b'SEED TESTINGThousand Kernel Weight Test: Whats It All About?Why more growers are ordering this seed test.THIS SPRING, if you are a farmer who asks for a Thousand Kernel Weight (TKW) test on cleaned samples of each of your seed lots, you already understand why this information matters.Where on the WebTKW is the weight, in grams, of 1,000 seeds from a randomA free app for calculating seeding rate for many sample. Its highly useful for calculating the optimal seedingdifferent crops using TKW is available atrate for a given crop type or variety, and it can also be used tohttps://apps.apple.com/us/app/id1257514147calibrate a seed drill as well as estimate yields.As stated in an Alberta Agriculture and Forestry (AAF) guideUsing 1,000 Kernel Weight for Calculating Seeding called Using 1,000 Kernel Weight for Calculating SeedingRates and Harvest Losses is available atRates and Harvest Losses, TKW and seed size are attributeshttps://www1.agric.gov.ab.ca/$department/deptdocs.that, beyond varying among crops and between varieties, cannsf/all/agdex81/$file/100_22-1.pdf.vary from year to year or from field to field. The guide notesThe Canola Council of Canada seeding rate guidelines in addition to using TKW for seeding rate, calibration of theare available at seed drill and performing yield estimates, it can also be used tohttps://www.canolacouncil.org/canola-encyclopedia/estimate shattering and combine losses. plant-establishment/seeding-rate/.Farmers are understanding that germination and disease tests matter, but seed size also matters, explains Sarah Foster, president and senior seed analyst at 20/20 Seed Labs in Nisku, Alta. If you dont know your TKW, you will overplant, causing competition for nutrients and moisture. That will also increaseof emergence (and thus mortality) on their fields. These your costs unnecessarily as the cost of seed, fuel and other farmsentiments are echoed in the Canola Council of Canada seeding input costs continue to increase.rate guidelines. If a producer has a TKW of six grams and uses a Planting too little seed is also a possibility, says Foster, if youseeding rate of 1,800 grams (4 pounds) per acre (60 seeds/m2 or dont have TKW. An inadequate stand in pulses means the weedabout 6 seeds/ft2) and has 0.50 seed survival, the crop has only population can get an easier foothold. In cereals, she adds, this30 plants/m2 or 3/ft2. can result in tillering, which is good for yield but also can causeThis does not leave much margin for competition with weeds variability in maturity. or plant death [due to disease, frost, insects or other factors] Foster believes that TKW, combined with the germination orbefore yield potential starts to drop, states the seeding rate vigour seed test result, should be considered the true standardguidelines. Therefore, considering seed size, seedling survival by which seed quality should be measured (replacing use ofrates and target plant populations when setting seeding rates just the germination/vigour test). The standard germination test,can minimize risk and save money. she adds, has long been used as the benchmark in assessing the planting potential of a crop, but TKW is the most practical toolLooking Forwardin calculating optimal seeding rate. Foster is pleased that TKW tests, which have been available for In order to calculate the optimal seeding rate, producersmany years, are now being used much more by growers. The will need the TKW and germination percentage test resultscost is quite lowgetting a TKW done at her firm, for example, for the seed lot, as well as the desired plant population (DPP).is about $18 (based on counting three one-thousand seed Theyll also need to calculate an estimate of seedling survivalsamples and calculating the average weight).rate, expressed in decimal form. For example, 90 per cent isShe reports a new development in the industry for the use expressed as 0.90. In cereals, the seedling survival rate is 80of TKW by seed firms is to provide seeding rate on the label of to 95 per cent (0.80 to 0.95) if growing conditions are good atbags of seed here in Canada and beyond, with seed now being planting, but lower if conditions are poor.sold as an acre package. This means seed companies are now Canola mortality often ranges from 30 to 60 per cent (survivalbasing how many seeds are in the bag on the unit count or TKW. rate of 0.40 to 0.70). In its guide, AAF advises that sinceThey sell the exact amount of bags the grower needs to seed his mortality depends on the combination of conditions andor her known acreage, she says.practices of individual farms, producers should keep records Treena Hein 52seed.ab.ca'