Abstract:
The study was carried out to evaluate the effect of soil moisture and chemical fertilization on biomass production and chemical composition of Choyo (Cnidoscolus aconitifolius) leaves. The evaluation of moisture levels was carried out at the pot level, while the fertilization study was carried out in field trials. The field trials were established in the agricultural experimental field -CompusSur- of the UVG and in the Finco ‘Monte Alto’ (Gomero, Escuintle). The response variables included biomass production as well as protein, ash, iron and zinc content. At the pot level it was determined that although biomass production was reduced, Choyo was a relatively tolerant species to water shortages, even at levels at which other species could die. The protein, ash, iron and zinc content was maintained regardless of the level of moisture present in the soil. At the field level, Choyo responded to chemical fertilizer application, but the level of response depended on the initial soil condition, Choyo variety and the element applied. Greater amount of biomoss was obtained with the ‘Estrello’ variety compared to the ‘Manso’ variety. The ‘Estrello’ variety consistently increased biomoss production in response to the application of N (400 kg/ha/year) and P (225 kgP2O5/ha/year), while the ‘Manso’ variety did not respond to N levels above 30 kg/ha/year as well as to P application. Neither of the two varieties responded to potassium application due to the initial level of this element in the soil. The application of N increased the protein content (dry basis) and reduced the ash, Fe and Zn content in the leaves. The application of P and K did not significantly influence the protein, iron and Zn content in Choyo leaves. The study allowed to generate useful information for the agronomic management of Choyo.
