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Vegetable Production |
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| Vegetable Reports 2008 | photos |
| Sudeep Mathew is the new vegetable educator in
Michigan's Southeast Region, based in Monroe County. He has been visiting
growers with retired educator Paul Marks and with other members of the
Vegetable Area of Expertise team. He plans to make weekly reports as he
helps area vegetable growers scout and troubleshoot their crops. With the
instructive photos, these reports may help more growers diagnose nutrient,
disease and insect problems as they appear. The latest report will be at the
top of the list below. For statewide reports and other current information
relating to vegetable production, see
http://www.ipm.msu.edu/vegetable.htm For current pesticide recommendations for any of these crop problems, please refer to MSU bulletin E-312, "Control of Insects, Diseases and Nematodes in Commercial Vegetables", available at county MSU Extension offices or online. Go to http://web2.msue.msu.edu/bulletins/ to purchase, or http://web4.msue.msu.edu/veginfo/E312/index.cfm to search the bulletin. To review information or diagnostic photos from prior year's reports, you can go to Vegetable Report2007, 2006 and 2005 |
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| September 3 Weather has been very dry
for the past three weeks. Cool nights have returned as we are getting into
some fall type weather. Soil temperatures ranged from 620F - 830F.
Precipitation deficits and moisture stress is wide spread. The total
precipitation received at the Enviro-weather station in Dundee for the
entire month of August is just 0.76 inches this year while we received 8.39
inches at the same time in 2007.
For all the crops grown here harvest is progressing in full swing and some fields are now completed. Water stress is taking a toll on growers as well as crops. Any late sweet corn still in the field is being irrigated. Late plantings that lack irrigation are being abandoned. No European corn borer moths in my traps this week. There was one corn ear worm in my trap. Powdery mildew is widespread in pumpkin, squashes and gourds. Pumpkins are maturing and making the sizes. Squash are in good quality irrespective of the dry conditions. Foliar applied fertilizers caused some phytotoxicity in muskmelons because of dry weather and temperature conditions at the time of application (Photo 1). Phytophthora is continuing to be seen in pumpkin fields. Watermelons are in short supply because of delayed harvest. No squash vine borer found in my trap. Pepper harvest is steady. There are aphids in peppers. Cauliflower is having disease free growth. There was some carryover problem from Treflan herbicide (Photo 2 & 3) in cauliflower. Herbicide carryover problems were much more prevalent in sandier soils. Dry weather is favoring Cabbage under irrigation, which is making good growth without much disease pressure. Plants are healthy and forming good sized heads. Both processing and market tomato harvest is in full swing. Growers are getting good yield in irrigated fields and I am seeing about 1.5 – 3 tons/acre yield reduction in non-irrigated fields due to the lack of rain. Potatoes harvest is progressing. There is good demand for processing potatoes. Although vines are senesced, tubers are still green in many fields. Leaf hoppers found in very small numbers. There were 2 variegated cutworms found in the trap. |
 Photo 1 fertilizer burn on melons
Photo 2 carryover of herbicide in cauliflower
Photo 3 lingering carryover effects of herbicide in cauliflower
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| August 13, 2008
Weather continued dry except for isolated showers in some pockets. The
Enviro-weather station in Dundee received a total precipitation of 0.47
inches during the past week. The total estimated evapotranspiration rate for
this past week was 1.49 inches. That means loss of water from plant and soil
surfaces to the atmosphere is continuing at high rates for the last three
weeks. Although water requirements vary greatly between crops, for nearly
all vegetables the two most sensitive periods for water shortage are during
harvest and two to three weeks prior to harvest. I see significant
differences in crop development between irrigated and non-irrigated fields.
Soil temperatures ranged from 610F - 810F.
Sweet corn harvest is continuing with later planted non-irrigated fields now looking dry due to lack of rains over the last three weeks. Although European corn borer moths are visible in the fields, I didn’t catch any European corn borer or corn ear worm in the traps during this week. Pumpkins and squash have made decent growth over the last two weeks although it’s been very dry with fruits now showing in most fields. Some color is also visible in earliest fields. Squash bug egg masses have been found in plants. Powdery mildew has increased again this week in many fields. There were no squash vine borers in the trap this week. Musk melon harvest is in progress and will continue during the following weeks. Cabbage and cauliflower are looking good. Cauliflower being sensitive to water stress at all stages of growth, it is responding to drought with slower growth than normal. Green bell and banana peppers are looking good with uniform and good sized fruit. Green peach aphids have been found in green bell peppers. Blossom end rot has been found on green bell peppers (Photo 1). Management of blossom end rot is dependent upon maintaining adequate supplies of moisture and calcium to the developing fruits. Sunscalded peppers were also visible in fields. Processing tomato harvest has begun over last weekend. Market tomatoes are in sufficient supply with good quality. Etherel application is in progress in many processing tomato fields. Whiteflies have been found in cherry and heirloom tomatoes. Early blight symptoms found in some fields. Potatoes continue to be harvested for market and processing. Alternaria early blight symptoms have been found in few vines. Potatoes are in good demand, especially for processing. There was one variegated cut worm on the trap. |
 Photo 1, blossom end rot in pepper |
| August 6
Weather 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 670F - 830F.
According to the Enviro-weather station in Dundee the total estimated
evapotranspiration rate for this past week was 1.71 inches. That is a 0.32
inches increase from last week.
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 ECB and one CEW 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 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. Very little disease and insect pressure in this crop. Variegated cut worm trap had 11 moths present. |
 photo 1 pumpkin phytophthora stem rot
photo 2 drought-stressed peppers |
| July 30 Weather Last week's dry
weather continued all week long. Every one is looking towards a rain. Most
of the growers irrigated this past week especially for maturing potatoes.
Soil temperatures ranged from 66°F - 83°F.
According to the Enviro-weather station in Dundee the total estimated
evapotranspiration rate for this past week was 1.39 inches.
For sweet corn planted early under tunnels, harvest is over. Other fields’ sweet corn is in different growth stages to harvesting. There is European corn borer damage in some fields. I could see nitrogen deficiency in sweet corn on sandy soils. It could be the impact of early July rain followed by the dry weather which has caused substantial leaching and denitrification on sandy soils. There is some uneven corn growth and development due to dry soil conditions. I haven’t found any European corn borer or corn ear worm in traps. Cucumber, squash, zucchini and melon harvest is going on. Downy mildew situation is stable. Vine crops are showing stress towards the dry weather with smaller fruit sizes. Melons have good fruit size and quality. Squash bug eggs and nymphs (Photo 1& 2) found on zucchini plant. Powdery mildew was found in butternut squash, yellow squash and pumpkin (Photo 3). There was one squash vine borer in the trap. Peppers are in good quality. Fresh market peppers continue to be harvested and marketed this week. Colorado potato beetle was found in moderate numbers in eggplants. Eggplant fruit was also injured by the Colorado potato beetle. Cabbage pythium stem rot was found on a cabbage field. Tomatoes are continued to blossom and set fruits. Fruit loads are heavy. Heirloom tomatoes are still growing taller. Very low disease pressure from fungal pathogens but bacterial diseases are present in few plants. Potatoes started to mature. Few vines are senescing and most vines are remaining green. Early planted potatoes have started harvesting this past week. Fields are getting an average yield of 400- 450 cwt/acre at this point. Tubers sizes are in the range of 8 -11 inches in circumference (Photo 4). There were 10 variegated cut worms found in the trap. |
Photo 1 squash bug eggs
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| July 23 Weather
It was dry during the past week. Humid conditions have provided conducive
environments for disease development and spread. MAWN weather station in
Dundee received a total rainfall of 0.14 inches. Soil temperatures ranged
from 700F - 840F. Relative humidity averaged 78.76 for this past week.
Sweet corn is silking in many fields and also harvest is going on in early planted fields. There was some fall armyworm feeding on harvestable sweet corn ears. Japanese beetles are every where. They are present in the fields of sweet corn, cucumbers, peppers and tomatoes. There wasn’t any European corn borer or corn ear worm in our traps during past week. Cucumber picking is going on. All the commercial growers are on continuous spray schedule to restrict further spread of downy mildew. Cucumber beetles (Photo 1) are present in many fields in moderate numbers. Pumpkins are having a very good growth. Cantaloupe and melons are harvested this week. There were few corn borer type injuries on mature melons and cantaloupe fruits. I found one Squash vine borer in the trap. Cabbage harvest is in full swing. I have seen sclerotinia (white mold) symptom on fully formed heads of cabbage (Photo 2). Cabbage planting is continuing on the fields were sweet corn is harvested. I have learned from many growers that it will continue beyond this week. Green bell peppers and Hungarian peppers are maturing for harvest. European corn borer feeding was evident on some green bell peppers. Harvest of market tomatoes began this past week. I saw symptoms of bacterial speck/spot (Photo 3) in the vines of the staked tomatoes. Processing tomatoes are looking good although many plants lost some flowers during the cool nights of this season. Potatoes are growing well with green vines and completing canopy closure. Not much disease pressure at this time. Colorado potato beetles are found in mild to moderate numbers in Monroe and moderate to heavy numbers in the Washtenaw area fields. There were 16 variegated cutworm moths found in our trap. |
 Photo 1 cucumber beetles
Photo 2 White mold on cabbage
Photo 3 Bacterial spot/speck on tomato leaf
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| July 16 Weather We had dry weather
with some widespread rains during the past week. There is some water damage
in pepper, potatoes and cucumber fields. According to the Enviro-weather
station in Dundee, we received a total rainfall of 1.34 inches during the
past week. Soil temperatures this last week ranged from 52°F to 86°F.
Crop report Sweet corn harvest is moving into full swing this week. In some of the late planted sweet corn fields, thrips feeding is evident on fully emerged leaves. It was interesting to see that the thrips population was only noticed at this particular growth stage of sweet corn. Our European corn borer traps didn’t find any moths this past week. However, I did find one corn earworm moth in the corn earworm trap. Peppers are maturing well. Preliminary rounds of harvesting are going on in fields. Green beans are in high demand and the crop is in excellent condition. Cucumbers, melons, cantaloupes, pumpkins and squash are maturing. The first few rounds of picking are progressing in cucumber fields. Cucumber downy mildew is spreading (Photo 1). I have seen symptoms in a few more fields this week. Home gardeners also started to bring samples to our office. Let me remind everyone how important it is to follow the spray schedule recommended by Dr. Mary Hausbeck to minimize yield impact. Squash vine borer was found in a pumpkin field (Photo 2). There were four squash vine borers found in our trap. Cauliflower is being planted in fields where sweet corn has been harvested. Cabbage packing and wholesale sales are gaining momentum. Area growers are busy with the shipping of harvested crops. I was at a growers harvesting site this week and it was impressive to see the excellent quality of cabbage and cauliflower from the region. Greenhouse grown and field market tomatoes are being harvested. Processing tomatoes are making good growth. Vines are maturing and the fruits are setting a good quality fruit (Photo 3). Potatoes are also looking good. Canopy closure and tuber bulking is forming at a fast pace. Very few leafhoppers were found in many potato fields. I have found 10 variegated cutworm moths in our trap. |
 Photo 1Downy mildew on cucumber leaf
Photo 2 squash vine borer, adult moth
Photo 3 Processing tomatoes |
| July 9: Weather
We have received plenty of rain in the past two weeks. There are some wet
pockets in most fields with dying plants. According to the Enviro-weather
station in Dundee we received a total rainfall of 4.18 inches during the
past two weeks. I have heard from several growers that received from 1 to
4.5 inches of rain. Soil temperatures this last week ranged from 44°F -
88°F.
Sweet corn is making very good growth. Harvest has begun in some early planted under tunnels fields. In general, most of the fields are in silking stage. Many growers expect to begin harvest next week. Peppers are looking good. Most plants are setting very good fruit. Some farmers have started to harvest. There is some water injury to peppers in the low lying areas of many fields. Cucumber fields are developing well although cucumber downy mildew was identified last Wednesday in one local field. Since we are in a period of high precipitation, a weather pattern which is very conducive for spore development, growers need to pay a close attention to restrict further spread of the disease. Cucumber beetles are present in many cucumber fields. Pumpkins, melons and squashes are improving. Pumpkins have flowers in many fields. Market tomatoes are just starting to be harvested and have very nice fruit quality. There is good fruit load in many early planted market and processing tomato fields. There are not any severe insects or diseases present at this time. I saw two processing tomato fields with herbicide drift appeared to have come from adjacent glyphosate resistant corn fields. Potatoes are in a variety of growth stages from maturing vines to tuber settings. I have seen some early symptoms of rhizoctonia (Photo 1) on some table stock varieties. Colorado potato beetle (Photo 2) activities have been found in several fields. Most of them are in high numbers and growers are following spray schedules. |
 Photo 1. Symptoms of rhizoctonia on table stock variety potatoes.
Photo 2. Colorado potato beetles found in several potato fields. |
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July 3 Special alert to cucumber and melon growers! Dr. Mary Hausbeck's technician has found the beginnings of downy mildew on a few leaves of Cucumber yesterday (July 2, 2008) in Monroe. At the lab they determined the leaves were sporulating which indicates the disease is present. Growers, who have been on high alert, now should follow the control recommendations as soon as possible. Click HERE for Mary's article with the recommendations. Also below is the link to Dr. Hausbeck's web page http://plantpathology.msu.edu/labs/hausbeck/ForGrowers.html If you need help in identification or tissue sampling, please don't hesitate to contact me smathew@msu.edu |
 Sporulating Downy Mildew on cucumber leaf. |
| June 25 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.
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. |
| June 18 Weather: This past week
we had some mixed weather with cool winds, isolated showers and dry
conditions. According to the MSU weather station in Dundee, we received a
total rainfall of 0.52 inches during the week. Field temperatures were in
the range of 48°F to 85°F. There were some wet pockets from last week’s
rain, but they didn’t damage the vegetable crops. It could be possible that
the nitrogen and potassium may have leached out in the area where sandy
soils are more prevalent.
Early planted sweet corn, which was under tunnels, is progressing beyond silking. Silks are turning brown and forwarding to the ear filling stage. Developments vary greatly across the region according to the planting dates and management practices. Sweet corn that had frost injury two weeks ago has recovered well from the injury and made a phenomenal growth (Photo 1 and 2). Early open field planted sweet corn is now at tassel emergence. European corn borer in our traps averaged 12 moths per trap this week. European corn borer larva and eggs are both present in local fields. Processing tomato planting is nearing completion. Early planted tomatoes are blossoming and bearing to set fruit. There was one Sencor® (metribuzin) herbicide injury symptom reported on transplanted tomatoes on sandy soils (Photo 3). Several growers report tomato processors have been seeking additional acres in Michigan the last several weeks due to heavy losses in southern Indiana from continued rainfall. Peppers are looking great across the region. Vine crops are developing well. No downy mildew symptom has been found yet at any cucumber fields. Spotted cucumber beetle was found at a pumpkin field (Photo 4). Colorado potato beetle injuries were found at an eggplant field (Photo 5). The grower made an insecticide application and it is under control. Potatoes have a variety of development going across the region from emerging to blossoming. Many growers have completed hilling. Optimal hilling time in recent years is to have a couple weeks after emergence to reduce root damage to prevent soil-born diseases. Repeated hilling is not recommended unless heavy winds or rain damages hills to a great extend. |
Photo 1 and 2
Photo 3.
Photo 4. Photo 5. |
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June 11
Weather
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 Photo 1- Sweet corn progressing to the silking stage
Photo 2 - Downy spore traps monitoring system |
| June 4 The
cool and dry weather of the past weeks came to a halt with 0.52 inch rain
yesterday. Absorption was quicker because of much drier soils in our area.
Temperatures were in the 32°F-83°F range during the past week.
Sweet corn fields are making progress in growth. Early planted sweet corn in plastic mulch and tunnel combinations is well advanced and made impressive growth. It was interesting to see how last week’s frost had a more serious impact on sweet corn (Photo 1) than peppers in the same field. Damage appeared worse in higher areas of the field with lighter soils. Much of the damage was on new leaves where the corn was at emerging tassel stage. One sweet corn field I visited this week that has been rotated following soybeans has a serious Japanese beetle grub problem. This week there were no European corn borer moths in my ECB pheromone traps. Tomatoes, cucumbers and peppers didn’t show much frost damage symptoms. Early planted zucchini will be at harvest this week. Early planted cabbage has developed good heads and harvest has started in some fields. Cabbage root maggots (Photo 2) were found at several cabbage fields. Potatoes are developing in our area with good stand, color and vigor. This week I found low numbers of potato leafhoppers (Photo 3) in a potato field. Though it was below the threshold level, it was interesting to see leafhoppers this early. I think the strong winds of the past week may have helped their travel. |
 Photo 1. Sweet corn frost damage
Photo 2. Cabbage root maggots
Photo 3. Potato leafhoppers. |
