Produção de mudas de aceloreira sob condições de salinidade da água de irrigação.

Abstract

The use of waler of marginal qualily is as one of lhe main cause of failure of lhe production of seedlings. Studies on (olerance of salinily, in Wesl Indian cherry (Malpighia emaginata D.C) clones are inexistenl; for íhal reason. ívvo experimenls were conducled in a nursery of lhe Experimental Cenler of Pacajus (ECP), vvilh lhe recommended clones BVI (rootstock) and BV7 (grafl) of Wesl Indian cherry. In Experimenl I, conducled in a complelely randomized design vvilh replica!ions, lhe effecls of six leveis of salinily of lhe irrigalion water - ECw (0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 dS m"1) were studied in the productive final phase of seedlings. In lhe second experimenl, lhe same leveis of ECw were employed, starting from the final phase of formation (50 days before the grafting) of the rootstock, in a complelely radomized design wilh Ihree replicalions. The irrigalion walers were prepared with NaCI, CaCl2.2H-0 and MgC^OHtO, maintaining lhe equivalem proporlion 7:2:1 among Na:Ca:Mg, respeclively In lhe germinalion of lhe West Indian cherry, the saline stress affected in a iinearly and the percentage of plants emerged decreased by 6.23% and the emergency speed by 9.04%. wilh unil incremenl of lhe salinily of lhe irrigalion waler above 0.5 dS nfwhile the number of days for emergency increased by 5.52%. The effect of the salinily was more severe on the root system compared lo the aerial parts in lhe formalion of lhe young seedlings. In lhe final phase of formation of lhe young planlling rootstock, the West Indian cherry tolerated until 1.16 dS m" of ECw, and may be classified as 'moderalely sensitive'; above lhat levei, lhe decrease rale observed was 15.03% for unil increase of salinity. The salinity of the irrigation water up to 5.5 dS m"1 did not affect the necessary condilions for grafting in Wesl Indian cherry seedlings submilted lo lhe saline stress in lhe final phase formation of lhe rootstock When lhe use of saline water is used from lhe beginning (seedling) lhe percentage of living sedlings decreases 9.97% for unil increase of ECw above 0,5 dS m" . The salinity does not affect the percentage of living seedlings in case of for the salinity stress starting from the final phase of formation rootstock. AAer lhe grafting, seedlings roots system submilted lo the saline stress from the germination phase is !ess aíTecled ílian lhe aerial paris, and in stress starting from lhe final phase olTormalion ofthe rootstock lhe aerial paris is less aíTecled than lhe roots system.