Nitrogen fertilization as top dressing and different substrates on the production of 'Formosa' papaya (Carica papaya L.) seedlings

Aiming at evaluating the seedling production of papaya (Carica papaya L.) on different substrates and nitrogen fertilization as top dressing, an experiment was carried out at the plant formation area of Federal University of Lavras orchard. Five doses of nitrogen were tested, viz.: 0; 400; 800; 1600, and 3200 mg N dm(-3) substrate, applied five times, and in each application, 20 mL of the solution containing the N was added to the polyethylene bags (500 mL capacity). Two substrate composition were tested, namely A (organic compost + sand + soil at 1: 1: 3 volume proportion) and B (Plantmax + sand + soil at 1: 1: 3 volume proportion). A randomized block design was used with factorial scheme 5x2, with four replications and five plants per plot. One hundred and eighty days after the sowing the following characteristics were evaluated: height of the aerial parts (cm), length of roots (cm), number of leaves/plant, dry matter of aerial part, root, and total plant (g/plant). It was observed that the doses up to 1.800 mg N dm(-3) as top dressing promoted better quality in the formation of seedlings. The substrate B promoted the best results in the production of 'Formosa' papaya plants.