Fruit production and quality of guava ‘Paluma’ as a function of humic substances and soil mulching

The uses of humic substances and organic residues for soil mulching have been more common during last years. This way, an experiment was carried out to evaluate the fruit quality and yield of guava cv. Paluma as a function of humic substances and organic soil mulching in Brazil. The experiment was performed from January 2012 to June 2013 (first trial) and from July to November 2013 (second trial) using a randomized blocks with treatments distributed in a factorial arrangement (5 × 2 × 2) of five humic substances doses (0, 10, 20, 30 and 40 mL of Humitec plant-1), two organic mulching use (with and without organic mulching) and two consecutive harvests, with four replications of two plants each. Humic substances enhance fruit production more efficiently in guava plants grown without soil mulching. Guava fruit production increases from the first to the second harvest. Fruit quality for titratable acidity, soluble solids, vitamin C and soluble solids/titratable acidity ratio is adequate independently of soil mulching use. Humic substances improve fruit quality of guava cv. Paluma. Under soil and climate conditions, and considering the first two production cycles of guava, it is possible to recommend about 20 mL L-1 of humic substances for production of high quality guava fruits.Key words: Humic acids, post-harvest, Psidium guajava