Características fitotécnicas de cultivares de lisiantos (Eustoma grandiflorum Raf. Shinn) em diferentes épocas de plantio no sul do Brasil

Abstract

For the production of good quality lisiantos (Eustoma grandiflorum) throughout the year, it is necessary to know the characteristics of different cultivars, at different planting times. The work aimed to estimate the lower base temperature of the culture, the growth and the production of six cultivars of lisianthus at different planting times, in the south of Rio Grande do Sul. For this, seven experiments were carried out and these were formalized in 3 articles. In article 1 (A1) the objective was to determine the lower base temperature of six cultivars of lisianthus, grown at seven different planting times in the Pelotas region. In article 2 (A2) the objective of the work was to evaluate the growth of six cultivars of lisianthus produced in different growing seasons in the southern region of Rio Grande do Sul. In article 3 (A3) the objective was to evaluate was to evaluate the performance, the flowering and final harvest of six cultivars of lisianthus, at different times. The experiments were carried out in a protected environment (plastic greenhouse) located on a rural property in the municipality of Capão do Leão, RS, Brazil. The plants were grown in beds in the soil. The cultivars of lisianthus evaluated were „Blue Echo‟, „Robella‟, White Excalibur ‟,„ Echo Champagne ‟,„ Blue Picotee ‟and„ Arena Red ‟. The crop was evaluated by monitoring experiments carried out at seven different planting times 1 (October 2017 to January 2018), 2 (November 2017 to February 2018), 3 (April to November 2018), 4 ( July to December 2018), 5 (August to December 2018), 6 (January to April 2019) and 7 (February to June 2019). In A1, the lower base temperature (Tb) found for lisianthus cultivars was between 14.0 and 15.0 ºC for the least variability method and between 13.9 and 15.0 ºC for the development ratio method. The greatest thermal accumulation was found in season 2 (November 2017 to February 2018) for all cultivars. In A2, the growth of lisianthus was significantly influenced by the growing seasons. The cultivars „Blue Echo‟, „Robella‟, „White Excalibur‟, „Blue Picotee‟ and „Echo Champagne‟ show a similar growth pattern in all growing seasons. The maximum dry mass value was obtained by the cultivar „Robella‟ (20.3 g / plant-1) in season 3 (April to November 2018). In seasons 1 (October 2017 to January 2018) and 2 (November 2017 to February 2018), the cultivars showed higher speed in the growth rate of the plants, resulting in the shortening of the cycle. The cultivars conducted in seasons 3 (April to November 2018) and 4 (July to December 2018) had a longer cultivation time, due to the influence of climatic variables in the autumn/winter period. In article 3, the cultivars „Blue Echo‟, „Robella‟ and „White Excalibur‟ showed better performance and „Arena Red‟ was lower for the quality and production parameters evaluated. All cultivars produced in seasons 3 (April to November 2018) and 4 (July to December 2018) had their cycle extended by approximately 70 to 100 days. The highest productivity of lisianthus was obtained by the cultivar Robella 8.2 packs / m2 in season 3 (April to November 2018). The cultivars „Blue Echo‟, „Echo Champaign‟ and „Robella‟ are more precocious in the production cycle. The cultivars „White Excalibur‟ and „Blue Picotee‟ have an intermediate cycle and „Arena Red‟ the latest under the conditions studied.