In this issue
Tree fruit news
§ Section 18 specific exemption granted for Agry-Gent for fire blight control
§ Bacterial canker and cold spring temperatures
§ New fungicide labels for use in apples and stone fruit
§ Control options for mites in fruit crops
Small fruit news
§ Blueberry insecticide label update
§ Hoplia beetles chewing on blueberry flower buds
Other news
§ Twilight blueberry meeting
§ Southwest grape IPM meeting
§ Regional reports
§ Weather news
Next issue May 6
George Sundin, Plant Pathology
The EPA has granted a Section 18 Specific Exemption for the use of Agry-Gent 10-W (gentamicin) for
the control of the blossom blight phase of fire blight. This use is for
orchards where streptomycin-resistant fire blight bacteria are present. The
Section 18 is applicable to Berrien,
The conditions and restrictions of the Section 18 specific exemption appear to be identical to those effective in 2007. These include the following:
1. A maximum of 7,000 acres of apples can be treated. Apply gentamicin only when the pathogen is resistant to streptomycin.
2. Agry-Gent 10-W should only be applied when the fire blight state experts and/or disease forecasting model determine that the weather conditions favor disease epidemics. Thus, the use of this material is limited to epidemic conditions; if these conditions are not present this year, other fire blight control materials such as Mycoshield should be used.
Authorization for use will come from
3. A maximum of two applications of Agry-Gent can be made at a rate of 3.5 lbs/acre. Applications are restricted to ground equipment and cannot be made through any type of irrigation system.
4. Do not apply gentamicin as the first spray of the season. It should be applied only after the first spray of registered antibiotics (streptomycin and/or oxytetracycline).
5. Do not make consecutive applications of gentamicin.
6. Do not use in orchards in which the soil has been fertilized with animal manure. This restriction addresses concerns that gentamicin resistance could be transferred to E. coli bacteria present in animal manure.
7. Upon expiration of the exemption, all unopened and unused product must be returned to the dealer where purchased or to the manufacturer.
Agry-Gent 10-W (gentamicin), from
Gowan, is an alternative antibiotic for fire blight management. Agry-Gent 10-W
will work equally on streptomycin-resistant and streptomycin-sensitive strains.
The label rate is 3.5 lbs./acre. A maximum of two applications of Agry-Gent
10-W will be allowable during the bloom period in 2008 (check code-a-phone
updates for use authorization). Agry-Gent must not be used as the first spray
of the season. A first spray of registered antibiotics (Mycoshield and/or
streptomycin) must be applied. Also, do not make consecutive sprays of
Agry-Gent. This material may be sensitive to pH and thus the pH of the spray
solution should be buffered to 6.0 to 6.5. In addition, do not use Agry-Gent
10-W with other spray materials with clay-based carriers such as Captan as the
clay can bind up the gentamicin rendering it less effective.
Nikki Rothwell and Erin Lizotte, NWMHRS
George Sundin, Plant Pathology
Bacterial canker is caused by the bacterium Pseudomonas syringae, and this pathogen
can infect sweet and tart cherry and plums throughout
Early copper sprays are the most common methods of control for bacterial canker on cherry. However, sweet cherry tissues are extremely sensitive to copper, and the sprays must be adequately timed to reduce P. syringae inoculum without causing phytotoxicity. If the trees are still in the dormant stage, two copper applications can be applied at 1-2 week intervals at a rate 1.2-2 lbs of metallic copper with either one pint of spray oil per 100 gallons of water or 6-9 lbs of hydrated lime per acre. Copper products sprayed during the dormant stage should have good retention properties to enhance disease control as longer residuals for copper should translate into an extended period of bacterial disease suppression after the spray is applied (Rosenberger, 2007). If the trees have broken dormancy and are in the pre-bloom stage (bud swell through white bud), copper rates should be reduced to 25-35 percent of the dormant rate. Up to two copper applications with a one week interval should be used at this time. In tart cherries, copper compounds can be used at the 1.2-2 lb actual copper rate at bud burst with weekly repeated applications until late May. Some of these later sprays may result in some leaf yellowing, bronzing, and potentially defoliation. Adding hydrated lime at 6-9 lbs/acre will reduce the phytotoxic effects of copper.
Literature cited:
Rosenberger, D. 2007. Early season copper sprays. Scaffolds Fruit Journal. April 9. 16:4.
Georg Sundin, Plant Pathology
Two fungicides with new labels for apple this spring are
Indar (Dow Agrosciences) and Inspire Super MP (Syngenta). Two formulations of
Indar (75WSP and 2F) are labeled for use against apple scab, powdery mildew,
cedar apple rust, sooty blotch and flyspeck. Indar is a systemic,
sterol-inhibitor (SI) fungicide. Remember that resistance to SI fungicides in
the apple scab pathogen is widespread in
Inspire Super MP is also a systemic, SI fungicide. This fungicide will be packaged together with Vangard, an anilinopyrimidine fungicide with a different mode of action. A multi-pack will be sold containing two 40 oz. jugs, one of which is labeled Inspire Super MP and the other is labeled Vangard. These are to be mixed together, resulting in enough material to spray 10 acres at a 4 oz/acre rate of Inspire and 4 oz/acre rate of Vangard. The active ingredient of Inspire (difenoconazole) is also more effective in controlling SI-resistant scab strains than other SI fungicides. Since the product is tank-mixed with Vangard, the two modes of action should be effective for resistance management.
Adament 50WG (Bayer) has a new label this spring for use in
stone fruit. This fungicide is a pre-mix of two active ingredients
(tebuconazole and trifloxystrobin) that we already knew as Elite and
John Wise, Rufus Isaacs and Larry Gut, Entomology
Mites can be significant pests of fruit crops. There is an array of miticides available for control of the European red mite (ERM), two-spotted spider mite (TSSM) and rust mites (including apple and pear rust mites, pear blister mite, plum nursery mite, blueberry bud mite) (RM), but their performance characteristics are not all alike. The accompanying table is designed to summarize several key variables that can help you determine which miticides are optimal for your integrated pest management program.
Rufus Isaacs and John Wise, Entomology
Guthion WP (azinphosmethyl) is still registered for use during 2008. The EPA’s plan for phasing Guthion out of blueberry production starts taking effect this season. Guthion is still registered, but here are the main label restrictions that blueberry growers need to be aware of:
§ The seasonal limit is reduced from 3.0 to 2.5 pounds/acre.
§ Maximum single application remains at 1.5 pounds/acre.
§ Aerial application is still allowed.
§ 7 day REI and 7 day PHI, except in U-pick fields (30 or more days, depending on the rate used – see label for details).
§ Buffer zone to bodies of water is 60 ft for ground application and 150 ft for aerial application.
§ Buffer zone to occupied dwellings or recreational areas is 60 ft.
One important practical implication of the new restrictions is that if you plan on using two sprays of Guthion after bloom for fruitworm control, if the first spray is at the 1.5 pound rate, the next can only be 1 pound. Another option is to apply 1.25 pounds twice if you have high fruitworm pressure and need to apply at high rates. Of course, one application at 1-1.5 pounds or a 1 pound rate applied twice would be allowed too. These changes are the first of the restrictions affecting Guthion in blueberry that will continue to limit the use through 2012. By September 30 of that year, EPA’s plan has Guthion restricted completely from blueberries. The next significant changes are in 2010, when the seasonal limit will drop to 1.5 lb, and no aerial application will be allowed.
Given the Guthion phase-out plan, testing alternative options for fruitworm control on some of your fields would be prudent this year. Look in next week’s edition of the Fruit CAT Alert for an article on monitoring and management of fruitworms that will provide information on the various options available.
MSU and the
This spring and summer, MSU Extension will hold a series of IPM meetings and fruitworm management will be a main topic of the meeting on May 14.
Intrepid 2F (methoxyfenozide) has received a supplemental label for use in blueberry and other bush berry crops. This is an insect growth regulator and is a more active version of Confirm. If you have used Confirm in recent years for control of fruitworms, you should expect better performance from this product. It is safe for bees, allowing application during bloom and it provides good residual control of moth larvae with high worker safety and a good environmental profile. Intrepid is registered for control of many of the most economically-important blueberry moth pests including cherry fruitworm, cranberry fruitworm, obliquebanded leafroller, and gypsy moth. Tussock moth is not on the label, but this product will be very effective for that pest if applied with good coverage when the larvae are still small. While the label indicates 16 ounces per acre for most of these pests, this is a very high rate and I expect a high level of control at 12 ounces per acre. As with Confirm, this insecticide must be applied with excellent coverage to be effective: the larvae must eat the residue, or it needs to be in contact with the eggs to work. For example, the label states a minimum of 30 gallons of water should be used from ground equipment and 10 gallons if applying by air. Intrepid has a 7-day PHI.
Assail 30SG (acetamiprid) is registered for use in blueberries for control of aphids and leafhoppers at 2-5-5.3 ounces per acre. It is in the same chemical class as Provado, the neonicotinoids, but it has a wider range of pest activity that includes moth pests. A higher range (4.5 - 5.3 ounces per acre) is registered for use against cranberry and cherry fruitworms, Japanese beetle, blueberry maggot and some other insect pests. We have seen good to excellent control of these pests in small plot trials conducted at the Trevor Nichols Research Station, and we are looking forward to gaining more experience at commercial farms this season. Assail 30SG has a 1-day PHI. It is also labeled for use on strawberries, other bush berries and cane berries, and can be applied by ground or air.
Delegate WG (spinetoram) is a new insecticide from the same chemical class as SpinTor (the spinosyns) and is highly effective against lepidopteran pests. It is labeled at 3-6 oz per acre for armyworm, cranberry fruitworm, leafroller, and spanworm control in blueberries, with a 3-day PHI.
Danitol 2.4 EC
(fenpropathrin) is a new pyrethroid insecticide labeled for cranberry
fruitworm, plum curculio, blueberry maggot and Japanese beetle. It has a 3 day
PHI, and in our on-farm trials at
Labeled late in 2007, Mustang Max (zeta-cypermethrin) is a pyrethroid insecticide registered for leafroller control. Activity on other insects is expected, but we have very little experience with this insecticide in blueberry. It has a 1 day PHI.
Rufus Isaacs, Entomology
The warm weather over the past few weeks has brought out one
of the earliest scarab beetles we find in
These beetles have marks on each elytra (wing covering) and are a little hairy. This distinguishes them from rose chafer or Japanese beetle which also emerge later. Hoplia beetles may be tan or grey and they are usually here for just a short time, especially in hot weather. It is not known how much economic damage they can do, but the number of flowers or buds affected is usually a very small percentage of the total number. We also do not know whether damaged buds or flowers can still set fruit.
There is no well-studied threshold for this beetle in blueberry. As a rough threshold, if more than 2 percent of flower buds are eaten completely off, you should consider control. This is based on 2 percent of a typical yield being worth more than the cost of an application. In fields of concern, sample a representative 10 bushes spread throughout the field and sample ten flower buds on each bush to give 100 buds sampled. If more than two of these buds are eaten and beetles are still active, consider an application of one of the insecticides that work well against Japanese beetle. Be aware that there are no insecticides registered for use in blueberry for Hoplia flower beetle that have this beetle on the label. Also be aware that we are approaching blueberry bloom and any application of insecticide with long residual activity runs the risk of causing harm to bees. A week from bloom, avoid broad spectrum insecticides. Spray insecticides only if this pest is causing economic levels of damage.
Bloom meeting
May 14 from 6:00-8:00PM
Van Buren County, Cornerstone Ag (Bodtke’s)
Please contact, Paul Jenkins (jenki132@msu.edu), Rufus Isaacs (isaacsr@msu.edu) or Annemiek Schilder (schilder@msu.edu) if you have questions.
May 21 from 10:00 AM to 12:00 PM
2:00-4:00 PM
Please contact, Paul Jenkins (jenki132@msu.edu), Rufus Isaacs (isaacsr@msu.edu) or Annemiek Schilder (schilder@msu.edu) if you have questions.
Mark Longstroth
Bill Shane
Greg Vlaming
Eleven days of warm temperatures with highs in the 70s and
lows near 50ºF moved plant growth quickly. Most plants are greened up and many
new leaves have emerged. Soils began to dry out quickly with the warm, dry,
windy weather. Significant rain fell in
|
Grapes, from April 1
|
|||
|
Location |
GDD 42 |
GDD 45 |
GDD 50 |
GDD 50 |
|
321 |
253 |
165 |
159 |
|
|
347 |
277 |
183 |
178 |
|
|
282 |
219 |
141 |
137 |
|
Tree fruits are blooming and would be damaged by temperatures below 28ºF. Insect activity increased last week. Oriental fruit moth were caught and biofixed last week. This was only a
light flight and the cool weather has shut down the traps. We often see this where we get biofix and then cool weather shuts down trap catch. Unless you are monitoring your own orchards and caught a significant number of moths, we recommend that early season Oriental fruit moth controls be timed on biofix on moth catch after this cool period. Redbanded leafroller are flying.
Apricots were blooming last week and are now generally in the shuck.
Peaches are blooming. Oriental fruit moth were caught and biofixed last week. The main worry during bloom is brown rot. This disease requires wet and warm conditions, 5 to 6 hours of wetness at 70ºF. Peaches are less susceptible after bloom.
Sweet cherries bloomed last week and the leaves are emerging. Sweet cherries are very susceptible to brown rot and easily get the disease through their development. Once the leaves are out and fully developed, they are susceptible to cherry leaf spot.
Tart cherries are blooming. Tart cherries seldom get blossom brown rot unless the temperature conditions are very good.
In plums, Japanese plums bloomed last week and are now at petal fall. European
plums are blooming.
Apples are at
pink. King bloom of early varieties such as Idared and Zestar are open. Rain on
Saturday, April 19, at green tip, was an apple scab infection for
Pears are at first bloom. Pear psylla are laying eggs. Growers should protect against pear scab.
Blueberry fruit
buds are at pink bud. Early varieties are nearing bloom. Bluecrop is at early
pink bud and
Grapes buds are opening. Juice grapes are at bud
burst and wine grapes are a little behind at swollen bud development stages. At
this bud stage,
injury would occur at temperatures in the high 20s. There is still time to
apply dormant sprays of copper, sulfur to varieties that are not sensitive to
these materials. This cool weather will slow
grape bud development and increase the likelihood of cutworm damage.
New strawberry leaves are out and flower trusses are emerging from the ground in southern Berrien. If the flower buds are in the ground, they will be damaged at 10ºF. Once the buds emerge they are damaged at temperatures below 20ºF. Many strawberry growers protected Monday night using sprinklers.
Raspberry and blackberry leaves are unfolding and new primocanes are emerging. In fall bearing plantings where all the shots have been removed, the new primocanes are about 6 inches tall.
Cranberry beds are greening up and tip buds are swelling and beginning to burst.
Lots of bees have been moved into the area to pollinate crops. Last week growers were planting trees and applying fungicide sprays.
The next Monday Fruit Update
meeting will be Monday, May 5 at
the Fruit Acres Farm in
Weather
Our late start to
the 2008 growing season has now been reversed with a string of 11 warm days and nights to push
our season ahead of normal. Based on degree days, I think that our season is
now running 5 to 7 days ahead of normal, and based on flowering stage we are
about a week ahead of normal. As a horticulturalist, it has been very
interesting and yet a bit frightening to see fruit growth and development occur
so rapidly over the last two weeks.
Cold temperatures
last night and this morning are in the low to mid-30’s for most reporting
stations across the eastern part of the state. Exceptions to this were
Our region has
missed several good rains over the last three weeks. While our top soils are a
bit on the dry side, for the most part we have more than adequate amount of
subsoil moisture. Most fruit growers have been planting tree and small fruits
and are wrapping up that process. These growers are now looking for some good
rains to get those plants off to a good start.
Early in my career
as a district horticulture educator, I had several well seasoned fruit growers share
their observations over their many seasons as to the strength and viability of
our fruit flower bud and crop based on their observation of how forsythia have
flowered that seasoned. Over the years, I have come to see that there is a
great deal of truth in observing the vigor of the forsythia bloom and to make a
projection on the viability and abundance of our fruit crop. This year’s
forsythia bloom has been wonderful as I observe flowering from across the
region. As I look at the potential fruit crop across the region, I would also
say that we are off to a start of a great season.
|
Location |
GDD42 |
GDD45 |
GDD50 |
|
Commerce ( |
301 |
236 |
152 |
|
Emmett (St Clair) |
279 |
226 |
145 |
|
|
321 |
262 |
174 |
|
Lapeer (Lapeer) |
316 |
253 |
170 |
|
|
311 |
242 |
155 |
|
Romeo ( |
304 |
240 |
153 |
Apples in the
southern part of the region are at pink and with warmer temperatures expected
later in the week, I would anticipate bloom by late this week or over the
weekend. In the central (
Pears are mostly at white bud. I expect to see bloom over the weekend at most farms. Pear psylla adult activity has been heavy over the extended warm period. Late last week I began to see egg laying of pear psylla.
Peaches are at pink to first bloom in many varieties. There are no pest problems this time. Remember the need for brown rot control sprays fairly quickly.
Sweet cherries are at full bloom across the region, with most growers reporting full bloom on April 24-26. Since bloom opened at many farms, we’ve had cool temperatures and a distinct lack of bee activity. This is a major concern at this time of the year in sweet cherries. Sweet cherry blossoms stand a chance of being injured in tonight’s frost/freeze event.
Tart cherries are in full bloom with most growers reporting full bloom on April 27. Again there has been a distinct lack of good pollinating weather in tart cherries. I am also concerned about brown rot sprays. Tart cherry blossoms stand a chance of being hurt in tonight’s frost/freeze event.
Plums are at popcorn to first bloom. Many growers reported having an extensive amount of black knot in plum over the last season.
Strawberries have
grown very nicely over the last two weeks with the warm temperatures. Strawberries
in the
Raspberries are showing a fair amount of tissue development. Fall red raspberries have now emerged from the ground with 2 to 4 inches of new growth. I continue to see tip burn on summer red, purple and black raspberries as a result of winter injury.
Blueberries are currently at ¼-inch green to early pink bud, with a wonderful crop of berries coming along this year. Many growers are wrapping up the pruning program on blueberries this last week. I am seeing a fair amount of blueberry stem gall wasp gall growth at several farms across the region.
Phil Schwallier
Amy Irish Brown
Carlos Garcia-Salazar
Most apples are in the tight cluster stage and will probably stay there for the next several days until some warmer weather comes back. With the current weather forecast, it’s looking like we might reach pink in some early apple varieties early next week.
Early sweet cherry varieties are in full bloom. Peaches are just coming into bloom. Pollination could be a concern with the very cool days because honey bees won’t be very active. Bumblebees have been observed working fruit blossoms.
Recent overnight lows have been hovering near freezing to a couple of degrees below 32°F. It looks like we might be in for some cold temperatures on the morning of Wednesday, April 30 that could give us some bud damage for many or most of our tree fruit crops especially in low frost pockets.
Degree day accumulations at the Sparta weather station are running about a week ahead of average from the warmer-than-normal weather of last week. The cooler weather lately is moving degree day accumulations back closer to normal.
A moderate apple scab infection was recorded for the general
European red mite eggs can be found, but numbers appear to be normal so far. No egg hatch has been observed.
Obliquebanded leafroller larvae have been observed feeding in terminals. Most are in the second instar stage. Overall, obliquebanded leafroller numbers are very low this year as they’ve been controlled very well over the past few years.
Redbanded leafroller started flying late last week.
Aphids are active. Both apple grain aphids and rosy apple aphids have been seen.
Once this cooler spell breaks, I would expect Oriental fruit moth to start flying. Mating disruption works especially well for Oriental fruit moth, so get those ties up right away if you’re using it in peaches or apples. It’s not too early to start putting pheromone ties up for codling moth in apples as well.
There is good news for the blueberry industry regarding pest control tools. After several
years of research and development, in 2008 we will start evaluating in
commercial fields a newly developed cranberry fruitworm phenology model. The
model was developed with data collected for five years in 12 blueberry farms: 4
in
The Cranberry Fruitworm Phenology Model requires the use of pheromone-loaded traps to monitor the emergence of the overwintering cranberry fruitworm male moths, and the daily growing degree day accumulation above 50°F. For this, it is necessary to install a weather recording device (a portable weather station or a simple maximum and minimum thermometer) near to the monitoring pheromone traps or use the nearest weather station. So far, results of our validation trials showed that our degree-day model was very accurate in predicting the emergence of overwintering cranberry fruitworm moths and egg-laying dynamics at all testing sites. However, accuracy was greater when weather data to calculate degree-day accumulation was collected next to the pheromone traps used to monitor the Cranberry fruitworm population dynamics. When the testing site was more than a mile away from the weather station, accuracy decreased but still predicted population dynamics within an acceptable range (1-2 day difference between predicted and observed population dynamics). Timing application of insecticide using the degree-day model will allow growers to accurately time sprays for cranberry fruitworm and increase the effectiveness of Confirm and other reduce-risk insecticides replacing organophosphorous insecticides such as Guthion. The following table shows some important events in the life cycle of the cranberry fruitworm.
|
Life stage or event |
Degree-days base (50°F since March 1) |
Degree-day accumulation from Biofix |
|
First spring male moth |
375 ± 20 |
0 |
|
First eggs |
460 ± 20 |
85 ± 20 |
|
Egg hatch |
714 ± 60 |
339 ± 60 |
Regarding the 2008 Blueberry IPM Scout training, we had 40
people registered. So far, we have completed the classroom portion of the
program and on May 15, 2008 we will offer the first hands-on field training. This
will be conducted at the MSU Trevor
Nichols Research Station in
Regarding the market for blueberries, as of April 29, prices for the 2008 blueberry harvest coming from Florida and Chile are in the range of $28-$30 per flat (12 4.4 oz cups). So we expect prices to remain high for the rest of the season.
We are completing the development of the curriculum for the
Strawberries IPM Scouting training. It is possible that we may have a final
version by the end of the summer. Advances also include the development of a
Pocket Guide for IPM Scouting in Strawberries. In this effort, Annemiek
Schilder and Rufus Isaacs are taking the lead. The development of both the
Strawberry IPM Scouting curriculum and the pocket guide is an effort involving
our partners from
This has been quite a change in weather. After almost two
weeks of very nice and unusually warm, almost summer-like temperatures this
cool-down seems even colder. The last two nights have been particularly of
concern when the temperatures dropped down below freezing. Automated weather
stations are showing that last night (April 28) was anywhere between 2 to 5
degrees colder than a night before.
Apples are in
advanced stages of tight cluster with indication of one or two flowers
beginning to separate. In some more protected, warmer areas or sandy knolls,
first pink is showing on king blooms in Idareds.
This last rain event that started April 24 and ended April
26 resulted in moderate apple scab infection for Oceana and Mason counties and
heavy infection period in
Pears are in open cluster.
Peaches are showing 0.5-inch green.
Plums are in open cluster.
Tart cherries are in open cluster.
Sweet cherries are from open cluster to white bud and plus-5 percent bloom depending on the location.
|
Location |
DD42 |
DD45 |
DD50 |
Rainfall since 4/1 |
|
Hart |
250 |
193 |
121 |
3.91 |
|
Ludington |
214 |
165 |
100 |
3.98 |
|
Manistee |
264 |
208 |
135 |
4.07 |
Bacterial canker or as it is also referred to as bacterial gummosis and bacterial blast is an opportunistic disease that moves in after the freeze event like we had in the last couple of nights. Besides sweet cherries, it attacks other stone fruit (peaches, plums) and pears. At this stage of development, fixed copper (copper hydroxide, copper oxychloride) applications will work better and be less phytotoxic than copper sulfate alone. It will provide suppression of thebacteria (Pseudomonas sp.) population, a contributor to spur and shoot death after the frost event.
Nikki Rothwell
Duke Elsner, Erin
Lizotte, Rob Sirrine
GDD42 223
GDD50 107
Apples are in tight cluster.
In sweet cherries, Hedelfingen and
Napoleon are at early white bud. Gold are at late bud burst.
Tart cherries are at bud burst.
Apricots are at first bloom.
Plums are at early green cluster.
Grapes are at early bud swell.
Last week’s weather was extremely warm for April, and most days were in the low to mid-70’s. Temperatures dropped over the past weekend, and recent nighttime temperatures have hovered around the freezing point with the cold night temperature predictions, growers are concerned about potential bud damage. Recent weather events have come hand in hand with windy conditions. Growing degree days accumulated up to this point are similar to 2007, but overall, we have collected more growing degree days this season than our 18-year average. We also received considerable rainfall on April 25, over 1.5 inches.
Tree development has moved along quickly with the past week’s warm temperatures. On April 14, cherry trees were still in the dormant stage, and ten days later, trees were at the bud burst stage. Apricots are in early bloom here at the station, and we see a bit of white on sweet cherry buds in early varieties or in warm sites. Growers are finishing up pruning, and there is lots of planting currently underway. Conditions for planting have been good with last Friday’s significant rainfall. Honey bee hives have been placed into many cherry orchards in the region.
Things are still pretty quiet in the northwest region. Spotted tentiform leafminer are showing up in traps here at the station. We are also seeing a few obliquebanded leafroller larvae in apples. With the heavy rain over the weekend, we saw moderate to heavy apple scab infections predicted.
We are receiving additional reports of San Jose scale in sweet cherries, an emerging problem in our region. The weather has also made bacterial canker a concern, especially on sweet cherry. If we have the drop in temperature predicted, it may predispose tissue to bacterial infection.
Jeff Andresen
Agricultural Meteorology
Geography
High pressure across the central
By mid-day Wednesday, the center of the high pressure will
drift east of
Fair and drier weather is expected again by next Monday. Temperatures will warm from below normal levels Tuesday to slightly above normal levels by Friday, with highs ranging from the low 50's north to near 60ºF south Wednesday increasing to a range from 56ºF north to near 70ºF south by Friday. Low temperatures should increase from lows in the upper 20's to low 30's Wednesday morning to the mid-40's north to low 50's south late in the week. Slightly cooler temperatures are likely next weekend, with highs in the mid-50's to low 60's and lows in the upper 30's to low or mid-40's.
Further ahead, medium‑range, forecast guidance
suggests a series of upper air troughs moving from the western