• the current R/MR/MS/S (resistant, moderately resistant, moderately susceptible, susceptible) ratings as a % of Westar will remain the same, refers to minor gene resistance
• a label to identify the major resistance genes in the variety will be added i.e. Resistance A to Resistance P (see chart below). This is a voluntary label extension at this time.

e.g. Canterra CS2100 rating is “R – ACG”, which describes a resistant  variety with 3 resistance groups containing major resistance  genes Rlm1 (or LepR3), Rlm3 and RlmS, respectively

• growers can proactively manage blackleg by rotating to a variety with a different letter(s), and therefore a different source of resistance

The following exclusive WinField United products are available at Shur-Gro Farm Services, Munro Farm Supplies and South East Seeds:

Ascend SL™

 Product Type:  Ascend SL is a (soluble liquid) plant growth regulator (PGR) that contains an optimal combination of 3 plant growth regulators, which can result in vigorous early plant germination and emergence, a robust root system, and larger leaves and wider stems to help increase yield.  Ascend SL can be used as a seed treatment, in-furrow or as a foliar application.  Application can be made by ground or air.

Active ingredients:  Proprietary blend of cytokinin 0.090%, gibberellic acid 0.030% and indolebutyric acid 0.045%.  This combination of plant growth regulators promotes cell division and elongation in leaves and stems as well as vigorous root formation and elongation.

Use Rate:  Registered crops include alfalfa, canola, cereals, corn, dry beans and peas, soybeans and sunflowers.  A typical foliar use rate is 100 ml/ac (95 ac/9.46 L jug) and may be applied multiple (2-3) times in most crops.  SRP = $6.30/ac per application.

As a seed treatment for wheat, 260 ml/100 kg of seed is recommended.  Each jug will treat 134 bu of wheat seed.  SRP = $4.45/bu.

As an in-furrow treatment for corn, 177 ml/ac is recommended.  Each jug will treat 54 ac of corn.  SRP = $11.00/ac.

HiActivate™

Product Type:  Non-ionic spreader/activator adjuvant in a low-foaming formulation.  For use with most post-emergent crop protection products to improve the properties of spray droplets for enhanced efficacy.

Active ingredients:  90% blend of glycerol, sodium xylene sulfonate and alkyl phenol ethoxylate.

Use Rate:  Average use rate is 1 litre/100 US gallons or 0.25% v/v.  One 9.46 litre jug will treat 1000 US gallons of water.  SRP = $1.50/ac for 10 US gpa.

InterLock®

 Product Type:  Crop-based adjuvant that improves spray droplet coverage and helps droplets stay on target.  InterLock reduces the amount of fine particles in the spray pattern which helps to improve canopy penetration and reduce drift and evaporation of spray droplets. Works effectively with herbicides, fungicides, insecticides, dessicants and defoliants.

Active ingredients:  100% modified vegetable oil, polyoxyethylene sorbitan fatty acid ester, vegetable oil.

Use Rate:  As a deposition aid, one 9.46 L jug will treat 80-160 acres, SRP = $1.10 – $2.20/ac.  For drift reduction, one jug will treat 53-80 acres, SRP = $2.20 – $3.30/ac.  Use higher rates of InterLock at higher pressures or increased spray volume (within the 5 to 25 US gpa range).

In 2016, Hugh Beckie, Scott Shirriff and Julia Leeson of Agriculture Canada led a field survey of Manitoba to determine the incidence of weed resistance.  In late summer of that year, 150 randomly-selected fields were surveyed throughout Manitoba.  Before harvest, mature seeds from all residual weed species were sampled and subsequently plants were tested with Group 1 or 2 herbicides.  Survey results indicated:

• 68% of fields had a herbicide-resistant (HR) weed, this compared with 48% in 2008 and 32% in 2002
• 78% of fields had Group 1 resistant wild oats
• 43% of fields had Group 2 resistant wild oats
• 42% of fields had Group 1 and 2 multiple-resistant wild oats

This trend is being driven by a lack of new herbicide chemistries in the last 30 years, so growers use the same tools to manage their weed issues.  The inevitable consequence is a rise in weed resistance incidence.  Growers are also advised to be wary of HR broadleaf weeds.  Resistant populations of kochia, cleavers and chickweed to Group 2 herbicides are common.  Another weed of concern is glyphosate-resistant kochia, with Manitoba reporting its first few cases.  In the U.S. Midwest and southern states, herbicide resistant issues with the pigweed complex (Palmer amaranth, waterhemp, redroot and smooth pigweed) are causing major production challenges.  Hugh Beckie states, “It’s probably the number one global focal point for resistance now.”

Hugh Beckie has developed a “Top 10” list of the best management practices (BMPs) to address weed resistance.  Adopting these BMPs will improve weed control and slow the rate of weed resistance development:

• Crop diversity (rotation)
• Use competitive crops and practices that promote competitiveness
• Scout fields before and after herbicide applications, know your enemy
• Use multiple modes of action through herbicide mixtures and sequences
• Herbicide group rotation
• Rotate in-crop herbicide modes of action (selective mechanisms) in wheat
• Weed sanitation – border control, slow down the dispersal of HR weeds
• Site-specific (patch) weed management
• Strategic tillage – if, where, or when needed
• Accurate record-keeping of herbicides used and weeds present, invaluable reference

Please contact your local Shur-Gro, Munro, or South East Seeds agronomist to help plan an effective program to combat weed resistance.