tank as many growers traditionally tank-mix this application with fungicides and/or insecticides. Our concern is that the pH of the tank will be lowered considerably with ethephon which may inactive the pesticides in the tank.
Table 1 represents the pH of each product in tap water. We measured pH after agitation and 30 minutes of ‘spray time’. The more ethephon added to water, the lower the pH. At 3 pints per 100 gallons of water, the pH is down to 2.8, an extremely acidic environment. Many growers use a 2 pint per 50 gallon rate, and this amount of ethephon would also lower the pH below 3. The pH of the tank at these rates is much too low for fungicides and insecticides, as these chemistries are most efficacious in a neutral pH range. See Table 2 for a list of optimal pH’s for common pesticides (courtesy of Annemiek Schilder).
Table 3 is a summary of a few insecticides mixed with copper/lime and ethephon at 1, 2, and 3 pint rates. Based on these results, pH is altered with copper/lime and with ethephon and potentially to a point where the activity of insecticides is altered. Lowering the pH of the tank with ethephon may reduce the efficacy of insecticide in the tank; therefore, growers should be aware of tank-mixing ethephon with insecticides or fungicides. Additionally, lime will raise the pH of the tank and ethephon works optimally at a lower pH. Tank mixing copper/lime with ethephon is not recommended.
Table 1. pH of all products individually when mixed with tap water.
|
pH |
Tap Water (NWMHRS) |
7.1 |
Ethephon, 1 pt/100 gal |
6.4 |
Ethephon, 2 pt/100 gal |
5.2 |
Ethephon, 3 pt/100 gal |
2.8 |
Cuprofix 20 DF |
7.4 |
Lime 3 lbs |
10.0 |
Lime 6 lbs |
10.0 |
Warrior |
7.5 |
Provado |
7.6 |
Actara |
7.5 |
Imidan |
7.4 |
Table 2. Llist of optimal pH’s for common pesticides (courtesy of Annemiek Schilder)
Product |
Active ingredient |
Optimum pH |
Half Life / Time until 50% Hydrolysis** |
|
Insecticides/Miticides |
||||
Admire |
Imidacloprid |
7.5 |
Greater than 31 days at pH 5 - 9 |
|
Agri-Mek |
Avermectin |
|
Stable at pH 5 - 9 |
|
Ambush |
Permethrin |
7 |
Stable at pH 6 - 8 |
|
Apollo |
clofentezine |
|
pH 7 = 34 hrs; pH 9.2 = 4.8 hrs |
|
Assail |
acetamiprid |
5 - 6 |
Unstable at pH below 4 and above 7 |
|
Avaunt |
indoxacarb |
|
Stable for 3 days at pH 5 – 10 |
|
Carzol |
formetanate hydrochloride |
5 |
Not stable in alkaline water; use within 4 hrs of mixing. |
|
Cygon/Lagon |
dimethoate |
5 |
pH 4 = 20 hrs; pH 6 = 12 hrs; pH 9 = 48 min |
|
Cymbush |
cypermethrin |
|
pH 9 = 39 hours |
|
Diazinon |
phosphorothioate |
7 |
pH 5 = 2 wks; pH 7 = 10 wks; pH 8 = 3 wks; pH 9 = 29 days |
|
Dipel/Foray |
B. thuringiensis |
6 |
Unstable at pH above 8 |
|
Dylox |
trichlorfon |
|
pH 6 = 3.7 days; pH 7 = 6.5 hrs; pH 8 = 63 min |
|
Endosulfan |
endosulfan |
|
70% loss after 7 days at pH 7.3 – 8 |
|
Furadan |
carbofuran |
|
pH 6 = 8 days; pH 9 = 78 hrs |
|
Guthion |
azinphos-methyl |
|
pH 5 = 17 days; pH 7 = 10 days; pH 9 = 12 hrs |
|
Imidan |
phosmet |
5 |
pH 5 = 7 days; pH 7 < 12 hrs; pH 8 = 4 hrs |
|
Kelthane |
dicofol |
5.5 |
pH 5 = 20 days; pH 7 = 5 days; pH 9 = 1hr |
|
Lannate |
methomyl |
|
Stable at pH below 7 |
|
Lorsban |
chlorpyrifos |
|
pH 5 = 63 days; pH 7 = 35 days; pH 8 = 1.5 days |
|
Malathion |
dimethyl dithiophosphate |
5 |
pH 6 = 8 days; pH 7 = 3 days; pH 8 = 19 hrs; pH 9 = 5 hrs |
|
Matador |
lambda-cyhalothrin |
6.5 |
Stable at pH 5 - 9 |
|
Mavrik |
tau-fluvalinate |
|
pH 6 = 30 days; pH 9 = 1 - 2 days |
|
Mitac |
amitraz |
5 |
pH 5 = 35 hrs; pH 7 = 15 hrs; pH 9 = 1.5 hrs |
|
Omite |
propargite |
|
Effectiveness reduced at pH above 7 |
|
Orthene |
acephate |
|
pH 5 = 55 days; pH 7 = 17 days; pH 9 = 3 days |
|
Pounce |
permethrin |
6 |
pH 5.7 to 7.7 is optimal |
|
Pyramite |
pyridaben |
|
Stable at pH 4 – 9 |
|
Sevin XLR |
carbaryl |
7 |
pH 6 = 100 days; pH 7 = 24 days; pH 8 = 2.5 days; pH 9 = 1 day |
|
SpinTor |
spinosad |
6 |
Stable at pH 5 – 7; pH 9 = 200 days |
|
Thiodan |
endosulfan |
6.5 |
70% loss after 7 days at pH 7.3 to 8 |
|
Zolone |
phosalone |
6 |
Stable at pH 5 – 7; pH 9 = 9 days |
|
Fungicides |
|
|||
Aliette |
fosetyl-al |
6 |
Stable at pH 4.0 to 8.0 |
|
Benlate |
benomyl |
|
pH 5 = 80 hrs; pH 6 = 7 hrs; pH 7 = 1 hr; pH 9 = 45 min |
|
Bravo |
chlorothalonil |
7 |
Stable over a wide range of pH values |
|
Captan |
captan |
5 |
pH 5 = 32 hrs; pH 7 = 8 hrs; pH 8 = 10 min |
|
Dithane |
mancozeb |
6 |
pH 5 = 20 days; pH 7 = 17 hrs; pH 9 = 34 hrs |
|
Nova |
myclobutanil |
|
Not affected by pH |
|
Ridomil |
mefenoxam |
|
pH 5 – 9 = more than 4 weeks |
|
Rovral |
iprodione |
|
Chemical breakdown could take place at high pH |
|
Orbit |
propiconazole |
|
Stable at pH 5 – 9 |
|
Herbicides |
|
|||
Banvel |
dicamba |
|
Stable at pH 5 - 6 |
|
Fusilade |
fluazifop-p |
|
pH 4.5 = 455 days; pH 7 = 147 days; pH 9 = 17 days |
|
Ignite |
glufosinate-ammonium |
5.5 |
|
|
Gramoxone |
paraquat |
|
Not stable at pH above 7 |
|
Poast |
sethoxydim |
7 |
Stable at pH 4.0 to 10 |
|
Princep |
simazine |
|
pH 4.5 = 20 days; pH 5 = 96 days; pH 9 = 24 days |
|
Prowl |
pendimethalin |
|
Stable over a wide range of pH values |
|
Roundup |
glyphosate |
5 - 6 |
|
|
Touchdown |
glyphosate |
5 - 6 |
|
|
Treflan |
triflularin |
|
Very stable over a wide range of pH values |
|
Weedar |
2,4-d |
|
Stable at pH 4.5 to 7 |
|
**The half-life is the period of time it takes for one half of the amount of pesticide in the water to degrade. Other factors than the pH can affect the rate of hydrolysis, incl. temperature, solubility, concentration, type of agitation, humidity, and other pesticides and adjuvants in the mixture.
Table 3. pH of Warrior, Provado, Actara, and Imidan when tank mixed with lime, copper, and 3 rates of ethephon.
|
pH |
Warrior |
7.5 |
Warrior, 3 lbs Lime, Cu |
10.9 |
Warrior, 3 lbs Lime, Cu, 1 pt Ethephon |
5.2 |
Warrior, 3 lbs Lime, Cu, 2 pt Ethephon |
4.4 |
Warrior, 3 lbs Lime, Cu, 3 pt Ethephon |
3.8 |
Provado |
7.6 |
Provado, Lime, Cu |
8.9 |
Provado, 3 lbs Lime, Cu, 1 pt Ethephon |
5.2 |
Provado, 3 lbs Lime, Cu, 2 pt Ethephon |
4.8 |
Provado, 3 lbs Lime, Cu, 3 pt Ethephon |
4.2 |
Actara |
7.5 |
Actara, Lime, Cu |
9.3 |
Actara, 3 lbs Lime, Cu, 1 pt Ethephon |
5.6 |
Actara, 3 lbs Lime, Cu, 2 pt Ethephon |
5.4 |
Actara, 3 lbs Lime, Cu, 3 pt Ethephon |
4.9 |
Imidan |
7.4 |
Imidan, Lime, Cu |
9.2 |
Imidan, 3 lbs Lime, Cu, 1 pt Ethephon |
5.5 |
Imidan, 3 lbs Lime, Cu, 2 pt Ethephon |
5.0 |
Imidan, 3 lbs Lime, Cu, 3 pt Ethephon |
4.7
|
KEEP AN EYE ON PESTICIDE PREHARVEST INTERVALS AS HARVEST APPROACHES
Erin Lizotte, IPM/IFP District Educator
As harvest approaches, growers should be aware of the PHI’s of commonly sprayed pesticides. By request, we have put together a table to help growers make appropriate insecticide management decisions, particularly as sweet cherry harvest is around the corner. Additionally, even though apple harvest seems a long way out, there are pesticides with long PHI’s listed in the table below.
INDAR® 2F SUPPLEMENTAL LABELING
Leslie Abbott, Dow AgroSciences, provided the following note and label.
“We submitted a request for a state label allowing for Indar to be used at higher use rates for brown rot control in stone fruit. This label allows Michigan growers to use up to 12 oz. per application with a season long limit of 48 oz. and has now been approved by the state.
I believe 8 to 9 oz. would be all that is needed in orchards where you have experienced problems controlling brown rot in past seasons.
The grower should have this label on hand if they are planning to use the higher use rates.”
Supplemental Labeling
Dow AgroSciences LLC 9330 Zionsville Road Indianapolis, IN 46268-1054 USA
Indar® 2F
EPA Reg. No. 62719-416
EPA 24(c) Special Local Need Registration SLN MI-090002
For Distribution and Use Only in the State of Michigan
Control of Blossom Blight and Fruit Brown Rot in Cherries, Peaches and Nectarines
ATTENTION
• It is a violation of Federal law to use this product in a manner inconsistent with its labeling.
• This labeling must be in the possession of the user at the time of application.
• Read the label affixed to the container for Indar® 2F fungicide before applying. Carefully follow all precautionary statements and applicable use directions.
• Use of Indar 2F according to this supplemental labeling is subject to all use precautions and limitations imposed by the label affixed to the container for Indar 2F.
Directions for Use
Refer to product label for Mixing, Handling and Application instructions.
Indar 2F is a protectant fungicide. Best disease control is achieved when a protectant application schedule is followed.
Use 6 to 12 fl oz of Indar 2F (0.094 to 0.188 lb active) per acre in a minimum of 20 gallons of water by ground or 10 gallons of water by air. Indar 2F may be applied up to the day of harvest.
To control blossom blight in cherries, peaches and nectarines, begin applications at early red bud stage before infection occurs. If conditions are favorable for disease development, apply again at full bloom and at petal fall.
To control fruit brown rot in cherries, peaches and nectarines, begin applications 2 to 3 weeks before harvest using a 7- to 10-day spray interval.
Specific Use Restrictions:
• Do not make more than 8 applications at the 6 fl oz rate or 4 applications at the 12 fl oz rate.
• Do not apply more than 48 fl oz of Indar 2F (0.75 lb active) per acre per season.
• Do not graze livestock in treated areas or feed cover crops grown in treated areas to livestock.
• Chemigation: Do not apply this product through any type of irrigation system.
Expiration Date: May 12, 2014
®Trademark of Dow AgroSciences LLC
R349-007
Accepted: 05/12/09
Initial printing
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: 6-30-09
