Many companies use coated seeds. They tend to claim better germination as their reasoning. What isn’t known is that many of the growers of clovers and legumes don’t use coatings on the seeds that they sell. Most companies now are forced to use coated seed to be cost competitive. Many of the coated seeds contain between 35 and 50% of the seed being coatings. The typical coatings being a bentonite based ingredient. The difference in price put on many price sheets in the industry shows between 10-20% savings for their coated seed offerings. The cost to coat seed is about only 3% of the cost of many legumes. So there is about 20-30% increased profit margin for companies offering coated seed.
Another point I’d like to bring up is for anyone planting any of the usda/government program mixes, the formulas all use pure live seed. If you had a mix that called for 2 pounds of medium red clover, 2 pounds ladino clover and 2 pounds of orchard grass, here is how you would calculate your seed needs.
CALCULATING PURE LIVE SEED
The first thing that needs to be understood when dealing with seeding rates, recommended planting rates and seed mixtures is how to determine PLS. As defined above PLS is the percentage of good viable seed that has the potential to germinate. To calculate PLS you will need to know the % total germination and % purity of each seed lot that you plan on planting. This information is included on the seed analysis tag or a copy of the seed
analysis report that by law should have been supplied with each lot of seed purchased. If you don’t have this
information or you have purchased seed without an analysis tag or report than you are taking a chance on whether the seed you plant may be viable or not.
The basic formula to calculate PLS is: Percent (%) Purity x Percent (%)
Total Germination /100 = % PLS
The seed tag below indicates this lot has 98.75% purity and a total germination of 93% (germination 88% and dormant seed 5%)
The calculation to figure PLS for this lot would be: 98.75 x 93/100 = 91.83% PLS
Kind Ladino Clover
Variety LNPI Selection
Lot Number SRE-02-08
Date Tested 11/29/2008
Net Weight 50 LB.
Pure Seed 98.75%
Inert Matter 1.00%
Other Crop 0.00%
Weed Seed 0.00%
Dormant Seed 5.00%
Total Germ & Dormant Seed 93.00%
So if the usda called for 6 pounds of pure live seed per acre you would need to buy 6 / .9183= 6.53 lbs. of this seed lot.
Now compare if a company has 35% coated seed that had the same germination percentage. You would need to purchase 63.75x93/100=59.28% PLS 6/.58.28=10.30 pounds of coated ladino seed you would need to buy.