EFFECT OF SUBSTRATES AND FERTIGATION ON GROWTH AND PHOTOSYNTHETIC EFFICIENCY OF MAGUEY PULQUERO PLANTS OF MEZQUITAL VALLEY LANDRACES

Abstract

Maguey pulquero (Agave spp.) seedling cultivation is an emerging alternative capable of supply the demand of its diverse products. This research aimed to evaluate the growth and maximum quantum yield of Photosystem II (Fv/Fm) of three landraces of maguey pulquero young plants (10 months-old) germinated from seeds, growing under greenhouse within interaction effect of four substrates and four concentration levels of nutrient solution. The hypothesis was that phenotypic variation of young maguey pulquero landraces growing under greenhouse conditions could help to identify genotypes ideal for commercial production and to elucidate its nutrient and substrate requirements. The variables evaluated were: Fv/Fm, number of leaves, length and width (cm) of biggest leaf, and plant dry biomass (g), the results were analyzed by a two-way ANOVA and means comparison by Tukey’s test. The results demonstrated that Penca larga landrace (Agave mapisaga Trel.) had the highest values in all the growth variables evaluated compared to Manso and Xamini landraces (both A. salmiana Otto ex Salm-Dyck). Penca larga exhibited similar growth in the substrate agricultural soil and volcanic scoria mixture (SVM), and substrate agricultural soil alone (S) regardless of the nutrient solution concentration used, while both A. salmiana landraces exhibited total biomass reduction in the maximum nutrient concentration added in the S substrate (S+L4 treatment) compared to their respective effect on SVM substrate without nutrient addition (SVM+L1 treatment). All landraces exhibited growth inhibition in the commercial substrate mixture (CSM) and volcanic scoria alone (VS) without nutrient addition (CSM+L1 and VS+L1), while growth increase of all landraces in those substrates was relative to the increasing nutrient concentration. Photoinhibition was observed in all landraces in the treatment VS+L1. The growth variations observed across the landraces were helpful to identify potential genotypes ideal for commercial production and to set adequate substrates and nutrient requirements for agave cultivation,