By the OMAFRA Field Crop Team
Most corn is at the 6 or 7 leaf stage and progressing nicely. Fields are generally beyond the critical weed free period. In dry areas, there have been some weed escapes where herbicides didn’t get adequate rainfall for activation. Cooler weather, especially low overnight temperatures have slowed growth over the past week.
Foliar disease levels are low to date and no need for fungicides as a result. In recent years, Northern Corn Leaf Blight (NCLB) has affected many areas in the province as new races continue to develop. Common rust is increasing in the southern US and OMAFRA will continue to monitor the disease’s movement north. If fungicides are needed as a result of disease, they should be applied as close to tasselling as possible. There are many products registered for control of NCLB, common rust, grey leaf spot and others. Consult the Field Crop Protection Guide, which is now available online www.omafra.gov.on.ca/english/
Soil nitrate tests are showing variable nitrate levels. Cool weather has resulted in some low nitrate levels however dry soil conditions have kept some nitrogen near the soil surface and will require moisture for plant uptake. Further information on the recent OMAFRA Field Crop Team Soil N survey is available at www.fieldcropnews.com, and full reporting of the GFO sponsored Soil Nitrogen Sentinel project can be viewed at bit.ly/GFO-N_Sentinel
Variable plant growth in fields where portions of the field were too wet at planting, especially heavy-textured soils, have resulted in stunted, sometimes purpling plants with horizontal root growth. Side-wall compaction followed by dry conditions has resulted in reduced vigour and lower plant stands.
Soybean growth ranges from “still waiting to germinate” to third trifoliate stage in earliest planted fields. Seed corn maggot, wireworm and millipede feeding continue to be reported, especially where beans have remained un-emerged for several weeks. Emergence on eroded knolls, dry, heavy-textured soils and areas of fields not planted into moisture is patchy and some replanting is occurring, however, planting into moisture is important.
There are still a lot of weedy fields that are moving beyond the first trifoliate. Grassy weeds in particular are getting large. Where pre-emergence herbicides were put down and received some rain, the weed control looks much better. Some fleabane escapes from un-activated herbicides will be difficult to control. Recent windy days have hampered spraying.
First-cut alfalfa is flowering and grasses have headed, as forage harvest continues, mainly for non-dairy hay. Reported yields are normal to slightly below normal, but quality is excellent. Forage regrowth and newly seeded forages would benefit from moisture.
Many producers are applying nutrients or manure immediately after harvest to build potash levels especially, but phosphorus and sulphur are also being applied. Traffic for manure or fertilizer applications on hay fields should occur as soon after harvest as possible so that damage to stands as second growth begins can be avoided.
The winter wheat crop continues to look promising. Most of the acres have received fungicide for stripe rust and to prevent Fusarium head blight. The wheat has headed out a week to ten days earlier than usual, so harvest is also expected to be earlier. Dry weather in some areas has likely contributed to lower head counts, small wheat heads, and could reduce grain-fill. Some believe that yields may not be as high as anticipated earlier in the season.
There are some reports of army worm in the Binbrook and Cayuga area of Haldimand and of cereal leaf beetle in Eastern Ontario. Bleached wheat heads are also being reported in some areas. Although Fusarium head blight is the most common cause of bleached heads, there are other causes such as Take-all, Wheat Sawfly and Stem Maggots, or Eyespot/Strawbreaker.
Early planted canola fields in the Mount Forest area are in flower, and others planted later have not yet bolted. Swede midge levels are at or nearing thresholds across Ontario; each field will be different so monitor them closely. There are also threshold levels of cabbage seedpod weevil in the Mount Forest area. Early planted fields should be scouted with a sweep net for this pest. Refer to www.ontariocanola growers.cafor the notification on cabbage seedpod weevil and tips on scouting.
Planting is not yet complete but is getting close as most producers finished up last week. Some are still waiting on moisture before finishing planting. Earlier planted fields are at the first trifoliate but cool weather is not ideal for plant growth. There are also some replants happening because of poor emergence caused by crusting and plants emerging with bald heads.
There has been some damage on edible beans caused by Group 15 herbicides. The first leaves were knocked off but new trifoliates are coming and the plants should be fine in a week.