Seed & Chemical
Concern growing over slow corn crop development
By Top Crop Manager
Much of Ontario's corn crop is at late pollination to blister stage and concern over the crop's slow development is still increasing, reports Greg Stewart in the latest Ontario field crop report from OMAF.
Aug. 15, 2014, Ontario – Much of Ontario's corn crop is at late pollination to blister stage and concern over the crop's slow development is still increasing, reports Greg Stewart in the latest Ontario field crop report from OMAF.
Concern over the corn crop's slow development continues to increase, reports Greg Stewart. Later planting and a relatively cool July pushed pollination into August in many areas. Normal development for mid-August should be milk stage but a lot of the crop is at late-pollination to blister. We are beyond the window for further management decisions at this point in the season.
Detecting successful pollination without waiting for the kernel blisters to appear can be done by carefully removing the husks, turning the ear upside down and gently tapping it. The majority of silks should fall off indicating successful pollination. Silks that remain attached indicate kernels that have not been pollinated.
Winter wheat harvest provincially is now approximately 90 per cent complete, according to Peter Johnson. Only shorter season areas have significant wheat left. Yields remained highly variable, but better than expected. Quality was excellent: 95 per cent of the crop Grade 2 or better, with high test weights and low Fusarium. Low falling numbers are being reported and a concern for the crop left in the field. Straw yields are lower than expected, resulting in high demand and prices.
Pre-harvest burndowns are gaining favour, allowing faster combining and less harvest losses. Green stems, even at the end of harvest, hampered fields without preharvest treatments. Weed growth in many fields made harvest difficult. Foxtail was evident in many fields, while most broadleaf weeds were controlled. This is an indication of thin wheat: grass weeds do not compete in a thick winter wheat crop. Double cut red clover caused significant harvest issues in thin fields. As re-iterated many times, thin wheat should ONLY have single cut clover applied. Blends of double cut with single cut are the worst of both worlds, not the best of both worlds.
Weed management is critical in wheat stubble. Weeds can set seed in as little as four weeks. Clipping, herbicides, or tillage should be used to prevent weed seed set. Clip as low as possible in fields with clover, to prevent as much weed regrowth as possible. Clipping stimulates clover and increases growth. Preventing weed seed set will reduce weed pressure in the future. Cover crops should be planted as soon as possible. Oats should be the base of any mix. Even 40 pounds/acre of oats alone will give great benefits to the soil as a cover crop. Don’t miss this opportunity to “harvest the sun”. Plan to keep cover crops alive through to the end of the fall period to capture the benefits of the investment.
Spring cereals: Harvest is underway as weather permits. Early yields look promising, with oat yields reported well over 100 bu/ac. Lodging is an issue in some fields. Fusarium in spring wheat continues to be a concern. Keep combine wind speeds high to clean as many damaged kernels out of the sample as possible. High wind speeds can reduce toxin levels by as much as 50 per cent.
Early planted canola harvest is expected to begin the week of Aug. 18, reports Brian Hall. Harvest canola once seed moisture reaches 10 per cent, to avoid significant shatter losses at moistures below this. Shattering losses can be reduced by combining at higher moisture and drying the crop, or harvesting when dew is present or at night when conditions are damp. If swathing, note that green seed content cannot be lowered once canola is stored in the bin. Ideal swath timing is when 60 per cent of seeds (not pod colour) on the main stem are beginning to change colour from green to yellow-brown. A crop swathed too early (before 60 per cent seed colour change) may require more curing time in the swath especially if hot, dry conditions occur. Moisture (heavy dew or rainfall) post-swathing helps speed up the curing process.
In thin crops or fields with variable maturity, side branches contribute more to yield and swathing may need to be delayed until seed in side branches begin the colour change. For information on preharvest herbicide treatment visit www.fieldcropnews.com.
A large portion of the edible bean crop is at the 80 per cent-plus flower stage according to Brian Hall. Once flowering is complete, it is too late to spray for white mould. White mould is now evident, but fungicides cannot control mould already present. Heavy crop canopies make coverage and control much more difficult and less effective. Scout for anthracnose up to late pod stage. Scout water runs, low lying areas, field margins and heavy canopy areas for first signs of infection. A late fungicide application for anthracnose will not control anthracnose on infected plants but can limit its spread and protect seed quality by protecting pods. Fungicides provide 10 to 14 days of protection, but be aware of the 14 day pre-harvest interval. Insect pressure is low but scout fields in proximity to alfalfa fields and orchards for tarnished plant bugs which migrate from these fields. Action threshold is two plant bugs per sweep.
Scout fields for weeds that can cause staining and increase dirt tagging including nightshade family (i.e. berries), pokeweed, and corn (cobs). If they are present be prepared to use a desiccant to ensure you reduce the chance for these weeds to lower your harvest grade.
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