(a) A handful of the water fern Azolla pinnata and mass propagation for aqueous Azolla extract preparation, (b) sweet corn plants on 9-week after planting showing the tassel of male inflorescence (top part) and ear of female inflorescence (middle part), (c) representative mature ear harvested on 10-week after planting from each respective treatment plant and (d) three randomly selected kernels from each treatment plant.