Wheat Pete’s Word, June 24: Excess Water, Funky Coloured Crops, White Mould & An Early Alert for WBC

What a storm that was on Monday night! An incredible light show, tornado warnings, wind and so much rain made for a rather raucous start to the week. Thankfully, no one was seriously hurt, but cut hay and cash crops in the area didn’t need yet another deluge.

Excess water is where we’ll start with this week’s crop update, as the fallout affects every crop differently and sometimes in surprising ways. Peter Johnson, RealAgriculture agronomist and host of Wheat Pete’s Word, reminds us that when over 5? of rain falls in less than two hours, you’re going to lose soil to erosion, but some fields hold up far better than others, depending on the tillage management of those fields.

Before we get to the meat of this episode, @WheatPete reminds farmers that we’re rapidly approaching the June 30 deadline for edible bean planting. Many of these acres don’t look great, so time is running out on making the call to replant. Pull the trigger, if need be, and remember to report those acres by next week.

Water is partially to blame for some very varied colours showing up in many corn field. Much of the discoloration or stripes farmers are seeing is caused by wet feet, but other factors are a direct correlation to soil structure impacted by crop rotation, soil structure, and available nutrients.

For those noticing variability, it’s important to determine a zinc deficiency from a magnesium shorter, and both of those from a manganese issue. Johnson goes over what you’re looking for with each, and why at least one these issues isn’t going to be fixed in the corn crop.

The biggest worry still is nitrogen, and after a dry, warm May and now and excessively wet June, soil nitrate levels are dropping off and may not recover if you’ve had six to eight inches of rain in recent weeks. If you’re on the top end of that range, there is some research that suggests a late nitrogen app may boost yields, so Johnson runs through what strip treatment may be best to evaluate the addition.

Staying with the colour theme, farmers are reporting yellow soybeans — while there are several things that can cause yellowing @WheatPete says it’s most likely delayed or poor nodulation. For those wondering if corn stalks and residue is to blame, it is, but only because the soil is likely cooler where trash is heavy, not because the corn stalks are tying up N. Is there a yield impact? That remains to be seen, but of more concern is the soybean crop approaching full flower in the coming weeks — are you ready to spray for white mould suppression? For those with beans on beans, be ready, Johnson says.

Related: Why are my soybeans yellow?

And one more thing, Johnson says that if you’re putting a fungicide on with your last pass of glyphosate on soybeans, jsut stop. And he explains why, below.

On to wheat. Fusarium is definitely out there, though not severe, but Johnson reminds farmers to prioritize harvest on the worst fields and to use that combine as a management tool (crank that air!) come harvest time. Perhaps of greatest concern right now is the higher than expected cereal leaf beetle being found in spring cereal fields, so get out there and scout. Spring crops are also at a higher fusarium risk, based on the weather, Johnson notes.

Also, and early reminder for western bean cutworm in corn. There has been a moth found in traps. (Check out: How and when to scout for western bean cutworm).

Finally, we’re on to this week’s questions. What do you do about too-tall red clover in wheat (besides NOT growing double cut next year?) Plus, what night time temps turn down the volume on corn growth? (Check out What does a day mean in corn? for more details) Then, we round out this week’s Word with a look at N application troubleshooting and what to do about foaming in the sprayer.

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