Field drying and stacking
The rice plants are either left lying in the field or are also often stacked in piles with the panicles inside to protect them from rain, birds and rodents.
This can lead to massive heat build up inside the stacks. As a result molds grow quickly and infest the grains and discoloration usually develops within the first day of field drying. Another unwanted effect is that grains that are already dry often absorb water from the wetter straw, which leads to fissuring of the these grains and thus, reduces the potential head rice recovery.
It is impossible to produce good quality grains with field drying practices. This should therefore be avoided.