Ridgetown AgBreakfast Minutes, May 20, 2014

Synopsis: FRUSTRATING! Very little progress over the past 2 weeks. 3″ plus rainfall. South-west estimate 10-15% corn planted, 2% soybeans. Early corn is 1-2 leaf. Many growers will not switch corn hybrids: they will switch to soys. Sulphur deficiency is obvious in some wheat fields. Manganese deficiency in the odd field: but less prevalent with current wet conditions. You CANNOT grow wheat without phosphorus: corn row syndrome showing even in fields with liquid starter programs. Early wheat is flag leaf: herbicide options become limited. Only 30-65% of the wheat has had herbicide applied. Manure last fall was a curse on both wheat and forages.

Corn: Any planting progress has been on lighter soils.  Early sweet corn under plastic is 2 leaf. April 24th corn emerged only 3 days ahead of May 6th corn, as April days accumulated less GDD than May days.  It takes 150 GDD to emerge corn from 1.5″ planting depth. Only 2% of seed corn is planted.

Corn will shorten both the vegetative and grain fill period when planted late. An excellent table from Bob Thirlwall on Dekalb hybrids, GDD to 50% flower, test weight and dry down. An excellent post from Russ Barker summarizing the Exeter 2011 OCC corn trials.  Both of these analyses strongly support not switching hybrids in this region until May 30th.  If switching is necessary, all companies report good supplies of shorter season hybrids. The website “Useful to Useable”  offers growers another tool to help make hybrid switching decisions. On Weather Central (www.weathercentral.ca) there is a blacklayer calculator that growers can also use.  However, these tools do not take into consideration the shortening effct of late planting on any given hybrid.

Research from Neilson, Purdue suggests planting date is responsible for 23% of yield. Data from Stewart (Ontario) suggests that planting date only explains 5% of the variability in final average yield. Growers need to take heart, the outcome could still be good.

A few reports of issues with the new Fluency Agent, but in general it is working well. Watch the small screens in each row unit on John Deere planters, a few growers have found they can become partially plugged. One trial field that was suspected of wireworm potential found no wireworms when bait stations were installed and subsequently evaluated. If growers are forced to switch hybrids, it may become challenging to reach 100 neonic evaluation sites.

Soybeans: Very few soybeans planted. As planting dates are delayed, do not switch maturities until at least June 15th. Many growers on the heavy clay soils have indicated that they will not switch corn hybrids, but will switch to soybeans instead. This has significant rotation implications for an area that already has too many soys.

Wheat: Burned off wheat fields are now easily picked out. Some areas have a lot, other areas less than anticipated. Provincially, 15% reseed acres are expected. However, some areas will hit 50%.

Advanced wheat is at flag leaf emerging stage (GS 37). Any herbicide applications are now “revenge” spraying: yield loss from weeds has already occurred. Weed control at this stage is really a harvest aid. Move away from any hotter herbicides, as application at flag leaf can cause injury. In fields with clover, herbicide applications are still justified if significant weed pressure exists. Red clover stands are excellent. In fields without red clover, preharvest glyphosate may be the better harvest aid herbicide.

Wheat on pea ground is already beginning to show signs of lodging. Ethrel can be used as a growth regulator to reduce lodging: flag leaf timing is critical, and temperatures must be under 28°C.  Sulphur deficiency is showing in many fields and plots. Cool soils will have slowed release from the organic matter, making deficiency more common. DO NOT tankmix ammonium thiosulphate with fungicide or herbicide.  Unacceptable burn will occur. A few reports of manganese deficiency. Wet soils make Mn more available, so expect less fields to show Mn deficiency than normal.

Denitrification: Wet soils have growers concerned about nitrogen loss on wheat acres. Best research indicates losses of about 2%/day at soil temperatures of ~15°C, for each day that the soil is TOTALLY saturated (1%@10°C, 5%@25°C). When there is air in the soil, denitrification will not occur. Growers need to estimate number of days totally waterlogged, soil temperatures, and then an estimate can be made as to the amount of N loss.

Forages: Having grass in forage stands is proving to be of great benefit this spring, where alfalfa winterkilled. Proper stage for harvest will not occur for 7-10 days, significantly later than normal. Growth is good where the crop is not injured. Overall forage yields will be reduced, both from later development and winter injury.

Manure: Fall/winter applied manure has created some unusual impacts. Fall manure on wheat or forages has significantly reduced winter survival: several cases of split fields where the manure side was much more injured, or killed outright. Even rates as low as 1000 gal/acre showed this effect. On ploughed ground, manure applications seemed to “melt” the soil structure, and the difference was clearly visible even at 100 km/hr. The exact cause of this is unclear. Nitrogen impacts on hardening off, drainage effects, impacts on soil bacteria are all possible contributing factors. This is the first time that these imapcts have been noted at this level.

Soils: Worm counts have varied from 1-3 on sand to >120 on no-till, rotated, manure applied fields on good soil types (1/4 m² X 6″ deep). Radish breakdown is variable. Crimson clover has overwintered well enough at some locations that, along with the volunteer wheat, it will be taken as forage. Multi-species cover crops have only the rye and hairy vetch still alive. Oat residue slows down soil drying more so than other cover crops.

Weed control: Giant ragweed control in seed corn: 2,4-D LV ester recommended, do not mix with Eragon (too much burn for good uptake). Permit/Sandea is now scheduled and supplies are at retailers.  When planting resumes, many growers may not want to wait the 7 day label period between application of 2,4-D and planting soybeans. Research clearly shows that the risk of yield loss from planting closer than 7 days (often 0% yield loss) is far less than letting the glyphosate resistant giant ragweed go uncontrolled (90% yield loss). Spray as early as possible, and plant when you must.

Fall sprayed red clover, even if not 100% kill, has virtually no vigor compared to unsprayed clover. It appears uncompetitive and should be easy to kill.

Hort crops: Sugar beet stands are nearly ideal (200+/100′ row). 90% of beets are planted in Ontario, well ahead of progress in Michigan. Tomato planting is barely started. A few early tomato’s showed excellent root development on transplants with the few warm days they received. Early potatoes have emerged.

Breakfast was courtesy of Bob Thirlwall (Dekalb Canada

Next meeting:

7:15 am, June 3rd, Willson Hall, Ridgetown Campus, University of Guelph

Important Dates:

July 9 and 10, 2014 Ridgetown Diagnostic Days

January 6 and 7, 2015 (Southwest Agricultural Conference) – Ridgetown

Questions or comments on these minutes please contact: Albert Tenuta (albert.tenuta@ontario.ca) or Peter Johnson (peter.johnson@ontario.ca)