The development of the radicular and vegetative systems of almond trees with different rootstocks following the application of biostimulants

Aim of study: Recently, the development of almond crops on a global scale has increased their area under cultivation. The demand for both plants and products that stimulate the growth of almond trees has therefore become increasingly necessary. Accordingly, in this project we have studied the response in the vegetative and root systems of almond trees with different rootstocks to varying inputs of several root stimulants.Area of study: Valencia (Spain)Material and methods: Several different organic biostimulants were studied in isolation, i.e. not combined with synthetic chemical fertilizers, in order to ascertain if chemical fertilizers could be at least partially replaced.Main results: Good results were obtained by applying a biostimulant composed of organic matter rich in saccharides and carboxylates. Using an approach that enabled a distinguishing between them, plant radicular systems were shown to respond differently according to the biostimulant applied and the rootstock tested. The best results were obtained with a biostimulant composed of organic matter from corn hydrolysis and containing free amino acids and extracts from algae, as well as 0.07% zeaxanthins.Research highlights: Although biostimulants are promoters of young almond tree growth, they should be applied to only partially replace chemical fertilizers. The present paper shows the importance of using an organic-origin biostimulant, as a complement to chemical nutrition.