Improving the profitability & sustainability of Esperance port zone grain growers
Burnt Crop and Germination
By: Ben Curtis, Farmanco

Many unharvested crops that were burnt in the fire have had all of the straw and leaves burnt but have left the heads charred, intact but on the ground.

When you rub the grain out of the heads it looks mainly sound with some burnt sections. I have conducted a germination test on this grain to see how much has remained viable. It appears that only a very small percentage of this grain (1% or less) is likely to germinate. Even though many grains appear untouched the heat must have killed the germ. If you had a 4 tonne crop and the heads are on the ground, at 1% only 40kg/ha of grains will be viable. Obviously the conditions will determine how badly the grain is affected so the amount of viable grain will vary. Since it is laying on the top of the soil then I think it is fair to assume that only a small proportion of this small percentage of viable grain will germinate.

Burnt grain BC1

Figure 1. Poor germination from wheat grain rubbed from charred heads on the ground.

I have also taken samples from crop right next to burnt areas and tested for germination. Since these areas would have been subject to heat radiating from the fire there has been some concern about the viability of this grain. Having taken samples of standing heads which are charred, heads 1 metre from the edge of the fire and samples further in, it appears that all of this grain has retained it’s germination. If you are wanting to avoid delivering any charred grain with the risk of being downgraded I think it is a safe bet to harvest these areas and use this grain for seed as long as it meets all other criteria for seed. The odd grain which has been burnt will only be a tiny fraction of the overall sample.

Burnt Grain BC2

Figure 2. Good germination from wheat samples taken from standing crop adjacent to burnt areas.