Efeitos de substratos orgânicos no desenvolvimento inicial de cultivares do maracujazeiro amarelo (Passiflora edulis)

Abstract

Within the passion fruit production chain, the production of seedlings is essential to obtain vigorous plants in the implantation and/or renovation of the orchard. Therefore, an important factor is the use of a substrate that contributes to the initial development of the plant. In this context, the present work aimed to evaluate the development of passion fruit cultivars submitted to different substrates. The experiment was implemented in the CJUR/UFOPA greenhouse II, in a completely randomized design (CRD), in a 4x3 factorial scheme, with four cultivars and three different substrates, totaling twelve treatments. The four yellow passion fruit cultivars are: i) BRS Gigante Amarelo; ii) BRS Rubi do Cerrado; iii) BRS Sol do Cerrado; and Redondo Amarelo. The seeds were arranged in plastic seedbeds with the same substrate, and 28 days after germination, the most vigorous seedlings were selected and transplanted into 5-liter pots, which contained different substrates, namely: i) pure soil (100% ); ii) soil (80%) + poultry litter (20%); and iii) soil (80%) + cattle manure (20%). The treatments were arranged as follows: T1= BRS Sol do Cerrado + soil (100%); T2= BRS Sol do Cerrado + soil (80%) + cattle manure (20%); T3= BRS Sol do Cerrado + soil (80%) + poultry litter (20%); T4= BRS Rubi do Cerrado + soil (100%); T5= BRS Rubi do Cerrado + soil (80%) + cattle manure (20%); T6= BRS Rubi do Cerrado + soil (80%) + poultry litter (20%); T7= BRS Gigante Amarelo + soil (100%); T8= BRS Gigante Amarelo + soil (80%) + cattle manure (20%); T9= BRS Gigante Amarelo + soil (80%) + poultry manure (20%); T10= Redondo Amarelo + soil (100%); T11= Redondo Amarelo + soil (80%) + cattle manure (20%); T12= Redondo Amarelo + soil (80%) + poultry litter (20%). During the experiment, height, stem diameter and number of leaves were evaluated. At 28 days after transplanting, gas exchanges (A, Gs and E) were measured. And at the end of the experiment, the variables of fresh and dry mass of the root and area, and root volume were measured. The data obtained were subjected to analysis of variance, and the means compared by the Scott-Knott test, at a 5% significance level, using the SISVAR software. The use of organic sources in seedling production showed satisfactory responses in the vegetative development of yellow passion fruit cultivars. The substrate composed of soil and cattle manure was the most efficient, and the cultivars BRS Gigante Amarelo and BRS Sol do Cerrado showed the best development in the evaluated period.