Growth and gas exchanges of papaya tree seedlings grown on alternative substrates
This study aimed at evaluating the morphophysiological development of papaya tree cultivars under different substrates, produced from mixtures of soil material with sources of organic matter. The experiment was conducted under greenhouse conditions. The experimental design was a randomized block, using a factorial 5 x 2 design with three replications, being five substrates with different sources of organic matter (S1 = 3 parts of soil and 1 of sand - without organic matter (control); S2 = 2 parts of soil, 1 of sand and 1 of cattle manure; S3 = 2 parts of soil, 1 of sand and 1 of sheep manure; S4 = 2 parts of soil, 1 of sand and 1 of chicken manure; S5 = 2 parts of soil, ½ of sand, ½ of cattle manure, ½ of sheep manure and ½ of chicken manure) and two cultivars of papaya tree (Sunrise Solo and Tainung-01). The addition of organic matter, regardless of the source, favored the growth, the dry matter accumulation and the gas exchange of the papaya tree seedlings. The best growth is obtained when using the substrate '3', particularly when it relates to the dry mass of shoot and to the Dickson Quality Index.
Additional keywords: Carica papaya L.; organic fertilizer; propagation.