Bradbrook - 2012 - Rice Farming complete with methods to increase ric

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c. Separate weed seeds and seeds from other crops into one pile;
d. Separate inorganic matter into another pile;
e. Weigh the weed seeds and calculate the weed percentage:
Weight of weed seeds
x 100 = % weed
Total weight of sample
f Weigh inorganic matter and calculate inert matter percentage:
Weight of inter matter x 100 = % inert matter
Total weight of sample
g. Obtain the average for weed and inorganic matter percentage from three samples.
Certified seeds should contain no more than 0.08% weed seeds and a maximum of 2%
inorganic matter. Weed seeds, when accidentally planted, can become a nuisance to the rice
plant.
3. Testing for genetic purity
Each rice variety has a unique grain size and shape that distinguishes it from other varieties.
Comparing seed samples to published data for a specific variety is a simple test to determine
genetic purity of the seed lot.
a. Measuring grain dimension
i. Obtain seed samples from each bag and mix;
ii.
Collect twenty (20) seeds at random from the seed sample;
iii. Measure the length and width of each seed using a Vernier caliper or
photographic enlarger;
iv.
Obtain the length and width average from the twenty seeds;
V. Calculate the length-to-width ratio:
Average seed length = Length-to-width ratio
Average seed width
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