Coeficiente de cultura de mudas de jabuticabeira com diferentes substratos e cobertura morta

Abstract

The jabuticabeira [Plinia cauliflora (Mart.) Kausel] is one of Brazil's fruit tree species with high potential for commercialization of its fruits. However, for this species, information on the ideal conditions for the production of seedlings is limited. The objective of this study was to evaluate the water consumption, growth and chlorophyll content of jabuticabeira seedlings from mini-cuttings as a function of the addition of poultry litter compound to the substrate and the use of mulch. The experiment was carriedout in a greenhouse of the Teaching and Research Unit of Nursery of Production of Horticultural Saplings UTFPR – Dois Vizinhos - Paraná. Jabuticabeira seedlings from rooted mini-cuttings were used, which were transplanted to drainage lysimeters, made with 20l polyethylene pails. The same ones containing as substrate mixtures of red latosol, sand and poultry litter in the proportions: S1 - latosol + sand (2: 1 v / v); S2 – latosol + sand + poultry bed compound (2: 1: 0.5 v / v / v); S3 - latosol + sand + bird bed compound (2: 1: 1v / v / v); S4 - latosol + sand + bird bed compost (2: 1: 1.5 v / v / v); and S5 – latosol + sand + poultry bed compost (2: 1: 2 v / v / v). As mulch was used pigeon pea (Cajanus cajan) in the installation of the experiment, in proportion of 10 tons per hectare. The variables analyzed were: Colony diameter, plant height, number of leaves, treetop area, number of primary branches, length of primary branches, chlorophyll a, b, and total and leaf area. For the water consumption variables, (Eto) reference evapotranspiration calculations were performed using the Penman-Monteith method and crop evapotranspiration (ETc) and the crop coefficient (Kc) is calculated based on the methodology of Salassier, 2009. The experimental design was completely randomized, in a factorial scheme with five substrate compositions, with and without mulch and in five evaluation periods for chlorophyll and leaf area, and twelve evaluation periods for other variables, with four replicates considering each plant as Experimental unit. The effect of the addition of the poultry bed compound was contrary to expected, limiting the growth of the seedlings to S2 and leading to the death of the seedlings for S3, S4 and S5. The mulch was positive, except for "a" and "total" chlorophyll, presenting positive values mainly for S1 and S2. Regarding water consumption, the use of soil cover reduced ETc and Kc values, being effective in reducing water loss through evapotranspiration of the plant soil system. However, there was a low correlation between ETc and Kc values for the variables of Colony diameter, plant height, number of leaves, treetop area, number of primary branches, length of primary branches. Signifying that the growth of the seedlings was strongly influenced by the substrate used, restricting the growth of the seedlings. High initial ETc and Kc variations are also responsible for the low correlation between water consumption and seedling growth over time. The same is true for the relationship between seedling growth and time for S3, S4 and S5.