The past couple weeks have been fairly dry and sunny, and the amount of rain on Easter weekend was less than forecasted. However, this week looks cool in comparison, with nighttime temperatures dipping below freezing. The low temperatures should be considered by those thinking about planting or applying herbicides this week.
Winter wheat looks better than this time last year, generally speaking. Growth stage ranges from Zadok’s 27 or 28 up to Zadok’s 31 or 32. As usual, earlier planted fields look healthier than later planted fields. Some fields have spots with poor survival, although the regions noted as having winter survival issues were Essex and Lambton counties. Some winterkill losses appear to be caused by issues with tile. In 2019 many producers were able to fill gaps in winter wheat fields with spring wheat or oats, or other cover crops like red clover. This is key for weed control in those areas and keeping the soil in place.
Agricorp stated there have been over 160 winter wheat damage reports so far, which is lower than 2019. Call or email Agricorp if you have damage to report. Please check www.Agricorp.com, all updates or changes will be posted there.
Uneven emergence is observed in some fields, likely from uneven seed placement. This may be a result of high amount of residue on fields at seeding, drill performance, or producers not getting out to check seed depth as they plant. How do uneven fields yield compared to perfect uniform emergence? One trial at MSU, seeded on 5” rows with a Monosem planter at 1.6-1.8 MPH had perfect emergence and yielded 10% higher than where emergence was uneven, which is more than expected. This trial was only conducted in one year, and a report has therefore not been published yet.
Can you use plant growth regulators (PGRs) to even out a variable field early in the season? PGRs remove apical dominance for about 2 weeks, allowing tillers to catch up. This can even out the maturity of the field to a certain extent if the problem is late tillers. The challenge in a thin stand is that some plants are healthy and some are not. Removing apical dominance will not make a stand with unhealthy plants significantly more even, and PGRs do not increase yield so the cost of the product is not worth applying in that scenario. PGRs are targeted to managing lodging and can increase root growth. In the absence of lodging, they have been shown to increase yield in some instances and decrease yield in others. They should primarily be used on fields with a history of manure or where nitrogen applications rates will be high, with the intent to mitigate lodging. They are not a rescue treatment for late seeded or stressed wheat crops.
Gibberellic acid products (e.g. Proliant) can induce or enhance growth but if applied beyond Zadok’s stage 30 they can lead to lodging, so producers should ensure it is applied within the appropriate window. In public trials with Gibberellic acid, a response has not been observed in wheat where growth is being limited from water damage or other injury. Gibberellic acid is unlikely to provide a yield boost when applied in the spring.
Nitrogen is being applied to winter wheat, and participants stated that as much as 60 to 80% of the wheat has had an application. Some are split applying nitrogen; up to about 50% are planning to split apply. In more eastern or northern areas, if nitrogen is being applied in one shot rather than split applied, it is too early to apply that nitrogen on some fields. Below are results of 3 polls that were conducted on the call regarding nitrogen application, split nitrogen and overseeding red clover in wheat.
Weed control is discussed further in the “weeds” section below, but it was noted that herbicide injury in wheat caused by application during cool temperatures tends to be limited and does not typically reduce yield. However, spraying in cool conditions (below 5 degrees C) can reduce weed control. Spraying at temperatures above 5 degrees C has historically been recommended in Ontario, although it was noted that in Michigan the recommendation is to spray at temperatures above 10 degrees C. Most herbicide labels do not state any specific temperature restrictions, but instead make general statements like “extreme growing conditions such as near freezing temperatures prior to, at or following time of application may reduce weed control and increase the risk of crop injury”. Although there are exceptions, there are not many weeds observed in wheat right now, which means it is too early to apply herbicides.
There is a lot of interest in oats, including a lot of oat acres planned for northern Ontario. Those who have had issues with winter survival of winter wheat can consider oats instead. The average provincial yield is around 84 bu/ac, with the strongest yields typically coming from Grey, Bruce, Durham counties and northern Ontario. If you want to push yields, oats should be seeded before April 10th for central Ontario, April 15th for eastern regions, and May 10th for the north. There are advantages to frost seeding oats prior to those dates. To achieve top yields, producers should push nitrogen rates higher but watch for issues with lodging. Ontario research has shown that on average the most economic rate of nitrogen (MERN) is 84 lb/ac when a fungicide is used; however, the optimal rate will be impacted by crop rotation, soil type and history of manure applications so growers should be cautious when increasing rates to avoid lodging. Producers should also stay on top of crown rust to manage lodging, which is particularly prevalent in regions of southern Ontario. If oats are seeded early and managed well, high grain yields (e.g. 180 bu/ac in Brice County) and high straw yields are achievable.
Manipulator is registered on oats but MRLs (maximum residue limits) have not been established for all end use regions, so producers should confirm with buyers if they are permitted to use the PGR.
See GoCereals.ca for more information on oat varieties, including lodging and yield data. Details are also contained in this recent Field Crop News article: https://fieldcropnews.com/2020/04/managing-oats-for-maximum-yield-potential-and-profitability/ .
There were no reports of early soybean planting on the call. The benefits of ultra-early planting, such as capturing a longer growing season and earlier flowering, are generally small relative to early planting within the normal planting window (late April, early May). The forecast for the week is fairly cool and drops to -2 degrees C at night making it unlikely soybeans will germinate, so the risk of planting this week is probably not worth any potential benefit. It was noted though, for example, if a producer has over 1000 acres of soybeans to plant it may be beneficial to get started planting a couple hundred acres this week. It is also likely better to plant soybeans early than to plant corn early, if a producer has a lot of acres to plant. When planting early it is recommended not to plant too deep because there should be lots of moisture (1” deep is usually adequate in a no-till situation). The goal should be to get the plants emerged quickly and uniformly since poor stands can be an issue with early planted soybeans. With deeper planting, cooler soils will force that seed to sit for a long time increasing risks of insect feeding and seedling disease. Some agronomists in the US take the opposite approach and recommend planting ultra-early soybeans deep. The idea is to prevent temperature fluctuations and slow emergence to avoid early frosts.
Does applying nitrogen to corn residue prior to planting soybeans increase the speed of the residue breaking down? A lot of research has been conducted on this topic, and it was reported that growers in North Dakota and in Quebec conduct this practice, but we rarely see a yield benefit. Applying up to 50 units of N ahead of soybeans often results in observations of vigorous early top growth, but yield is made in the second half of the season, and the yield benefit is typically only a bushel or two at best.
A very small percentage of corn has been planted, with planting reported between Wellburn and Woodstock. It may be slow to emerge but the immediate forecast does not have excessive rain, so while those stands may not be perfect hopefully they will not have to be replanted. Most agree the next two weeks look too cool for planting corn. Some will likely start planting because the ground will be dry enough for it, but it was noted that producers with an urge to plant should consider starting with soybeans. There was some discussion on weed control; see the weeds section below.
There has been a bit of a rush on some canola seed. Canola has been planted on some acres in the southern part of the canola growing region, but no planting has occurred yet in Temiskaming and Cochrane Districts where there is still a bit of snow left to melt.
Dry bean acres are expected to be a bit higher this year than in 2019. Large seeded beans acres do not change a lot from year to year, but white bean acres are increasing, black bean acres are down, and adzuki are similar to last year. Contact your dealer as there are still some contract available. Sourcing seed has been a bit of a challenge this year because of production issues in 2019.
Much of the discussion surrounded burndowns and controlling Canada fleabane. It is important to get weeds burned down before planting, especially if herbicide was not applied in the fall. Since it is only mid-April now, it might be a bit early for some to be applying a burndown if they will not be planting until the second week of May. Temperatures are still relatively low and will be below zero at night this week, so some points worth noting are that glyphosate efficacy is improved at higher temperatures, and atrazine (a component of Acuron) antagonizes glyphosate at temperatures below zero.
While most weeds are not bolting or growing much yet, chickweed is advancing and becoming quite thick, particularly on sandy fields. It was suggested that if temperatures are above zero for 3 days in a row chickweed should be sprayed as soon as possible, particularly in early planted wheat fields. Dr. Peter Sikkema noted that in his trials any herbicide product with tribenuron (e.g. Refine, Barricade) provided 95% control of chickweed or better, while other products without tribenuron had a maximum of 80% control.
Discussing control of Canada fleabane seems to always be on the agenda. In many regions it is not yet too tall to control. Fleabane control is best when the plants are less than 10 cm in height or in diameter, which is quite small so be sure to scout and monitor its size. Dr. Sikkema’s trials have shown that one-pass “burndown” applications providing nearly season long control of fleabane (when applied at appropriate weed stage) are glyphosate + Eragon + Sencor 75DF (215 g/acre) in Roundup Ready soybeans, and glyphosate + Eragon + dicamba in Xtend soybeans. The pre-emergence treatments in corn of Integrity or Acuron provide consistent control of fleabane. One participant observed that when they have used Callisto with glyphosate in RR corn they’ve observed fewer fleabane seedlings the following spring as compared to where Primextra II Magnum is in the mix. Dr. Sikkema noted that this is because Primextra II Magnum does not provide effective control of Canada fleabane when compared to Callisto. It should be noted however that Callisto does reduce crop rotation options compared to Primextra II Magnum. There is a rate effect with Callisto; in corn the pre-plant rate is higher and provides better control of fleabane than the post-emergence rate. Cereal rye cover crops have also been shown to reduce plant density and supress growth of Canada fleabane which keeps the weed small in size, resulting in improved control with herbicides.
OSCIA Support for “Farming During a Pandemic”
OSCIA members have an opportunity to join a webinar to get tips on safety details for farming under the current COVI-19 virus pandemic. Visit HERE for more info, or contact Cathy Dibble (email@example.com ), or register at oscia.wildapricot.org/events. The first edition of the webinar is full but a second event on April 21st is open for registration for.