August 6, 2008
In this issue
§ Vegetable insect update
§ Regional reports
§ Weather news
Next issue August 13
Beth Bishop
Entomology
The second flight of European corn borer moths has begun in
many areas of
Ron Goldy
Temperatures have been near normal for the period with lows from 57°F to 70°F and highs from 76°F to 86°F. There was a half an inch of rain across the area for the week. Mornings have been foggy with heavy dew.
No new problems to report. Squash bugs and cucumber beetles are present in vine crops. No significant virus infections have been noted. Early planted pumpkins are beginning to turn color. Tomato, sweet corn, pepper and eggplant harvest have peaked. Early transplanted fall squash is being harvested. Some pickle fields planted early and mid-July are showing herbicide damage as a result of significant rainfall during the period from July 8 to July 20. Phytophthora symptoms continue to show up in susceptible crops.
Bill Steenwyk
Most of this region has received only one to three tenths of
an inch of rain in the past two weeks. The exceptions are parts of southern
Kent and northern Allegan and Barry counties, which have seen significantly
more. Most vegetable growers are irrigating.
Crop report
Celery harvest continues with results varying from fair to very good. Growers are spraying for the usual disease spectrum. Likewise, onion growers are spraying for numerous diseases, including botrytis, bacterial soft rot (erwinia), purple blotch, anthracnose and Stemphylium leaf blight. Thrips are usually present. Weed control is quite variable. The current radish crop looks good at all stages. Leek and parsnips are developing well.
Sweet corn harvest progresses and reports are positive for yield. Rust is present in some fields. No corn borer moths and ten corn earworm moths were counted in the pheromone traps. The squash harvest looks good so far, although I have seen numerous foliar disease symptoms. Angular leaf spot seems to be common. Squash bugs are also present. Potatoes, peppers and tomatoes are progressing well. The cabbage harvest continues to look good.
Norm Myers
Heavy dews, rain and fog has kept purple spot pressure high in asparagus. Drought has also caused some early die-back, which we now know is a symptom of Phytophthora asparagi.
Disease pressure remains high in the carrot crop and you can clearly see the results of the high aster yellows infectivity index in many fields. Irrigation continues in this crop.
Most foliar diseases other than downy mildew are active in vine crops. Dry weather has resulted in very few problems with Phytophthora capsici.
Irrigation also continues on the snap bean crop.
In sweet corn, the European corn borer and corn earworm traps are all zero and the catch of western bean cutworms is lessening too.
Jim Breinling
General precipitation in the one-third to half inch range was received in the area during the past week. Some isolated reports of one inch plus were reported. This was not enough to keep up with crop need, so irrigation systems continue to operate on a steady basis. High temperatures in the area have been quite consistent during the past week averaging about 85°F at the Fremont Enviro-weather site compared to an average high of about 80°F at Ludington. Low temperatures have been more variable ranging from about 55°F to 65°F with heavy dews.
Aster leafhopper and disease pressures continue in carrots. Harvest is scheduled to begin next
week for fresh market in
Onion crop development continues in the area. There were a number of market garden plantings of transplant sweet onions that were sizing well and of excellent quality.
Harvest of slicing cucumbers is now in full swing and hand harvest of pickling cucumbers has begun. Powdery mildew on summer squash is easily found where control measures have not been implemented.
European corn borer trap counts increased this week to 7 - 1
- 1 at the snap bean site in
Corn earworm trap counts at the sweet corn site in
Hannah Stevens
From one to nearly five inches of rain hammered this area last week and growers have been harvesting in wet conditions all week. Temperatures reached the mid-80s and relative humidity has been high.
While nearly every commodity is now being harvested, the following are my observations this week in the three county area.
Growers are having a challenge keeping up with sweet corn, as main harvest is in full swing. Corn borer numbers are on the rise for the second generation, but no corn earworms have arrived yet.
On vine crops, Phytophthora is appearing in scattered, particularly wet locations on crowns, vines and fruit on a variety of crops including summer and winter squash and muskmelons. The powered sugar-like spore masses can sometimes be seen on young fruit. Reports of downy mildew on cucumbers are coming in from many areas. Muskmelons are yielding very well so far.
The tomato harvest is underway, and is challenging on some varieties, with bacterial disease marring fruit quality and blighting foliage as well. I am seeing bacterial canker and speck and possible bacterial spot. Blossom end rot is not uncommon on the first fruit, but along with catfacing, it seems especially bad this year. Nevertheless, yield prospects for fresh market tomatoes seem excellent.
Onions for shipping and retail sales are enjoying very good growing conditions this season. Transplanted varieties are struggling through thrips and fungal pressure to produce large bulbs. Storage varieties are also sizing very well.
Shoppers who enjoy new potatoes at farms and farm markets have their pick this year of a large harvest of large and clean tubers, the best harvest in a number of years.
Garlic harvest is underway for retail sales.
All of our cole crops, except brussels sprouts, are being harvested.
Growers and others are invited to join two MSU vegetable
crop specialists and myself at the All Vegetable Crops Twilight Meeting on
Thursday, August 7 at UAP,
Dinner at 6:30 PM is courtesy of UAP. At 7:00 PM our program will feature Beth Bishop who will discuss some current insect pest affecting vegetable crops and what research she is engaged in. Mary Hausbeck will help us understand some of the disease problems of concern at the present time and what control strategies her research suggests.
New publications and upcoming programs will be introduced. Growers are encouraged to bring problem weeds and other samples in plastic bags for discussion before the meeting. Please contact Hannah Stevens at 586-469-6440 or at stevensh@msu.edu by Thursday morning if you plan to attend so that we will have dinner and materials for you.
Sudeep Mathew
We had very dry weather this past week. Soils are very dry.
Lack of water has increased potential for many issues in planting, fruit sizes
and harvest. Soil temperatures ranged from 67°F to 83°F. According to the Enviro-weather station
in
Sweet corn fields are maturing at a good pace under this week’s heat. Bird damage has been a problem for several growers during the dry conditions. Corn borer and earworm numbers continue to be very low. There was just one European corn borer and one corn earworm moth in my trap.
Pumpkins have fruit in most fields with no downy mildew seen in this crop at this point. Pumpkin phytophthora stem rot has been found in a pie-pumpkin field (Photo 1). The infection appeared first in low areas of the field and later spread to other areas. Powdery mildew has begun to show up in several fields this week. Adult squash vine borer and squash bugs are active. I have seen very little virus in this crop. Squash vine borer trap had just one adult.
Cantaloupe, muskmelons and watermelons are now being harvested. Size has been good, and there have been very few problems in these crops. In some fields, the schedule for harvest has been delayed because of dry weather.
Pepper harvest continues with good sizes and yields for the season. I have not seen any aphids in this crop. Late planted peppers are suffering from the dry conditions (Photo 2).
Cabbage planting for late season harvest has been a challenge with high temperatures and dry conditions over the last two weeks. A rain will improve these late plantings.
Market tomatoes are ripening slower than anticipated. Bacterial diseases are present in both market and processing tomato plantings. Fruit load looks good, but size may be less than normal due to dry weather and especially in non-irrigated fields.
Potatoes are being harvested for market with tubers more mature this week. There has been very little disease and insect pressure in this crop. Variegated cut worm trap had 11 moths present.
Jeff
Andresen
Agricultural Meteorology
Geography
During the past one to two weeks, a broad upper air ridge
has persisted across much of the central United States, resulting in oppressive
heat across sections of the southern and central Great Plains and generally
drier than normal conditions across much of the Upper Great Lakes region. That
general pattern is expected to continue for much of the next one to two weeks,
but with a shift of the ridge axis westward into the
In the short term, cooling temperatures aloft and a series of weak upper air disturbances will lead to the chance for scattered showers and a few thundershowers Thursday, August 7 and Friday. Given limited low level moisture, however, rainfall amounts and areal coverage are expected to be limited with most totals remaining in the 0.10-0.25-inch range or less where rain falls. Fair, dry, and cool weather is expected for the upcoming weekend. Temperatures Wednesday through Saturday will fall back from recent levels to highs ranging from near 70°F north to 80°F south, with lows from the low 50s north to near 60°F south. A weather system approaching from the west will bring the next chance for significant rainfall by next Monday or Tuesday. In the medium range period, forecast guidance suggests a general continuation of the upper air pattern mentioned above.
Both National Weather Service 6‑10 day, covering August 11 – 15, and 8‑14 day, covering August 13-19, outlooks call for below normal mean temperatures state- and region-wide. Precipitation totals are forecast to remain at below normal levels during the 6-10 day time frame and range from below normal in far southern sections of the state to above normal levels north during the 8-14 day period.
The latest long lead forecast guidance suggests that the El
Niño Southern Oscillation (ENSO) index will remain near neutral for the next
several months into early 2009 at least. Thus, while some impacts of the recent
past La Niña event may persist for another month or two(including increased
chances for hurricane activity in the northwestern
The latest NOAA Long Lead outlook for August calls for mean
temperatures in