# Thousand grain mass

The thousand grain mass (TKM) (or outdated: thousand grain weight (TKG)) is the mass of 1000 grains . The thousand-grain mass is a parameter in seeds , in the seed trade , in plant breeding , in the storage of seeds in crops and in grain mills .

## application

### In the seed industry

The international rules for seed testing are published by the International Seed Testing Association .

In the seed libraries you can find information on the TKM of

### In the milling

To determine the thousand grain mass of a batch of grains, random samples are taken and counting devices are used. Grains can be stored with a water content of less than 14%. If grains with a higher moisture content are harvested, special grain drying processes are used, with the drying temperature playing a special role in order not to impair the germination of the grains.

The TKM is a varietal characteristic that is subject to strong fluctuations due to the respective cultivation and weather conditions in the year of production. The higher the TKM, the better the ratio of grain mass and shell proportions - with a higher TKM of grain, the miller can achieve a higher flour yield .

## Average thousand grain mass

1000 storable grains weigh in:

 Tobacco : 0.1 g Teff : 0.3-0.5 g Amaranth : 0.5-2 g Clover : 1-2 g Quinoa : 1-3 g tomato 2-3 g Grass : 2-5 g Rapeseed : 2-7 g Buckwheat : 15-30 g Rice : 15-45 g Oats : 27-48 g Rye : 28-50 g Barley : 35-50 g Triticale : 40-58 g Wheat : 40-65 g Corn : 200-450 g Peas : 150-500 g Beans : 150-550 g Sycamore maple : 800 g

## Calculation of the sowing rate based on the thousand grain mass

The TKM is also required to calculate the amount of seeds to be sown .

${\ displaystyle {\ text {Seed rate (in kg / ha)}} = {\ dfrac {{{\ text {Desired number of plants per m}} ^ {2}} \ cdot \ mathrm {TKM}} {100-M} }}$

Example of sowing winter wheat:

• Target number of plants per m² = 300
• TKM = thousand grain mass in grams = 60
• M = reduced germination capacity in percent = 6
• Seed rate (required amount of seed) ≈ 191 kg / ha

Calculation of the sowing rate taking into account the estimated field emergence loss and the expected number of ears per seed:

${\ displaystyle {\ text {Seeding strength (in kg / ha)}} = {\ dfrac {{\ tfrac {{\ text {Desired number of plants per m}} ^ {2}} {\ text {Treatment coefficient}}} \ cdot \ mathrm {TKM}} {100- (M + F + U)}}}$

Calculation example for sowing winter wheat:

• Target number of plants per m² = 580
• Convenience coefficient = 2.2
• TKM = thousand grain mass in grams = 60
• M = reduced germination capacity in percent = 6
• F = field opening losses in percent = 5
• U = winter losses in percent = 3
${\ displaystyle {\ text {Seed rate}} = {\ frac {{\ frac {580} {2 {,} 2}} \ cdot 60} {100- (6 + 5 + 3)}} \, \ mathrm { kg / ha} \ approx 184 \, \ mathrm {kg / ha}}$