Resumen

SALAZAR-GARCIA, Samuel; COSSIO-VARGAS, Luis Eduardo  y  GONZALEZ-DURAN, Isidro José Luis. Site specific fertilization increased productivity of 'Hass' avocado in rainfed orchards. Agric. Téc. Méx [online]. 2009, vol.35, n.4, pp.439-448. ISSN 0568-2517.

The research was performed during 2001-2005 to test the effect of site specific fertilization on yield and fruit size on 'Hass' avocado grown under rainfed conditions. Three commercial 'Hass' avocado orchards, exploring the fertility of the predominant soils on the low, medium and high avocado producing zones of Tepic and Xalisco municipalities of the state of Nayarit were included. Fertilization dosages were calculated by considering tree's nutrient demand to produce 3 0 t ha^-1, nutrient inve stment on tree biomass, nutrient recycling, soil fertility, nutrient foliar analysis, and fertilization efficiency. Mineral fertilization included N, P, K, Ca, Mg, S, Zn, and B and consisted of two levels: normal, obtained by the calculations described above, and High, equivalent to the Normal rate plus 50%. Two fertilization regimes used regionally by avocado growers were used as controls: control-1 consisted in fertilization with N and K plus 50 kg composted chicken manure per tree per year; control-2 only included N and K. Soil fertility was improved with High fertilization rate. Fertilization based on N and K, alone or complemented with chicken manure did not improve yield nor fruit size. Yield, fruit size and economical analysis showed that High rate fertilization, that consisted in the application per tree of 2.140 kg N, 0.742 kg P₂O₅, 2.520 kg K₂O, 810 g Zn, and 94.30 g B, was the best to improve the productivity of 'Hass' avocado en Nayarit.

Palabras llave : Persea Americana Mill.; leaf analysis; mineral nutrition; productivity.