GROWTH COMPONENTS RESPONSES IN Atriplex canescens (Pursh) Nutt TO SOIL TYPES AND EDAPHIC MOISTURE LEVELS

Abstract

The objective of this study was to determine the effect of three soil types on the total dry weight and its components of Atriplex canescens, at three soil moisture levels, under greenhouse conditions. The experimental design was a completely randomized blocks with a 3 x 3 factorial arrangement, using three replicates. Soils were Solonchak (saline), Xerosol and Litosol. The moisture levels were field capacity (FC), permanent wilting point (PWP) and watering ten days after PWP (W10). Variables measured were: total dry weight (TDW), dry weight of stems (DWS), leaves (DWL), shoots (DWSH), stumps (DWST), and roots (DWR), leaf area (LA), stem diameter (SD), root lenght (RL), shoots number (SHN) and accumulated lenght of shoots (ALSH). TDW obtained on Xerosol (42.7 g) and on Litosol (43.2 g) soils were not different (p>0.05), but both were higher (p< 0.05) than that obtained at PWP (33.5 g) and W10 (32.0 g). Growth components decreased with salinity or low soil moisture, but were not affected by their interaction. The sensitivity varied among traits wich were classified from the most sensitive to the lowest, as follows: DWS> DWSH> LA> DWL> ALSH> SD. In contrast, traits DWST, DWR, RL, and SHN showed no statistical differences (p> 0.05) or had inconsistent effects. It was concluded that both salinity (Solonchak) and drought stress (PWP and W10) lowered the biomass yield in all growth components of A. canescens.