BARBOSA, R. C.; http://lattes.cnpq.br/7276892230550321; BARBOSA, Roberta Chaiene Almeida.
Resumen:
The citrus industry is an important activity for the Northeast region of Brazil due to the
generation of employment and income , however, in this region , the productivity of citrus
trees is reduced as a result of erratic rainfall and occurrence of droughts and dry , and there ,
under these conditions the need for irrigation . As in many places the water is saline, with
varying concentrations of salts, are relevant studies aiming at the use where water resources
are scarce best quality. Thus, the objective was to study the growth and physiology of citrus
genotypes, as recommended rootstocks under different levels of salinity of irrigation water, in
order to identify tolerant and susceptible genotypes to salt stress. The experiment was
conducted in greenhouse climate adversities , Campus UFCG in Pombal -PB , using the
randomized complete block design with three replications , consisting of factorial , 8 x 5 , 8
genotypes of citrus [Rangpur lime Santa Cruz ' ( LCRSTC ) , tangerine' Sunki Common ' (
TSKC ) x Swingle Swingle' ( CTSW ) - 028 x TSKC CTSW - 033 x TSKC CTSW - 041 ,
'Volkamer' lemon ( LVK ) x lemon Rangpur ( LCR ) - 038 , tangerine ' Sunki Florida ' (
TSKFL ) , and TSKC 'Rugoso Florida ' ( LRF ) ] and 5 salinity levels of irrigation water
(irrigation water with electrical conductivity of 0 , 8 , 1.6, 2.4 , 3.2 and 4.0 dS m - 1 ) , up to
120 days after sowing. Growth and physiological variables were assessed, data were
submitted to analysis of variance in cases of significance, and regression analysis was
conducted for the factor salinity of irrigation water and the means (Tukey) between salinities
at each assessment time in gas exchange. It was found that the concentration of salts in the
water drainage was twice the concentration of salt water applied. The relative growth rates are
more affected by salinity than the variable itself (plant height, stem diameter and number of
leaves). The salinity reduced the growth of most citrus genotypes, water may be used up to
2.4 dS m-1 to irrigate them and a satisfactory growth, the highest growth was observed in
TSKFL genotype, with respect to gas exchange, the variable most affected by salinity is
stomatal conductance, when producing rootstocks in tubes of 115ml, ideal for evaluation of
gas exchange period is 75 days after sowing. Salinity did not have significant effect on the
parameters of chlorophyll a fluorescence in both seasons. Relating to the growth variables
genotype less sensitive to salinity was the hybrid TSKC x CTSW - 041 and the most sensitive was the LRF.
