Would a perrenial crop be any advantage? In northern parts of Australia we can only grow winter crops by using stored water from the summer, otherwise there isn't enough rain. And obviously in most southern parts of Oz there isn't enough summer rain to grow much of anything. In other parts of the world there are different problems like it being frozen for 4 months every year so what use there?
Sorghum is a perennial plant. It will grow again the following year after the frosts finish. Yet the yield in the second year would be abysmal. So as far as I know, no one uses sorghum as a perennial crop. Some farmers in central and northern QLD might harvest a sorghum crop twice in a summer, as in say Dec and again in May, but the total yield is often not great as once again the second crop is usually very poor.
