Cutworms may be a problem |
Watch new vegetable transplants and seeded crops when barley intercrops are killed off. Cutworm larvae can overwinter as adults and feed on a variety of weeds and crops. When fields are tilled and new transplants put in, damage can occur within the first several days. Growers should check fields carefully after transplanting or after killing off intercrops. Look for cut-off plants and dig around in the top one-inch of soil to find larvae. Apply insecticide treatment immediately if damage and larvae are present. If treatment is needed, see Michigan State University
Extension bulletin E-312, Insect, disease, and nematode control
for commercial vegetables, available in hard copy from local
MSU Extension county offices or on line at: |
Seed corn maggot may be a problem in cool, wet soils |
In cool, wet soils, especially when seed germination is delayed, seed corn maggot may attack seeds or seedlings and damage or kill plants. Seeds most commonly attacked are cucurbits (cucumbers, melons, squash, pumpkins), beans and corn. An insecticide seed treatment applied before planting is recommended if this is available on your crop. Lorsban 50SL is registered for beans (many types), cucumbers, pumpkins, and sweet corn. In furrow applications may also be available and provide control, but may not be cost-effective unless there are other pests also targeted for control, such as striped cucumber beetles. For treatment options, see Michigan State University Extension bulletin E-312 at: http://web4.msue.msu.edu/veginfo/bulletins/E312/index.htm |
2004
|
Late blight was confirmed in three locations in July 2003 and on tubers in October. Further reports in the north central region were limited and sparse. However, the risk of potato late blight is always foremost in crop protection programs. Previous versions of the full recommendations for late blight control, which still apply, may be viewed at http://potato.msu.edu. In this note, only a summary of the recommendations is presented. In 2003, other diseases and disorders making news were increasing levels of black dot, early blight, common scab and white mold. Stem canker, caused by Rhizoctonia solani, is also becoming prominent. Studies at MSU have shown that varieties currently grown commercially are highly susceptible to late blight. Atlantic, Snowden, FL1879 and Pike are moderately susceptible but require an intensive fungicide application program. Computer programs are available that calculate disease severity values for both late blight and early blight based on weather data obtained within the crop. Michigan State University Late Blight project maintains a web site (http://potato.msu.edu) on which weather data and severity values are reported through the season from potato growing areas in Michigan. Recommendations for fungicides use rates and frequency of applications are given for all regions of Michigan. These (and other) trials form the basis of the recommendations for late blight control programs for 2004. In situations where disease is present, recommendations for the control of disease in combination with crop destruction practices are shown in Table 1. MSU Extension recommends that disease loci in crops be destroyed with Reglone and treated with fungicide (Supertin or Agritin (TPTH) 80WP) until the loci are completely dead. Recommendations
In seasons when the severity of weather conditions would not favor severe late blight development, programs based on chlorothalonil (e.g. Bravo WS 6SC, Echo 6SC, Equus 6SC or other formulations), EBDC (e.g. Dithane 75DF, Manzate 75DF, Manex 4FL, Penncozeb 75DF, Polyram 80WP) will reduce the risk of the establishment of the disease. The addition of TPTH 80WP to any of the protectant programs would enhance disease control particularly towards the end of the growing season. (TPTH 80WP has a seven-day pre-harvest interval, also note maximum use rate for 2004 is 11.25 oz per season). Fixed copper-based products (such as Champ and Kocide) can also be used in protectant programs. These products are best used early in programs or immediate post-harvest for killing spores perhaps from adjacent crops and should always be applied at the full recommended rate of application. The observations of individuals responsible for implementing programs should determine when best to change from one product to another. Of major note for 2004 is that the Fungicide Resistance Action Committee (FRAC) have specific recommendations for mixing fungicides with high risk of resistance development. Fungcides are now labeled with a Group number e.g. Headline, Tanos, Amistar, Gem are all Group 11; these fungicides should be not mixed or immediately alternated in a fungicide-based protectant program. The application of these fungicides as stand-alone products has never been recommended by MSU for late blight control. They should always be mixed with a protectant surface residual fungicide. The appropriate placement of translaminar and other systemic products within programs is determined by the mode of action of the product in relation to host and disease development, but all products are best used within a preventative protectant program. For example, Previcur, Acrobat, Amistar (formerly Quadris), Headline or Curzate may be applied to protect new growth early in development, Curzate and Previcur may be applied while the canopy is expanding but before senescence and Acrobat is most effective as a post-senescence product and can be applied up to late crop senescence. Recommended programs for late blight control are
not straightforward. The product of choice may well depend on how
and from where the disease has developed. Some possible scenarios
are shown in Table 1 where a range of containment procedures is
described for different variety types and different levels of disease
in the field. Acknowledgments to MPIC, Robert Schafer and Ron
Gnagey. Also to all sponsors of the late blight research program
at MSU. |
Table 1. Suggestions for appropriate fungicides for late blight control including semi-systemic fungicides under different late blight conditions in susceptible potato varieties.
Disease category |
Late maturing especially storage varieties |
|
No senescence - early senescence |
Mid - late senescence |
|
a) none |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC or Chlorothalonil Chlorothalonil (various + ZN) Quadris or Headline + EBDC or Gavel or chlorothalonil |
Curzate or Tanos or Acrobat or Previcur Flex + Supertin/Agritin+ EBDC or chlorothalonil Chlorothalonil or Gavel (various + ZN) |
b) few random lesions even distribution throughout field (0 - 1% foliar infection) |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC or Chlorothalonil fb EBDC+TPTH or Chlorothalonil + TPTH 5day fb Chlorothalonil (various + ZN) or Gavel |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC or Chlorothalonil fb EBDC+TPTH or Chlorothalonil + TPTH 5 day fb Chlorothalonil various + ZN) or Gavel |
c) one or more (up to 5) loci spreading from the edge of the field or from several centers within the field (1% overall field infection but locally heavily infected plants 5 - 10%) |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC or chlorothalonil kill infected area with Reglone**** fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC +TPTH kill infected area with Reglone fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead |
d) partial crop infection large areas infected with up to 20% loss of GLA evenly distributed throughout the field or large areas of the field |
Curzate or Tanos or Acrobat or Previcur Flex + EBDC+TPTH Chlorothalonil (various + ZN) + TPTH kill infected area with Reglone fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead
|
Curzate or Tanos or Acrobat or Previcur Flex + EBDC + TPTH Chlorothalonil (various + ZN) +TPTH kill infected area with Reglone fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead |
e) 20-100% crop infection with large loss of GLA*** |
kill infected area with Reglone fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead |
kill infected area with Reglone fb EBDC+TPTH or Chlorothalonil + TPTH every 5 days until vines dead |
fb followed by; GLA Green Leaf Area
Transitioning to drip irrigation |
Even though the month
of May has so far been very wet, this should not distract us from
getting ready for irrigation. During the last few years, vegetable
growers have experienced severe drought stress, especially during
the months of June and July. This year the equation may be even
more complicated because the new irrigation water use GAAMPs (Generally
Accepted Agricultural and Management Practices) are likely
going to put more pressure on vegetable growers. As a result, some growers are seriously thinking of transitioning
at least part of their acreage to drip irrigation. The advantages of drip
irrigation include: § Reduced water use (water is placed directly near plant roots) § Reduced disease problems (leaf wetness is minimized) § Low weed pressure § Reduced fertilizer input with fertigation § Compatible with bareground or plasticulture system With drip irrigation, water is usually pumped from the original source (well, lake, pond, municipal line, pit, stream or river) into the main line. This water travels to the layflat, then to the drip tube or tape where it is delivered to the crop through tiny openings called drip emitters. Any substance such as dirt, bacteria, algae, aquatic life or chemical precipitation of compounds in the irrigation line will ultimately clog the system, especially drips emitters. Laying the drip tape (drip tube) Flushing the system 1) Leave the ends of the main line (layflat) opened; 2) Flush the main line first; 3) Shut down the water and close the end of the main line; 4) Flush the drip tapes; 5) Shut down the water and close the ends of the tapes. Preventing system clogging Using filters |
What's happen to applied nitrogen? |
With the recent stretch of rainy weather, some being quite heavy, there is concern about what has happened to the nitrogen that was applied prior to planting. In areas where rainfall events have exceeded three inches, topdressing or sidedressing additional nitrogen (25 to 40 lb/A) will most likely be beneficial for plant growth. The best way to know the available nitrogen status of the soil and how much additional nitrogen to apply is to soil sample and have it tested. Most soil testing labs are able to provide the soil nitrate test results within 48 hours of receiving the sample. For the soil nitrate test it is important to dry the soil sample as quickly as possible. Soil temperatures have been sufficiently high for nitrogen applied in the urea or ammonium form to be readily converted to the nitrate form. The nitrate form of nitrogen is subject to loss by leaching or by denitrification. Leaching of the soil occurs when rainfall exceeds the amount of water the soil can hold. Once a soil is saturated, each inch of rain that infiltrates into the soil has the potential to move the wetting front downward three to five inches in sandy loam to sand soils. As water moves downward through the soil it carries soluble nutrients, especially nitrate, with it. In a sandy loam soil that is at field capacity, each inch of rain may move the nitrate downward 3 inches. However, the nitrate equilibrates with the soil solution as it moves so it isn't completely leached. Past field monitoring has shown that a rainfall of three or more inches of water may move a significant amount (25 to 50%) of nitrate below the active rooting zone, especially if the soil is already near its moisture holding capacity. When plants are small with a limited root system, any nitrate moved below six inches may be temporarily out of the root zone. As roots grow deeper some of the leached nitrate may be recovered. Significant amounts of nitrogen may also be lost by denitrification from soils that are saturated or near field capacity. When oxygen is limited in the soil, microorganisms use the oxygen in the nitrate molecule converting it to nitrous oxide or nitrogen gas. This process is referred to as denitrification. A source of organic carbon is needed for this process to occur. Therefore, denitrification will occur to a lesser degree in low organic matter sandy soils than in loamy soils with 2 to 3 percent organic matter. In organic soils denitrification can be more significant than leaching. |
How to take a PSNT soil test |
The Pre-Sidedress Nitrate Soil Test (PSNT) is most
widely used in field corn production, but is adaptable for use in
other field crops and vegetables. The PSNT is useful for determining
how much N is available in the soil just prior to sidedressing.
Soil microorganisms are continually feeding on organic matter and
crop residues in the soil. Nitrogen is released during this process
and becomes available to the plants. This nitrogen can be measured
and used as a credit against the total N requirement of the crop.
Timing Priority fields to test Cautions Taking the sample The PSNT in Michigan is based on the nitrate content of the top two feet of soil. It is recommended that soil cores be taken to a depth of 12 inches. The nitrate content of the 13- to 24-inch depth is estimated based on the content of the top 12 inches. Handling samples Delivering samples to the lab Using the MSU Soil and Plant Nutrient
Lab Expected return for your time
investment |
Section 18 label for Spartan 4F on strawberry in Michigan for 2004 |
The EPA has approved a Section 18 emergency label for use of Spartan 4F herbicide on strawberries in Michigan for 2004. Spartan may be applied at renovation from June 25-July 25, 2004, or at dormancy, after October 15 through December 15, 2004. Apply 4 to 8 fluid ounces of Spartan 4F (0.125-0.25 lb active ingredient) per acre per application. Apply in 20 to 40 gallons water per acre. A maximum of 12 fl. oz (0.375 lb ai) may be applied per acre per season. Spartan will control many broadleaves and grasses, including common groundsel, field pansy, mayweed chamomile, redroot pigweed, white campion (cockle) and yellow woodsorrel. It also will give some suppression of yellow nutsedge. The label should be available from chemical dealers, or may be downloaded from the vegetable AOE website, web1.msue.msu.edu/vegetable/. The label must be in the hands of applicators at the time of application. |
New Ag Network offers organic growing information |
Curious about organic farming practices? You can
read current season information at a new web site housed at Michigan
State University: This new reference site is designed for organic farmers and those considering transitioning to organic practices. The site was created and is maintained by a tri-state Extension team that includes specialists from Michigan State University, Purdue University and the University of Illinois. Named the New Agriculture Network, the site features a semi-monthly newsletter. Twice a month during the growing season a team of organic growers share crop updates and advice with Extension personnel from the three universities to generate information for the newsletter. University specialists also write articles about a variety of practices and new findings useful for organic growers or those wishing to transition to organic practices. The result is an online newsletter with a library of resources that can be read on the Internet or printed and distributed. Dale Mutch, MSU Extension specialist at MSU's Kellogg Biological Station who headed the network's development said, "The purpose of the site is to provide biological, non-chemical and long-term, science-based, research information to organic farmers. The network will bring farmers and researchers together to identify areas for future research." Initially, the site will only include information related to field crops and vegetables, but may expand to include other commodities later. The Network's homepage includes a link to sign up for email notification when new issues are available online. Information at the web site is edited and posted by the same communication team that oversees the CAT Alert newsletters - MSU's Integrated Pest Management Program. The site is already doing its own growing - Iowa State University recently offered to join the Network and will be contributing information beginning in June. Funding to establish the New Agriculture Network was provided by the American Farmland Trust and the Environmental Protection Agency. |
Regional Reports |
1 - SW Michigan Research and Extension Center |
Weather Commodity reports Asparagus harvest continues. Quality is variable depending on weather at harvest. Asparagus beetles continue to be active. Little change in other crops at this time. |
2 - Grand Rapids Area |
Weather Commodity reports
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4 - Mason-Newago Counties |
Weather Commodity reports Growers were able to get in the field and plant celery in Grant. The earliest carrot plantings are at third true leaf. An herbicide was applied yesterday (May 17) to kill barley windbreaks. With wet spots in carrot fields, growers will have crop damage. The extent cannot be determined at this time. Asparagus harvest continues and growers are hard pressed to keep up due to some above normal temperatures, excess rain and a tight labor supply. Asparagus beetle eggs were reported but no beetles. Cutworm damage is evident. There is also lots of purple spot. Even with all the rain, there seems to be a certain amount of undersized spindly spears. Harvest of the first field of overwinter spinach began over the weekend. Spring plantings generally look good given all the rainfall with some washing and standing water in some fields. We need soil to dry to get into fields and apply fertilizer. |
7 - Southeast |
Weather Commodity reports Carrot planting is nearly complete in the Imlay City
area. Leaf lettuce on plastic is nearing harvest for retail
markets. Cole crops are making steady progress. No root maggot
damage is visible yet. In sweet corn, the first several plantings of SE's have emerged evenly in most fields.
Sh2 cultivars may not be emerging quite as well, falling
prey to seed corn maggot in the wet soil. There are a couple of
reports of late seed delivery. I saw a
field of snap beans in the seed leaf stage that had emerged very well. Growers are watching
for leafhoppers to appear. Tomatoes, peppers and melon transplants are being hardened off on wagons. A small percentage has been planted but most growers are waiting for drier soil conditions. |
Weather news |
While one more day of fair, dry weather is likely across Michigan on Wednesday (May 19), changes are in store by Thursday and Friday with the return of an active weather pattern similar to last week's. High pressure over the state Wednesday morning will move eastward into New England by Thursday, while another frontal system currently over the northern Rockies will approach from the west. The frontal system will trigger the chance for showers and thunderstorms statewide, first in sections of the Upper and northern Lower Peninsulas by late Wednesday evening and statewide on Thursday. Best chances for rainfall during the next 24 to 48 hours will be across southern sections of the state, where some severe thunderstorms are a possibility Thursday afternoon and evening. Similar to the weather pattern of last week, the next frontal system is expected to linger in the region with continued chances for rainfall almost every day Friday through next Monday. High temperatures will range from the upper 50's and 60's north to the 70's to near 80 south with lows in the 40's north to 50's south. Maintaining continuity with the short term forecast above, the medium-range forecast guidance calls for very active weather pattern for late May with upper air troughing across the western US and broad ridging across the east, resulting in an active storm track through the Midwest (somewhat similar to the synoptic weather set up last week). For both the 6-10 day and 8-14 day time frames, covering May 24-28 and May 26 - June 1, the NOAA CPC outlooks call for above normal precipitation totals state- and region-wide. Temperatures are expected to fall back to below normal levels during both time frames. Given some disagreement amongst some of the numerical forecast guidance tools, forecaster confidence in both outlooks is considered lower than normal. |