Abstract
BACKGROUND: This experiment was conducted to examine the effects of organic Se concentration and the number of foliar applications on growth characteristics and Se content in rice. METHODS AND RESULTS: A series of multiple foliar applications were performed at (1) 3 times (maximum tillering stage + booting stage + heading stage), (2) 4 times I (effective tillering stage + maximum tillering stage + booting stage + heading stage), (3) 4 times II (maximum tillering stage + booting stage + heading stage + grain filling stage) according to the development stage. Each set of the foliar application plots was treated with 0, 10, 20, 40, 60, 100 ppm of Se and with mixed pesticide ($P^*$ + Se 40 ppm) in which the treatment time was the same as that of the treatment 4 times II. The total cultivation period of rice was 184 days. Se contents in rice (brown rice, white rice) were analyzed by ICP. CONCLUSION: The number of grains per head tended to decrease with increasing concentrations of organic Se in all treatments. However, number of panicles per hill did not show statically significant differences between the 3 times and 4 times I treatments. The grain yield decreased with the 3 times and 4 times II, but there was no significant difference in 4 times I. Se content in brown rice was the highest at 100 ppm Se (5268.64) treatment and lowest at 10 ppm Se ($1269.19{\mu}g{\cdot}kg^{-1}$) treatment. Se content in the polished rice was the highest at 100 ppm Se (5047.33) treatment and lowest at 10 ppm Se ($885.05{\mu}g{\cdot}kg^{-1}$) treatment. The higher selenium was treated, the higher Se content was found in the rice (brown rice, polished rice).
