Dry matter partitioning and mineral composition of roots, stems and leavesof guava grown under salt stress conditions

A greenhouse experiment was conducted with the objective of studying the re sponse of guava plants (Psidium guajava L.) to increasing levels of NaCl co ncentrations. Plants were grown in nutrient solutions, with 0, 25, 50, 75, 100, 125 and 150 mM of NaCl, and harvested 30 and 50 days after saline stre ss in a complete randomized design. The following traits were studied: shoo t, root and total plant dry matter and the percentage of Na, Cl, K, Ca and Mg in plant dry matter. Dry matter yield decreased when salinity increased. The root/shoot ratio decreased with the saline treatment. Salinity stress caused an increase in the levels of Na+ and Cl-. The highest ion accumulati on was found in the leaves followed by the roots. The Ca levels were stable in the roots, but decreased in stems and leaves. The K content was reduced with the increased levels of salinity, particularly in the leaves. On the other hand, Mg levels were not affected by salinity in stems and roots but decreased in the leaves. There was a positive relationship between Na and C l and a negative relationship between Na and K concentration in roots and l eaves. Mg concentration in leaves and roots did not vary with the concentra tion of Na. The concentration of Ca did not vary with Na in the leaves but showed an inverse relationship in the roots.