T he nutritional value of edible plant products can be improved or bio-fortified by genetic and agronomic means (Bouis, 2003;White and Broadley, 2005;Cakmak, 2008). Crop species can vary greatly for grain nutrient concentration as with wheat (Triticum aestivum L.) genotypes having 25 to 56 mg kg -1 Fe and 20 to 39 mg kg -1 Zn (Morgounov et al., 2007). Some crop varieties have been developed for increased nutrient availability including increased Fe, Zn, or vitamin A in rice (Oryza sativa L.), wheat, maize (Zea mays L.), bean (Phaseolus vulgaris L.), and cassava (Manihot esculenta L.) (Bouis et al., 2000;Bouis, 2003). The success of biofortification through genetic improvement ultimately depends on sufficient nutrient in soil solution, although efficiency in the allocation of plant nutrients to grain or storage roots can be a biofortification mechanism.Management practices, including fertilizer use, can affect nutrient concentrations (Cakmak, 2008). Fertilizer application may increase plant concentration for the nutrients applied such as for Se in maize (Chilimba et al., 2012) and wheat (Lyons et al., 2004), B in rice (Rehman et al., 2014), and Zn in wheat Cakmak (2008).The means of applying the nutrient can be important to biofortification. Rengel and Crowley (1999) reported the greatest efficiency with soil application of Zn and Cu, foliar application of Fe, and by adding I in irrigation water. Meena et al. (2017) reported greater biofortification for Zn and Fe with foliar compared with soil application, whereas Imran and Rehim (2016) reported success with both soil and foliar application of Zn, but the greatest bio-fortification with a combination of soil and foliar application of Zn. Biofortification of rice with B was achieved with soil application and seed treatment, but foliar application was most effective (Rehman et al., 2014).Application of N alone or together with Fe or Zn increased bio-fortification for these nutrients in wheat (Aciksoz et al., 2011). Application of P to pearl millet (Pennisetum glaucum L.
