Watch out for CUTWORM…

By Robert Moloney, Syngenta Seeds

This spring is shaping up to give us some issues with cutworm this year and Tracey Baute, OMAF, is reporting some damage north of Guelph already.  Cutworm moth counts in the U.S. have been very high and since cutworm blow into Ontario each spring this is setting us up for a problem.  We are also at greater risk due to the late planting season that we’re getting into.  If we get planted early the corn plants may be large enough (>5 leaf) to grow through whatever damage the cutworm cause but that’s not likely to be the case this year.  With the rainy weather we’ve had a lot of winter annuals (especially chickweed) have had a chance to get large and form a thick and attractive mat on the ground before being burnt off.  Undisturbed soybean stubble is also quite attractive to cutworm.

Cutworm moths are spring immigrants into Ontario. These pests are carried to Ontario from the U.S. by wind.  Growers in Essex, Kent, Elgin and Norfolk counties (especially along the north shore of Lake Erie) are the most often affected, but cutworm can sporadically show up anywhere in the province.  The adult moths lay eggs on low lying/matted weeds on the ground.  The larva will often start on the weeds then move on to corn plants after the weeds are killed and start to die.  They will continue feeding on developing corn plants through June.  Since the larva will tend to spend the day just below the surface of the ground, often the first indication you have of cutworm damage is holes in the leaves of the plant, a suddenly wilting plant (where the larva have cut partway through it or tunneled into the plant) or plants cut off entirely and fallen over.

Bt EVENTS ARE NOT EQUAL IN BLACK CUTWORM CONTROL!!

 Many Bt events provide no control at all on Black Cutworm larva.  These include the Yieldgard VT Doubles and Triples, Pride G2 and G3 and Agrisure CB and Agrisure 3000GT.  Agrisure Viptera 3111 provides the highest level of control available while Herculex and SmartStax (which contain Herculex) events will provide suppression/control of small larva.  Under high pressure of cutworm or (as is likely this spring) with larger cutworm scouting of all corn fields (including with fields planted with Bt hybrids providing control) is recommended.  This is since control is not perfect and level of control drops as larva get larger.  Cruiser or Poncho seed treatments also provide some protection, but only against small larva.

THRESHOLDS

If you have feeding on 10% or more of plants, plants are <6 leaf stage and the larva are less than 1 inch long spraying is recommended.  Matador 120EC is registered for control of cutworms.  Spray should be applied in the evening or nighttime hours when the cutworms have emerged from the soil and are actively feeding.  Keep water application volumes up for good coverage.

Later planted soys – do I need shorter maturity?

By Robert Moloney, Syngenta Seeds

Since someone seems to have forgotten to turn the tap off across most of Ontario, the planting season has been pushed back farther than we would like.  At this point (May 19), most growers are moving to shorter season corn hybrids.  But what should we be doing with our soybean maturities?

First realize that soybeans and corn react very differently to late planting in Ontario.  Corn generally requires X number of days and X amount of heat and sunlight to reach maturity.  The soybean varieties we grow in Ontario are considered indeterminant varieties, which means that flowering and seed production is controlled more or less by daylength rather than requiring a set amount of heat/time.  In the southern part of the United States they do grow determinant soybeans that behave more like corn.  And most of the edible beans varieties grown in Ontario are also determinant in their behavior (require a relatively fixed number of days to reach maturity).  What growing indeterminant soybean varieties means for us is that a 1 week delay in planting at this point will likely only cause a 2 day delay in maturity in the fall.  As we get into June a 1 week delay will likely cause less delay than this in the fall.  So as a general rule there is no need to move to shorter maturity bean until we get to June 15th.

 Some growers are concerned about moving to a shorter maturity soybean in order to get wheat planting done in a timely manner this fall.  While this seems logical, the odds are that harvest/wheat planting weather this fall is going to have a bigger influence on getting the wheat in than a small change in the maturity of the soybean variety you grow.  Obviously the sooner you can get the soybeans in the ground this spring will have an even bigger influence than either of these factors.  Choosing a soybean variety that is properly adapted to your farm (i.e. disease resistance, drought tolerance) will be of more benefit than trying to get a shorter maturity bean.

What to do if you’re planting late?

Do make sure you are planting into a fit seedbed.  Soybeans have a weaker root system than corn or wheat so they are much more sensitive to being “mucked in”.  As the planting season gets late for your area consider moving to narrower rows (7.5” ideally) as they will have a bigger advantage to wider rows.  As long as lodging or white mould are not a concern consider bumping your seeding rate up slightly.  Late planted soys will have less vegetative growth so narrow rows and higher seeding rates will help maximize filling in the rows.  A higher seeding rate will also tend to make the beans taller which should increase the height of the bottom pods and reduce harvest loss this fall.  Given the current conditions scout your fields regularly for Bean Leaf Beetle feeding (especially if you are not using Cruiser treated seed).  With the late planting and current cooler conditions slowing plant growth there will be lots of hungry Bean Leaf Beetles that may clip the seedlings before they get established.

2011 planting date emergence comparison

By Caitlin Harvey, Syngenta Summer Intern

The following comparison pictures were taken in plots in the Sunderland area.

Corn planted on April 19th (pictures as of May 18th) 

As of May 18th: 2-3 leaves and good root system

– 197 CHU’s accumulated from Apr 24-May 18

– Sprout was about ¼ inch long May 2nd (2 weeks after planting)

– Emergence appears to be uniform and even, young plants look healthy, reasonably good colour 

Corn planted on May 10th(pictures as of May 17th)

 As of May 17th: sprout about 1/4 inch long (1 week after planting)

– 115 CHU’s accumulated May 10 (planting date) – May 18th

– There was 82 CHU’s difference between the two planting dates

– For comparison it typically takes 75 CHU’s for each new leaf on an emerged corn plant

LATER PLANTED CORN is typically planted into warmer soils and therefore faster emerging.  Visually the late planted will catch with earlier planted but the early planted may have been planted into better soil conditions and typically has a larger root system.  Even if you are planting late make sure the seed bed is fit to plant.

Late planted Corn

In Ontario and Quebec in 2011 we will have the majority of the corn planted after the optimum date of May 10th. What does this mean and what should our expectations be?

At the time of writing this (May 18th) it appeared we would be at least a couple of days before we could be back planting. Should we switch hybrids? I would recommend in the shorter growing season areas (<2750 CHU) switching now (drop 100 CHU per week delay but do not go below a 2600 CHU hybrid) and for mid range (2800 – 3000 CHU) switch around May 25th and rest of the area's do not switch until June. (reference: Switching to Earlier Hybrids).

What should we expect for yield this fall due to the delayed planting conditions this spring? First remember many other factors still affect yield other than planting date such as fertility, population, hybrid selection, weather, seed depth, compaction, etc…

Yield : expect to lose one bushel per day delay from May 10th or around 10% if delayed until June.

Harvest Moisture: On average expect one point of moisture increase for every four days delayed from May 10th. If delayed to early June a five point increase or 30% moisture compared to 25% if planted early.

Test Weight: Long term average is one pound of test weight loss for every 10 days delay in planting or 2 lbs if delayed to early June.

What can we expect if delayed to early June? 20 bu per acre ($100.00 per acre) plus on an expected 150 bu/ac crop $0.20/bu drying cost increase (assumed drying $0.04 per point per bu) equals $26.00 per acre. Assuming we do not lose grade due to reduced bushel weight a delay until early June could end up costing $126.00 per acre at $5.00 per bushel corn.

Let’s hope for a break in the weather and get this corn crop into the ground.

Late planting corn – when do I switch?

Tell us when you are going to make the hard decision to switch corn hybird maturity because of the wet spring.

Planting Effective Plots

Quality data can only be achieved through quality plots. Establishment of the plot is critical we need to be aware of the following things:

Pre plant preparation

• Stakes, forms, GPS unit, safety equip.
• Check plot seed inventory – do you have the hybrids you want
• Plan ahead– If possible plant the plot early in the season.

Successful Plot establishment

• Site is level and of one soil type
• Watch for dead furrows
• Identifications stakes – 2 per variety in the corn row
• Documentation – fully completed (includes soil type, tillage, previous crop etc.)
• GPS location or map to find site
• Correct planting depth
• Population – watch seed size and changes in population
• Leave documentation with dealer or NK rep.

In season Assessment

Monitor that the stakes are correct
Trim fronts or make a path to and along the front of the plot for easier access.

Assessments

• Spring Vigour
• Flowering/pollination
• Pest pressure – insect/weed/disease
• Maturity – milk line or black layer

Harvest assessment

• Population
• Lodging
• Pest pressure – insect/weed/disease
• Stalk integrity – push test
• Moisture
• Test weight
• Yield

Remember using your plot information and information of other plots in the area and throughout North America as the best way to get the ‘right hybrid on the right field for the highest yield’.

Is it better in the bag or in the field?

It is hard to be patient at this time of year. We all know that the sooner we can get started planted the better or is it? Yes and only if the conditions are right for quick emergence is this true. It takes approximately 100 – 150 CHU to emerge corn and with the daytime temperatures to date we have accumulated nothing in the way of heat units. If you have corn planted you are playing the waiting game to see when (if?) it is going to emerge. With our current genetics, quality standards and seed treatments seed can survive delayed emergence significantly better than 10 – 15 years ago, but if three to four weeks go by and we still have not seen the corn it will be hard to be patient and wish that you left it in the bag. So what should you do? Plant as soon as the soil is fit.

Should I start changing my hybrids to lower heat units? No. Prior to May 10, Syngenta Agronomy Research shows only a one bushel (or 0.11 bu/day) of corn yield loss with a ten day delay in planting. If you did not get finished planting until May 7th this year compared to April 28th last your expected yield loss is one bushel per acre. What about after May 10th? You may want to consider switching your very long heat unit corn to a shorter day hybrid and plant the rest. Our research has shown a one bushel per day for every day of delayed planting. What about May 24th? This topic will be discussed if delay occurs.

In the meantime we need to practice patience. Our elders were correct – patience is a virtue.

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