Calculating Pure Live Seed... Make the most of your time and money.

Before we know it, Spring planting season will be here, some folks may very well even be thinking of frost seeding very soon. Often times we see planting recommendations for seeding rates as pounds of PLS/acre. Some of you may know what that means and others may not, but you thought what the heck I am just going to plant it! PLS (pure-live-seed) is the seed in your bag that is actually viable and is able to germinate upon being planted. Seed is available in a wide range of quality, no not all bags of seed are equal. Some bags contain higher levels of inert material such as seed hulls, damaged seed, and even weed seed. If you buy a 50lb bag of seed and your planting rate calls for 10lbs / acre you might be thinking that will be perfect for planting that 5 acre food plot. Well probably not! So you might wonder what difference that really makes. Planting rates are determined so that you optimize the available planting acres for the largest crop. What happens if you plant at a seeding rate less than what the label suggests? Most generally weeds fill in those open spots. That isn't necessarily all bad if it is an annual food plot and the weeds aren't invasive. But keeping weed competition to a minimum, means that the seed that you did invest money in produces to the maximum of its ability. If weeds are allowed to mature in a food plot, and you are not planting a crop that allows for weed control, the weed seed created increases the weed pressure for the following planting seasons. You may think no worry I will just plant at a higher rate than what the planting rate calls for. Well there are downsides to planting seeds to closely. Most often plants struggle to gain enough sunlight, moisture, and nutrients to reach their full potential. Leading to stunted plants that never mature or just eventually die! Spending money on bags of seed with low PLS as a relative % costs you money, making that bargain bag of seed not so much of a bargain.

The seed label will specify the germination rate of the desired seed expressed as a percentage. The germination rate indicates the percentage of desired seed that will readily germinate. There should also be a date stamp on the label indicating when the germination rate was tested. Keep in mind that seed with an older test date may very well have lost some of its germination potential. Calculating %PLS to assure an adequate amount of BULK-seed is planted you must convert the recommended PLS planting rate to a BULK-seed planting rate. This is easily done and begins with calculating the %PLS per pound of the BULK-seed. The %PLS is calculated based on the %PURITY and %GERMINATION of the BULK-seed. The following formula is used to calculate Bulk-seed %PLS. FORMULA: BULK-seed %PURITY x BULK-seed %GERMINATION 100 = BULK-seed %PLS

EXAMPLE A: hypothetical seed label %PURITY = 90% % GERMINATION = 70%

.90 x .70 x 100 = 63.0% PLS / bulk lb of your seed.

If your planting rate calls for 5 lbs of PLS/ acre

The following formula is used to convert the recommended PLS planting rate to a BULK-seed planting rate: FORMULA: 100 / divided by %PLS lb x seeding rate = BULK-seed lbs/Acre

100/ 63.0 x 5lbs = 7.94 lbs of bulk seed/acre to be planted

The math might seem a bit overwhelming, but after using the formulas just a few times the process is actually pretty simple. Seed dealers can you supply you with the information on a seed label before you purchase it so that you can successfully calculate the amount of seed necessary to seed your planting at the correct rate.

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