In this issue
Tree fruit news
§ Dogwood borer control in apples
§ High density apple orchard tour
Small fruit news
§ Managing cherry leaf spot in poor spraying weather
§ Strawberry black root rot and renovation meeting
§ Blueberry IPM Twilight meeting
§ NW Grape IPM Update “First Friday” meeting
Other news
§ Regional reports
§ Weather news
John Wise
Trevor Nichols Research Complex
The dogwood borer
can be a problem in
Burr knots are
aggregations of partially developed root initials that usually occur in
clusters at or below the graft union. Reddish frass on the surface of a burr
knot is a visible sign of infestation. Burr knots are fibrous and permit entry
of some insecticides such that larvae are readily exposed to a lethal dose
while still within the plant tissue. The larvae can be controlled with trunk
applications of Lorsban 4E at a rate of 1.5 quarts per 100 gallons of water. The
larvae can also be controlled with trunk applications of Lorsban 50 WP at the
rate of three pounds per 100 gallons, or Lorsban 75 WG at two pounds per 100
gallons of water. This must be applied directly to the trunk from a distance of
no more than four feet using low volume handgun or shielded spray equipment. Do
not allow spray to contact foliage or fruit. A single spray timed for the peak
egg hatch in late June to mid-July will provide good control.
A new insecticide
from the neonictinoid class, Assail 30SG, is now labeled for dogwood borer
control. It should be applied at eight ounces per acre after moth emergence, to
coincide with dogwood borer egg laying, followed by a second trunk spray 14 - 21
days later.
Erin Lizotte, IFP/IPM District Educator, MSU-E
George Sundin, Plant Pathology
With an almost constant barrage of wind and rain, getting into the orchards has been difficult to say the least. When managing cherry leaf spot, conventional wisdom has shown that protectant management strategies that keep leaves protected during infection periods are the most effective treatments. The key to controlling cherry leaf spot is to minimize infection and disease spread early in the season in order to help the trees retain leaves until later into the fall. Unfortunately, it has been almost impossible for growers to get their sprays on when necessary. Due to the weather, there have also been a lot of questions regarding how often to apply fungicides, how long the fungicides are providing protection when exposed to rain and what to apply if an application was missed.
The fungicides Gem (strobilurin) and Pristine (strobilurin and boscalid) are excellent options for application at the first cover timing. These products are often used at first cover because they control both cherry leaf spot and powdery mildew. Both fungicides are rain fast within two hours and move locally within leaves. This means that if you applied a strobilurin two hours before rainfall then the leaves are protected despite the rain. If you are applying a strobilurin on alternate rows then the spray interval should be tightened by two to three days, as long as the rainy warm weather continues.
If a spray was missed
because of high winds or rain, there is little compelling evidence that post
infection treatments are effective. The best shot at getting any back action
against cherry leaf spot is a full cover of
The High Density Apple Orchard tour will be held on
Thursday, July 10 from 1:00 PM. to 7:00 PM. Please RSVP by July 1 to: Donna at
(800)-767-1345, Fax: 616-693-2317 or email: stewar28@msu.edu.
Hosted by Pomesters,
Featuring Dr. Terence Robinson of
§
Tall
spindle
§ Vertical axe
Carlos Garcia-Salazar; MSUE educator
Bob Tritten; MSUE educator
When: July 10, 2008 – 6:00 to 8:00PM
Where: DeLange’s Redberry Farm,
Topics: Dr’s Annemiek Schilder and Jim Hancock of MSU have been working on
trying to piece together the strawberry black root rot complex or puzzle over
the last few years. Dr. Schilder established some plotwork at this farm that
she feels shows some real promise in understanding the nature of this
devastating strawberry disease, and some possible strategies for reducing its
severity in the future.
At this same meeting,
we will also review the strawberry renovation practices, including weed
control, fertilization, bed width, etc. This will not necessarily be a farm
tour, but a chance to look at some interesting plotwork and talk about
renovation. We also will look at fall red raspberries. A number of our MSU
Small Fruit Specialist Team members will be present for the meeting.
Directions to the
farm:
-From Hudsonville: Three
miles west of Hudsonville on
-From
Paul Jenkins
Small Fruit Education Coordinator
When: Tuesday, June 24, 6:00 – 8:00PM
Where: Carini
Farms,
What: Timely updates for control of pre-harvest diseases, insects and weeds.
This is a free meeting with a light dinner served at 6:00PM. Spray credits
available for attending. Hope to see you there!
For more
information, contact Paul Jenkins at: jenki132@msu.edu;
or 517-432-7751.
Paul Jenkins
Small Fruit Education Coordinator
When: Friday, July 11, 3:00 – 5:00PM
Where: Larry
Mawby’s vineyard,
What: Annemiek Schilder will lead a discussion on grape pathology issues.
For more
information, contact Paul Jenkins at: jenki132@msu.edu;
or 517-432-7751.
Last week’s weather was cool and dry with highs generally
near 70°F, and lows near 50°F. A few showers passed through the region on Saturday,
leaving little rain and some light hail. Soils are becoming dry. We expect
warmer temperatures later in the week with highs rising into the 80s and lows
near 50°F. Our GDD totals are now about three or four days behind 2007.
|
Grapes, from April 1
|
|||
|
Location |
GDD 42 |
GDD 45 |
GDD 50 |
GDD 50 |
|
1305 |
1093 |
787 |
781 |
|
|
1382 |
1163 |
840 |
835 |
|
|
1194 |
988 |
694 |
690 |
|
Deer
browsing continues. Insect activity has remained high. Leafroller larvae are
feeding in some orchards. Tarnished plant bug feeding
damage has been reported in apples and peaches. Adult rose chafer and Japanese
beetles are continuing to emerge. Aphid numbers are
building. We are catching lesser
peach tree borer. Trunk sprays or pheromone disruption are recommended for
borer control.
Apricots are 1.5 to 2.5 inches in diameter.
Peaches are about 1.5 inches in diameter. Pit hardening has not yet begun. Powdery mildew and bacterial spot, but not peach scab, have been reported. Most curled leaves caused by green peach aphids are empty indicating that they are migrating out of the orchard and control is no longer needed.
Sweet cherries are showing red color and birds are a problem. Early varieties are being harvested. General harvest of early varieties should begin late this week. The cool dry weather has suppressed brown rot infection. Brown rot requires warm, wet conditions, five to six hours of wetness at 70°F and growers should be prepared to protect against this disease at harvest. Rains Sunday were cherry leaf spot infections in some areas.
Tart cherries are coloring. Most fruit are straw
colored and ethephon sprays will be applied soon. Recent rains were a cherry
leaf spot infection. Few cherry leaf spot symptoms have been reported. An eastern cherry fruit fly
was caught this week in
Plums are almost an inch in diameter and the pits are hard. Shoot growth has stopped and growers no longer need to protect against black knot. Plum trees also need to be protected from the peach tree borers. Growers should scout for white apple leafhopper.
Apples are 1.5
inches in diameter. Some varieties such as Red Delicious and Empire have a
light crop. Apple scab symptoms can be
found so growers with active scab should continue to protect against
scab infection. Soon, waxy fruit will be resistant to scab. Fire blight
infections are larger and easier to find, but overall is relatively light for
the region. There is little oozing due to the dry conditions. Trap catch for codling
moth remains high. We are now about midway through egg hatch. Obliquebanded leafroller
adults were trapped June
9 and egg hatch should be soon. Spotted tentiform leafminer
trap catch is rising, indicating the beginning of the second generation. White apple leafhoppers
are scarce. European
red mites are moving about. San Jose scale
adults are flying. Sprays for San Jose scale crawler should be targeted for the
end of the week. Green
aphid populations are climbing. Young trees should receive sprays to kill potato leafhoppers.
Pears are about an inch in diameter and the crop looks good.
Blueberries are beginning to color. Harvest of early varieties in the south should begin in a little over a week. Cranberry fruitworm egg hatch is ending. Fruitworm feeding damage is easy to find in most fields. Look for shriveled blueberries in the clusters of green fruit. Cherry fruitworm only attack single fruit while cranberry fruitworm will move to other fruit in the cluster. Preharvest fungicide sprays should target alternaria and anthracnose. Blueberry maggot traps should be out.
Grapes are “BB” sized. Shatter continues. Rose chafer numbers are
declining, but they can still be found feeding on late blooming clusters of the
secondary and tertiary buds. Grape leafhopper can
be found in many vineyards. Insecticides to control grape berry moth
should be included in the post bloom fungicide sprays. Grape berry moth trap
catches are up and larvae can be found feeding in the fruit clusters. Wine
grapes need to be protected from potato leafhoppers. Fungicides
in the immediate post bloom period should target all four major fruit diseases;
powdery mildew, downy mildew, black rot and phomopsis. So far, phomopsis
is the only disease that is easy to find in vineyards. Wine grape growers also
need to apply sprays to control botrytis
bunch and berry rot.
Strawberry harvest is ending in some areas begun. Warm temperatures and dry conditions following the rains of June 5-7, have moved the crop rapidly. Fruit size and quality are excellent. Cool conditions should extend the season. Leather rot and sap beetles can be found in some fields.
Raspberry and blackberry bloom is ending. Some fruiting canes are looking weak due to winter injury. Plants on sandy ground are showing signs of drought stress. Growers should be scouting for Japanese beetles, raspberry sawfly larvae and leafroller larvae. Raspberry sawflies eat the leaves between the veins, so look for small green bristled worms under the leaves. Leafrollers curl and web the leaves together. Raspberry cane borers are laying eggs; look for wilting shoot tips and a ring of parallel girdles at the base of the wilting. The egg is laid between the girdles. Primocanes in fall bearing raspberries are 18 to 24 inches tall.
Cranberries are nearing full bloom.
The next Monday Fruit Update
meeting will be Monday, June 30 at
the Fruit Acres Farm in
The annual
Viticulture Day at the Southwest Michigan Research and
Cooler weather has been a welcomed relief for strawberry
growers and for the start of sweet cherry harvest. While many areas of east
|
Location |
GDD42 |
GDD45 |
GDD50 |
|
Commerce ( |
1286 |
1074 |
765 |
|
Emmett (St Clair) |
1248 |
1050 |
747 |
|
|
1299 |
1086 |
782 |
|
Lapeer (Lapeer) |
1280 |
1074 |
775 |
|
|
1366 |
1146 |
829 |
|
Romeo ( |
1299 |
1085 |
772 |
Apples continue to size nicely with most being in the range of 1.25 inches to 1.375-inches in diameter. Apple drop from frost and freeze injury as well as thinning is pretty well wrapped up across the region, however there continues to be a small percentage of large apples that have continued to drop. This may continue for the rest of the season. For the most part we have a fair crop of apples across the region; however the crop seems to be getting shorter all the time. The old saying that “a short crop gets shorter” seems to be true this year.
Apple maggot traps have been set for a few weeks; however I have not had any catches. I would expect to see it in the next week to ten days. Codling moth trap catches have generally come down across the region. I continue to see codling moth trap catch even in pheromone disrupted blocks; this is a concern to me. I have seen a few fruit scars from codling moth injury. Oriental fruit moth trap catches are also down across the region, and I see a few larvae in apple terminals. There are a few obliquebanded leafroller larvae; however their numbers are fairly low. Potato leafhopper adults are still common across the region; however the numbers are also fairly low. I am also starting to see a few white apple leafhopper nymphs. Most of the aphid populations are now on the decline. European red mite numbers remain low at most farms across the region due to a high number of predators. I am starting to see a few apple rust mites. There are good numbers of predators at many farms across the region. Over the last week or so, I have seen high numbers of small predator wasps.
As I reported in last week’s CAT Alert, we are now into secondary apple scab season, as primary ended on June 16. I continue to see a fair number of apple scab lesions across the district, mostly on leaves, but a few farms have it on fruit as well. The apple scab lesions appear to be burned out. There continues to be a few new fireblight strikes around the region, however numbers are generally low. Many blocks have powdery mildew in its susceptible varieties.
Pears are currently at around 1.125 inch to 1.25-inch in diameter. A few farms remain with high numbers of pear psylla adults, eggs and nymphs. Most farms have removed suckers which will reduce populations and break the lifecycle. I am starting to see a little bit of Fabraea leaf spot in pears.
Peaches continue to have a wide spectrum of fruit sizes with most of the larger fruit being at 1.25-inch to 1.50-inch. We are nearing pit hardening. Growers are aggressively thinning peaches. Oriental fruit moth trap catches are down, as I reported in the apple section. Tarnished plant bug numbers remain generally low across the region; however I can find them in most blocks of peaches. A bit of peach wart is starting to show up, as is powdery mildew. As I reported last week, X-disease symptoms are also scattered across the region. Bacterial canker symptoms are also starting to be seen in peach.
Sweet cherry harvest is underway for early varieties at most farms across the region. Fruit has continued to color nicely and fruit also has continued to size, with most fruit measuring 21 mm to 24 mm in size. Cherry fruit fly trap catch has been more widespread over the last week. Based on levels that I have seen, I would encourage growers to do a good job of checking their traps on a daily basis, and if they find trap catches then control measures are going to need to be taken during harvest. Bird feeding is starting to be seen in sweets.
Tart cherries have colored a great deal over the last week, and have picked up a bit of size with many measuring 13 mm to 16 mm in size. I continue to see a bit of fruit drop continuing, as well as fruit finish problems. Bacterial canker oozing has been seen at many farms. Some cherry leaf spot disease is starting to be seen.
Plums continue to
size, with most being close to one inch in diameter.
Strawberry harvest is now on the downhill side at most farms across the region. Farms to the south have had about a three and a half week season thus far, and should be finishing off here late this week or over the weekend. Slugs have been a major problem at several farms across the region over the past week. Leather rot continues to be seen at a few farms across the region, as does anthracnose. Keep an eye on potato leafhopper populations on newly planted strawberries. Newly planted strawberries continue to runner well.
Raspberries are sizing well, and I expect to see the beginning of harvest of early maturing summer red varieties in about ten days or so. Fall red raspberries are around 24 inches in length. Raspberries sawfly feeding activity seems to be on the decline again this week.
Blueberries have continued to size fairly well with the largest fruit measuring 14 mm to 16 mm in size. Now is the time to set blueberry maggot traps. In traps that I set last week, I have not yet seen any blueberry maggot catch.
Phil Schwallier
Amy Irish Brown
Carlos Garcia-Salazar
Degree day accumulations at the Sparta
weather station continue to be right at average. Fruit drop has stopped for the
most part, but could continue throughout the summer in lighter levels. Overall,
it’s looking like there is about 50 percent of an apple crop in the
Some trauma blight is being seen, but in very isolated amounts, it was most likely caused by the high winds and rain storms in the June 7- 8 storms.
Hourly wetness at the various weather stations in the Grand Rapids area are indicating that we are getting close to the timing when summer diseases will start to express themselves, so adding fungicides in the tank in the next week or so will be important to help prevent this. The weather forecast is calling for several days with chances of rain at the end of this week and into the weekend – along with high humidity levels. This potential wetting pattern will most likely get summer diseases started, so cover sprays ahead of the rains would be advised.
No new egg laying scars from plum curculio have been found in
the
Additional newly laid European red mite eggs can be found. New nymphs have been found as well. Continue to monitor mites closely.
A regional biofix for codling moth has been set for the
Obliquebanded leafroller are flying. A regional biofix was set for the region for June 14. We have accumulated just over 200 degree days base 42 since that date, which should put us at peak adult flight. Early egg hatch will probably start about a week from now or around July 1, if forecasted temperatures hold up.
A regional biofix for Oriental fruit moth has been set on May 8. We have accumulated 722 degree days base 45 since that biofix, so Oriental fruit moth egg hatch should be declining as first generation activity ends in about a week or so.
Green apple aphids are starting to be found in light numbers on terminals. Beneficial predators are not being seen in these populations very readily yet. Continue to monitor.
Blueberries are developing very fast and thanks to the rains from the past weeks, the fruit is sizing very well. There are a few problems related to weather including pest and disease management and fertilization. In many fields that were flooded, pest and disease control had to be delayed until the ground was in good condition to drive the equipment. In some cases, large commercial farms required the use of aerial applications to spray fields where the soil was too wet to drive the ground equipment. This created a difficult situation for small producers that rely on crop dusters for pest control, because aerial application providers gave preference to large producers. So far, we are seeing that in fields where applications were delayed, for any reason, cranberry fruit damage could reach up to one percent
It is important to mention that fields that were applied after the flooding with Intrepid or Confirm may not have the same level of control that those that used Guthion. Guthion is more effective in controlling fruitworms even though they are already inside the fruit.
Another situation resulting from past weather conditions is
the presence of disease. Phomopsis canker and twig blight is widely spread in
all counties, but is more problematic in fields that were affected by
freeze/frost events. If untreated, phomopsis infected canes may become a
serious problem later on, especially during the summer when high temperatures
could enhance the impact of the disease and kill or collapse entire bushes.
Therefore, it is advisable to keep a good control program against this disease
including pruning and removing of all infected wood in the field. Also, the
Shoestring virus is more prevalent this season than during the previous one. Low
temperatures that prevailed during spring time allowed the expression of the
symptoms in most infected plants, especially in old
The blueberry harvest continued in
This past week has been quite uneventful compared to the week before. Temperatures were cooler, staying mainly in the 60s and low to mid- 70s for highs, and into the 40s and low 50s for the lows. There were few rain events totaling only a few hundredths of an inch throughout the area. Soil moisture is satisfactory.
Crops are sizing well. Cherries
are changing color. Apples are
approaching an inch in diameter and so are the peaches. Plums are 22 mm in diameter. The USDA has set the estimate for the
cherry crop of northwest
|
Location |
DD42 |
DD45 |
DD50 |
Rainfall in last week |
Rainfall since April 1 |
|
Hart |
1081 |
887 |
608 |
0.07 |
9.97 |
|
Ludington |
1021 |
832 |
559 |
0.06 |
13.45 |
|
Manistee |
1060 |
870 |
598 |
0.07 |
12.97 |
The most recent wetting events resulted in a light apple scab
infection period for the Ludington
area only. The same wetting event produced low cherry leaf spot infections in Hart
and Ludington areas. Fireblight and shoot blight are showing up in many blocks
throughout the area, as a result of the previous week’s stormy weather. Nectria
shoot blight could be found in
Cherry leaves with cherry-yellows symptoms are causing serious leaf drop in many older cherry blocks. Powdery mildew is starting to become more visible in the blocks.
There has been a slight
drop in the codling moth activity. It appears that they reached the peak
emergence a week ago. Their numbers have dropped from an average of 9.6 per
trap to 5.9 per trap. Lesser peach tree borers are showing increased activity
in
|
Location |
GDD at biofix - May 24 |
Accumulated GDD since biofix |
|
Hart |
229 |
387 |
|
Ludington |
217 |
350 |
|
Manistee/Bear |
242 |
368 |
Nikki Rothwell
Duke Elsner, Erin
Lizotte, Rob Sirrine
GDD42 1037
GDD50 565
Apples are at 21-24 mm
Sweet cherries: Hedelfingen have 16 mm fruit. Napoleon have
15 mm fruit and Gold have 13 mm fruit.
Tart cherries: Montmorency and Balaton have 13 mm fruit.
Apricots have 28 mm fruit.
Plums are 20 mm.
Grapes have 10-16 inch shoots.
The weather warmed up as the week progressed and by the weekend, daytime temperatures were in the mid- to upper 70s. However, by Monday, June 23, temperatures cooled down again, and with high temperatures predicted for Monday to be in the mid-60s. We have had no rainfall since less than 0.09 inches fell on June 17, and only 0.01 was reported the following day. As of Tuesday, June 24, we have accumulated 1048 growing degree days base 42 and 585 growing degree days base 50.
The USDA estimate for the
§ Northwest: 75 million pounds
§ West Central: 40 million pounds
§ Southwest: 20 million pounds
Last year, the overall
For sweet cherries, the national estimate is 249,580 tons. For
Cherries are continuing to drop, and those remaining on the tree continue to size. Apple size is also increasing, and Goldens are at 22mm while Galas and Macs are at 24mm. Strawberry harvest began this weekend, and many growers are picking the variety Wendy.
Grapes seem to be still moving slowly, but things have picked up with the recent rains. Chardonnay shoots are between 10-16 inches in length.
Wetting events ending last Thursday and Friday (June 19-20) caused cherry leaf spot infections to be predicted at low to high levels in the northwest region. Bacterial canker is being observed at high levels in sweet cherries around the station and American brown rot has arrived earlier than usual, with active infections on green fruit. The cool temperatures have caused trees to retain damaged fruit for a longer period, increasing the likelihood of brown rot spreading through clustered fruit. We have accumulated 327 DD base 50 since full bloom, biofix for plum curculio. There have been a lot of oviposition scars on fruit, and we are able to easily beat weevils out of unsprayed trees at the research station. We are catching obliquebanded leafroller at about 12 per trap and observed our first cherry fruit fly last week at the station. The station often catches the first fruit fly well ahead of orchards throughout the region and should not be used to determine emergence for the entire region. Lesser peach tree borer continue to be caught in significant numbers, at an average of 10 per trap at the research station. The number of American plum borers is decreasing to around five per trap and greater peach tree borer are emerging at slightly higher numbers with four in one trap this week.
We are at the tail end of the primary apple scab season with less than 10 percent of mature spores yet to be discharged. Scab infections were predicted in the region at light to heavy levels based on rain last Thursday and Friday, symptoms of this infection period are predicted to appear around June 27-29. We biofixed for codling moth on June 3, and since then we have accumulated 248 DD base 50. The 250 DD base 50 mark is a good target for many insecticide applications for codling moth. Codling moths are averaging 18 per trap at the station, and Oriental fruit moth numbers are down from last week with trap catches dipping below 10.
An interesting, but usually minor pest, grape plume moth, is appearing in higher than anticipated levels at area vineyards. Rose chafers have also arrived in the region, and at the station we are seeing high numbers in unsprayed sweet cherry blocks.
Aaron Pollyea
Geography
Temperatures during the next few days will be generally steady, with highs Tuesday through Monday generally ranging from the upper 70s north to the lower 80s south and lows from the upper 50s to low 60s north to the lower 60s south. In the medium range forecast, the upper air pattern mentioned above is expected continue for much of the remainder of June.
The National Weather
Service 6 ‑ 10 day outlook
covering June 25 through June 29 calls for near normal temperatures and for
precipitation totals to remain at below normal levels. The outlook for the 8 - 14 day period (July 1- July 7)
calls for mean temperatures to range from near normal levels across southern
sections of the state to below normal levels in the central to northern areas,
and for below normal precipitation totals across the state. Further ahead, it
is interesting to note that forecast guidance is also hinting that the very
turbulent, active upper air pattern of late May and early June may return to
the upper