COSTA, T. A. R.; http://lattes.cnpq.br/6746558271758122; COSTA, Thais Aparecida Rocha da.
Résumé:
The cashew is a crop widely cultivated in the Brazilian Northeast, however the main sources of
water used for irrigation in this region have high concentrations of salts, being a limiting factor for
agricultural production in this region. To this end, it is necessary to use strategies that mitigate the
harmful effects of saline stress on plants. Among the alternatives, mineral fertilization stands out.
In this context, the objective was to evaluate the growth, physiological indices and quality of
rootstocks of the early dwarf cashew tree 'FAGA 11' grown under different salinity levels of
irrigation water and combinations of nitrogen and potassium fertilization. The experiment was
conducted under greenhouse conditions, in a randomized block experimental design in a 4 × 3
factorial scheme, referring to four levels of electrical conductivity of the water - CEa (0.3; 1.8; 3.
3 and 4.8 dS m-1), three combinations of nitrogen (N) and potassium (K2O) doses (100:50; 50:100
and 100:100%) with three replications and two plants per plot. The combination of fertilizer with
100:50% N:K of the recommended dose provided a higher relative water content in 'FAGA 11'
cashew seedlings irrigated with water with an electrical conductivity of up to 0.3 dS m-1, with no
significant difference in in relation to higher salinities. Fertilization using combinations of 100:50%
N:K proved to be effective in increasing the stem diameter of early dwarf cashew seedlings.
Irrigation with an electrical water conductivity of 4.8 dS m-1 reduced the growth of dwarf-early
cashew seedlings, with negative impacts on plant height, number of leaves and leaf area. However,
the interaction between the electrical conductivities of irrigation water and the N:K fertilizer
combinations did not affect the Dickson Quality Index.
