In this issue
§ Diamondback moth larvae are out
§ Website to locate beekeepers who rent honey bee colonies for pollination
§ Kill interplanted barley in carrots and onions
§ Early season irrigation
§ Vacuuming pests with a leaf blower
§ 2007 MSU Weed Tour
§ Regional Reports
§ Weather
Walter Pett
Entomology
Diamondback moth larvae have been found in recently planted
cabbage fields in southeast
Treatment thresholds for fresh market cabbage are at 20 percent plants infested prior to heading and 10 percent plants infested when plants start to head. Bt (Bacillis thuriengiensis) insecticides are generally effective against diamondback moth, and are recommended as they do not kill natural enemies.
Consult MSU Bulletin E312, 2076 Insect, Disease and Nematode Control for Commercial Vegetables, for a list of insecticides registered to control diamondback moth.
Walter Pett
Entomology
Zachary Huang, MSU Department of Entomology, maintains a website (http://www.cyberbee.net/) that provides useful information about honey bees and beekeepers. One service of this site allows growers to find beekeepers that provide honey bee colonies for pollination services. To use this feature go to the URL listed above and then click on Beebase. At that link, you can find beekeepers by name, zip code, area code, or county. The site also has some great photographs of bees.
Bernard Zandstra
Horticulture
This spring has had periods of warm and cool, wet and dry weather, and growers have planted carrots and onions over about six weeks. Interplanted barley continues to grow during both cool and warm periods. Growers need to monitor the size of the cover crops and to kill them before they begin to compete with or stunt the crop for harvest.
If onions or carrots are small and still need protection but
barley is four to six inches tall, it may be a good idea to apply a reduced
rate of a graminicide to stunt, but not kill, the barley. Fusilade, Poast, or
SelectMax may be used on labeled crops to treat the barley. A rate of 10 to 25
percent of the normal use rate, plus COC or
Early season irrigation
Lyndon Kelley
Extension Educator Purdue/MSU
How to achieve the most agronomical and economical start from irrigation during planting season is important. Achieving the maximum uniform germination and emergence can be assured through proper early season water management. Irrigating fields prior to or just after planting, can keep the planter moving and still meet the “plant into moisture” requirement.
Irrigation water applied at ½ to ¾ inch will wet dry soil down to six inches to replace water loss to tillage. An inch of irrigation will often be needed in a field that has not received rainfall since the cover crop was destroyed. Monitoring newly emerged crops that were “irrigated up” is essential. It is important to water enough to keep roots growing down into the moisture. Most year rainfall is plentiful enough to replenish water lost to tillage or cover crop, but a dry layer six inches to eight inches down can greatly hinder crops development, and needs to be replenished by rain or irrigation.
Early season irrigation can be both the cause and solution to soil crusting and emergence problems. Depending on soil type, crop residue, and irrigation application equipment early season irrigation can create some soil crusting accelerated by rapid surface drying. Small applications of water 0.2 to 0.3 of an inch may help to allow emergence of seed through the crust.
Many herbicide options can be assisted by a timely rain or irrigation. Applications of 0.3 to 0.5 of an inch of water will move activated herbicides if rainfall does not occur within two days after herbicide application. Irrigating in herbicides can also create the problem of different levels of weed control between the dry corners and the irrigated portion of the field. Timely and directed scouting for weeds in dry corners will be needed later in the season.
Early season irrigation can be more accurately scheduled from monitoring soil moisture in the root zone rather than checkbook irrigation scheduling system for newly emerged crops. Later in the season, checkbook irrigation scheduling will show its advantages over scheduling by soil moisture in the root zone alone. To learn more about checkbook irrigation scheduling click on the following link: http://www.msue.msu.edu/portal/default.cfm?pageset_id=28706&page_id=361029&msue_portal_id=25643 and see the irrigation scheduling tool fact sheet.
For more information on irrigating, contact Lyndon Kelley, Extension Educator Purdue/MSU, Irrigation at 269/467-5511.
Vicki Morrone
Organic Vegetable and Crop Outreach Specialist
Most leaf blowers have the capacity of serving as a vacuum and a blower. There is very little conversion needed to use a leaf blower to suck up insects for sampling purposes, or to provide an eco-friendly way to remove them from crop plants.
When selecting a leaf blower, find one that has a large diameter opening and tube (approximately 8 inches) to provide adequate coverage per plant. You can even buy one that fits like a back pack with padded straps and a frame; if you want that type of handling. To prevent insects from clogging the system, you should use a nylon cloth. Nylon “knee highs” work great. Just open one up and attach the opened end to the opening of the vacuum with a strong rubber band. This will catch the insects for counting or disposal, depending on your needs. If you have a large number of insects, you need to empty them periodically. To keep them from flying away, you can empty the stocking into a container of soapy water, the soapy film will make it more difficult for them to fly away.
Walt Pett, an MSU professor in entomology, among others in the bug world, uses this system to sample insects for his research. He also uses this to remove Colorado potato beetle from potatoes. He has observed that this system not only removes insect pests from the plant, but also pulls some soil (especially in sandy soils) up and in the process damages any egg masses located on the underside of the leaves. He stated he has not noticed damage to the plants, but he uses it mostly on potato plants to manage the Colorado potato beetle. You may need to be cautious when using it on young transplants. Having a wider suction nozzle will also reduce the tendency to suck up the plant.
Christy Sprague,
Crop and Soil Sciences
The 2007 Weed Tour will be held on the
Ron Goldy
Temperatures during the week ranged from highs of 69o
to 86oF and lows from 43o to 58oF. The area
received about one inch of rain with half an inch on May 9 and half an inch on
May 15. Some locations received hail on May 15.
Timely rainfall events have allowed field activity to proceed. Growers continue preparing fields, laying plastic and planting with little difficulty.
Warm temperatures have advanced asparagus harvest. Some growers feel they are already at 50 percent harvest. Forecasted cooler temperatures should slow growth and prolong harvest. Asparagus beetles are active and laying eggs.
Growth of cucumbers, squash and tomatoes has been excellent in and out of tunnels. Growth difference with tunnels does not appear to be that great, but that should change with the cool, sunny conditions forecasted for the next several days.
Bill
Steenwyk
A welcome third to a half inch of rain fell in the late afternoon/evening yesterday, May 15. This will be very helpful in activating pre-emergent herbicides, and limiting ammonia volatilization from any ammonium-based nitrogen fertilizer left at or near the soil surface.
Conditions have been dry, with planting, transplanting and spraying continuing at a rapid pace. On muck fields, onion planting is nearly complete, with shoot growth in most fields ranging from one to five inches.
Barley companion/cover crops have not been killed.
Celery greenhouse planting and field transplanting continues steadily.
Red beets, leeks, radish and cabbage are established and growing well. On upland soils, cabbage and other cole crops are growing well, sweet corn growth ranges from the two true-leaf stage to just spiking.
Disease and insect pest pressures remain light. Overall
field progress and crop development in
Norm Myers
Asparagus yields have been average over the first 10 days of the harvest season, with older fields lagging behind, but younger fields doing very well. Quality of this year’s crop, especially for the fresh market has been exceptional. Labor is still a struggle during warm periods. Common asparagus beetle eggs are a problem on some farms and growers have been treating accordingly. With the return of damp, cool weather, purple spot may be a problem for the next few days. Crown planting is progressing, but still running behind.
Our carrots are mostly emerged. Some emerged quickly enough that growers didn’t get pre-emergent herbicides down, so there are some weed problems to worry about. Stands are generally good with a few exceptions. Cover crops have been advanced enough to protect fields from the high winds we have experienced.
Early plantings of sweet corn are emerged and planting of the late fresh market crop is continuing.
Hannah Stevens
Field work resumed over the weekend and until yesterday
evening as soil dried from the rain last Wednesday, May 9. High temperatures
for the week occurred yesterday at 88 oF in central
Carrot seeding was almost completed last week, and cover crops and emergence looked good, although later than last year.
Seeded onions are emerging and transplants are getting established. The weather yesterday may have done some damage.
Garlic (see photo) overwintered well this year.
Lettuce transplants looked very good last week, and successive seedings were emerging.
Cole crops are looking good with the exception of some flea beetle activity.
Sweet corn first seedings have emerged, and growers were busy seeding second plantings
Tomato and melon transplants were being covered as quickly as possible to protect them from possible frosts (see photo).
Paul Mark
Rain this last week mainly on Tuesday, May 15 and Wednesday brought a total in the range of 1.5 to 2.5 inches in our area. Strong winds for a short time with Tuesday’s rain may have exposed some plants to potential bacterial diseases. Frost early Sunday morning caused minor damage to many tomato and pepper plants that have been planted. Degree days at base 50 are running ahead of the long term normal at 354 as of May 15. Soil temperature has been in the mid 50’s at night and the mid to upper 70’s during the day.
Tomatoes that were exposed to Sunday morning frost appear to be recovering with mostly foliar damage. Those, which had been in the field for more than five days, were damaged less than those that had been out for only a day or two (see photos). Processing tomato planting is approaching 50 percent complete.
Peppers are very similar to the tomato report above.
Cabbage is making very good growth. Imported cabbage worm adults are now active. Diamondback moths have increased in numbers as adults, and larvae are larger with infestations as high as 15 percent.
Sweet corn planted early has very good stands, and is uniform in the fields. Plant development is in the five to six leaves in open fileds.
Jeff
Andresen
Agricultural Meteorology
Geography
A Canadian-origin area of high pressure will move into the
Great Lakes region Wednesday, May 16, bringing cooler than normal temperatures
to
Fair and dry weather are a good bet Thursday and Friday. Another
frontal boundary will approach the state from the north Saturday, bringing the
chance for light rain or showers, beginning in northern sections of the state
overnight Friday and Saturday across the Lower Peninsula. Temperatures will
fall back from recent levels, with daytime readings Wednesday and Thursday
remaining in the in mid 50's to mid 60's. Highs this Friday and Saturday should
warm into the 60's to low 70s=.
Low temperatures will fall back into the 30's and 40's in most locations
through Friday. Given the very dry air mass in place across the region (dew
point temperatures dropping back to the mid and upper 20's are possible), frost
and freezing temperatures will be a threat again Thursday in northern sections
of the state and again Friday morning over most of the rest of the
In the medium range, forecast guidance is suggesting a
relatively flat, west to east upper air pattern during the 6-10 day time frame
with the gradual formation of a troughing feature across eastern