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GRAANGIDS
2016
GRAIN GUIDE
Kobie de Beer, manager: Insurance Services (Crop), Santam Agriculture, Bloemfontein
Where only plant establishment can be taken into account, the following guidelines
are applicable:
• Bitter varieties require 120 000 plants/ha for an LBY of 4,0 ton/ha. You can also take ± 40 g/
plant where plant establishment is 120 000 plants/ha.
• Sweet varieties require 140 000 plants/ha for the same LBY. You can also take ± 30 g/plant
where plant establishment is 120 000 plants/ha.
• In difficult seasons you should preferably work conservatively.
Where actual ears and seed count are taken into account, the following guidelines
are applicable:
3. Weight/plant: Select five representative ears. Select and remove three branches (side ears) from
the top, middle and bottom of each ear. Count the number of kernels on each branch and note
this down.
1. Ear count/10 m:
Ears/10 m/3 rows
=
xx
= xx ears/10 m
3
3
2. Row width:
Distance measured across rows
= xx m = xx m
number of row spaces
EAR NUMBER
1
2
3
4
5
Top branch
Middle branch
Bottom branch
TOTAL
Total
÷ 15 = xx kernels/branch
Count the number of branches on the five ears, add the 15 used above, divide by five to get the
average number of branches/ear and multiply this by the number of kernels/branch to obtain the
number of kernels/ear.
Kernels/ear = branches on 5 ears + 15 ÷ 5 X xx kernels/branch = xx kernels/ear
Weight/ear (g) = xx kernels/ear X 0,019* g/kernel = xx g/ear
* Adjust the 0,019 g/kernel according to conditions.
4. Crop yield: xx ears/10 m ÷ row width (m) X weight/ear (g/ear) ÷ 1 000 = xx t/ha
= xx ears/10 m ÷ xx m X xx g/ears ÷ 1 000 = xx t/ha
6. General comments
It is important that the masses above be regarded only as guidelines and that you realise that they
can be affected by factors like appearance of the plant, climate, region, cultivar, etc.