Early soys: they’re slow, but they’re coming

Contributed by: Robert Moloney, NK Brand Seeds

Some soybeans managed to get planted in the end of April to start of May timeframe before the rain and cold weather set in.  Now a lot of those fields have been in the ground for 3 weeks or more and they still haven’t emerged yet.  Should you be concerned?  The short answer in most cases is “no, you shouldn’t be concerned”.  Based on early planted fields I’ve looked at, the beans are still healthy and coming, they just need some heat to get them out of the ground.

Why aren’t they up yet?  Look to the weather we had in the first part of May.  Our May weather seemed start out as the April weather we never got.  Generally across the southwestern part of the province it was cool and damp (Eastern Ontario was warmer and drier).  Fortunately most of the early beans were planted into good soil conditions and the soil was still warm when they were planted and through early germination.  The cool weather since then seems to have put the germinated seed on ice and kept it from growing much.  The one positive was that it was generally too cold for seedling diseases or much insect activity to cause damage.  The cool weather that slowed plant development is likely most of these fields have been slow emerging.

If you are concerned about your beans, the key thing to do is to dig up some beans and check them out.  Healthy beans are going to be firm and white.  You can get some green or green/purple/red on the top parts once they are exposed to light.

Healthy soybean seedling

The cotyledons (the 2 halves of the seed) will point downward until the growing stem pulls them out of the ground, then they will flip up and grow on.  Small holes in the cotyledons can be a sign of insect feeding, but unless the growing point (at the end of the cotyledons where they attach to the stems) is affected, the plant will likely survive.  Significant browning (ignore dirt on the root) or a mushy feel to the stem or cotyledons is not a good sign and indicates the seedling likely won’t survive.

Crusting could be a concern in some fields after the rains we’ve had.  Just remember that beans can push through an awful lot (especially in 15” or 30” rows where the plants are closer together and can help each other push out).  If you feel you need to do something about a heavy crust, running an empty no-till drill over the field will probably do more good than a rotary hoe.  If the crust is tough enough to impede the beans, the rotary hoe likely won’t crack it either.  Make sure you check where the beans are at before you try either option though, as beans that are just knuckling through the ground are very susceptible to being snapped off and killed.  There are two common signs that crusting is causing the seedling beans a problem: 1 – if your beans have excessive swelling just below the crook of the seedling (i.e. it is swollen significantly just below the crook compared to the rest of the stem down to the root) this can indicate bean is trying to grow, but being stopped by the crust.  Once the beans have a lot of this swelling they won’t be able to continue growing up.  The 2nd sign is if the beans that are starting to leaf out underground.  This usually follows swelling and at this point the seedling likely won’t survive.

Soybean seedling leafing out underground

So if your bean seedlings are still firm and white, the stems aren’t swelling and you don’t have a severe crust you should be good.  All you can (and should) do is to sit back and wait for the warm (hot) weather to let your beans get growing.

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