June 13, 2007
In this issue
§ European corn borer update
§ Corn earworm/tomato fruitworm found in traps
§ Downy mildew reported on cucumbers growing in Canadian greenhouses
§ Are your asparagus transplants turning white?
§ How effective is your irrigation system?- Field day on June 27
§ Regional reports
§ Weather
Beth Bishop
Entomology
The numbers of European corn borer moths caught in pheromone
traps were down last week, compared with the previous week, at all locations in
In some sweet corn fields, heavy infestations of corn borer larvae are reported feeding in the whorls. Insecticide treatment may be required if 20 percent or more of whorl-stage corn shows evidence of feeding. Treat corn four days or less before tassel emergence to prevent corn borer larvae from entering the developing ears. Consult Bulletin E-312, 2007 Insect, disease and nematode control for commercial vegetables insecticides registered for control of European corn borer in sweet corn. You can find this bulletin online at http://web4.msue.msu.edu/veginfo/E312.
|
Location |
Moths per trap |
|
|
9.6 |
|
|
0.0 |
|
|
2.7 |
|
|
1.0 |
|
|
0.0 |
|
|
0.0 |
|
|
1.0 |
|
|
13.3 |
Beth Bishop
Entomology
A few corn earworm moths were caught in pheromone traps in
It is unlikely that large populations of corn earworm moths
are present in
Mary Hausbeck
Plant Pathology
Downy mildew has been confirmed on greenhouse cucumbers in
The field cucumber growers in
It is my opinion that cucumber growers in
Sprays can be banded for fields that are young and newly emerged. Cucumbers that have been growing under tunnels will be larger and will need to be covered completely with spray to be protected.
A spray interval of 10 days is currently recommended. The following fungicides are recommended:
§ Gavel
§ Previcur Flex
§ Ranman
§ Tanos
Alternate these products and mix each with either mancozeb or chlorothalonil (i.e. Bravo). This development will be watched carefully and new information and recommendations posted.
Mathieu Ngouajio
Horticulture
In the near future, most large scale asparagus growers will
continue to establish new production fields from one-year-old crowns. However,
there has been some interest in experimenting with greenhouse-grown transplants
as alternative planting material, at least on a small scale. Asparagus
establishment from greenhouse-grown transplants is not new, but has not been
widely used by
We have observed this problem in our greenhouse trials. In our trials, white ferns occurred first in trays with smaller cells and last in trays with the larger cell volume. Some growers have indicated that increasing the amount of fertilizer did not solve the problem, which was also the case in our tests. The light environment and nutritional status of the plant may play a role in this problem, but this usually occurs when the root system has occupied most of the cell volume. Under these conditions, the cell volume becomes a limiting factor in the growth of the transplant. That is probably the reason why adding more fertilizer does not solve the problem. If the ferns on your asparagus transplants are turning white despite adequate fertilization and lighting schedules, that is probably a good indication that they should be hardened off and transplanted. New green ferns will develop once the transplant is well established in the field.
Learn how to check your irrigation system with MSU Extension
educators. An irrigation system field day will be offered Wednesday, June 27.
This event will be held at three different locations and times for your
convenience. Bosch’s Countryview nursery at 10:00 AM,
Dr. Tom Fernandez, Department of Horticulture, will be demonstrating the techniques you can use to do your own system checks.
Ron Goldy
Temperatures during the week ranged from highs of 70 oF to 89oF and lows from 40oF to 65oF. The area received no precipitation. Transplanting conditions have been excellent provided irrigation is available.
Crop reports
In general, there are few disease and insect problems to report. The biggest concern is keeping up with irrigation needs.
Tomato, pepper and eggplant transplanting, staking and tying continue. Early, non-tunnel-grown tomatoes and peppers are at bloom and early fruit set. Tunnels are being removed from tunnel-grown plantings. Early planted peppers are producing secondary branches.
Watermelon and cantaloupe are beginning to runner off the plastic. Cucumbers have responded well to warm temperatures and those grown under tunnels have 4 to 6 inch fruit. Harvest will probably begin next week. Early, non-tunneled plantings of cucumbers and squash are at early fruit set. Still no reports of cucumber beetles at this time.
Zucchini and yellow squash harvest will begin soon from tunnel-grown plants.
Sweet corn growth is at 14 to 16-inches.
Early potatoes are in full bloom. Colorado potato beetle adults are active and eggs can be found.
Bill Steenwyk
Warm, windy and dry are the terms that sum up our crop growth environment this past week. Rainfall was negligible, with Hudsonville receiving 0.13 inch on June 7, but most of the area received only a few hundredths, if any at all. High winds and warm temperatures combined to draw 2.0 to 2.5 inches of water from the soil. For dryland producers, the deficit will become serious soon.
The present condition of most of our crops, remains quite
good. On muck soils in Van Buren, Allegan and
On upland soils, tomatoes are in bloom and look good. Cabbage continues its vigorous growth, with only minor feeding from diamondback moth and imported cabbage worm larvae.
Peppers, squash and most other crops are progressing well.
Where irrigation is not sufficient, water availability, especially on coarse-textured soils, will soon begin to limit yield. Growers should continue to watch for weed outbreaks. With the current dry conditions, yield loss from competition can be substantial.
I continue to find Stewart's bacterial wilt in
Norm Myers
We’ve had a very hot, dry week. The front that came through last Thursday, June 7 and Friday, June 8, dumped very little rain, but the high winds associated with it sandblasted a lot of crops in our area. Most growers are struggling to ramp up their irrigation systems ahead of the very hot, very humid weather predicted by this weekend.
Much of the asparagus that was through the ground last Thursday, curled enough from the sand damage that it was only good for cuts and tips. Weeds, especially pigweed, are really coming on now, so most growers are planning to use a burn down herbicide with their post-harvest herbicide application. Most growers are still harvesting, but the predicted heat this weekend will probably finish off production in a lot of fields, even though the fresh and processed markets are both screaming for more asparagus. Growers with irrigation available are planning to use it on both newly planted and established fields. Those that used irrigation during the hot, dry June of 2005 feel that it helped their asparagus for several years after, because it allowed it to put up healthier fern than it would otherwise have done, even though the growers picked later than most of their neighbors.
In carrots, sandy spots in many fields, especially the latest plantings, eroded pretty severely. Scouts report that there are still a few globular springtails around, and aster leafhopper numbers are beginning to rise.
Winter squash and
pumpkins are mostly emerged and
forming true leaves. Some of those fields were beat up pretty badly by last
Thursday’s wind. It has been pretty dry since planting, so I am anticipating
that our herbicides will probably not work well. Our soybean aphid trap in
In zucchini, most of the first planting of the processing and fresh fields have been planted. Some very early processing zucchini is emerged.
One of my fresh market sweet corn growers is also reporting large amounts of Stewart’s wilt even on “tolerant” varieties. My European corn borer traps were empty this week. Perhaps it is too dry.
Jim Breinling
The weather event of interest during the past week was the
strong sustained winds that occurred on Thursday, June 7. Temperatures in the
high 80’s were also recorded on that day at the Fremont and Ludington MAWN
stations. The front that moved through the Ludington area about 1:00 AM Friday
morning resulted in 0.76 inch of rainfall at the Ludington MAWN station.
Rainfall amounts north of Ludington in
Some isolated wind damage was observed in carrot fields in
Snap bean
plantings at a European corn borer site in
Winter squash plantings in Newaygo and Mason counties are at 2 true leaf stage. Although leaves are battered in some parts of fields, plant loss appears to be minimal.
Hannah Stevens
Sunny, windy and dry characterize the weather this week
throughout the region. High temperatures have ranged from 69oF one
week ago to 91oF this Thursday, June 14. High temperatures were
followed by windy conditions on Friday that caused some damage to young plants
and probably brought in some migratory insects. While
In sweet corn, European corn borer flight is down this week, reflected by an average trap catch of 13.3 down from 48.3 last week. A sharp grower noticed a little feeding damage on his oldest corn. Except for plasticulture corn, which is robust, knee-high and tillering, it seems unlikely that corn at this time will be vulnerable to ear damage. Will tassels be emerging in four days? Check your fields.
On muck soils most barley cover crops are now burned down, and fields are taking on their colors. Onions are being cultivated, and the crop stands appear to be uniform. Some early onion maggot has been reported. Romaine lettuce harvest got underway on June 10. Carrot stands look good as well with some scattered herbicide burn reported to foliage. Radish harvest is well underway.
Garlic for retail sales are beginning to send up scapes, which are being removed.
Pumpkins and hard squash seedings are emerging.
Summer squash is beginning to flower, and harvest may be two to three weeks away.
In melons, row covers are coming off as plants are beginning to run and flower. Female flowers with their tiny fruit are easy to find but male flowers, particularly those of the seedless watermelon pollinizers, are not in abundance yet.
Cool season crops such as greens, chard, beets and others that survived two to three frost events are coming around.
Paul Marks
No rain during the last seven days, combined with warm
temperatures and low humidity, has dried our soils very quickly. Potential
evapotranspiration as calculated from the Michigan Automated Weather Network
station at
Sweet corn is now showing tassels in many early plantings without any mulch or tunnels. Corn borer counts this week dropped to an average of just under four compared with 23 last week. Fields are heavily infested with very small larvae. Some Stewart’s wilt is now showing up in larger corn, some of which is tasseling.
Earliest tomatoes for market now have fruits two inches and larger present with later plantings in open fields just beginning to blossom. Processing tomatoes are basically done being planted with earliest fields now having twin rows filled. No disease seen in this crop.
Potato fields in all stages of growth have leafhoppers above threshold, even later planted fields which have not totally emerged. No potato beetles seen and no diseases seen in this crop.
Pumpkin planting is nearly done with this string of very cooperative weather. Earliest fields have emerged.
Cucumbers for slicers and for pickles have made very good growth this last week. Pickles are at the first true leaves, while slicers are in all stages from first harvest in tunneled plantings to emergence in later plantings. No downy mildew found so far this season. Cucumber beetle pressure is very low so far.
Cabbage harvest has begun. Diamondback and imported cabbage worm larvae pressure has remained low. I have not found any thrips in this crop yet, but suspect with the warmer weather, and maturing small grains and grasses, it won’t be long.
Peppers have made very good growth this week. First flowers are now showing in earliest fields. No aphids found in this crop, so far.
Jeff
Andresen
Agricultural Meteorology
Geography
A strong upper air ridge and associated surface high
pressure across the central
Temperatures will remain at slightly above normal levels, with highs ranging from the upper 70's in northern lakeshore areas to the upper 80's south and lows falling into the mid 50's north to mid 60's south. An upper air trough and associated cool front are expected to move into the region by the middle of next week, which will likely be the next chance for significant precipitation. Best guess at this point is the chance of showers and thunderstorms again in western sections of the state Monday and statewide on Tuesday.
Following the movement of the troughing feature through the region next week, current medium range forecast guidance for the 6-10 day and 8-14 day time frames covering June 18-22 and June 20-26 respectively, suggests that the troughing pattern mentioned above will linger for much of the latter part of next week, resulting in a cooler and more unsettled weather pattern.
The official NOAA 6‑10 day outlook calls for temperatures to range from near normal in eastern sections of the state to below normal in the west, and for precipitation totals to increase to above normal levels statewide. During the 8-14 day period, temperatures are expected to fall back to below normal levels statewide, with near normal precipitation levels.