# Estimating the size of retained canola seed

Page last updated: Friday, 4 October 2019 - 2:25pm

Please note: This content may be out of date and is currently under review.

To work out the seeding rate, one of the things needed is the seed size, or the number of seeds per kilogram. How do you find that out for farmer retained seed? It is as simple as lining up your canola seed along a 10 centimetre length.

• ## P15_5718 ART Bonito Canola seeds on ruler.jpg

There is a close relationship between the number of canola seeds that line up along a 10cm length of ruler and the number of seeds per kg (R2=0.97).

This makes it simple to estimate the seed size of your retained open pollinated seed. Line up the seed as closely as possible along a 10cm portion of your ruler, then count the number of seeds used. Refer to the table below and match the number of seeds per 10cm with the estimate of the number of seeds per kilogram.

Table 1 A guide to estimate seeds per kilogram using seeds per 10cm
Canola seeds per 10cm line Canola seeds per kg
45 130 000
46 144 000
47 157 000
48 170 000
49 184 000
50 197 000
51 210 000
52 223 000
53 237 000
54 250 000
55 263 000
56 277 000
57 290 000
58 303 000
59 317 000
60 330 000
61 343 000
62 357 000
63 370 000
64 383 000
65 397 000
66 410 000

The photo at the top of the page shows 52 ATR Bonito seeds along 10cm of ruler. Use the table to see that this correlates with 223 000 seeds/kg.

Another way to estimate the number of seeds/kg, is to count out 1000 seeds and weigh, on scales that can measure 0.1 of a gram (or count out more seed for less accurate scales).

Seeds per kg = (1000 x 1000) / weight of 1000 seeds (g)

For example, 1000 seeds of retained open pollinated (OP) seed weighed 2.9g.

Therefore seeds per kg = (1000 x 1000) / 2.9 = 344 828 seeds per kg.

Another alternative is to use the seed testing services of AGWEST Plant Laboratories.

#### Acknowledgments

This work was completed through the Department of Primary Industries and Regional Development's Tactical Break Crop Agronomy project. This project is co-funded by DPIRD and Grains Research and Development Corporation.

Mark Seymour
Jackie Bucat