Chlorophyll content in leaves of highland potatoes for estimating tubers quality

In this study, we assessed the relationship between tubers quality of three varieties (INIAP Libertad, INIAP Josefina and Diacol Capiro) of Ecuador highland early of potato and two formulations of edaphic fertilizer sources. Leaf chlorophyll content (LCC) was evaluated with Chlorophyll Meter SPAD-502Plus. Samples were taken at different heights in three phenological stages: vegetative grow, flowering–formation of tubers and ripening-thickening. Several responses were found in the three potato varieties. Correlation between SPAD value and weight of tubers (W), dry matter (DM), specific gravity (SG) and good chips (GC) were significantly correlated with potato leaves chlorophyll content. For Libertad variety and formulation (KNO3 + NH4H2PO4 + KCl), at vegetative grow in upper strata of plant, the optimal mathematic function for SPAD value andW, DM, SG and GC were: y = 0.262x (R = 0.9938), y = 42.948e (R = 0.5240), y = 10x (R = 0.3277) and y = 10x (R = 0.8681); at plant flowering-formation of tuber stage, the optimal function models were: y = 10 x (R = 0.8553), y = 28.789 e (R = 0.9103), y = 10 x(R = 0.7543) and y = 0.468x + 64.361 (R = 0.9935); at plant ripening-thickening, the optimal function models were: y = 0.664 e (R = 0.7924), y = 29.370 e (R = 0.9572), y = 10 x (R = 0.8247) and y = 0.576x + 62.675 (R = 0.9690), respectively. Our results showed that the use of SPAD-520PLUS proved to be a rapid method for the determination of LCC, being an effective tool for estimating potato tuber quality.