| Grant number: | 10/17589-9 |
| Support type: | Regular Research Grants |
| Duration: | May 01, 2011 - July 31, 2013 |
| Field of knowledge: | Agronomical Sciences - Agronomy - Soil Science |
| Principal Investigator: | Jose Antonio Quaggio |
| Grantee: | Jose Antonio Quaggio |
| Home Institution: | Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil |
| Assoc. researchers: | Dirceu de Mattos Junior ; Rodrigo Marcelli Boaretto |
Abstract
Zinc (Zn), manganese (Mn) and boron (B) are important micronutrient for citrus production, which deficiency symptoms are frequent in the citrus groves. Likewise, copper (Cu) has become important in the citriculture, especially in new planted groves. Few studies have evaluated the application of metallic micronutrients applied to the soil and their use by plants, and which showed significant responses on increased leaf nutrient levels and fruit production. These responses depend on the interaction of nutrients with the soil colloidal matrix, and micronutrient sources and rates, which knowledge is important to the establishment of revised recommendations for citrus best management. We emphasize that for high yield citrus groves nutrient demand and efficiency of use become increasingly more important. Based on the above, the overall objective of this project is to develop information which allows recommendations of micronutrients application to the new citrus production systems. The specific objectives are: i) to evaluate the availability of Zn and Mn sources, applied to different soil types, on plant nutrition status; ii) to evaluate the efficiency of Zn sources applied to different soil types, using the stable isotope 68Zn. iii) to compare the uptake of copper and zinc supplied either by fertigation or foliar spray; iv) to evaluate the efficiency of different fertilizer sources on plant growth and fruit quality; To achieve these goals, three experiments will be conducted in a greenhouse, two of which to evaluate the effect of sources and levels of Zn (ZnO and ZnSO4; 1 and 5 g plant-1 of Zn)and Mn (MnCO3 and MnSO4; 0.7 and 3.5 g planta-1 of Mn) applied to different types of soil and a third one, similarly to the previous, with the Zn source enriched in stable isotope (68ZnO and 68ZnSO4; 1.8 g plant-1 of Zn), which will allow a better comprehension of Zn absorption and mobilization by roots of orange trees. Two other experiments will be carried out in the field where Zn (ZnSO4, Zn(NO3)2 and Zn-EDTA) and Cu (CuSO4, Cu(NO3)2 and Cu-EDTA) sources and fertilizer application (fertigation and foliar) will be evaluated. The results will compose the basis for micronutrients recommendation to citrus and will contribute to increased fertilizer use efficiency and consequently to increased production efficiency of groves. (AU)