Effect of salinity and different light on biomass sharing of the ornamental species euphorbia milii and zamioculcas zamiifolia

Abstract

Part of the Northeast region of Brazil presents abiotic limitations for the production of flowers and ornamental plants, especially salinity and excessive solar radiation. This research aimed to test the effects of increasing salinity levels and different light conditions on the biomass partitioning of the ornamental species Euphorbia milii and Zamioculcas zamiifolia. The experimental design was in randomized blocks in subdivided plots, with five repetitions, with the plots referring to the environmental factor (full sun, 30, 50 and 70% shade), the subplots to the salinity levels in the irrigation water - ECw (0.5; 2.0; 3.5; and 5.0 dS m-1), and the subplots to the ornamental species Euphorbia milii and Zamioculcas zamiifolia, with two plants per repetition, totaling 320 experimental units. Shading at 30% stimulated greater biomass partitioning to flowers, however, at higher shading levels a reduction in the proportion of flowers and an increase in biomass in leaves was observed in the Euphorbia milii species. Zamioculcas zamiifolia allocated the highest biomass fraction (about 65% of photoassimilates) to the roots and rhizomes at all salinity levels, but shading had little influence on photoassimilate partitioning in this species.