July 11, 2007
In this issue
§ European corn borer and corn earworm update
§ New insecticide label: Hero ®
§ Japanese beetle adults have emerged
§ Controlling Japanese beetles
§
Downy mildew confirmed in
§ Two-day workshop on building healthy soils in vegetable and grain crops for organic and sustainable systems
§ Regional reports
§ Weather
Beth Bishop
Entomology
Few moths of either species were caught in pheromone traps during the past week. Weather conditions have not yet been conducive for corn earworm (which migrates from the south each year) to be carried into the state. For European corn borer, we are nearing the start of the second adult flight. In general, we expect that flight to start at approximately 1500 degree days (base 50). Once egg laying starts, sweet corn at tassel and beyond, as well as peppers and snap beans with fruit, should be treated to prevent corn borer infestation.
Beth Bishop
Entomology
The pyrethroid, Hero ® (FMC Corp) is now labeled for use on a variety of vegetables, including sweet corn, cole crops, lettuce, snap beans, peas, tomatoes, peppers and eggplant. Hero contains a combination of zeta-cypermethrin (the active ingredient in Mustang ®) and bifenthrin (the active ingredient in Capture®). Hero is registered for a control of a variety of caterpillars, beetle and bug pests of vegetables.
Beth Bishop
Entomology
These beetles feed on over 300 different species of plants, although they have definite preferences and are primarily pests of fruit and ornamental plants. If you find large numbers of Japanese beetles in your vegetable fields, it is important to distinguish whether or not they are feeding on the crop. Adults tend to aggregate and numbers can be shockingly high, but if they are not feeding there is no need for control. Japanese beetles can, however, clip sweet corn silks. In general, if there are more than two Japanese beetles per ear and the corn is less than 50 percent pollinated an insecticide application may be warranted to reduce clipping and ensure adequate pollination.
Rufus Isaacs, John Wise and David Epstein
Entomology
The following is an article written for the Fruit CAT Alert that contains insecticide recommendations for controlling Japanese beetle. Before making an application to your vegetable crop, make sure the beetles are feeding and make sure the insecticide is registered for use on your crop. Consult Bulletin E-312, 2007 Insect, disease and nematode control for commercial vegetables. You can find this bulletin online at http://web4.msue.msu.edu/veginfo/E312.
Japanese beetles have only one generation per year, but
these beetles emerge over a long period in July and August, and they live for
over 30 days. They feed on the foliage and fruit of various fruit crops grown
in
The carbamates Sevin and Lannate provide immediate kill of beetles present during the spray. They are also stomach poisons, so if beetles eat treated foliage they will also receive a higher dose. This can be a good property for control of Japanese beetles, since they eat so much that a strong dose of insecticide is taken up. Lannate has a short residual activity of a few days, whereas Sevin provides a week or more of protection. Sevin has a three or seven day PHI depending on the crop, and Lannate ranges from 3-14 days. The organophosphates Guthion and Imidan (buffer to pH 6.0) provide excellent lethal activity on adult beetles, although it can take a few days for their effects on Japanese beetles to be seen as the beetles take up the insecticide. They provide 10-14 days of activity, with 3-21 day PHI, depending on the crop. The pyrethroids Danitol, Warrior, Asana, Brigade, Baythroid, Mustang Max and Capture give instant knockdown and mortality of adult beetles, with 7-10 days of activity. It is important to remember that the pyrethroid class of insecticides is quite sensitive to hot and sunny conditions, so performance in mid-summer will be less than that expected in the spring. Beetles that do not receive a lethal dose of pyrethroid may also be repelled from treated fields, providing an additional mode for reducing infestation of crops. PHI’s for pyrethroid insecticides may vary widely across crops, so check the label before using this class of materials.
The labeling of Provado for use in some fruit crops after bloom provides a selective option for Japanese beetle management. Provado provides two to three days of lethal activity from the surface residues before it is absorbed into the foliage. Thereafter, beetles must eat treated foliage to get a dose of the insecticide. Once inside the foliage, Provado is rainfast and provides significant sub-lethal effects of repellency and knockdown activity, but with much less direct mortality from the residues. This neonicotinoid will also control aphids and leafhoppers. It has a zero to seven day PHI depending on the fruit crop. Another member of this chemical class, Assail, can provide some protection of foliage from feeding by Japanese beetles, though the level of beetle mortality may be lower than expected from the broad-spectrum options. The rate allowed in different crops will have a big impact on the effectiveness of Assail. Other neonicotinoids labeled in fruit crops include Actara, Calypso, Clutch and Venom.
For growers looking for beetle control immediately before harvest or in organically grown fruit crops, some selective insecticides with zero day PHI’s can provide a tool to repel beetles and help achieve beetle-free fruit during harvest. Compounds containing neem (Azadirect, Ecozin, Neemix etc.) have a zero day PHI and pyrethrum (Pyganic) has a 12 hour PHI. These compounds are labeled for organic use, and have a short but effective impact on adult Japanese beetles, with some mortality, some knockdown off the crop and some repellent activity. Typically, there is only one to two days of activity against beetles because the residues do not remain active for long. The non-organic form of Pyganic, called Evergreen, also has a 12 hour PHI, and is much more effective against Japanese beetle than Pyganic due to the addition of a chemical that inhibits the beetle’s ability to break down the insecticide.
Japanese beetles typically lay their eggs in moist grassy
areas and many fruit farms have a large amount of this suitable habitat. An
additional approach to managing Japanese beetle populations is to target the
grub stage of this pest in these areas to reduce the abundance of beetles in
the following year. If the location of high grub densities near fruit fields is
known, these areas could be treated with a soil insecticide to get maximum
return on this treatment. Our experience in
Dr. Mary Hausbeck
Plant Pathology
Downy mildew was confirmed on cucumber in
Fungicides should be applied to cucumbers every FIVE (5) to SEVEN (7) days.
Fungicides should be applied to pumpkins, melons, cantaloupes, squash, zucchini and gourds every SEVEN (7) to TEN (10) days.
|
Applied before disease (7-day intervals) |
Applied after disease (5-day intervals) |
|
— Gavel 75WG (5 day PHI) |
— Previcur Flex 6SC (2 day PHI) |
|
— Previcur Flex 6SC (2 day PHI) |
— Ranman 3.6SC (0 day PHI) |
|
— Ranman 3.6SC (0 day PHI) |
— Tanos 50WG (3 day PHI) |
|
— Tanos 50WG (3 day PHI) |
|
|
Alternate products and mix each with either: — Dithane (mancozeb) 3 lb or — Bravo (chlorothalonil) 1.5 pt |
Alternate products and mix each with either: — Dithane (mancozeb) 3 lb or — Bravo (chlorothalonil) 2 pt |
How downy mildew spores are monitored:
Five spore traps were placed in
different counties in
1)
2)
3)
4)
5)
The reel inside the spore trap must be changed every seven days. At that time, a new reel is placed in the trap, and the reel with the spores is brought back to the lab where it is processed. Processing of one spore trap reel takes approximately four hours. The tape on the reel is removed and placed onto a cutting block, where it is cut into seven pieces that represent 24 hours and each hour is marked. Each 24-hour section of tape is put onto a microscope slide and stained. A cover slip is applied, sealed to the slide and allowed to dry. Once the slides are prepared, they are placed under the microscope and the entire tape is examined for downy mildew spores. Spores are counted and logged into a data sheet under the specific hour of the specific day that they were in the air around that particular spore trap. To count one reel of slides takes one to two days.
Table 2 summarizes the spore numbers that have been counted so far for 2007 in the highlighted columns. For comparison purposes, spore counts from 2006 are in the adjacent, non-highlighted columns. The entire table containing all of 2006 data is available at my website (http://plantpathology.msu.edu/labs/hausbeck/Hausbeck%20Lab%20For%20Growers.html). This table is continually being updated as new counts are completed.
|
Date |
|
|||||||||
|
Allegan |
Bay |
|
|
|
||||||
|
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
2007 |
2006 |
|
|
Jun 8 |
– |
– |
– |
– |
S 2 |
– |
– |
– |
– |
– |
|
9 |
– |
– |
– |
– |
2 |
DM – |
– |
– |
– |
– |
|
10 |
– |
– |
– |
– |
6 |
– |
– |
– |
– |
– |
|
11 |
– |
– |
– |
– |
2 |
– |
– |
– |
– |
– |
|
12 |
S 0 |
– |
– |
– |
0 |
– |
– |
– |
– |
– |
|
13 |
2 |
– |
– |
– |
0 |
– |
– |
– |
– |
– |
|
14 |
0 |
– |
– |
– |
3 |
– |
– |
– |
S 0 |
– |
|
15 |
2 |
– |
S 2 |
– |
2 |
– |
S 2 |
– |
5 |
– |
|
16 |
5 |
– |
0 |
S 0 |
2 |
S 27 |
2 |
– |
2 |
S 6 |
|
17 |
0 |
S
3 |
0 |
0 |
2 |
54 |
0 |
– |
2 |
0 |
|
18 |
2 |
0 |
2 |
2 |
0 |
24 |
2 |
– |
2 |
5 |
|
19 |
2 |
8 |
2 |
2 |
0 |
5,072 |
2 |
– |
0 |
10 |
|
20 |
140 |
3 |
2 |
0 |
2 |
1,886 |
3 |
– |
0 |
14 |
|
21 |
12 |
2 |
2 |
5 |
2 |
30 |
0 |
– |
0 |
5 |
|
22 |
30 |
0 |
0 |
14 |
0 |
597 |
0 |
– |
0 |
19 |
|
23 |
108 |
5 |
2 |
0 |
2 |
6 |
3 |
– |
2 |
11 |
|
24 |
102 |
0 |
0 |
3 |
0 |
5 |
2 |
– |
3 |
8 |
|
25 |
(½
day) 0 |
5 |
2 |
11 |
DM 0 |
3 |
3 |
– |
5 |
13 |
|
26 |
– |
0 |
2 |
2 |
0 |
6 |
2 |
– |
0 |
3 |
|
27 |
– |
2 |
0 |
5 |
0 |
5 |
2 |
S 6 |
0 |
5 |
|
28 |
(½
day) 12 |
0 |
0 |
2 |
0 |
5 |
0 |
42 |
0 |
10 |
|
29 |
70 |
0 |
0 |
3 |
0 |
54 |
0 |
38 |
65 |
3 |
|
30 |
63 |
2 |
2 |
5 |
0 |
3,336 |
0 |
24 |
131 |
11 |
|
Jul 1 |
10 |
0 |
0 |
10 |
0 |
*52 |
0 |
12 |
388 |
7 |
|
2 |
|
2 |
0 |
8 |
0 |
115 |
0 |
8 |
145 |
2 |
|
3 |
|
0 |
0 |
5 |
|
8,933 |
0 |
32 |
|
0 |
|
4 |
|
2 |
0 |
8 |
|
4,345 |
0 |
12 |
|
0 |
SSpore trapping started on this date.
DMDisease was found in the county on this date.
*Spores present but soil prevented accurate count.
Vicki Morrone
Mott Group for Sustainable Food Systems
Wednesday and Thursday, August
29-30, 2007
9:30 AM to 4:30 PM
Location: Morgan Composting
4281
Phone 231-734-2451
Presenting Dr. Paul Hepperly, Rodale Research Institute. He will share new perspectives of Rodale’s on-farm research of compost and compost teams. (See Using compost to enhance soil fertility and improve disease suppression).
Wednesday, August 29: Maximizing the benefits of compost in field crops. Thursday, August 30: Building the soil and suppressing disease with compost and compost teas. Lunch is included from locally grown food and mostly organic. Early-bird registration: $25 for one day or $40 for both days. Registrations postmarked after Aug. 20: $35 for one day or $50 for both days 517-282-3557 or sorrone@msu.edu or www.michiganorganic.msu.edu Make checks payable to Michigan State University and send to: 303 Natural Resources, East Lansing, MI 48824.
Ron Goldy
Temperatures during the week were generally above average 83oF with highs of 80oF to 95oF and lows from 55oF to 71oF. The area received a trace to 0.1 inches of precipitation. Since May 1, we have had 3.08 inches of rain and since June 1 only 1.03 inches. Since May 1, we have had temperatures of 90oF or higher for 12 days, which is usually our average for the summer. Cooler temperatures should bring a needed slow down for harvest activity.
Due to the dry weather there are few disease problems to report. The biggest concern continues to be keeping up with irrigation needs.
Sweet corn harvest began about 10 days ago from covered plants. General harvest from early non-enhanced plantings will begin in 7 to 10 days.
Grape tomato harvest from tunnel-grown plants has begun. Harvest from fresh market tunnel-grown plants will begin soon.
Vine crops continue to grow well. Pumpkins are runnering and will flower soon – seed corn maggots have been found in some plantings. Watermelon is volley ball size and cantaloupe harvest will start soon from tunnel-grown transplants. Summer squash and zucchini harvest continues with few problems. Growers need to apply protective measures for squash vine borer and squash bugs.
Pepper harvest will begin next week. At this time, there are no signs of blossom end rot, which is surprising given the hot weather.
Irrigation systems are keeping busy. Tarnished plant bug populations are high. The bright side of the dry weather is that disease pressures are low.
Bill Steenwyk
Weather
To no one's surprise, West Central Michigan has been hot and
very dry. In the past 14 days, much of
Crop reports
On the muck, celery
continues to look good. Fields that were established early under cover are
being harvested, while others are just being transplanted now. Red beets are also at varied stages,
but are doing well, with the most mature being harvested. Onions and leek continue to develop. Non-irrigated muck fields are
powder dry in the top 3-4 inches, but moisture can be found at 6-8 inches and
below. This continues to sustain much of our onion crop, although more
water is badly needed.
On upland, mineral soils, cabbage is being harvested, with the crop is looking good overall. Irrigated tomatoes and peppers are developing fruit and appear vigorous. Sweet corn is a mixed story. The early crop is about two weeks away. Irrigated fields look good, but many dryland sweet corn fields look ragged, showing substantial drought stress. One European corn borer moth was found in the three pheromone traps.
Cucumbers, melons and squash have grown a great deal and are developing fruit. Pickle harvest will begin soon. An unsettling number of these fields show wilting and death of some plants. Some are less than five percent affected, while others approach thirty percent. I am submitting samples for a confirmed diagnosis.
Norm Myers
Very light rain fell across Oceana County Monday, July 9 during
the afternoon and night. Totals for both rains were generally less than 0.1 of
an inch.
Asparagus: This year’s fern while it looks okay shows how thin the fields have become since the flooding of 2004 spread Phytophthora through out most of our fields. In terms of pests, growers and consultants report high numbers of Japanese beetle in some fields. Some growers have treated for this new insect pest. Both of the foliar diseases, purple spot and rust are active, but generally under control.
In carrots, fields vary in their stands. No blights have been confirmed as of yet, but they should be showing up anytime. Growers are putting on first fungicides and insecticides now, even though disease and aster leafhopper numbers have been relatively low. Most growers are unwilling to go into the predicted wet, cool period with their fields uncovered.
Zucchini harvest is now under way on the earliest planted fields. These fields are in for an early processor down south. Fresh harvest will probably begin late next week. There is still no sign of virus.
Winter squash and pumpkin fields are well ahead of normal, and pumpkin growers are a little worried about having to hold pumpkins for a prolonged period this fall.
Snap bean fields were planted the weekend before July 4, and some growers are rotary hoeing fields to remove crusts.
Jim Breinling
The area received a much needed rainfall on July 3 and 4.
Official amounts were 2.41 inches at Ludington and 2.05 inches at
Carrot fields have responded well with additional moisture. Aster leafhopper counts remain very low in the area, but I have observed the start of some aster yellows in one field. Harvest could begin in approximately three weeks.
Root rot was observed in snap bean fields where heavy rainfall occurred in mid-June. European
corn borer trap counts this past week for
Local sweet corn
is now available in
Harvest of slicing
cucumbers, not on plastic under tunnels, began early last week on July 2 in
Squash plantings,
both summer and winter, are growing well with warm temperatures and ample
moisture. Harvest of zucchini for
processing began late last week on July 6 in
Hannah Stevens
In the two weeks since my last report, there have been some isolated showers, but for the most part it has been hot and windy with very little precipitation for over a month. At my station in Romeo, I have recorded 0.2 inch since June 6 and a seasonal high of 97oF on July 8.
It is reminiscent of the drought of 1988, except that
growers in this region are now better prepared to irrigate and all systems are
in operation. It’s an exhausting business
moving equipment and maintaining the systems, and many crops are still badly in
need of rain. Planting of late season cole crops is on hold pending some rain, and
there have been some losses of these late fields.
In sweet corn, European corn borer flight continues in this area with an average trap count of 18, but in this case a two week catch. However, some live moths in the traps indicate that they are still flying. Stewart’s wilt is very visible now in some early varieties and in some fields, perhaps those that had heavy flea beetle pressure. It has appeared early enough to stunt the corn, but beyond the seedling stage. Growers who have the capability to irrigate their corn are doing so as the ears are small and pollination seems to be poor in some areas. Plasticulture corn has been on the market for two days.
Summer squash, including zucchini and yellow squash, harvest is active as the fruit is developing rapidly in the heat. Watermelon mosaic virus was confirmed in a yellow squash field, but only on a few plants in the field margin. So far we have no widespread virus problems.
Muskmelons and watermelons continue to size with variable yields. Bee activity is reported to be heavy, particularly in the morning hours with wild bees making up a good percentage of the foragers.
Tomato plants seem to be holding up well in these conditions. I have seen lower leaves with some marginal necrosis and yellowing that might be stress related, and received one call regarding severe leaf rolling. I believe the heat may be retarding ripening.
The carrot and onion crops on muck soils are in need of rain to help them size. Thrips numbers remain low on onions.
Paul Marks
It has been hot and dry for the last seven days in most of our area. Accumulated degree days, base 50, now total 1381 for this season putting us about two calendar days ahead of normal. Very isolated showers late last week brought some needed relief to less than 20 percent of our growing area. All irrigation systems are running to help replace the more than 2.1 inches of potential evapotranspiration used by crops this last week, averaging just 0.3 of an inch per day. Dry conditions have, no doubt, reduced crop disease infestations.
All vine crops have made tremendous growth and development this last week with hot days and warm nights. Slicers are in good supply. Hand harvest of pickles is just beginning.
Muskmelons will be starting either the end of this week or early next week. The set in this crop appears to be below normal in many fields. No new downy mildew infestations identified this last week.
Pumpkins look very good on most farms with flowering just beginning in early plantings. Several farms have very poor pumpkins due to heavy rain damage just after planting.
Squash vine borers and squash bugs are still active.
Commercial sweet corn harvest has just begun on a limited basis with early corn not very uniform in most fields complicating harvest and packing. Much better corn will begin next week. My corn borer and corn earworm traps were empty again this week.
Potatoes are beginning to mature vines in early fields with latest fields just setting tubers. Harvest has begun from early fields with very immature tubers at this time. No insect or disease problem in this crop so far.
Market tomatoes are just beginning to be harvested in earliest fields with what appears to be nice quality fruits for first harvest. Most growers will be into tomatoes next week. Processing tomatoes are in full bloom in midseason fields with good fruit load developing in earliest fields. The only disease I have seen in tomatoes is some bacterial speck and canker in market tomatoes.
Pepper harvest has begun for fresh market on several farms with very nice fruits for this early in the season. Most fields have very good fruit sets.
Cabbage harvest is going strong. Growers who are transplanting cole crops for fall harvest have had problems keeping moisture in this crop.
Peter Kurtz
Geography
This past Sunday, July 9, a slow moving cold front brought
widespread precipitation to the Upper Peninsula and then to the northern
sections of the Lower Peninsula Sunday night and Monday. Blistering heat this
past weekend covered the central and southern sections of the state with highs
in the low and mid 90's commonplace. This heat wave continued Monday and
Tuesday in the south half of the
Currently, a major change in the weather pattern has
occurred with the ridge in the Ohio Valley (that produced the heat wave in many
sections of the state) replaced by a large trough that will give us
unseasonably cool weather for this time of year today, July 11 through Friday.
Some areas received rainfall last night, reports of over 0.50 inch, but many
areas unfortunately missed the needed rainfall completely, especially in the
south. A stationary upper level low over Hudson Bay in
The 6-10 day outlook
covering the period July 16-20 issued yesterday indicates an unseasonably
amplified pattern for this time of year over the country with a deep trough
over the east at the beginning of this period. The outlook calls for below
normal temperatures statewide, but I wouldn’t be surprised to see today’s
outlook issued this afternoon either near or above normal due to the
anticipated significant warming next week. Precipitation is forecast to be near
normal in the