When one uses a soil insecticide it is important to remember that protection of the primary portion of the root system from larval attack is the goal. Also, one needs to understand that products do not provide 100% control and occasionally some damage may occur depending on the larval population, weather, product performance, planting date, plant development, and time of larval hatch. All of these factors can ultimately impact product performance and must be considered when using a soil insecticide. The important thing for producers to understand is the positive and negative aspects of each product, and determine which one(s) fits best under their farming system. Also, one needs to understand what the warranty for each product really means. Additionally, it makes sense to have untreated check strips in fields to gauge the performance and economics of the products used.
The following guidelines, formulated from 2001 research and observations, should be taken into consideration when making rootworm management decisions for 2002 corn following 2001 soybean.
Northern Indiana (approx. north of Interstate 70):
Southern Indiana (approx. south of Interstate 70):
The 2001 revision of the Seed Corn Pest Management Manual for the Midwest (IPM-2) has been dramatically improved to aid field personnel in crop troubleshooting, field scouting, and pest identification in seed corn production fields in the Midwest. This manual contains descriptions, scouting procedures, and management guidelines (just developed) for the major insect, weed, disease, nematode, and vertebrate pests of seed corn. A problem diagnostic guide, as well as keys to the identifcation of insect and weed pests are also included. Nutmerous color and black and white pictures, and line drawings have been added to aid the user in pest identification and diagnosis. The Seed Corn Pest Management Manual for the Midwest can be purchased through the Media Distribution Center at Purdue University <www.agcom.purdue.edu/AgCom/Pubs/index.html>.
With new pre-applied insecticide seed treatments available for corn, producers have been asking questions about the validity of using such products. At this time, we are not recommending using seed applied insecticides for corn rootworm control, i.e., Prescribe® and ProShield® in areas where risk to rootworm injury to corn is high. This is because of the inconsistencies that have observed in university trials throughout the Midwest. For producers in areas with low to moderate rootworm pressure, these seed treatments may be beneficial and may also offer protection from other soil insect pests, e.g., wireworms, seedcorn maggots, etc.
Industry and university trials have shown some promising results with Cruiser® and Gaucho® against wireworms and seedcorn maggot. The systemic activity of these products results in some early suppression/control of corn flea beetle as well, although this insect is not a major pest of yellow dent corn. Certainly the biggest question for producers and researchers is how effective these products are against white grubs. Limited trials have shown a mixed bag of results, as is true with many granular soil insecticides. Most likely there will be some suppression of grubs, but not control.
Should one use the pre-applied seed treatments where rootworm is NOT a consideration? There is no simple answer. Return on investment of seed applied treatments will improve if:
Below are rootworm efficacy trial results for pre-applied insecticide seed treatments from Indiana, Illinois, and Iowa for 2001:
In response to a severe drought in 1988 that resulted in high levels of aflatoxin in the Indiana corn crop, Purdue University launched a program in 1989 to survey Indiana corn fields to determine the level of pre-harvest ear rots and mycotoxins. Each year, the Indiana Agricultural Statistics Service (IASS) selects the fields to be sampled and two sites within each field are sampled during the fall prior to harvest. Samples consist of the primary ears from five consecutive plants in a single row. The ears with the husks intact are placed in cloth bags and mailed to Purdue University. Upon arrival, the husks are removed and the ears examined for ear rot symptoms. Each year, we examine samples from about 160 fields. Data are recorded for the percentage of kernels with symptoms of the following diseases: Fusarium ear/kernel rot, Gibberella ear rot, Aspergillus ear rot, Diplodia ear rot, and ear rots caused by Alternaria, Nigrospora, Penicillium and Trichoderma. Samples having disease severity of 10 percent or greater are tested for mycotoxins (aflatoxin, ochratoxin, zearalenone, deoxynivalenol and fumonisin) by the Animal Disease Diagnostic Laboratory at Purdue.
The 2001 survey is nearly complete, and as a general assessment, the Indiana crop looks excellent. We have examined 1455 ears from 291 samples. No sample had more than 5 percent ear rot. The incidence and severity of Fusarium ear/kernel rot was low. We have seen a decline in this disease in our survey since the severe outbreak of 1991. We expect no problems with fumonisin contamination in the 2001 corn crop. However, we are analyzing 20 samples for fumonisin, because fumonisin contamination does not always correlate with disease severity. The incidence of Diplodia ear rot in our survey was also low. Last year, the disease was found in 55 samples from 30 of the 60 counties surveyed. This year we observed just six samples with Diplodia ear rot, which is similar to what we observed in 1997, 1998 and 1999.
Keeping an eye on ag. chem. companies is almost a full time job in itself. In the past several years weed science has seen an ever decreasing number of companies due to what has been called “merger madness.” I thought that for that last Pest&Crop issue for the year a little run down on which primary companies are still here and some scoop on new products would be interesting.
In the domestic arena, we have Dow AgroSciences, DuPont, FMC, and Monsanto. In the foreign owned arena there are Bayer-Aventis (acquisition still in the works),BASF, Syngenta, and Valent. Annual sales reported by these companies rank them in the order Syngenta, Bayer-Aventis, Monsanto, DuPont, BASF, and Dow AgroSciences.
Some of the products listed below may have been available this year. If you are familiar with them, then this will be just a reminder.
Two products introduced this year are Outlook and Guardsman Max. They both contain the active isomer of Frontier (dimethenamid). However, Guardsman Max has the addition of atrazine. In the Gaurdsman Max, the rate of dimethenamid-p has been decreased from the Guardsman to 1.7 lb ai./gal and atrazine has been increased to 3.3 lb ai./gal
Outlook can be used PRE in corn (field, popcorn, sweet and seed), soybean, grain sorghum, dry beans, and peanuts to control annual grasses, some annual broadleaves and sedges. Outlook is a 6 lb ai/gal EC formulation and has a 10 to 21 fluid oz/A use rate.
Guardsman Max is labeled to be used PRE in field corn, popcorn, sweet corn, seed corn, and grain sorghum. Due to the mix with atrazine, Guardsman Max is a restricted use product. Also because of atrazine, the use rates are soil specific. See label for rates for your soil type.
Three products obtained fall application labels for soybeans, Canopy XL (sulfentrazone + chlorimuron ethyl), Express (tribenuron methyl), and Basis (rimsulfuron + thifensulfuron methyl).
Fairly new product called Steadfast consisting of 50% nicosulfuron and 25% rimsulfuron. It is labeled for POST residual grass control and broadleaf suppression in field corn at a rate of 3/4 oz/A. However, be aware that it has a 12” corn height restriction.
DuPont has dropped the production of Canopy (metribuzin + chlorimuron ethyl) and Pinnacle (thifensulfuron-methyl). However, the soybean uses have been added to Harmony GT label to fill any gap.
Soybean has been added to Aim’s (carfentrazone) label. It now has a label for corn (field, sweet, pop, seed and silage), soybean, grain sorghum, rice, wheat, barley, and oats. Soybean applications can be made 30 days prior to planting up to the third trifoliate at rates of 1/3 to 1 oz/A.
Command Xtra, composed of Command (clomozone) and Authority (sulfentrazone) packaged separately as a “B” and “G” co-pack, is labeled for PRE in soybeans. This is being marketed as a “one-pass” PRE program.
Gauntlet which consists of Authority + FirstRate (cloransulam) also in a co-pack is labeled for PRE control of grasses and broadleaves in soybean.
A new formulation of Touchdown, being termed “IQ Technology” is expected to reduce yellow flash in RR soybean. This will contain 3 lb glyphosate acid/gal and will be labeled for several situations including glyphosate tolerant soybean and corn.
Gramoxone Extra’s 2.5 lb ai/gal (paraquat) has been concentrated a little to a 3 lb ai/gal, so be aware of the rate changes. The new product, available last year, is called Gramoxone Max. This is a restricted use herbicide.
Last, but definitely not least in Syngenta’s new products list is Callisto. With a new compound called mesotrione (4 lb ai/gal) it is being marketed as a PRE and POST in field, seed, and silage corn. Mesotrione works by inhibiting the HPPD enzyme in plants, which in general terms causes a bleaching effect. Callisto can be applied alone at 6 to 7.7 oz/A PRE or 3 oz/A POST. Callisto can be applied to corn up to 30” tall or to the 8 leaf stage. Do not apply to pop, sweet, or ornamental corn. Atrazine can be tank mixed with Callisto to broaden control. Callisto rates decrease a little and atrazine use restrictions apply.
Callisto has good control (80% and up) of pigweed, lambsquarters, velvetleaf, tall waterhemp, and common ragweed, with fair (60 to 70%) control of morningglory species, common cocklebur, and giant ragweed PRE. POST applications show better control of morningglory and giant ragweed.
United Ag. Products
Mirage, a 4 lb ai/gal formulation of glyphosate, has been labeled for glyphosate tolerant soybean and corn varieties.
Valent has two new products, Valor (51% flumioxazin) and Pheonix (lactofen). Valor has been labeled as a PRE in soybean. Valor has good control (80% and above) control of pigweed, lambsquarters, velvetleaf, black nightshade, tall waterhemp, jimsonweed, and common ragweed. Valor provides fair control (60% - 70%) of morningglory and cocklebur. Rates are soil specific and the label should be consulted for you situation.
Phoenix is labeled as a POST in soybean. A new surfactant system results in less of the soybean injury that was sometimes seen in Cobra. Formulation is a 2 lb ai/gal EC, using a rate of 8 to 12.5 oz/A + NIS (0.25%). Phoenix is most effective on smaller weeds and has good waterhemp activity.
Armyworm Can March Through Corn-7
Armyworm in Wheat-8
Armyworms Marching Big Time, This is NO Parade-9
More “Worm” Reports-9
Armyworm…Get out the Camera, You May Never See This Again! –10
Armyworm, Natural Control to the Rescue? –11
Lots of Moths, They’re Likely Armyworm-12
All Quiet On the Armyworm Front-14
Bean Leaf Beetle
Black Light Catch Report
Corn Flea Beetle
European Corn Borer
Southwestern Corn Borer
You can Track Heat Units for Black Cutworm in Your Area-6
Transgenics and Cross-Pollination-A Problem? -3
Heat Unit Accumulations, Indiana Weather Summary and Heat Unit Forecasts appear in most issues of the newsletter.