Physical mechanisms produced in the development of nursery almond trees (Prunus dulcis Miller) as a response to the plant adaptation to different substrates

Abstract

[EN] Aims: The aim pursued in this work is to compare the changes induced in the plant of young almond tree by two different culture media, analysing how those changes are interrelated with a better adaptation of the plant to the open field. Methods: Two different rootstocks, GF 677 and GxN rootstock Garnem® (GN), were tested in two types of growing media: substrate 1, consisting on a substrate prepared on request and based on a mixture of 25% silica, 38% vaporized peat and 37% of washed river sand and substrate 2, based on cocopeat with coarse particle size (10¿25 mm). All plants received the same nutritive solution during the analysis. Twenty weeks after the plantation trees were uprooted and several parameters were recorded in both vegetative and radicular systems to observe the impact of the substrates. Results: The results of this study indicated that the use of different substrates produces statistically significant changes not only in root development and distribution but also in the vegetative growth. Plants grown under cocopeat substrate presented, among others, further development of the trunk and an increase in the total fresh weight of the radicular system produced mostly by a massive increase of absorbing roots, while plants under substrate 1 presented greater root system longitude. Conclusions: The selection of an appropriate substrate in the nursery of almond trees is a key factor in the early development of the young tree. Knowledge about root growth and root architecture during the first stages of development would help nursery industry to determine which should be the most suitable substrate regarding later field adaptation, survival and plant performance, focusing on the soil and climatic characteristics of the final destination of the plant.