Abstract

SALAS, Danilo; VALDEZ, Evelyn  and  FERNANDEZ, Yolanda. Contribution to the knowledge of the Yerba Mate (Ilex paraguariensis St. Hil) behavior under natural light conditions in the Mbaracayú Forest Nature Reserve. Rev. Soc. cient. Parag. [online]. 2019, vol.24, n.1, pp.74-98. ISSN 2617-4731.  https://doi.org/10.32480/rscp.2019-24-1.74-98.

It is important to determine the most favorable lighting conditions for yerba mate cultivation. To achieve this, two independent experiments were carried out, both followed a quasi-experimental design with a quantitative approach. The studied population were yerba mate plants implanted in scrubland under two conditions of luminosity during four months, from July to November 2017. In the first case the objective was to evaluate the growth of the yerba mate plants in scrubland under two luminosity conditions in the Reserve. Each light condition icnluded 36 plants, distributed in six plots. The variables evaluated were luminosity, height, neck diameter, leaf area and leaf number as well as the plant survival. The highest luminosity was recorded in the clearing condition in July with an average of (1797.5±211.9 lx). The growth was greater in the clearing condition, where the following averages were obtained: height (26.89±5.2 cm), neck diameter (4.10±0.4 mm), leaf area (253.31±139.7 cm2) and leaf number (15±6 leaves). In relation to the increase in height, diameter of neck, leaf area and leaf number, there were significant differences between the two conditions of luminosity. The increase was greater in the clearing condition, where the following averages were obtained: (10.81±5.2 cm), (1.55±0.5 mm), (81.35±144.3 cm2) and (4±6 leaves) respectively. The survival of plants was slightly higher in the closed canopy condition with 75% survival. In the second case, the objective was to evaluate the influence of the luminosity on the foliar morphology and phenology of yerba mate, for this purpose 80 plants were installed (scrubland and full sun), 40 per condition. Variables such as luminosity, total amount, number of sprouts and persistence of leaves, average morphology (length and width), and leaf area were measured while survival was recorded at the end of the study. The plantation in full sun was affected by the frost at the beginning of the study. The luminosity presented variations in both conditions, there was a decrease in luminosity from September in the plantation in full sun while there was an increase in luminosity in those of scrubland due to the fall of a tree. The number of sprouts was greater in full sun, with a total of 7 ±5.9 leaves/plant, however, there were no significant differences with those of scrubland. The same condition registered the highest leaf fall between August and September, while those of scrubland showed greater persistence of leaves. The yerba mate leaves of scrubland were wider (3.7±0.8 cm), therefore the leaf area was greater with a total of 245.5±139.7 cm2. There were significant differences by condition for these variables. The survival of plants was 90% for both conditions.

Keywords : Yerba mate; light conditions; Mbaracayú; physiology..

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