Fontes de matéria orgânica como atenuante do estresse salino na produção de mudas de pitaia vermelha (hylocereus costaricensis)

Abstract

Red pitaya is one of the most promising fruit trees with high cultivation potential thanks to organoleptic and functional qualities of their fruits. However, some factors, as salinity, may impair the growth of the seedling, affecting the productive yield of the culture, but some alternatives might be adopted. Materials which are abounding in organic substances can minimize the damages provoked by toxic ions on the soil and/or in the water. Thus, the objective of this research was to evaluate the influence of organic material sources as mitigating of saline stress on the production of red pitaya seedlings (Hylocereus costaricensis). The experiment was accomplished on seedling production sector of the Federal Rural University of Semiarid. The treatments were arranged in a completely randomized design in a factorial scheme 4 x 5, totalizing twenty treatments and four repetitions, with two plants in each experimental unit. The treatments were four organic material sources (humus, ovine manure, biofertilizer and organic compound) and the control (sand + soil), in the ratio 1:1:1 and three salinity levels (2,6 dSm-1, 46 dSm-1, 6.6 dSm-1) and the control had 0.6 dSm-1. Morphological, biochemical and chemical of the substrata were analyzed in the end of the experiment. Data were submitted to variance analysis by the test F (p <0,05). We observed plants responded negatively to the effects of salinity, but the treatments with biofertilizer, organic compound and ovine manure allowed better conditions to the growth. With respect to the criteria of assessment of salt tolerance, the seedlings of red pitaya were moderately tolerant to the salinity. We may conclude organic sources of biofertilzer, organic compounds and ovine manure mitigated the deleterious effects on the production of red pitaya seedlings. Red pitaya showed moderate tolerance to the salinity levels 2.6, 4.6 and 6.6 dSm-1