Effect of mini-plug container depth on root and shoot growth of four forest tree species during early developmental stages

The container type used in nursery culture is among the most important determinants οf containerised seedling quality. The objective of the present study was to analyse root and shoot growth, root growth potential, and photochemical efficiency of seedlings of Picea abies, Robinia pseudoacacia, Pinus brutia, and Pinus nigra cultivated for 5 weeks in mini-plugs of 2 different cavity depths (37 and 60 mm). The results showed that precultivation of P. nigra and, to a lesser extent, of R. pseudoacacia in deeper mini-plug containers improved seedling morphological attributes and quality, but shallow containers produced better quality seedlings of P. abies. In P. brutia, the use of shallow containers led to the development of a superior root system, while the use of deeper containers produced seedlings with better above-ground characteristics.