AgSolutions Advisor. Strategies for Sustainable Chemfallow Applications. April 2013

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1 AgSolutions Advisor April 2013 Strategies for Sustainable Chemfallow Applications Rotating herbicide modes of action helps manage glyphosate resistance. Written by: Bryce Geisel Glyphosate is one of the most important herbicides used on chemfallow in Western Canada. However with the evolution of herbicide-resistant weeds, glyphosate resistance is becoming a bigger concern. Volunteer, glyphosate-resistant crops can be a problem to control in chemfallow and will potentially continue to be a problem in the future. In 2011, glyphosate-resistant Kochia was found in Southern Alberta. Managing glyphosate-resistant weeds has been an issue in other parts of the world, however this was the first confirmed glyphosateresistant weed in Western Canada. Glyphosate-resistant Kochia complicates the options for control because it is also resistant to Group 2 (ALS) herbicides. Growers concerned with glyphosate-resistant Kochia need to be diligent in looking for products with alternative modes of action to control the resistant biotypes. Growers also have to be aware that multiple applications of glyphosate alone increase the selection pressure for developing glyphosate resistance in other weed species. Growers should also be mindful of other herbicide-resistant weeds growing in their fields. If Group 2 resistant weeds are present and the grower is topping up glyphosate with a Group 2 product, that puts as much selection pressure on those weed species as a straight application of glyphosate would. For alternative modes of action, BASF has two products, HEAT and DISTINCT herbicides, which fit as glyphosate top-up products and provide alternatives to Group 2 herbicide chemistry. HEAT (powered by KIXOR ) is a herbicide designed as a glyphosate tank-mix partner for pre-seed burn-down treatment prior to cereal and pulse crops, or as a chemfallow treatment. HEAT uses KIXOR, a unique, Group 14 (PPO inhibitor) active ingredient. It delivers rapid and complete control of all major dicot weeds up to the 8 leaf stage, including biotypes resistant to glyphosate, acetolactate synthase (ALS) and triazine herbicides. HEAT provides complementary activity with glyphosate for utility in multiple crop and non-crop use segments, with crop rotation flexibility and a favorable environmental, toxicological and ecotoxicological profile.

2 HEAT tank mixed with glyphosate for chemfallow applications provides rapid burndown of broadleaf weeds in as little as 4 to 7 days. This quick burndown earlier in the season provides control of many winter annual and early emerging spring broadleaf weeds. Included in this list are many broadleaf weeds that are hard to control with glyphosate, including Narrow-leaved hawk s beard, spring-emerged Dandelion, Wild buckwheat, glyphosate-tolerant canola and Kochia, among others. DISTINCT herbicide contains the active ingredients dicamba (Group 4) and diflufenzopyr (Group 19). Diflufenzopyr (DFFP) is an innovative chemistry that synergizes the dicamba. When DFFP is added to dicamba, the dicamba becomes 2 to 3 times more active than the corresponding rate of dicamba applied alone. This synergistic effect allows the innovative product to provide high levels of weed control, while keeping the use rate relatively low. DISTINCT provides a second mode of action to add to glyphosate that differs from HEAT. Adding DISTINCT to later season chemfallow glyphosate applications provides additional activity on hardto-control weeds including glyphosate and Group 2 resistant Kochia, Wild buckwheat, Russian thistle and a number of other broadleaf weeds. Rotating herbicide modes of action, even within the glyphosate top-up market, provides additional benefits in herbicide resistance management. Rotating HEAT and DISTINCT on chemfallow acres, reduces the selection pressure on those herbicide groups, and is an effective way to manage glyphosate resistance.

3 AgSolutions Advisor April 2013 Fusarium Head Blight Management and CARAMBA Using CARAMBA fungicide at the right time for best results. Written by: Kristina Polziehn One of the most serious diseases affecting cereal crops within Canada is Fusarium Head Blight (FHB). Significant reductions in grain yield and grain quality as well as contamination by mycotoxins, such as deoxynivalenol (DON) can have serious economic implications to feed, malting, milling, biofuel and brewing industries. Losses experienced in the Canadian grain industry since the 1990s have ranged from $50 to $300 million per annum. Several different Fusarium species can cause Fusarium Head Blight (FHB). In North America, the most common species is Fusarium graminearum. However, other Fusarium species including Fusarium avenaceum, Fusarium poae, Fusarium sporotrichioides, Fusarium equiseti and Fusarium culmorum have also been identified on cereals across Canada. Fusarium species persist by overwintering in crop residues at or below the soil surface. Spores are dispersed from residue through rain splash and wind infecting heads during the flowering and grain-fill growth stages. More specifically, in barley the most susceptible growth stages for infection are heading to soft dough, whereas in wheat the greatest susceptibility is between flowering and soft dough. FHB requires a specific set of environmental conditions for infection to occur during flowering, including prolonged periods of moisture or high relative humidity and warm temperatures. Crop varieties also differ widely in their susceptibility to FHB. To understand the FHB tolerance of a specific variety, review local variety data and take note of the Fusarium Ratings. These ratings compare the susceptibility of the different varieties, and while some varieties do have better ratings than others it is important to remember that no varieties are totally resistant to FHB. Key symptoms of FHB are pink to salmon orange spore masses that can be seen on infected spikelets and glumes. Infected kernels appear shriveled and lightweight, ranging from pink to a dull gray in color. Tombstone kernels are often used to describe the infected kernels because of their shriveled, white, chalky appearance (Figure 1).

4 Figure 1. Red arrows pointing to Fusarium Damaged Kernels in winter wheat harvested from BASF demo trial in Bryanston, ON (2008). head emergence to up to 3 days after full head emergence. Successful management of FHB requires adopting an integrated approach of various cultural and chemical control practices, including using varieties with improved resistance to FHB, crop rotation to non-host crops, controlling weeds that act as a source of inoculum for FHB and utilizing protective fungicides. CARAMBA, which contains the active ingredient metconazole (Group 3), is a strong and reliable foliar fungicide that suppresses FHB and controls late occurring cereal leaf diseases, including Tan Spot, Septoria Leaf Spot, Net Blotch, Scald, Leaf Rust and Crown Rust. To maximize yield and quality and suppress FHB in wheat, rye and oats, CARAMBA should be applied from 20 to 50% flowering or when anthers are visibly protruding from 20 to 50% of the glumes (Figure 2). In barley, applications should be made between full Variability may occur in growth stages and duration of flower timing due to differences in environmental conditions, topography, soil characteristics, crop variety and seeding dates. To manage variability, CARAMBA can be applied to wheat when 75 to 100% of the main stem heads have emerged to when 50% of the heads are flowering. Notably, the window of application to apply CARAMBA for optimal suppression of FHB is narrow between 3 to 5 days. Growers are encouraged to be prepared and equipped with the proper nozzle setups (alternating forward and backward nozzles or nozzles with two-directional spray to maximize coverage). Coupling the proper nozzles with maximum water volumes at the proper timing will optimize the suppression of FHB in cereals. The incidence of FHB across Canada continues to make it one of the most challenging cereal diseases. To minimize the impact of FHB and to maximize yield, quality and profitability in cereals in 2013, an integration of beneficial agronomic practices with the application of CARAMBA should be considered. Figure 2. Application timing of CARAMBA in wheat, from 20 to 50% flowering, respectively listed as A and B.

5 AgSolutions Advisor April 2013 Disease Management for Sclerotinia in Pulses Effective strategies for a successful crop. Written by: Kevin Robson Looking forward to the 2013 growing season, Sclerotinia will be an important disease that needs to be managed properly to achieve high pulse crop yields. In 2012 Sclerotinia was a hot topic in both pulse and oilseed crops, becoming a detrimental disease to many of the Western Canada pulse producing regions. Sclerotinia has been a devastating disease in central Saskatchewan for the last three years on lentils, says BASF Senior Business Representative, Dick Gelley. It has not only hurt yield but has had a huge impact on quality if left untreated. Growers have managed this disease by using LANCE prior to canopy closure. They have seen fantastic results, with yield increases of up to ten bushels per acre. This disease has the ability to infect several crops and thrives in damp, warm conditions, which is why it has been prevalent in Western Canada in the past few years. The Sclerotinia stem rot that is found in most pulses and oilseeds is caused by the Sclerotinia sclerotiorum fungal pathogen. This pathogen survives in the soil as overwintering bodies referred to as sclerotia. Sclerotia are the hard black bodies that are formed inside the stem of an infected plant. In following years, these sclerotia germinate and form small apothecia, which release spores into the air. In canola these spores land all over the plant but are only able to directly feed on the petals, as they cannot directly penetrate the stalk. However, when the infected petals drop and land on the canola stem and leaves, the actively growing fungus is able to penetrate and infect the host plant leading to disease and possible yield loss. Unlike in canola, the Sclerotinia spores are able to infect all portions of the lentil plant including the stem, leaves and pods. This means that this disease can infect the lentil at any time in its life cycle and management of the disease must be considered at any time in the crops life should the appropriate environmental conditions occur. The risk of developing a potential Sclerotinia problem can be assessed by looking at past cropping rotations, past disease levels, and geographical location. In general, if you have grown lentil or canola on a piece of land, there will be Sclerotinia inoculum present in the soil. Because of this, most producers are, or should introduce Sclerotinia management plans to reduce the impact of this disease.

6 To reduce the risk of Sclerotinia infection, rotating between host and non-host crops is essential. However, in Western Canada this type of crop rotation needs to be carefully managed, as many of the common crops grown, including pulses, forages, sunflowers, and canola, are all susceptible to Sclerotinia, and therefore contribute to the disease inoculum in the soil. The best ways to manage the levels of Sclerotinia stem rot in a pulse crop include variety selection, planting methods, and applying a preventative fungicide. Applying PRIAXOR DS fungicide at early flower followed by LANCE fungicide 10 to 14 days later is very helpful for suppressing the development of disease. First, the type of pulse grown can have an effect on the severity of Sclerotinia levels, with the larger, bushier varieties having higher disease incidence. These bushier varieties, such as large greens, more readily create a microclimate within the crop canopy. This microclimate is more conducive to disease growth when compared to thinner varieties like the red lentils. Altering planting methods will also help to reduce disease pressure. Planting at lower rates in wider row spacings effectively reduces the plant density and increases airflow through the crop canopy. However, these planting methods can also decrease the seed yield, since planting fewer plants per acre can have a negative impact on yield. Another important way to limit the development of Sclerotinia in pulse crops is a preventative fungicide application of PRIAXOR DS followed by LANCE. Both of these fungicides provide activity on Sclerotinia, with LANCE providing excellent late season activity on Sclerotinia and PRIAXOR DS working to suppress Sclerotinia earlier on in its life cycle. PRIAXOR DS also provides unsurpassed Anthracnose and Ascochyta control as well as AgCelence for plant health benefits. For all those planning to grow a pulse crop in the 2013 season, Sclerotinia management will be important to the success of the crop and must be considered. To maximize the crop yield, quality and profitability, proper management strategies that include good agronomic practices and the application of preventative fungicides are essential to minimizing the impact Sclerotinia will have on your 2013 crop.