poster - International Conference of Agricultural Engineering

Enxerto ( mg kg -1 )
Ramos ( mg kg-1)
Raízes ( mg kg -1 )
Porta- enxerto (m g kg -1 )
4
4
3
3
2
2
1
Y = 0,6411 + 1,7408**X - 0,3261**X2
R² = 0,9401
0
0,8 1,6 2,4 3,2 4,0
1
Y = 1,9970 + 0,3095**X
R² = 0,9844
0
0,8 1,6 2,4 3,2 4,0
CEa ( dS m -1 )
CEa ( dS m -1 )
C
4
D
4
3
3
2
2
1
Y = 2,0005 + 0,1989**X
R² = 0,6890
0
0,8 1,6 2,4 3,2 4,0
CEa ( dS m -1 )
1
Y = 1,7740 + 0,8406**X - 0,1331nsX 2
R² = 0,9218
0
0,8 1,6 2,4 3,2 4,0
CEa ( dS m -1 )
Figure 2: Sodium contents of the roots (A), rootstocks (B) grafts (C) and branches (D) in
precocious dwarf cashew tree CCP76 clone in function of electrical conductivity (ECw) used
in irrigation after 90 days of salt stress in fruiting phase.
In plant parts where the salinity had a significant effect on the levels of sodium, except for
roots, we observed an increasing sodium concentration with salinity which could be
consistent with that reported by Silva et al. (1997), cited by Fernandes (2000) who say that
sodium may act by stimulating plant growth, therefore, is considered a useful complement to
many cultures for physiological effects themselves or by replacing part of K + required by the
plant. The degree of substitution will depend on the potential for absorption and translocation
of Na + to the shoot of the plant and the efficiency of plant using K + , which is possibly
accepted in view of the plant is at the stage of fruit, a phase responsible for a period of very
large demand for potassium, with a view to the formation of the fruits. For example, in the
presence of high external concentration of sodium, potassium and calcium absorption can
be inhibited, causing deficiencies of these nutrients and increase the sodium content in plant
cells (Fernandes, 2000).
4. Conclusions
The sodium and chloride contents, in general, were affected by the accumulation of salts in
the root zone caused by irrigation water.
For both rootstocks and grafts, there was an increase in chloride content with salinity of
irrigation water. But in the leaves it was observed a decreasing. With the exception of roots,
other plant parts of dwarf cashew tree had an increasing in the sodium content by the salinity
of irrigation water.
5. References
AUDRY, P.; SUASSUNA, J. A salinidade das águas disponíveis para a pequena irrigação
no sertão do Nordeste: caracterização, variação sazonal, limitação de uso. Recife: CNPq,
1995. 128 p.