Effect of different foliar zinc application at different growth stages on seed zinc concentration and its impact on seedling vigor in rice

Abstract

This study evaluated how zinc (Zn) concentration of rice (Oryza sativa L.) seed may be increased and subsequent seedling growth improved by foliar Zn application. Eight foliar Zn treatments of 0.5% zinc sulfate (ZnSO 4 Á 7H 2 O) were applied to the rice plant at different growth stages. The resulting seeds were germinated to evaluate effects of seed Zn on seedling growth. Foliar Zn increased paddy Zn concentration only when applied after flowering, with larger increases when applications were repeated. The largest increases of up to ten-fold were in the husk, and smaller increases in brown rice Zn. In the first few days of germination, seedlings from seeds with 42 to 67 mg Zn kg À1 had longer roots and coleoptiles than those from seeds with 18 mg Zn kg À1 , but this effect disappeared later. The benefit of high seed Zn in seedling growth is also indicated by a positive correlation between Zn concentration in germinating seeds and the combined roots and shoot dry weight (r ¼ 0.55, p < 0.05). Zinc in rice grains can be effectively raised by foliar Zn application after flowering, with a potential benefit of this to rice eaters indicated by up to 55% increases of brown rice Zn, and agronomically in more rapid early growth and establishment.

Evaluation of Soil and Foliar Applied Zinc Sources on Rice (Oryza sativa) Genotypes in Saline Environments

“…Application of ZnSO4 compared to Zn-EDTA releases more Zn at early stages. Zn-EDTA is a slow release nutrient fertilizer and it becomes more available from the vegetative growth up to the maturity (Boonchuay et al, 2013).…”

Application of silicon fertilizer affects nutritional quality of rice

“…E et al (2005) found that an increase in the amount of P fertilizer applied enhanced the Mg concentration in milled rice and that a rational application of K increased the accumulation of Fe, Zn, Cu and Mn in milled rice. Boonchuay et al (2013) confirmed that the Zn concentration of rice grains could be effectively increased by foliar application of ZnSO 4…”

“…Insufficient intake of these mineral elements from food results in the impairment of human health, such as the occurrence of anemia (Shan, 2006). It has been reported that approximately one-third of the world's population suffers from Fe and Zn malnutrition, a problem that is particularly severe in developing countries (Boonchuay et al, 2013). As a staple cereal crop, rice (Oryza sativa L.) provides not only carbohydrates but also protein, vitamin and mineral nutrition for more than half of the world's population.…”

“…In general, mineral elements, such as Fe, Cu, Mn, Zn, Ca and Mg, are indispensable to the human body as they play important roles in controlling immunological function in adults and intelligence development in children (Belder et al, 2005;Boonchuay et al, 2013). Insufficient intake of these mineral elements from food results in the impairment of human health, such as the occurrence of anemia (Shan, 2006).…”

Role of seed-Zn content on seed longevity of pigeonpea genotypes

“…Correlation between seed quality parameters and seedZn content: There is evidence in literature demonstrating the role and association of Zn in enhancing the seed germination and vigour (Rengel 2008 andBoonchuay et al, 2013). Zinc is involved in biosynthesis of plant hormone, indole acetic acid (IAA), auxin metabolism and is component of variety of enzymes like, carbonic anhydrase, alcohol dehydrogenase, glutamic dehydrogenase etc.…”