Crescimento de Campomanesia adamantium (Cambess.) O. Berg em substrato com bioestimulador

Abstract

‘Guavira’ [Campomanesia adamantium (Camb.) O. Berg, Myrtaceae] is fruiting plant native to the ‘Cerrado’. The leaves and fruit peels have medicinal properties, such as urinary tract antiseptics, anti-inflammatory, antidiarrheal, antiviral, antidepressant, antinoceptive and antiproliferative. However, there are few studies for its ex situ cultivation, especially those related to the use of biostimulators of the soil microbiota, which aim to increase the availability of nutrients in the soil. The objective of this study was to evaluate the effect of biostimulator doses on the chemical and microbiological attributes of the substrate and on the growth and development of the ex situ guavira plant. Six doses of the biostimulator (0, 50, 100, 150, 200 and 250 g ha-1) were applied to substrate composed of soil (dRL), earthworm humus, manioc leaves (6:2:2/v:v:v), in randomized complete block design with four replicates. The experimental unit was composed of ten plastic bags (1.3 L), with one plant in each. During the cycle, plant height, collar diameter, leaf number, chlorophyll-a fluorescence, chlorophyll indices, fresh and dry leaf masses, stem and root, leaf and root areas were evaluated; length of the largest root and Dickson quality index. The chemical and microbiological attributes of the substrates, macro and micronutrient contents of the aerial part and the roots of the plants of each treatment were also determined. The highest availability of chemical attributes occurred on the substrate without and with addition of 50 g ha-1 of the biostimulator. The carbon of the microbial biomass increased with the application of the biostimulator, such increase reached 41.22% at the dose 200 g ha-1 compared to the substrate without biostimulator. The decreasing order of nutrient content in the aerial part was N>Ca>K>Mg>P>Fe>Mn>Zn>Cu and in the root was N>Ca>K>P>Mg>Mn>Zn>Cu in the bstrates, regardless of the dose of the biostimulator. The highest plant height (21.84 cm) and collar diameter (2.71 mm) occurred at 180 DAT. The number of leaves was higher (26.2) in the plants grown with 50 g ha-1 of the biostimulator at 180 DAT. The highest photochemical efficiency of photosystem II (0.800) occurred in the leaves of plants grown on the substrate with 85 g ha-1 of the biostimulator. The highest dry matter yield and highest leaf area were of the plants cultivated with 150 g ha-1 of the biostimulator. The highest IDQ was from the plants cultivated in substrate with a dose of 150 g ha-1 of the biostimulator. It was concluded that for the cultivation of guavira in polyethylene bags filled with substrate formed by distroferric Red Latosol, worm compost and decomposed manioc leaves it isn’t necessary to use a biostimulator.