Wheat:  Most wheat looks EXCELLENT, but late wheat is disappointing.  The crop will be short.  Wheat flag leaves are spiking from lack of water.  Lots of late herbicide/fungicide applications in wheat causing significant burn.  The value of weed control at this stage is extremely limited, and growers should rethink if it is worth it: the damage is done.  Lots of N and S  deficiencies showing, giving rise to “rainbow” wheat.  Early N applications have suffered significant loss, late N applications have had no rain for activation, with only a 2 day “sweet spot” for N applications in between.  Late N applications are showing every streamer bar with 28%, and are still quite N deficient with urea.  Past sins are becoming obvious as dry weather continues.  Lots of corn row syndrome showing, compaction, micronutrient deficiencies, etc.  Clover is suffering.

Corn: Early corn emerged in 8 days, later corn is taking 2 weeks with cooler temperatures.  Corn is greening up rapidly after emergence and stands look good.  There appears to be about 5% of seedlings in many different seed lots (across companies) that have poor germ/vigour.  Plants have good root development but no or very slow shoot development.

Soybeans: Range from 70% to 95% planted, although some individual growers have not yet started (felt soil conditions unfit).  Some beans have been planted 1″ into dry dirt.  Get beans into moisture  ( up to 3″) or the results will be disappointing.  (Quote for seed and seeding depth: “you can get it up, but you can’t push it down” once it is in the ground). Early beans are at the unifoliate stage and look good.

Forages: Well managed hay fields appear to have excellent yield potential, and harvest will begin in earnest this weekend or next week.  Alfalfa weevil has been found at high levels in Elgin County and the Niagara Peninsula.  2-3 per stem, or 40% leaf tip feeding means either immediate harvest or control is warranted.  The PHI for Matador and generics is 3 days.  Poorly managed fields are struggling  clearly the tonnage from the last cut in the fall just comes right out of the first cut this spring.

Rye for forage has been harvested, with many growers very pleased with amount and quality of the product.

Weed Control: Grave disappointment over the lack of grower uptake of tankmix products for glyphosate resistant weed management.  This is partly due to the cost, and partly due to “days to plant” restrictions.  Despite the 2,4-D label of 7 days, no yield loss was found in research trials when applied the day of planting (some leaf distortoin was noted).  Cost is small versus the cost of poor weed control and no effective rescue products.  Continue to promote burndown tankmix options.  Growers seem to have lost the management skill for burndowns versus planting.

Conventional herbicide issues are starting to be reported with lack of rainfall.  Generally, 2 leaf weeds are escapes from soil applied herbicides.

Drift reports are just starting to come in, but given windy conditions may be a big problem this year.  Fall weed control trials are showing excellent results.  Report of a failure of a slightly below label rate of glyphosate mixed with MangoPhos.  Remember that antagonism with Mn is common, and glyphosate rates need to be kept up if tankmixing.

Tillage: Heavy clay soils have gone extremely hard and are difficult to make a seedbed out of.  ”It takes 4 passes to no-till soys” was the quip.  Some in the group felt that the problem was tillage of any nature, as all the talk about 260 bu corn residue requiring some form of tillage has not become reality.  Older no-till equipment has had no trouble cutting through residue and placing seed into moisture (some discussion here, and not total agrement!!). “Quasi” vertical tillage units have not functioned well, bringing up lumps that required multiple passes with the cultivator and roller to beat into a seedbed.  A great dislike for unit mount (“nose”) coulters was expressed by many in the group: all they do is destroy the ability for proper depth control.  Perhaps these coulters are why airbag down pressure is necessary.   The value of rollers where soil was lumpy was expressed, with a soon to be released video showing the bounce of Keeton seed firmers with residue or lumps in the field.  Trash whippers were praised, although depth control is an issue.  Chopping heads without any tillage was felt to delay planting 4 days.

Cover Crops: Water infiltration measured with an oat cover crop versus no cover crop showed tremendous improvement, with a 1″ simulated rainfall taking only 1/3 the amount of time to infiltrate.  A similar experiment with tillage radish was more difficult to assess, but the value of cover crops in this regard is extremely obvious.

Other: A few frost injury claims on tomatoes and asparagus.  Some frost reported on alfalfa.  Planting a day too early has left slots open and very poor stands, especially in sensitive crops such as sugar beets.   A few replants have resulted.  Seed corn is 50% planted.  Bee producers are reporting very poor winter survival.  There have been a few reports of bee kills in the area.  PMRA is investigating.

Diagnostic Days:  July 3/4, Ridgetown Campus, University of Guelph.

Next Meeting: 7:00 am, Tuesday June 4th, Dar’s Restaurant.

Weather:
Recent rains have been sporadic ranging from none, to 5 mm, to heavy rains north of Kitchener. The lack of moisture is an issue. Forage and wheat crops will be shorter than normal. Rainfall amounts required to activate pre-emerge corn and soybean herbicides are one-quarter inch on moist soil or one half inch on dry soil, received at once. Several light rains of a few mm at a time will not initiate activity. If activating rains are not received within the next 5 days, rescue spraying should begin.

Cereals:
Cereal Rye has headed in Norfolk. Winter wheat stage varies from about 4 days pre heading for the most advanced, to tillering in late planted fields. Early October planted wheat is 2 weeks or more away from heading in Haldimand. Powdery mildew has been observed in lush, early planted fields. An observation comparing nitrogen application using a 3 streamer nozzles with 5 and 7 streamer nozzles showed notable streaking in wheat.

Producers are being trained on staging for fungicide applications. Estimates are that over two-thirds of wheat acres get at least one fungicide application and 15% of acres get a second application. A third application is only recommended for high yield potential (95 bu) and pricing. First fungicide application is most important for improving straw quality. First fungicide application is complete in Norfolk, most in Haldimand. A second application will be applied in a week to 10 days for late September/ early October planted wheat. The second application is more challenging for timing as due to spatial variations in heading within fields. Most producers spray one application, while the second is variable.

Corn and Soybeans:
Corn and soybean planting is all but completed in Norfolk and Niagara, and 95% for corn and 75% for soybeans on heavy textured soils. Most advanced corn is at 3-leaf stage and most advanced soybeans are at first trifoliate. Emergence has been good. More soybeans have been no-tilled this year compared to last year when time consumed by vertical tillage operations gave no pay back.

Forages:
With alfalfa forage harvest just over 1 week away for farms planning 4 cut harvest, forage growth is shorter than normal and The other major issue is alfalfa weevil, which is being sprayed in Niagara east, Haldimand and Norfolk. Pre-harvest is 3 days where matador is used. Dry conditions combined with weevil damage will contribute to a continued forage shortage.
Rye cover crop harvested as forage is more common this spring to meet forage shortages. A forage rye field harvested at head emerging, near Tillsonburg, yielded 3-5 ton wet/ac of feed (2-2.5 dry ton). Yield from a field comparison where rye was harvested last fall and this spring was equal compared to a field harvested just this spring.

Weed Control:
Most of the burn down for soybeans has been completed in Norfolk. Calls are already being fielded for weed escapes such as lambsquarters. Dealing with glyphosate resistance varies among producers. If the dry weather continues, in emergence problems will occur for corn and soybeans planted more recently (last week) and not into moisture. Some large weeds are being observed in wheat fields. Some thick crops of Dandelions are difficult to control this time of year and should ideally be attacked in fall after soybean or wheat harvest when glyphosate has best chance to provide good and economical control.

Other Crops:
Tobacco started last week, vegetables are going in, ginseng seedlings and potatoes are emerging, tunnels are being cut open to let zucchini out, and sweet corn is at 4-6 leaf and some fields are being irrigated.

Agricorp Update:
The deadline for reporting acreage is July 1. There are 5 ways to report:
phone 1-888-247-4999; (phones answered during business hours)
fax 1-519-826-4118;
email contact@agricorp.com (not preferred);
mail Agricorp Box 3660, Station Central Guelph, ON N1H 8M4; or
online www.agricorp.com (click online tools).

Quiet year (so far) for Agricorp claims. Oxford, Middlesex Elgin, this year has had exceptionally few claims with 1500 ac total compared to 2,500 ac to east (most from Grey, Bruce, Wellington, Waterloo). Chatam Kent area reported 3,300 ac. Most reports are from East of 400 (particularly Ottawa Valley) and are for wheat and new seeding alfalfa. There has only been 1 new seeding report from this area. There was one frost affected vegetable claim in Leamington area; and no field crop frost damage reports.

Harvest of dairy haylage is likely to be in full swing by the week of May 27^th in southern Ontario. Dairy producers generally target harvesting first-cut alfalfa haylage at an optimum 40% NDF.   “Scissors-cut” field sampling and rapid laboratory analysis can help predict optimal harvest dates. “PEAQ sticks” and GDD estimates of NDF are also useful. If practical, delaying harvest of stressed fields will improve plant health and increase yield. In mixed stands, be sure to watch the maturity of the grasses when making cutting decisions. (Using Scissors Cutting To Optimize Forage Quality http://fieldcropnews.com/?p=2610)   

Alfalfa weevil larvae are being reported in increasing numbers in the south-west. Some are above threshold levels with spraying being done. Feeding damage starts as leaf pinholes, progresses to feeding between the leaf veins and results in a skeletonized appearance. Larvae are bright green with a distinctive white stripe down the centre of the back.  Scout to determine if they are above economic threshold levels. Insecticide is recommended only when cutting is impractical, such as when the alfalfa is more than 10 days before harvest maturity. (Alfalfa Weevil http://fieldcropnews.com/?p=3108)

Alfalfa weevil damage.

Section 1 Questions: 5 questions.
Section 2 Review: correct answers will be supported by explanations.
Clicking submit shows your results.

Note: During weed identification it is always helpful to use guides such as Weed Info and the Ontario Weeds Gallery.

Alfalfa weevil damage.

Alfalfa weevil can be an issue in Ontario, particularly in south-western parts of the province. While outbreaks tend to be isolated, they can be severe and dramatically reduce forage yield and quality. Typically, alfalfa weevil do not reach significant levels until we are ready to take first-cut. However, sometimes alfalfa weevil larvae development is advanced relative to the alfalfa crop, and can do significant damage before the crop is ready to cut. Control options are to cut early or spray. Insecticides are recommended only when cutting is impractical, such as when the alfalfa is in the pre-bud stage.

Description

The adult alfalfa weevil overwinters as a 4 – 5 mm (3/16 inch) brown snout beetle. There is a single generation per year. Adults overwinter in plant debris and become active in April. They chew small holes in the base of alfalfa stems and deposit their eggs. Larvae hatch from eggs and crawl to the tops of alfalfa, where they feed on developing leaf buds and leaves. The developmental stage of alfalfa weevil can be predicted with a Growing Degree Day (Base 10ºC) model.

Larvae are pale to bright green, with a black head and white stripe down the centre of the back. The 1^st instar larvae are yellow-green and about 2 mm (1/16^th inch) at hatch. They are hard to notice unless you unfold newly formed leaves. Larvae grow to a length of about 8 mm (5/16 inch) at the fully grown 4^th instar stage. This usually takes 3 or 4 weeks. Mature larvae create a cocoon and pupate. Adult beetles emerge in late-June and early-July, but usually do relatively little damage.

Figure 1.  Alfalfa weevil larva.  (photo credit: University of Nebraska)

Clover leaf weevil are sometimes mistaken for alfalfa weevil. They grow much larger, and have a light brown head. The white stripe has a pinkish edge. Clover leaf weevil rarely cause economic yield loss.

Damage

Larvae initially feed within the leaf buds and then move to the tips of the plant. Damage starts out as pinholes, and progresses to larvae feeding between the leaf veins. Heavy infestations can result in severely skeletonized leaves that give the field a grayish white appearance. Loss of leaf tissue can quickly result in lower feed quality (digestibility and protein), as well as yield. Accumulation of carbohydrates in the roots is also delayed.

Figure 2 – Alfalfa weevil larvae feed on leaves, causing skeletonization. Note that larvae have black heads and a white stripe down their back.

Biological Controls

Entomologists consider alfalfa weevil biological control as a success story. Since the 1950’s, when the weevil was introduced to this part of North America with devastating results, over a dozen parasitoids and predators have been released to control the weevil. Once they became established, weevil numbers and damage decreased dramatically.

In Ontario, species of parasitoid wasps (Microctonus aethiopoides and M. colesi) attack and kill alfalfa weevil by laying their eggs inside the larvae or adult alfalfa weevil. The eggs hatch inside the pest where the young wasp feed and develop, eventually killing the weevil. Severe alfalfa weevil outbreaks can be controlled by insecticide application, but the down side is that the parasitic wasps are also killed. This increases the potential for future outbreaks. For this reason it is important to spray only when warranted by scouting and threshold levels.

Alfalfa weevil is also controlled significantly by a fungal pathogen, Zoophthora phythonomi. A dry spring may inhibit this fungus and allow weevil populations to increase. Rain and high humidity during periods of peak larval numbers can cause the weevil population to crash quickly. Infected larvae curl around leaves at the tops of plants and then turn brown.

Scouting

If there is a potential problem, scouting should be done twice a week. You can initially save some time by using a sweep net to determine if larvae are present. Fields seeded last year, pure alfalfa stands, and south facing slopes are more susceptible to early and heavy damage, so check them first.

A “Rule of Thumb” is that if there is 40 percent tip feeding, and 2 or 3 active weevil per stem, and there is more than 7 to 10 days to preferred harvest date, consider spraying. Tip feeding refers to the percent of plant tips showing obvious signs of damage, which is not to be confused with the percent defoliation.

To count larvae, collect 30 stems by cutting or breaking them off at ground level. Use an M-shaped pattern in the field. Place them inside a white pail and shake them against the side to knock off the 3^rd and 4^th stage instar larvae. First and 2^nd instars are very small, pale yellow to light green, with the white stripe not yet distinguishable. They may be in the upper leaves, but don’t include them in the count.

Check to see whether the weevil larvae look active and healthy. Infected larvae are slow-moving, yellow or tan. When they die they turn dark brown. Higher thresholds should be considered when a significant percentage of the larvae is infected by fungus or parasitoids.

Action Thresholds

No action required

• < 1 active larvae per stem (but continue to monitor)

 Action required

• > 1 active larva per stem AND alfalfa < 30 cm (12 in) tall
• 2 or more active larva per stem AND alfalfa < 40 cm (16 in) tall
• > 3 active larvae at any height.

Early Cutting

Peak larval activity usually coincides with the bud stage of the alfalfa, which is also the optimum time to cut for maximum quality. Occasionally, weevil development is ahead of alfalfa development, and damage will occur before it is practical to cut. Cutting before the bud stage can result in extensive damage to second cut regrowth and lower yield. Also, with high infestations, farmers may not be able to harvest fast enough to stay ahead of the weevil damage.

Cutting removes large numbers of these larvae from the field. Remaining larvae usually dry out and starve. If cutting is an option, it is preferable over insecticide application for a number of reasons, including the cost of spraying and damage to beneficial parasitic wasps and honeybees. Also consider that spraying will tramp some of the forage crop.

Insecticides

Registered products are listed in Table 1. Refer to the OMAFRA Publication 812, “Field Crop Protection Guide”, and product labels. Keep in mind that there are “days to harvest” restrictions with these products. Local beekeepers should be contacted so they have an opportunity to move colonies out of the danger area.

Table 1.  Registered insecticides for alfalfa weevil control. (OMAFRA Publication 812, Field Crop Protection Guide 2011-2012)

http://www.omafra.gov.on.ca/english/crops/pub812/3weevil.htm

Monitor Second-Cut Regrowth

Occasionally, if weevil populations are high on a late first-cut, surviving larvae will feed on the re-growth as quickly as it develops. Such feeding can eliminate alfalfa re-growth which may lead to a loss of the stand. On severe infestations, monitor weevil activity on stubble regrowth for 5 to 7 days. The characteristic symptom is the alfalfa plant does not “green up” due to larvae and newly hatched adults feeding on the developing crown buds. The presence of 2 or more active larvae per crown, or 4 to 8 larvae per square foot indicates a need to spray the stubble with insecticide.

Figure 3 – Alfalfa weevil larvae feeding on 2nd cut regrowth

You may be faced with a scenario where there is an abundance of weeds at or near the maximum leaf-stage for effective control, yet the soybean crop is not at the growth stage specified on the product label. As a producer or consultant, do you focus on targeting the weeds when at their labeled growth stage or do you wait until the crop reaches the labeled growth stage?

The Department of Plant Agriculture (University of Guelph) in partnership with OMAF/MRA conducted a series of field trials with the following objectives:

1. To identify if there is an increased risk of crop injury when applying post-emergent broadleaf soybean herbicides prior to the 1st trifoliate growth stage specified on the product label.
2. To identify if there is a negative yield impact by applying post-emergent broadleaf soybean herbicides prior to the 1st trifoliate growth stage.

Methodology

Trials were conducted at the Elora Research Station in 2006 and 2007. Three common post-emergent broadleaf soybean herbicides were applied at 3 different soybean growth stages (cotyledon, unifoliate and 2nd trifoliate) and at two different application rates (normal field rates and twice the normal field rate). Visual crop injury, plant population, plant biomass and yield data were taken and compared to an untreated, weed-free control.

Results

• Soybean tolerance to all three herbicides was general greater when applications were made prior to the 1st trifoliate stage (See Figure 1).
• When all herbicide treatments were averaged, crop injury at the cotyledon, unifoliate and 2nd trifoliate stage was 2.5%, 7% and 14% respectively.
• Visual injury was temporary and no longer apparent by the end of July.
• Soybean yields were unaffected by herbicide applications made prior to the 1st trifoliate stage of soybean.

Conclusion

Broadleaf weeds emerging before or with the crop are extremely competitive and should be controlled when they are small (prior to the 8 leaf stage of weed growth in general). Based on two years of data, it would appear that if a herbicide is applied prior to the labeled crop growth stage there is no increased risk of crop injury and no impact on soybean yields.

Topographic Zones
Red is high (1020-1050ft), orange are side slopes, Green is low (970-980 ft)

Initial assessment of the field needs to question how variable the field actually is, and more to the point – what is driving the variability across that field? Greg Stewart and I began this discussion with Greg Kitching (Integrated Solutions Consultant, Premier Equipment) who is the industry partner with OSCIA on the Oxford County Farm & Food Care WRAMI project discussed in last week’s Precision Ag post. Paul and Josh Beuhlow (near Ayr) volunteered two fields for this project, one for variable rate corn population and one for variable rate nitrogen (VR-N) application. The Buehlows only had the 2012 soybean yield map. Given the extremely dry conditions last summer starting a zone management strategy from that particular growing season was not ideal. After a look at the 2012 soybean yield zones, and a visit to the field, it was determined that topography was definitely influencing yield response across that field.

  Five topographic zones were composite soil sampled and included lab soil textural analysis, and a new test known as the “Nitrogen Potential Assessment” (NPA) offered by Brookside Laboratories. NPA recommendations are based on estimated nitrogen release (lbs/ac), soil health (microbial activity rating), and yield goal. 

The entire field had approximately 30lbs of ESN uniformly applied on May 8th.  Variable rate 28% was then pre-plant incorporated on May 9th using a 90ft sprayer (below).

Beuhlow Farms Variable Rate Nitrogen (28% UAN) Application Map. Based on a 200 bu/ac yield goal. The green areas will receive 52-69 gal/ac, the yellow/orange areas will receive 35-44 gal/ac and the red areas will receive 27 gal/ac.

The corn was then planted in 30″ rows later that same day using a 12 row planter. After looking at the as-applied map, Greg Kitching noted some things to think about as you prepare your first VR-N application plan ”check your nozzles before going to the field, look at the map and the range in the application rates, if it quite large ensure that your nozzles are rated to handle that kind of range, also make sure you watch your ground speed in zones where rates are higher”.

Two passes did not receive 28% and three (30ft) uniform rates of N will be applied at side dress time.  The goal is to check yield response from uniform rate after harvest in the low, medium and high topographic zones.

We assumed initially under more conventional tillage practices that high slope position on this field have less organic matter, less available N, and potentially less moisture holding capacity and vice versa in the low spots. We will evaluate what N rates made the most sense across that field in terms of yield response. Can we be certain that topography (and the relationship to organic matter etc.) is  the only driver here? PSNT sampling will be done by topographic position in the passes that did not receive 28%. This will allow for a comparison with the new NPA soil test recommendations from Brookside Laboratories.  Check back in June when we report more on this VR-N trial. 

Underseeding to cereals and cereal-pea mixtures was very common as a strategy to provide some early, extra forage. Many new alfalfa-grass mixture seedings were done in eastern and northern Ontario to replace winterkilled stands. Many new seedings have emerged with the most advanced at the unifoliate stage. Watch new seedings closely for annual broadleaf weeds and to determine optimum time of spraying. The risk of injury to alfalfa seedlings is greatly increased when 2,4-DB application is made outside of the first- to the third-trifoliate stage window.  2,4-DB can suppress legume growth for a period of 2 – 3 weeks and severe injury can occur under drought or high temperatures. Field experience has demonstrated that reducing the rate of herbicide can reduce the risk of injury to alfalfa seedlings while providing acceptable suppression or control of weed seedlings. Refer to Publication 75, Guide To Weed Control. http://www.omafra.gov.on.ca/english/crops/pub75/chapter10.htm

The fall rye is growing rapidly with some already past the boot-stage. Many dairy farmers target harvest at the flag-leaf stage for high nutrient quality. Delaying harvest to early-head will reduce digestible energy, but increase yield. (Double Cropping Fall Rye For Extra Forage” http://fieldcropnews.com/?p=5241

Economic Returns

Nitrogen deficiency in grasses shows up as a light-green to yellowing colour, and stunting of plants. If an alfalfa stand is uniformly thin or weakened but the grass content is good, the application of nitrogen can significantly increase yields as well as the forage protein level. Healthy stands of productive cool-season grass species (such as orchardgrass, bromegrass, timothy, tall fescue, etc) can have a significant yield response to large amounts of N to optimize yield. (Figure 1) Research shows that 1 lb of N can yield an additional 25 – 40 lbs of hay. In other words, if we value hay at a very modest 8¢/lb, applying 1 lb of N worth 70¢ will result in an extra 25 – 40 lbs of hay worth $2.00 to $3.20. 

How Much?

As a general rule, 60 lbs/ac N should be applied to stands with one-third to one-half legume. For stands with less than one-third legume, nitrogen recommendations have been developed using growth response (yield) curves to various N rates and nitrogen / hay price ratios. Assuming urea at $675/tonne and hay at a 8¢/lb, current nitrogen / hay price ratios are about 10:1. (Table 1)  These rates reflect optimum conditions of a uniform, vigorous grass stand with no other yield limitations, such as lack of rainfall, low P and K, bare patches, excessive weeds, or a delayed application. Nitrogen rates for less productive stands should be adjusted downward accordingly. For many stands this spring, an initial application of 90 lbs/ac N may be optimal.

Table 1- Nitrogen Recommendations For Improved Grass Stands Under Optimal Conditions (adapted from Table 3-6 OMAFRA Agronomy Guide, Publication 811)

Application

Number           N required lbs/ac (kg/ha)

1                      125 (140)        

2                      100 (110)        

3                      80 (90)

When?

Nitrogen applications on hay fields should be split for optimum response. The first application should be made just as the grass is starting to green-up, early in the spring. This is the largest application to take advantage of the large first-cut yield potential. In many pasture situations, the initial application is skipped because there may already be more early spring pasture growth than can be utilized, unless this growth is being cut for stored forage.

Without rain, yield response to nitrogen will be limited. If rain is not limiting, a second application can be made right after the first-cut, and a third application after the second-cut. Each of these applications is about 20% less than the one preceding it. To avoid nitrate toxicity, never apply more than 170 kg/ha (150 lb/ac) of N at one time.

When manure is applied to a field to be used for hay or haylage, N application should be reduced according to the type and amount of manure. In pasture situations, reduce N rates in the Table by one-third, because of N recycling through manure and urine.

Orchardgrass response to nitrogen – no N applied (bottom left) vs N applied (top right)

Frost damaged corn seedling

Most of the cereals, new forage seedings, corn and part of the soybean acreage were seeded/planted between May 1^st to 10^th.  Fertilizer supply/delivery chain was stretch to the maximum. Next stress point will be the weed control, which will occur simultaneously for all crops.

Forages:

From AgriCorp – Can still make claims for 2012 new seedings if a stand failed to establish (a stand is more than 6 plants/ft²). There are no restrictions on how the new seeding is handled subsequently; it can be re-seeded or can have a cut harvested and then the field rotated to another crop.

 Alfalfa is showing 6 to 10 inches of new growth. Grasses will be short at heading unless we get more rain soon. Canada blue grass is starting to head, while orchard grass is at the late boot stage. The cereal rye seeded last fall is progressing rapidly and should be ready to cut next week.

Most advanced new seedings are at the unifoliate stage. Weeds are emerging alongside the new seedlings. Herbicide should be applied before the 4^th trifoliate.

There are still a number of very thin hay fields which should be rotated to another crop. Article on “Forage Options When Alfalfa Winterkill Strikes” at http://bit.ly/15KgmSV .

Thin hay stand

Adult Snout Beetles are active in infested areas.

 Cereals:  

Winter wheat – herbicides should be applied as the crop will soon be beyond the spray window.

Spring cereals planted in the last week of April have emerged and are at the shoot stage, not yet tillering. A few growers are pushing the nitrogen rate to 110 to 120 pounds per acre (lbs/ac), while most are applying 90 lbs/ac of nitrogen.

No disease pressure to speak of yet on spring cereals. It is too early for fungicide application. If applying herbicide at the end of the spray window, the addition of a fungicide with the herbicide has shown about 1.5 bushel per acre yield increase in spring wheat. Stripe & Leaf Rust are making its way to central US. The USDA cereal rust disease bulletins will assist in tracking progress: (http://www.ars.usda.gov/Main/docs.htm?docid=9757).

Corn:  90% of corn is planted in eastern Ontario and emergence is good. Adapted hybrids can be planted for another week. A large amount of fertilizer was needed in a short time period, creating momentary shortages. A significant percentage of the planned pre-emerge herbicide treatments was not applied due to the short planting window and quick emergence.

Soybeans: About 50% of the intended soybean acreage is planted. I.P. soybean acreage requirement met, but the industry could utilize additional acreage. Some of the conventional soybean herbicides are in short supply. Growers using the pre-inoculated soybeans seeds need to protect the seed from the sunlight and heat prior to planting to protect the viability of the inoculant.

Insecticide seed treatments and corn planting:  If there are incidences of affected bee hives this year contact: Linda McIntosh Regional Manager Pesticide Compliance Program – Health Canada 255 Woodlawn Rd W, Unit 109 Guelph ON, N1H 8J1 Phone: 519-826-2895.

 Resources

• Revised Guide to Weed Control, Pub 75 as pdf, 2013 revisions highlighted in yellow
• Protecting Pollinators During Corn Planting Season
• WeedPro75 – Herbicide Selector, smart phone/mobile version at: m.weedpro75.com
• Weed Info website – knowledge base of weed information website
• CropLine – 1-888-449-0937
• CropPest Website

Eastern Ontario Crop Diagnostic Day will be on Tuesday, July 16, 2013 at the Winchester Research Farm of the University of Guelph, Kemptville Campus. Still opportunity to have input into the demonstration stops.

NEXT MEETING: Country Kitchen, Winchester, 7:30 am, May 28, 2013

Corn: Emergence has been excellent in early fields, taking 8 to 10 days. Current cool temps are slowing this progress.  Early areas are 90% plus planted, while later areas (clays, livestock areas with lots of manure to haul) range from just getting going to 50% planted.

Neonicotinoid’s and corn planting: We are aware that PMRA has been notified of some bee kills again this spring that coincide with the timing of corn planting in the area.   Continue to push growers to follow BMP’s for reducing the risk to bees.

Soybeans: range from not started to 15% planted.  Typical discussion around planting when temperatures are cold.  The key to this issue appears to be a cold rain.  Beans planted into cold soil (5C) have not shown cold water imbibition injury in Ontario trials previously, as long as temperatures warm up through the day.  Beans planted in front of a cold rain, however, have resulted in reduced stands and poor vigour.  Bottom line: if seed quality is good and no cold rain is forecast, plant beans.

Wheat: More nitrogen (N) was left to apply last week than previously thought: quite late for N applications.  Temperatures have been ideal for wheat, close to 18C day and 10C night.  Lodging potential should be reduced from these temperatures.  Advanced wheat in Essex started to push the flag leaf out last Wednesday, and is now at full flag leaf stage.  Most wheat in this region is second node, so any herbicide applications need to happen immediately.  Herbicide applications have been on hold for the last 2 days due to cold temperatures.  Second node is ideal timing for the first fungicide application.

Sulphur deficiency is quite evident in many fields, even on some good soils with a history of manure: 2013 appears to be like 2011, wet and cool with very little release from the organic matter.  Some Mn deficiency also showing: some growers questioning if they can mix S with Mn, and perhaps a fungicide, and go after everything all at once: there is essentially no research done on this concept, but Peter Sikkema may look at it this spring. Leave out the herbicide if you decide to mix ammonium thiosulphate with the fungicide.  3 gal thiosol in 20 gal of spray solution should rectify any S deficiency.

Septoria can be found at low levels in most wheat fields now.  Cereal Leaf Beetle damage can be seen in the traditional CLB areas: Clinton, Delhi, Simcoe.  Natural parasites which give excellent control do not overwinter well in sand soil, nor move far in the spring, thus the repeated hot spots for CLB injury.  No armyworm found to date.

Spring Cereals:  Seeding is complete, although later than preferred.  Very few straight oat fields were planted.  Growers wanting to plant oat as a cover crop following wheat may have difficulty finding seed, as oats seem to be nearly non-existent.  There are none in western Canada.  Growers may have to use barley instead. (Martin Harry, Secan).

Forages:  Alfalfa growth has responded to warmer temperatures last week.  There is renewed hope for a decent first cut.  Grass stands have responded very well to N applications.  New seedings are emerging.  Alfalfa weevil has been reported in Ohio: growers need to scout.

Rye for forage is at the flag leaf to early boot, depending on planting date.  Growers wanting quality need to harvest immediately.  Growers wanting more yield should wait.  Once rye is harvested, remember to scout the following crop for cutworm, as rye stands are very attractive to migrating cutworm moths.

Weed Control:  Canada fleabane and giant ragweed resistant to glyphosate have been confirmed in Huron county, with testing of common ragweed ongoing but suspicious.  EVERY field should get a soil applied herbicide, followed by clean up with glyphosate in RR crops.  In no-till situations, Eragon is preferred for fleabane control, and .3 l/ac of 2,4-D LV Ester 700 for ragweed, with a 7 day pre-plant requirement. In tilled situations, metribuzin or Broadstike would offer fleabane control, while Firstrate would be the product of choice on ragweed that does not have multiple resistance.  In situations where fleabane existed that had cross resistance, growers have been forced to till the crop down in early June and start again.  This is not something to be taken lightly. (Peter Sikkema)

Supplies of some herbicides are tight, but most dealers have enough to get through.

Agricorp: Provincially 124 damage reports on wheat, with only 28 of those in Perth Huron Middlesex.  Bruce county is a bit of a hot spot with 44.  However, these numbers are still well below normal (~2% of acres).

Thanks to Eric Devaere for chairing the meeting and getting us out before 9 am.  Pat Feryn will chair the meeting in 2 weeks. Huron research Station will host the meeting June 25th, and provide breakfast.  Following the normal meeting, there will be a 1 hour tour offered by Peter Sikkema, Chris Gilliard and Dave Hooker of some of the key research efforts underway on station.

Thanks to all that attended.  Next meeting May 28th, Malibu restaurant, 7:00 am breakfast, 7:30 meeting.

If you have questions or concerns about these minutes, please contact Peter Johnson peter.johnson@ontario.ca or Horst Bohner, horst.bohner@ontario.ca

Yesterday was a sunny and successful variable rate planting day at Blythe Brae Farms in Oxford County. Greg Stewart and I created a normalized multi-year corn yield map (6 corn years in total) and then simplified the normalized yield map into 3 zones: low, medium, and high. Next the management zones were converted into a variable rate population map with 3 rates: 30,000 | 34,000| 38,000 seeds/ac assigned to the low, medium and high yielding zones respectively. Three replicated uniform rates were also placed strategically across the fields to examine yield response across all the zones from the multi-year corn analysis. Stay tuned for more precision agriculture news as the season unfolds!

The above monitor shows the map of the field that will be planted at 3 different populations of corn. The red areas in the above map will be planted at 30,000 seeds/ac, the yellow areas will be planted at 34,000 seeds/ac and the green areas will be planted at 38,000 seeds/ac.

Project Background: The Oxford Soil and Crop Improvement Association (SCIA) was a Water Resource Adaptation and Management Initiative (WRAMI) funding recipient from Farm and Foodcare. Blythe Brae Farms volunteered two fields for research trials. OMAF and MRA specialists are assisting Oxford SCIA with two precision agriculture project objectives that increase producer preparedness in managing low and excess water conditions:

• site-specific nitrogen management in corn to reduce the potential of N leaching
• site-specific corn population strategy to improve water use efficiency and address soil moisture field variation effectively

Alfalfa frost damage can sometimes occur in the spring after growth has started, resulting in damaged growing points. Some wilting can be visible about 24 hours after frost or some yellowish or brownish discolouration 3 or 4 days later. The top of the stems will typically bend over with a “shepherd’s hook”. Damage is often minimal and plants will grow out of it, but some yield loss and development delay can result. Thin alfalfa stands are more susceptible to frost damage.

“Light Frost” Damage

The extent of frost damage to the alfalfa will depend on the severity of the freezing. Temperatures in the plant canopy level are usually “layered” and higher than reported “air” temperatures. Soil temperatures, slope, wind and the microclimate within a field can all have an effect. In mild cases, leaves at the tops of the plants become wilted and discoloured, but plants should completely recover. If the “shepherd’s hook” straightens, normal growth resumes. Frosts of as low as -3ºC can freeze leaf margins (resulting in white spots on leaves), but not damage stems or growing points.

“Heavy Frost” Damage

In more severe cases, alfalfa stems freeze to various degrees and growing points are destroyed. Growth of alfalfa is from the tip of the stem where the growing point is located within a dense cluster of unfolded leaves. Temperatures below -4ºC for 4 hours or more will damage growing points and stems will die. However, it would take a lot of hard frost to kill an entire alfalfa crown and this very rarely occurs.

Frost damaged alfalfa plants usually recover and regrow from:

1. axillary buds on lower parts of the plant (if lower stems are not damaged), and/or

2. newly formed crown buds.

In most cases, axillary buds will become the main growing point if the terminal buds are damaged.

Forage Crop Impacts

Plants use up some of their root reserves for their initial spring growth. After growing points are frozen, these plants will then have to initiate regrowth from new crown or axillary buds. This will delay the growth and developments of the crop as well as use up more of the remaining root reserves. Healthy stands will recover more quickly. Depending on weather conditions, some first-cut yield reduction and a delay in maturity can be anticipated. Where damage is uneven across a field, there can be some unevenness in maturity. If possible, delay cutting of severely affected fields to allow rebuilding of root reserves and full recovery.

Should I Cut It Now?

There is usually no benefit to cutting frosted plants. Cutting will not enhance recovery and forage quality drops rapidly. Severe frost kills the growing points, the same as cutting does. Regrowth would have to come from new crown buds and may further weaken the stand. Yield will be extremely low with poor quality. In extreme cases, frozen alfalfa that is harvested can be at increased risk for high nitrate levels.

New Seedings

Damage to new seedings of alfalfa is usually minimal. Companion crops protect new alfalfa seedlings somewhat against frost damage. Alfalfa generally has excellent frost tolerance up to the cotyledon and unifoliate stage. Some frost damage can occur starting in the first-trifoliate stage.  Only a few hours of temperatures below -4ºC can kill alfalfa seedlings at the beginning of the second-trifoliate stage. After contractile growth, where the cotyledons are pulled below the soil surface to form a crown, alfalfa becomes more tolerant again. Observe new seedings for 3-5 days after frost. Plants will initially wilt back. If the entire plant dies back to the ground, it is dead. To survive and recover, one set of leaves must survive. Reseeding may be required if less than 15 – 20 viable plants per square foot survive.

Wheat:  Wheat continues to look excellent, with Essex wheat the best it has been in years.  Advanced fields are just starting to emerge the flag leaf.  It is too late for herbicide applications at this stage.  Early applied nitrogen is showing some variable growth, with concerns over potential N loss.  Very little disease pressure to date but with cooler temperatures and rain growers should be scouting for leaf diseases such as powdery mildew and Septoria.  Rust diseases being reported in the southern US and the following link to the USDA cereal rust disease bulletins will assist in tracking progress (http://www.ars.usda.gov/Main/docs.htm?docid=9757). Both Mn and S deficiencies are showing: 2013 appears to be more similar to 2011, with S deficiency more common.  This is probably tied to a cool spring and less S release from organic matter.  Residue accumulation in wheat was discussed as it pertained to poor winter wheat stands (cooler, wetter soils).

Alfalfa: Looks much better than 2 weeks ago but some fields which were cut late last year had greater winter injury.  Grass forages are doing very well.  Agricorp reports that there is much greater damage in eastern Ontario.  Insurance is establishment based (used to be re-seeding based) and a claim can be made when there are less than 6 plants/ft2 .  There are no restrictions on how the crop is handled subsequently; it can be re-seeded or can have a cutting followed by planting to corn.

Corn:  70% of corn planted with the majority south of the 401 (80% plus sands and 5-10% clays).  Corn planted in the Stayner area April 19 is emerged.  Timing on pre-emerge products will have to be watched, as corn is emerging in 7 to 10 days.  Some products must not be applied to emerged corn.  A friendly reminder to check planter settings/performance for populations and spacing and don’t wait till you have an unusually high number of left over bags!

Rye: crop in good shape particularly after corn silage or wheat.  Cutting will begin next week.

Weed Control:  Dr. Peter Sikkema confirmed the following glyphosate resistant (GR) and multiple herbicide (MR) resistant populations in Ontario:

1) GR giant ragweed – 82 sites in 7 counties (Essex, Kent, Lambton, Elgin, Middlesex, Huron and Lennox & Addington)

2) GR Canada fleabane – 155 sites in 8 counties (Essex, Kent, Lambton, Elgin, Middlesex, Huron, Haldimand and Niagara)

3) GR common ragweed – 1 site in Essex county (studies continue to determine distribution in Essex and other counties)

4) MR Multiple resistant giant ragweed – 5 sites in 3 counties (Essex, Kent and Lambton)

5) MR Multiple resistant  Canada fleabane – 19 sites in 5 counties (Essex, Kent, Lambton, Elgin and Middlesex)

Cross resistance is a major concern for Canada Fleabane, as Firstrate would be the product of choice, but will not work on biotypes that are resistant to both glyphosate and Group 2 herbicides.

Peter stressed the importance of fall week control especially for chickweed, which can be of further benefit in reducing potential cutworm issues in the spring.  A reminder glyphosate alone for spreading atriplex control gives variable results: control is dependent on size, and atriplex is getting big.  Be sure to have a tank mix partner to increase control (metribuzin works well).

NOTE:  June 18 Ridgetown Breakfast Meeting will be held at the University of Guelph Ridgetown Campus in the Wilson Hall Campus Centre with breakfast starting at 7:15am.  Following breakfast discussion, Drs. Peter Sikkema and Darren Robinson have invited attendees to tour their weed management trials on campus.  Please plan to attend this special opportunity and on behalf of the group we would like to extend our appreciation to Peter and Darren for coordinating the meal and tour.

Sample Requests:  OMAF Ridgetown is working with the US North Central Research Program to determine the incidence, severity and distribution of various early season soybean seedling pathogens (Phytophthora, Pythium, Rhizoctonia and Fusarium) in northern soybean production regions.  If you come across any early season disease problems please contact Albert Tenuta (519 360 8307 or albert.tenuta@ontario.ca) for sample collection.  Thanks for your assistance.

Next Meeting: Ridgetown Agribusiness meetings are held at Dar’s restaurant (Daniel’s Esso) on Hwy 21, just south of the 401. Meetings start at 7 am and run alternating Tuesday’s.  Next meeting May 21.

Upcoming Events

Southwest Crop Diagnostic Days, July 3 or 4, 2013