Abstract

The amount of available water for nursery irrigation is forecasted to decline on this decade and over or deficit watering of seedlings may have adverse consequences. To produce quality seedlings for accelerate the restoration of ecosystems and prevent further environmental damage, nursery water management should be reformed, especially for endangered species, such as Aspidosperma polyneuron Müll. Arg. The objective of this work was to evaluate the effect of three gross irrigation depths (8, 11 and 14 mm) applied daily and two irrigation frequencies (two and four times a day) on growth, irrigation efficiency and initial development of Aspidosperma polyneuron seedlings. Irrigation efficiency, in A. polyneuron seedlings, is related to the shoot part development degree (height and shoot dry mass). Increases in irrigation efficiency do not necessarily produce a greater development of morphological parameters and root system quality in the nursery. The 11 mm irrigation depth produces the same amount of seedlings with able root systems that the 14 mm irrigation depth, and uses 21% less water. The 11 mm irrigation depth applied in two irrigation frequencies produce A. polyneuron seedlings with optimum roots system and proper morphological development in the nursery, which continues after planting.

Key words: Peroba-rosa, land degradation, tropical forest, gross irrigation depth, irrigation frequency, runoff, forest nurseries, development after planting.