Abstract

Although small fruits, with some exceptions, are not yet as popular in Brazil, some farmers have invested in this market and the genus Physalis can be an important alternative source of income due to its high added value and possibility of cultivation in small areas. To date, there are no specific fertilizer recommendations for even the most cultivated species (Physalis peruviana) and therefore the goal of this study was to evaluate the effects of nitrogen fertilization on quality of fruits of Physalis peruviana and Physalis pubescens. Plants were grown in 5 L pots containing soil and maintained in a controlled environment, in greenhouse. Treatments consisted of five N levels (kg ha^-1): 0, 200, 250, 300 and 350, with seven replicates per treatment. Variables evaluated were total soluble sugars and reducing sugars, phenolics, pH, titratable acidity and fruit diameter.  Nitrogen increased soluble sugars (350 kg ha^-1) and reducing sugars (300 kg ha^-1), mainly in P. pubescens. There was a slight increase of juice pH, but concentrations of total phenols and citric acid decreased with increasing levels of N. Fruit diameter of the two species of Physalis was increased by N fertilization, and the best N level was 300 kg ha^-1.

Key words: Physalis peruviana, Physalis pubescens, reducing sugars, titratable acidity, total phenolics.