For Eastern Canada 2019 will be remembered as one of the most challenging springs on record. With a cool, wet spring that delayed planting and field work substantially; it forced many plans to change. What can we still do in the 2019 growing season to help maintain our yields and feed quality for this fall?
Planting Time Impacts on Silage – with the delayed spring many growers changed hybrid maturities to try and hedge against late planting. In this case it will be likely that the feed quality and harvest timing will stay around normal. Lower maturity hybrids will have a shorter grain fill period and should help maintain starch levels and a ‘normal’ harvest window. For example, a lower maturity hybrid that is planted 2 weeks later than normal and is 150-250CHU lower than a standard maturity hybrid, would be expected to be harvested around the same time. However, we would expect that the tonnage on later planting and shorter season hybrids to be lower than your average crop. It is hard to estimate exactly the short fall on yield but a 10% reduction would not be out of the question. For example, if you have 100 acres of silage and your normal yield is 25 tonne/ac a 10% yield reduction equates to 250 tonne of silage. It is important to have a plan in place to maintain your feed inventory this fall.
Now, if you still planted later than normal but stuck with the hybrids that you normally plant, we would expect that you will see a delayed harvest this fall and possibly and some lower energy content feed. These hybrids will have less time this fall to accumulate starch and therefore have less energy in the feed; the tradeoff would be that hopefully you can maintain most of your tonnage. Potentially, with other feed stuffs like cobmeal or high moisture corn, the energy content could be easily increased in the diet.
What Can We Still Do?
Nitrogen – with a cooler, wetter spring the mineralization of nitrogen this year has been lower than average. If you rely on your manure for a large part of your nitrogen source you could be in a nitrogen shortfall for your corn crop this year. Also with excess rainfall we had saturated soils which lead to denitrification and potentially leaching from lighter soils. Since 35 to 40 % of the corn crop nitrogen is taken up after tassel it may still be important for you to consider the corn crop N status. Soil N testing can be quite difficult to evaluate once the corn crop gets over knee high, tissue testing might be of some help, or perhaps just a visual assessment of the crop. If the corn is pre-tassel and you notice significant firing on lower leaves, more N may be required. This is important to note because it is not too late to top up your nitrogen program if you have access to some high clearance equipment. In some situations it may still be possible to side-dress nitrogen with a higher clearance toolbar, in most cases high clearance spinner spreaders that broadcast urea into standing corn or a drop tube approach on a high clearance sprayer applying 28% UAN will be the necessary options.
Fungicides – another way that we have been consistently improving silage and grain yields is by applying a foliar fungicide as the corn tassels. Our replicated trials at Maizex have shown consistent yield increases when applying foliar fungicides at VT to R1 (tassel emergence to late silk stage). When considering applying a foliar fungicide to your silage or grain corn there are different products that you can use depending on your end goal. If yield is your primary target we would suggest that you use products that control foliar diseases like Northern corn leaf blight that can have a huge impact on your corn yield and grain fill. There is a wide range of products that fit this window such as Trivapro, Stratego PRO, Headline AMP, Priaxor, etc. These products will generally provide a nice up in yield as your corn crop is protected from detrimental leaf diseases. With more green leaves and plant material feed quality and Relative Feed Values are often higher on silage sprayed with a foliar fungicide. The optimal timing for these fungicides is VT (Tassel Emergence) until silk browning.
The other target to consider is reducing mycotoxins in your silage. There are certain fungicides that can help to reduce the risk of mould infection and resulting toxins in your feed. Application timing for these fungicides needs to be more carefully managed. Fungicides to reduce ear mould and DON need to be applied when the silk on the ear of the corn plant has emerged and is still green. Ideally this would be 3-7 days after the first silk has emerged from the ear and certainly before any silks have turned brown. The products that can be used for helping to reduce mycotoxins in your feed are Caramba, Proline and a new product from Syngenta for 2019 called Miravis Neo.
In some cases fungicide products or product combinations can be used for both yield and quality improvements but remember that application timing will still be critical for any quality (mould reduction) enhancements.
A note of caution would be that if you are already pushing the maturity of your corn Hybrid and did not get it planted early. Applying a fungicide to silage corn can increase the moisture content 1-2% at harvest or delay harvest by 3-5 days. Therefor if you are already stretching your harvest timing because of this spring, a fungicide may hinder you harvest even further.
Insects – one other watch-out this summer would be to monitor for Western Bean Cutworm (WBC). WBC can cause significant damage to the ears of corn reducing yield and more importantly causing ear mould infection and the production of toxins (DON) on the ear. WBC normally migrate up from the south arriving in July with peak flight typically in late July to early August. WBC prefer untasseled corn fields to lay their eggs on which later hatch and can damage the ear. Late planted and therefore late tasseling corn may be more prone to WBC pressure that other years, particularly fields that are delayed compared to most others in the area. We strongly recommend that you monitor the presence of WBC in your fields, for scouting tips please visit http://fieldcropnews.com/wp-content/uploads/2019/07/WBC-Scouting-and-Management-2019-Corn-Final.pdf. Most of the fungicides listed above can be tank mixed with insecticides in an attempt to make the single pass over the field as efficient as possible. There are a range of products that control WBC such as Coragen, Delegate, Voliam Xpress and Matador.
In summary, with patience and hard work the majority of the corn in Eastern Canada has good potential. It is important now to make sure that your crop has what it needs to finish and protect it from insects and diseases that may arrive yet this summer.