Effect of foliar application of the selenium-rich nutrient solution on the selenium accumulation in grains of Foxtail millet (Zhangzagu 10)

The foliar application of selenium (Se) is an effective method for biofortification of Se in crop grains in order to provide sufficient Se for human health. As a staple food in China, the foxtail millet ( Setaria italica L.), which had been Se biofortification, would be helpful to overcome Se deficiency in the diet. The Se fertilizer and its application technology are vital for reducing environmental risk while enriching selenium. Hence, the Se-rich nutrient solution developed by ourselves was used, and the effect of its amount and growth stage applied on the accumulation of Se in grains of foxtail millet ( Setaria italica L.) was studied in the present study. The results were as follows: (1) the Se concentration in grains increased with the Se application rate increasing, and the highest Se concentration in grains was 1.83 mg kg -1 at the sprayed concentration of 61.5 gSe hm -2 ; (2) the accumulation of Se sprayed in the grain-filling stage was 1.3–1.6 times higher than that in the joint stage; and (3) the organ damage could be found under low Se/S ratio, which happened in the rice leaves when the Se rate was higher than 76.875 gSe m -2 with the low sulfate application compared with the formulation. This Se-rich nutrient solution could be used to produce the Se-rich millet grains and foliar application in the reproductive stage to produce qualified Se-rich millet.