I was talking to a farmer the other day about plant stands in wheat. He wasn’t concerned at all because he has had crops with thin plant stands yield well. I do understand where he was coming from because he has observed a wheat crops ability to make up for a thin stand by throwing out more tillers. At the same time it concerns me because seeding rate is very important when it comes to growing good crops, for a number of reasons. The wheat’s ability to compensate shouldn’t be an indication to just throw random amounts of seed down, it should be a last resort, after doing everything possible to achieve a solid plant stand that is going to maximize yield, decrease weed competition and speed up maturity.
Right from seeding things like disease, insects, negative environmental conditions (flooding, drought, heat etc), weeds and more are doing everything to keep you from achieving your target yield. Putting in place the right practices can fend off these pressures and ensure a profitable yield for your farm.
Starting with clean, certified seed is one of the best investments you can make. This may sound repetitive, but certified seed consistently out yields bin ran seed time and time again, the extra cost is worth it.
Once you have your certified seed, be sure to have the vigour and germ tested and use those numbers to calculate your seeding rate based on the seeds thousand kernel weight (TKW). To calculate this count out 1000 seeds and weigh those seeds (in grams).
The formula looks like this:
target plant population/ft square X TKW (in grams) / seedling survival (decimal) / 10.4
EX: 32 plt/ft sq, 35grams for TKW, .90 (90%) seedling mortality in wheat looks like:
I have been reading a few good tweets about this on Twitter lately from a few guys and its good to see more trying to spread the word on just how important this formula is to use. But now what does using this formula and extra work do for you?
Guys used to aim for that 24plts/ft sq, and for dryland guys sometimes that is more realistic as in some areas the lack of moisture is going to allow those thinner plant stands to do better than a higher target of 30plts/ft sq, but upping your target can speed up and even maturity. The majority of yield (95+%) comes from the main head (50%+) and the first 2 tillers (20-25% each). Knowing this we can see that anything beyond 2 tillers is a waste of energy for the plant. This means the crop is taking more time, more moisture and more nutrients to finish off that 3rd or 4th tiller delaying maturity by up to a week, and taking away potential moisture or nutrients for next year without gaining any real yield advantage. Not efficient for your farms bottom line, to say the least.
Weeds constantly are robbing your crop of yield. A thicker and more even plant stand is better able to compete against this weeds and secure the use of moisture and nutrients for your crop which is going to add to yield. A thin plant stand is susceptible to increased competitions of weeds and choking your crop out, which hurts your yield that year and adds to your fields weed seed bank for the next year.
Insects and disease are constantly thinning your stand out. Wireworms and seedling disease are on your crop like white on rice from the second you put seed in the ground. Having a solid target stand is going to combat against these issues. If you target 30plt/ft sq (which is higher than a lot of growers I have talked too) then even if 2 plants are taken out by a wireworm and 2 are taken out by disease you are still securing yourself 26 plants per foot, a number that sets you up for a good yield come August.
I know this usually isnt an issue, but there is a lot of moisture in a lot of area as I write this, meaning there is potential for some big crops. Don’t be afraid to seed heavy this year because there is moisture and potential for big crops. A thicker plant stand is also better able to combat excessive moisture, so keep that in mind.
The last step to take is “insuring” your seed by putting a registered seed treatment on before seeding. Studies show consistent yield increases and enhancements in the “pop up effect” from these treatments and battle negative seedling diseases. These can be a fungicide, insecticide or a combination of the two. There are other options out there such as nutrient seed dressings and biological organisms to enhance your seeds ability to get out of the ground. The proper seed placed fertility program, seed depth and seeding speed can also help you hit that proper target plant stand, but those are for another time.