Christmas trees
Field crops
Fruit
Home and yard
Nursery and landscape
Turfgrass
Vegetable

Diagnostic Services
Soil/Plant Nutrient Lab
Enviro-weather
Regional IPM Center
Pesticide safety
Organic: New Ag Network
Invasive species
Sustainable ag & food systems

MSU ANR departments
MSU Extension

Site index
Contacts/permissions

Most celery, carrot and lettuce growers have recently sprayed fields to control aster leafhoppers and the number of aster leafhoppers found last week decreased. Diagnostic Services tested six populations of leafhoppers collected from celery and carrot fields in west Michigan. The proportion of leafhoppers infected with aster yellows varied from location to location; about 2.5 percent of those collected from a carrot field in Oceana County carried aster yellows. Leafhopper populations collected from celery fields in Allegan, Van Buren, Ottawa and Newaygo counties were from zero to six percent infected with aster yellows. Aster leafhoppers Earlier this year, in late May and early June, aster leafhoppers carried very little aster yellows. In mid-June, storm fronts carried new leafhoppers into the state and some of these leafhoppers were infected with aster yellows. Consequently, we have a mixture of old and new, infected and uninfected aster leafhoppers. Growers may wish to be conservative and use the treatment thresholds published last week because of the variability in infection rate. Treatments Celery fields should be treated if the number of aster leafhoppers caught in sweep net samples exceeds three to five leafhoppers per 100 sweeps. Carrot fields should be treated if the number of aster leafhoppers exceeds three to seven per 100 sweeps. Lettuce fields should be treated if the number of leafhoppers exceed two to four leafhoppers per 100 sweeps.

back to top

Downy mildew is in Ontario field cucumbers: Michigan growers need to be on high alert Mary Hausbeck Plant Pathology Downy mildew has been confirmed in a small commercial slicing cucumber field in the Aylmer area which is located south of London in Ontario, Canada. Approximately 10 percent of the plants were infected by the downy mildew with 1-2 leaves showing disease. If last year is any indication, then Michigan growers can expect to see downy mildew symptoms appear in their fields within the next couple of weeks. It is possible that downy mildew has already made its way to Michigan fields with a light infection that has not yet been found. Growers (especially those in southeast Michigan) may consider initiating a fungicide spray to protect vulnerable cucumber and melon plantings. Although squash and pumpkins have not been hard hit by downy mildew in past years, growers of these crops should remain vigilant and ready to spray these crops if downy mildew should appear in these fields. Table 1. Recommended products for managing downy mildew on cucumber Table 2. Results of downy mildew field trial 2007

back to top

Asiatic garden beetles emerging in St. Joseph County - Watch for potato injury in 2008 Bruce MacKellar St. Joseph County MSUE educator Asiatic garden beetle is a new pest in southwest Michigan. The larval stage of this insect was first identified causing root-feeding injury in commercial corn in St. Joseph County and Elkhart County in Indiana in the summer of 2007. The pest contributed to the unevenness that was seen in the corn crop in the extreme southern portion of Michigan during last growing season. Corn fields that were the most severely impacted were rotated fields planted to soybeans the previous year. During MSUE winter meetings last year, we learned that potato producers in southern St. Joseph County were seeing significant numbers of small grubs showing up in the trucks and at the grading stations as they harvested their later plantings. They reported small pock-marked feeding injury on the tubers, which could occasionally be detected in frying quality tests. Subsequent discussions with the producers and pest managers confirmed that there was activity in the fields with a beetle similar to a Japanese beetle in several potato fields last summer. We have been closely monitoring Asiatic garden beetle activity in St. Joseph County this spring as part of research initiative funded by Project GREEEN to study how well soil insecticides and seed treatments prevent Asiatic garden beetle grub root feeding and stand loss in commercial corn. We are also conducting a survey to look at how far north the Asiatic garden beetle can be found in significant numbers. Last year, significant damage to unprotected corn was thought to be confined to St. Joseph and eastern Cass counties in Southwest Michigan. Beetles were observed as far north as Battle Creek and West to the Paw Paw area last summer.  This week the first Asiatic garden beetle adults began to emerge. The beetles were observed in a seedcorn field in central St. Joseph County. From the number of emergence channels, I estimate that there were a fair number of beetles in the field. Interestingly, the field was treated with a soil insecticide, and the plants are reasonably uniform in height; no visible signs of damage to the roots could be seen by looking at the growth of the plants. Meanwhile, in potato an agronomist reported finding Asiatic garden beetle adults in several potato fields in the Winamac Indiana area earlier this week. Most of the activity was confined to field edges at this point, but a few fields had high levels of Asiatic garden beetle activity. MSU Field Crops Entomologist Chris DiFonzo is hoping to develop a method for predicting when Asiatic garden beetle larvae pupate and when adults are likely to emerge. We are looking at both soil and air growing degree day accumulations at the MSU Enviro-weather stations in Mendon and Constantine to chart how these values against adult beetle emergence. It may take several seasons to get a model in place to accurately predict when the adults are likely to emerge. Chris and Dr. Walt Pett are interested in learning more about when Asiatic garden beetles enter potato fields to lay eggs. Unlike their close cousins, the Japanese beetle, Asiatic garden beetle adults are more active at night than in the daytime. They hope to work with potato producers in St. Joseph County to learn more about the egg-laying behavior of female beetles in potatoes and to monitor development of the larvae to understand when damage occurs and potential ways to prevent it. We are stepping up monitoring activities near soybean and potato fields in St. Joseph County to try to pinpoint when Asiatic garden beetle adults may be moving into fields. Last year, we caught quite a few Asiatic garden beetle adults in milk jug traps set out for western bean cutworm. The thought is that the insects may be attracted to the antifreeze (which is sweet) used in the traps to contain trap the cutworm moths. We will update growers on our findings as the season progresses.

back to top

Learn from the cover cropping in vegetable systems tour held June 12 Kate Leich MSU Department of Community, Agriculture, Recreation and Resource Studies June 12 was a wonderful day at the Kellogg Biological Station (KBS); the weather was great, the speakers were fascinating and the cover crops were looking good. We started the day indoors, listening to five talks from professors and Extension educators. PowerPoint presentations from this program are available at http://michiganorganic.anr.msu.edu/. A summary of the workshop is given below and on the main page with links to the presentations. Anne Verhallen from the Ontario Ministry of Agriculture, Food and Rural Affairs, gave an overview on cover crop attributes in vegetable systems. Her talk was particularly attuned to the audience's interests and there was opportunity for feedback and questions throughout her presentation. Mathieu Ngouajio, associate professor of horticulture at Michigan State University (MSU), taught us about biofumigant cover crops. We learned about the biochemistry of biofumigants and how this information can help to develop more efficient cover cropping practices. Darryl Warncke, MSU professor and Extension specialist in the Department of Crop and Soil Sciences, talked about nutrient management using cover crops. He provided a lot of interesting information about the dynamics of nutrient cycling and how understanding those dynamics can help improve nutrient availability. George Abawi, professor of plant pathology at Cornell University's New York State Agricultural Experiment Station, gave a presentation on the role cover crops play in soil health and root disease management. We learned a lot about a particular soil testing system Dr. Abawi is developing. Daniel Brainard, assistant professor of horticulture at MSU, spoke about cover crop mixtures for integrated weed and nitrogen management. Throughout his talk he made points about the financial pros and cons of cover cropping. During the second half of the day we ventured into the KBS fields to examine cover crops from another angle. Sieg Snapp of KBS introduced us to perennial wheat. We got a good look at the wheat's roots, and had discussion about the differences and similarities between perennial and annual wheat (e.g., gluten content). We witnessed a demonstration of a crimper in use; this piece of equipment is useful in killing a cover crop by breaking its stems, yielding a nice, green mulch. Photos of the meeting are posted at http://michiganorganic.anr.msu.edu/. If you have any questions, please contact Vicki Morrone (sorrone@msu.edu) or Kate Leitch (leitchka@msu.edu).

back to top

Regional reports 1 -- Southwest Ron Goldy Weather Temperatures were below normal for the period with lows from 47°F to 53°F and highs from 66°F to 81°F. There was a trace to 0.1 inches of rain across the immediate area. Soil moisture levels continue to drop and in many soils irrigation is necessary. Crop report Watermelon and cantaloupe look good, but growth has slowed due to cool temperatures. Cucumber, yellow squash and zucchini harvest continues from tunneled plantings. Some pollination problems have been observed. This may be due to the earliness of the planting and bees not yet finding it, or it may be weather related since we experienced some cool, windy conditions seven to ten days ago when these crops would have been in bloom. Pumpkins are mostly planted and are growing well. Onions are starting to bulb. Pepper and tomatoes are growing as well as expected given the cool temperatures. No serious disease or insect pressures have been reported in the area.

back to top

2 -- Grand Rapids Area Bill Steenwyk Weather Temperatures remained cooler than desired, but have warmed in recent days. Many fields could benefit from a little rainfall, even as we recover from the early June flooding, however storm clouds are gathering as this article is being written. Crop growth and development varies, and continued warmer temperatures will be important to advance. As reported for the past two weeks, muck and poorly drained upland soils suffered from the June 7 - 8 storms. However, we are still discovering the extent to which fields are or are not recovering in terms of yield quantity, quality and timely maturity. Many are wisely, sidedressing additional nitrogen to replace what was lost from leaching and denitrification. One grower intended to sidedress urea and hope for rain to incorporate the nitrogen into the soil. Let me remind everyone that any fertilizer product containing the ammonium form of nitrogen must be incorporated mechanically or by irrigation/rainfall to avoid major nitrogen loss. When left on the surface, much of that expensive nitrogen will be converted to ammonia gas and simply float away. Crop report On muck soils, celery, radishes, lettuce, cabbage and sweet corn are being planted, transplanted or replanted. Post-flood plantings look good overall. Onions are quite variable with healthy and water-stressed fields growing near each other. Bulb initiation is beginning. In some cases, the onion plant hasn't developed enough leaf tissue to support good bulb development. Leeks have been stressed, but should recover. On upland and some muck soils, cabbage looks good. Sweet corn is growing again, with the earlier plantings exceeding two feet. Corn borer trap counts as of June 24 were less than one per trap. Vine crops are growing, although significant acreages of squash in some areas of Ottawa County were damaged by the heavy rains and needed to be replanted. Tomatoes and peppers are doing well overall and in flower or developing fruit.  Peas are being harvested.

back to top

3 -- Oceana County Norm Myers Weather With the exception of yesterday, Oceana County has had a very cool, dry week. We are actually at the point that some soils could use a little rain. Cool weather has kept plant growth slow and high winds have resulted in less than ideal spray weather. We mostly avoided the hail that hit northwest Michigan last weekend. Crop report Asparagus growers are in the midst of shutdown and so are many of the processors. However, the largest processor will receive into next week. We are also riding a very hot fresh market and I am sure that some growers will pick through the weekend for that market. Growers are still getting good yields and good quality, probably as a result of the abundant rain and cool temperatures. Most growers feel that they will be a little ahead of last year’s production, but it is important to remember that 2007, was a record low year for asparagus. Fortunately, growers all sprayed their carrots last week as a result of the new aster leafhopper threshold and scouts are not reporting finding new leafhoppers this week. We are setting out our Tom-Cast sensors this week, but don’t anticipate any disease yet. Zucchini, pumpkins and pickles are emerging normally except where they were planted on heavy soils and needed to be replanted. In sweet corn, I had only one catch in each of my European corn borer traps, but I did catch five corn earworms. So far nothing has been caught in my western bean cutworm traps.

back to top

4 -- Mason-Newaygo counties Jim Breinling Weather The only rainfall reported during the past week was 0.06 inch at the Ludington Enviro-weather station. Temperatures in the area were below normal with highs generally in the low 70s and lows about 50°F. Crop report Crown maggots were found in spinach on Friday, June 20 above a threshold level of one per 100 plants. Also, some leaf feeding on new growth was observed, but no chewing type insects could be found. Harvest of processing peas was completed during the past week in Newaygo County. Early planted fields (April 15) of carrots are now at 0.25 inch in diameter and up to ten inches in length depending on variety and type. They will be approaching the start of harvest in approximately six weeks. In cucurbit crops, reports of some replant due to cold temperatures and then wet weather. Fields of winter squash are now at the three true leaf stage of growth. Snap bean planting is now in full swing in the area. Planting was delayed about a week due to cool weather, which was fortunate that no plantings were in before the heavy rains occurred. The fields in Mason County where the European corn borer traps are located were planted June 21 -24. Trap counts on June 23 were 11 - 0 - 5. Sweet corn development at the Mason County insect trapping site is progressing at about 18 inches tall, but still behind normal. Corn earworm trap catch on June 23 was at 19 in the large trap and five in the small trap. Two moths that I identified as western bean cutworm were found in the corn earworm traps, the sample was then sent to MSU Entomology for confirmation.

back to top

5 -- Macomb, St. Clair and Lapeer counties Hannah Stevens Weather and crop conditions The cool and wet conditions persist with the maximum temperatures barely reaching 80°F throughout these counties. The area has also received highly variable amounts of rainfall on at least five days this week, from 0.2 inch to two inches have been reported, including wind and damaging hail. Nevertheless, there have been opportunities for sidedressing nitrogen, weed control, tunnel removal and planting of late season cole crops, sweet corn and others. Wild pollinators appear to be in abundance on trees, shrubs and herbs that are in lush bloom in the landscape. Crop report The potato crop is in excellent condition with some new potatoes due at farmers markets this weekend. Most untreated onion fields have thrips present, even on small ones. Onion smut may be seen occasionally as well as a small amount of maggot injury. Spring bunching onions as well as very early green bulb onions are being pulled for direct sales. (view photos). Growers are trying to finish transplanting of the late crop of broccoli, brussels sprouts, cauliflower and cabbage. Imported cabbage worm butterflies were very visible this week in the landscape. Early broccoli is now being retailed. Alternaria leaf spot was found on a field margin of early carrots. In sweet corn, corn borer numbers are holding steady at relatively low levels as the first crop of bare soil corn begins to show tassels in the whorl. I did not notice any foliar feeding injury at this time, but I suspect growers will begin to see it soon. Tunnels have been removed with muskmelons and watermelon quickly vining out, flowering and beginning to fruit. Angular leaf spot is present in one cucumber field (view photo). Growers are watching closely for downy mildew in our location and angular leaf spot, a bacterial pathogen, can resemble this more destructive fungal disease. Nevertheless, angular leaf spot may require treatment as cool and wet conditions persist. The first crop of radishes from Imlay City has gone to market with successive plantings following close behind. Edible podded, snap and shell peas are now at farmers markets. Green onions at the market. Bulb onions at the market. Angular leaf spot present on cucumber.

back to top

6 -- Monroe County Sudeep Mathew Weather We had some isolated showers this past week. Most other areas were dry with some windy conditions. According to the Enviro-weather station in Dundee, we received a total rainfall of 0.40 inch during the week. Soil temperatures ranged from 43°F - 81°F. Crop report Sweet corn is progressing well. Sweet corn smut was found in a conventionally planted sweet corn field (Photo 1). Leaves were infected, developing small galls, usually on the midrib, causing some leaf distortion. It is usually not economically important, although in some years yield losses in sweet corn may be as high as 20 percent. European corn borer larvae between one-sixteenth and one-eighth of an inch in size were found in sweet corn. A granular application was recommended, however growers who do not have the equipment could put a foliar spray schedule with an interval of five to six days. It is important to make sure the plant is covered at the tassels emerging stage to restrict that caterpillar activity. Not many eggs were found. European corn borer moths in our traps averaged two moths per trap for this week. Cabbages are forming heads and continue to be harvested in the early planted fields. Cabbage rhizoctonia secondary infection was found in some rotted cabbage heads (Photo 2). It is not wide spread across the fields; the symptoms are only in isolated areas. Cucumber beetle activities were found at several fields. Most growers made an insecticide application. Melons, squashes and pumpkins are coming up very well. Since we heard the news about downy mildew in Ontario, every one is on high alert. I haven’t found any downy mildew symptoms yet at any cucumber fields. Tomatoes are progressing well on stakes. Plants have thick canopy with fruits forming. Fruits are 1.5 to 2 inches in diameter. I have noticed tomato blossoms falling off in some fields. I feel it was because we had many evening temperatures that fell below 55°F this season. There is no serious insect or disease pressure at this time. Peppers are progressing well. There was some wind damage in few fields (Photo 3). Snap beans are having a very vigorous growth. Potatoes are blossoming with good canopy. There are very low numbers of leafhoppers in many fields, but we did find ten leafhoppers in twenty sweeps in a fingerling potato field. Photo 1. Sweet corn smut was found in a conventionally planted sweet corn field. Photo 2. Cabbage rhizoctonia secondary infection was found in some rotted cabbage heads. Photo 3. Wind damage to peppers.

back to top

Weather news Jeff Andresen Agricultural Meteorology Geography Shortwave troughs will be the major effect on the state’s weather over the next couple of days, producing rainfall across the state. Along with a deepening upper air flow with a moist airmass pushed in front of it, the amount of precipitation will be less then a half an inch across the state by the night of Wednesday, June 25. The low should enter our region by Friday, June 27, producing the previously mentioned possible severe weather and rainfall. The warmer temperatures should persist until late this weekend when a slight cooling over the state should occur. Temperatures during the next few days will be generally steady, with highs Wednesday through Tuesday generally ranging from the upper 70s north to the lower 80s south and lows from the upper 50s to low 60s north to the lower 60s south. In the medium range forecast, the upper air pattern mentioned above is expected to continue for much of the remainder of June. The National Weather Service 6‑10 day outlook covering June 30 through July 4 calls for below normal temperatures and for precipitation totals to remain at near normal levels. The outlook for the 8-14 day period (July 2- July 8) calls for mean temperatures to range from near normal levels across the lower peninsula to above normal levels in upper peninsula, and for near normal precipitation totals across the state. Further ahead, it is interesting to note that forecast guidance is also hinting that the very turbulent, active upper air pattern of late May and early June may return to the upper Midwest, possibly during early July.

Back to top