Efecto de la aplicación de zinc sobre el cultivo de triticale de doble aptitud

Zinc (Zn) is an essential mineral and its deficiency causes numerous alterations in livestock. The Mediterranean region is estimated to be deficient in Zn. Agronomic biofortification by Zn fertilization has been shown to be a very effective technique for increasing Zn concentration in plants. Double aptitude triticale is a very interesting cereal for animal feed because it can be used in winter and at the end of the crop season, matching the forage scarce seasons of the Extremadura dehesas, winter and summer. An experiment was designed using subdivided plots to study the efficiency of agronomic biofortification in double aptitude triticale crops. In the main plot, treatments regarding Zn fertilization were considered: no application of Zn (Control), soil application of 50 kg ha-1 of ZnSO4 (Soil), foliar application of 8 kg ha-1 of ZnSO4 during tillering (Foliar), and the previous two combined (Soil+Foliar). As subplot the summer harvest with or without winter cut were considered. The aim was to study both productivity and Zn accumulation, determining which treatment is the most appropriate. In winter, a non-significant increase in the yield of the Soil treatment was observed, applied both isolated and combined with the foliar application. For the whole season, the Soil and Soil+Foliar treatments were on average 15% more productive than the Control treatment. Zinc concentration in the winter cut was more than five times higher in both Foliar and Soil+Foliar treatments, reaching more than 160 mg Zn kg-1. This increase was only 1.5 times in spring, insufficient to make up for deficiencies in livestock diets. Winter harvesting had negative influences both on the final yield and on the accumulation of Zn in the summer cut. New doses and moments of application should be studied to increase the effectiveness of biofortification in this crop.