Evaluation of the effect of a whey-basedbiofertilizer on agronomic and biochemicalparameters in sweet potato [Ipomoea batatas (L.)Lam.]

Abstract

Objective: To compare the effect of the applying of an organic biofertilizer (APIS®) formulated from whey, on agronomic and biochemicals variables in sweet potato.

Design/methodology/approach: A randomized block design was used, distributed over 1.5 ha in open field, APIS®, Bayfolan Forte® (commercial fertilizer), and only water (control) were applied to sweet potato plants by foliar application at 35 and 65 days post-transplant (dpt). Three sampling were carried out at 35, 60 and 85 dpt and morphological parameters, quantification of total bacteria and filamentous fungi, elemental quantification, chlorophyll content, total protein, total polyphenols, and soluble sugars as well as H₂O₂ were determinate.

Results: The organic biofertilizer (APIS®) produced more quantity of tubers and consequently a higher yield per hectare (22 and 32 % higher in compared to the treatments Bayfolan Forte® and control respectively). APIS® increased the microorganism load in the second sampling, witch consequently decreased in the third sampling. Regarding morphological parameters, chlorophyll content, total protein, total polyphenols, total soluble sugars and H₂O₂, no significant differences were observed between the control and APIS® treatments, observing an increased in the concentration of H₂O₂ between Bayfolan Forte® and the control treatment.

Limitations on study/implications: The study was carried out only during one agriculture cycle.

Findings/conclusions: APIS® can be used in sweet potato fields because it has a similar or better effect than the commercial fertilizer.