Crop & Pest Report - All
Weather Forecast: (June 25 - July 1)
If you watched any of the U.S. Open golf coverage this past weekend the word “fescue” was repeated frequently, plus you likely heard how dry it has been in the Pacific Northwest. If you have listened to any weather summaries recently or if you read my past two Crop and Pest Report forecasts, the word “ridge” has been commonly mentioned. The ridge that has been over the northern Pacific Ocean will shift east into the northern Rockies over the next several days. Figure 1 illustrates the projected upper-level flow pattern (parallel to the black lines) and height anomalies from average for Monday.
This pattern of a western ridge and an eastern trough will bring very warm weather to the western one-half of the United States and below average temperatures for the eastern part of the country. For our area it will bring above to well above average temperatures. Plus, with the storm track coming in out of Canada, any precipitation that develops will generally be light and highly scattered. Therefore, the week will overall be dominated by mostly dry and warm conditions, with western North Dakota and eastern Montana getting hot (90s), especially this Sunday and Monday. This ridge is expected to shift back to the North Pacific Ocean toward the middle of next week, meaning much cooler temperatures and a rain threat would return to the Northern Plains leading into the Independence Day weekend.
With minimal rain threats and a dominating air mass from the Canadian prairies, near surface relative humidity levels are expected to be frequently low (Figure 3) which will lessen fungal growth potential, drying the top soils and aiding in higher daytime maximums through early next week. Projected growing degree days (GDDs), base 34°, 44° and 50° for the period June 25 through July 1, 2015 are presented in Figure 2. The next 7 days are expected to produce more GDDs than any other such period so far this growing season.
Assistant State Climatologist/Meteorologist
(701-231-8209) Twitter: @darylritchison
Areas in the region received high amounts of rainfall over the weekend. NDAWN data indicates that Dickinson received 1.61 inches of rain over the past week (June 17-23), with 1.1 inch of rain recorded on Sunday June 21st. While areas have excess water in the region, some areas could use rain. Dry weather and heat will be well received to allow access to fields, take down hay, and corn could benefit from some warmer temperatures.
The wet conditions and moderate temperatures have been conducive to diseases with reports of powdery mildew on wheat in Adams County, and multiple reports of stripe rust as well as wheat streak mosaic virus are being found. Be sure to keep an eye out for diseases and manage as necessary.
Area Extension Specialist/Cropping Systems
Barley fields are heading this week and many wheat fields are in the boot stage. Overall, the small grain crop is looking good to excellent. My IPM scout hasn’t found new fields with stripe rust, however keep vigilant. A string of mid-80°Fs is predicted for the weekend which could inhibit development.
Our canola is at variable crop stages from the earliest-seeded canola at early bloom to cotyledon-staged plants due to frost replant. The most recent sclerotinia risk model has infection risk at moderate for most of the region with a high risk around Michigan, Inkster and Humboldt. You can find the statewide risk map here: https://www.ag.ndsu.edu/sclerotinia/.
With help from the Pembina and Towner County Agents, Jan Knodel and I are setting up pheromone traps for swede midge detection in canola along the northern border. One swede midge was detected in the Canadian trapping network near Winkler MB in 2014. This canola pest has limited control options, short adult life i.e. a small window to kill, and can cause deformation on canola flowering structures resulting in yield loss.
Area Extension Specialist/Agronomy
In the last week the NCREC received approximately 2.6” of precipitation. With the rain events, some areas received hail ranging in size from pea to golf ball size. Many crops, especially canola, were hit hard, with most just beginning to bolt. Most small grains should recover, but growth may be delayed. In general, minimal foliar disease and insect pests are present in the area, based on IPM scouting reports.
The Northern Canola Growers will be sponsoring the annual canola day tour at the NCREC beginning at 9 a.m. on Tuesday, June 30. Topics include winter canola, canola diseases and fertility. A catered lunch will follow and anyone interested in canola production is welcome to attend.
Area Extension Specialist/Cropping Systems
One Persons Weed is another Person’s Ingredient for Salad
I live in an area of south Fargo that is under residential development. There are very few homes in my part of town and plenty of weeds along recently constructed roads. I noticed a group of people harvesting lambsquarter leaves recently. I was surprised and went to the internet to investigate lambsquarters as a source of food for human consumption.
Lambsquarters (Chenopodium album) is a member of the goosefoot family and is a relative of spinach, quinoa, and beets. Stems, leaves and seeds can be used as a source of food. Lambsquarters leaves are used in the kitchen as a wild spinach substitute, added to salads, stir fry, soups, and casseroles. Dried leaves make flour and are mixed with water to make a tortilla. Lambsquarters is the second highest in nutrition of all wild foods (amaranth is number one) and are rich in beta carotene, vitamin B2, niacin, calcium, iron, and phosphorus.
There are a few precautions, perhaps with green plants in general. Lambsquarters can absorb nitrate from contaminated soil so be careful where you harvest this plant. Avoid too much raw consumption of plants as it contains oxalic acid. Cooking will destroy some of the oxalic acid but for salad and smoothies use lemon juice to neutralize the oxalic acid. Seeds of lambsquarters can be dried and sprouted or ground into flour for bread, pancakes, muffins, cakes, and cookies. The seeds are also used as a seasoning and a coffee substitute.
Extension Sugarbeet Agronomist, NDSU & U of MN
Plant Sugarbeet into Fields with Known Herbicide History
Last week I walked a sugarbeet field with nearly 100% stand loss on the low organic matter, eroded, higher elevation areas of the field. Field history was incomplete as the field had been farmed by the current grower for only two years. Upon closer evaluation and consultation with Dr. Dexter, retired Extension Sugarbeet Specialist, we believe the symptoms on dying sugarbeet were from an imadazolinone herbicide, such as Pursuit or Raptor. I have walked other fields where damaged sugarbeet appear to be result of herbicide carryover.
Recall that following the wet spring, 2014 was relatively dry in many areas. We did not have much snow cover and spring 2015 started very dry. I believe my observations are a product of cold and dry conditions and are accentuated in areas where there are overlaps including head lands of fields.
Sugarbeet is more sensitive than most crops to carryover of herbicides. Record of herbicide use in the previous year is essential but herbicides carry over for several years. Long term herbicide history is needed if very persistent herbicides may have been used in the field. For example, Pursuit herbicide damaged sugarbeet six years after application in soybean on a pH 5.2 soil.
Premixes might be another culprit. There are several (many) packaged premixes that contain imazethapyr, the active ingredient in Pursuit. Read the label and, if needed, get advice on the various components of mixtures and the risk of injury from your sugarbeet agriculturalist, extension agent/specialist or company representative.
Extension Sugarbeet Agronomist, NDSU & U of MN
Barley Injury following Pursuit and Raptor
Question: In this area of the state soil pH is 5.4-6.0 and organic matter is 3.2-3.5%. Some growers are planting barley on sunflower stalks treated the prior year with Beyond herbicide at 4 fl oz/A. We see injury early in barley with the yellow flash and we even see more injury on soybean land treated the previous year with Extreme at 1.75-2 pts/A or Pursuit at 1.5-1.75 fl oz/A. If Beyond was applied to sunflower in the 2 to 4-leaf sunflower stage at 2.5 fl oz/A instead of 4 fl oz/A, will there be less carryover and less barley injury the following year? What factors influence breakdown of Imi herbicides?
Answer: This topic was partially covered earlier this year in Crop and Pest Report #1, May 7, 2015. Imi herbicides, in fact most all ALS herbicides do not show a significant rate response in activity. In other words, they can work as well at reduced rates as at full rates on susceptible weeds. Weeds with some tolerance will require full herbicide rates. Before the Roundup Ready crop era we did a significant amount of research with Accent and Steadfast (grass control in corn). These herbicides applied with effective adjuvants would control weeds whether used at reduced or at full rates. We also saw the same ‘no rate response’ from Pursuit and Raptor. Raptor at 2 fl oz/A + MSO produced the same weed control as Raptor at 4 fl oz/A + NIS. This is what we mean by very little rate response. For many susceptible weeds, the rate can be reduced and will still get equivalent weed control as the full rate ONLY if you use the most effective adjuvant = MSO at 1-1.5 pt/A, NOT 1% v/v! Research also shows that multiple applications of Pursuit and Raptor at low rates (1-2 fl oz/A) always gives better control than 1 application at the full rate. Remember though that reduced rates encourages herbicide resistance in weeds. That is why we recommend always using full label rates.
For breakdown and soil residues of Imi herbicide read paragraph Y2 on page 100 in the 2015 ND Weed Guide. Especially read #8 in that section: “Imi herbicides are strongly bound to organic matter at pH <6.5. Amount of Imi herbicide adsorbed to soil and organic matter changes little from 6.5 to 8. At soil pH <6.5, pH reduction as small as 0.2 pH units can DOUBLE the amount adsorbed. Large variation in pH can exist in the same field. In low pH, residues of Imi herbicides can injure sensitive plants for many years.” Imi herbicides are broken down by microbes and when Imi molecules are bound (adsorbed to soil) to soil particles at pH <6.5 then microbial degradation is slow. Soil pH and moisture are the two most important factors affecting microbial breakdown of Imi herbicides. Actually, I am surprised you do not see more barley injury with your low soil pH. As mentioned in that section (Y2) that the injury will be more pronounced on any soil with pH <6.5. Imi herbicides are so biologically active that even by cutting the rate I am not sure that will help to reduce your risk of barley injury. With the exception of increasing the soil pH, I am not sure there is good way to improve barley safety of barley planted the year after Raptor application.
Extension Weed Specialist
HSMOC Adjuvants – More Questions
Question #1: I got a call this morning from someone that insists on adding HSMOC with straight glyphosate. He said he gets greater weed efficacy even with glyphosate alone. Can you clarify?
Question #2: I have MSO questions for the dry bean micro mix. 1. Have you done research on which MSO’s work best with the bean mix. I was told Scoil used to be best, I don’t think it is made any more. 2. Should I be using the HSMOC with the bean mix or the regular MSO? Regular MSO is about $17/gal and HSMOC is about $27/gal. Thank you.
Question #3: We are having a debate about adjuvants for use in a specific tank-mix:
AMS + Glyphosate + Sharpen + HSMOC OR AMS + Glyphosate + Sharpen + MSO + NIS.
The crux of the issue, as usual, is cost. At 1 pint/acre the HSMOC cost would be $5.63/acre just for the HSMOC compared to MSO + NIS ≈ $2.75 (1 pt/acre) + $0.88 (0.25% @ 10 gpa) = $3.63/acre.
Some HSMOC labels do not show surfactant content but others show 25% surfactant so at 1 pt/A they would give an adequate surfactant load with a loaded glyphosate. We have an HSMOC in our warehouse and were going to use it with the above tank-mix in place of MSO. So, our questions are: Should we use a standard MSO + NIS and save the $2.00/acre? Or is the HSMOC worth the added cost to potentially not antagonize the glyphosate? Or could we simply add a little more glyphosate to overcome potential antagonism from the MSO? Sorry for the long winded e-mail over a $2.00/acre debate.
I suggest reading the section on HSMOC in the weed guide? - See page 70 in the e-file below:
The amount of emulsifier (surfactant) in HSMOC is very important but what is equally or even more important is the quality of emulsifier in the HSMOC. The emulsifier can either be glyphosate friendly or unfriendly (antagonize glyphosate). The emulsifier’s in HSMOC adjuvants differ and even if you add surfactant to MSO to create your own HSMOC, it may still antagonize glyphosate activity. Perhaps you might get lucky and choose a good one but I don’t know which are good and which are bad with glyphosate. In addition to MSO having a low NIS content, they almost all have glyphosate unfriendly emulsifiers. I have taken many phone calls the last few days about cost of HSMOCs and ways to reduce the cost and maintain high herbicide activity. Everyone is looking for ways to reduce adjuvant cost and the answer is – marketing is your department – I just test for efficacy. Sorry.
Regarding adding more glyphosate to overcome the antagonism from oil adjuvants…..a great scientist (Dr. John Nalewaja) once said the following, “The best adjuvant for Roundup is more Roundup”. High glyphosate rates can overcome the antagonism from oil and can be considered to diminish the need for the more expensive HSMOC adjuvants.
Extension Weed Specialist
Use of HSMOC Adjuvants with Herbicides
I have been getting many questions about the use HSMOC adjuvants. These questions show the confusion about use and function of this adjuvant type. Below I have rephrased the questions and provided answers to help folks understand conditions for which they are intended.
Background information: Acronym HSMOC = high surfactant methylated oil concentrate – see page 126 in the 2015 weed guide for various brand names.
Question #1: I was reading section A5 on page 74 of the weed control guide concerning oil adjuvants. You say we should use PO at 1 to 2 pts/A with 2 pts/A being optimum rather than going by %v/v (as in 1% v/v) because of the various gal/A used by farmers. Does PO mean petroleum oil?
Answer: Yes, PO is the abbreviation for petroleum oil. PO is used instead of crop oil concentrate (COC) because the oil is petroleum based not crop based as one might infer with COC. Also, we recommend oil adjuvants be applied on an area basis to ensure the minimum amount of oil adjuvant regardless of spray water volume used. See the chart accompanying this article for the penalty of using oil adjuvants at a % v/v rate in low gpa. When applying PO or MSO adjuvants at 1% v/v at 10 gpa (9.4 gpa) the amount of oil applied per acre is only 0.75 pt which is far less than the minimum amount needed to enhance and fully optimize post herbicides = 1 to 2 pt/A.
Question #2: Is that 2 pt/A rate for both MSO and PO (COC) adjuvants?
Answer: The golden rule of 2 pt/A was established first for PO adjuvants. PO at 2 pt/A was the rate used for decades since atrazine was introduced in the 1950s. The 2 pt/A rate has been eroded down to 1% v/v for reasons I have not been able to determine. MSO - When Dr John Nalewaja and the NDSU Weed Science group invented MSO adjuvants in the early 90s the research showed that 1.5 pt/A was the optimum rate. This 1.5 pt/A rate was used with Accent, Steadfast, Raptor, Pursuit, and other herbicides. That 1.5 pt/A rate has also been eroded to 1% v/v. Growers using MSO with very active herbicides (Raptor, Flexstar, others) on less tolerant crops (dry beans) adjust the rate based on temp and humidity to minimize crop injury. For example, in warm temps and average humidity growers may use 1.5 pt but in hot temps and high humidity they may use 1 pt/A or less or 1% v/v or less.
Question #3: Would that also mean 0.5 pts to 1 pt/ac when using the HSMOC adjuvant formulations?
Answer: This is where there is much confusion. A new adjuvant class has been invented called HSMOC (high surfactant methylated oil concentrate). The function of this adjuvant class is for use with tank-mixtures of glyphosate + lipophilic (oil loving) herbicides. Oil antagonizes glyphosate but HSMOC adjuvants enhance the oil loving herbicide without antagonizing glyphosate. Glyphosate is the most water soluble herbicide and is enhanced by surfactant. Oil loving herbicides (Raptor, Flexstar, 2,4-D, Banvel, Laudis, Sharpen, and almost all POST herbicides) are enhanced most by oil based adjuvants. These HSMOC adjuvants have at least 25-50% emulsifier rather than the 17% in PO or the 10% in MSO. This HSMOC adjuvant class invention was needed for these water + oil soluble herbicide mixtures but then everything got discombobulated when adjuvant companies charged twice as much per gallon as compared to PO or MSO and recommending cutting the rate in half of whatever the oil concentrate adjuvant they were using. For example, recommendations were to use 0.5 pt of HSMOC instead of 1 pt of MSO or to use 0.5% v/v of HSMOC rather than 1% v/v of MSO. NDSU research clearly shows that 0.5 pt and 0.5% are not sufficient to enhance the lipophilic herbicides. HSMOC adjuvant cost per acre is high which decreases the likelihood of growers using them at the rates which provide the greatest herbicide activity – a minimum of 1 pt/A. Thus creates a dilemma for you in your cost analysis.
Question #4: I typically have sprayed my pinto beans using an HSMOC at 0.5 pts/A. However, now I am thinking I should be using HSMOC anywhere from 0.5 to 1 pt/ac to be in your optimum range for oil adjuvants. I'm considering using 0.8 pts/ac this year. Will this be okay?
Answer:There is no need for you to use an HSMOC adjuvant or incur the high cost from an HSMOC with your dry bean herbicide program because glyphosate is not part of the tank-mixture. HSMOC are for glyphosate + lipophilic (oil loving) herbicide mixtures and you are not using glyphosate in your dry beans. You only need a reputable MSO and adjust the rate from 0.75 to 1.5 pt/A depending on herbicides mixtures you use, and the temperature, humidity and vigor of the dry bean crop.
Extension Weed Specialist