"Niágara rosada" table grape cultivated with seaweed extracts

Abstract

The present research was carried out with the aim of elucidating the effect of leaf sprays with extracts of seaweed Ascophyllum nodosum, Hypnea musciformis, Lithothamnium sp., Sargassum vulgare 0.6% on the physiological, nutritional, productive behavior and post-harvest quality characteristics of the vine 'Niagara Rosada'. Seaweed extracts were applied at four different stages of 'Niagara Rosada', at 20 days after bud break, flowering, berries growing stage and maturation of the grapes during two crop seasons, 2014 and 2015. The experiment was conducted under field conditions, a randomized block with split plot. Seaweed extracts provided significantly higher values in most of the periods evaluated for net photosynthetic rate, stomatal conductance, water use efficiency and carboxylation efficiency. The leaf contents of K, Mg, B, Cu and Zn were positively affected by pulverization with seaweed extracts. Plants treated with Ascophyllum nodosum presented levels of these nutrients at higher levels in relation to the control. The production per plant and productivity estimate was affected by pulverization with seaweed, presenting higher values in plants treated with Ascophyllum nodosum. The length and width characteristics of the bunches, fresh mass of berries and fresh mass of the bunch were affected by spraying with seaweed. Total soluble solids, total titratable acidity, ratio, total soluble sugars and pH were affected by treatments with marine algae, being the highest values found with Ascophyllum nodosum. The lower L * value found in grapes treated with Ascophyllum nodosum product suggests grapes with a darker coloring, tending to be more red.