Production and quality of zinnia under different growing seasons and irrigation levels

• Published in: Ciência e agrotecnologia 2021-01, Vol.45
• Main Authors: Martins, Rosária da Costa Faria, Pêgo, Rogério Gomes, Cruz, Eleandro Silva da, Abreu, João Felício Gonçalves, Carvalho, Daniel Fonseca de
• Format: Article
• Language: English
• Subjects: AGRICULTURE, MULTIDISCIPLINARY; classification standard; Cut flower; water deficit
• ISSN: 1413-7054; 1981-1829; 1981-1829
• DOI: 10.1590/1413-7054202145033720

ABSTRACT Zinnia (Zinnia elegans Jacq.) is a fast-growing and easy to cultivate plant that has flowers of different colors. This species has become an option to be introduced commercially in many countries as cut flower and its floral quality is influenced by different cultivation techniques. We evaluated the production and the quality of floral stems of zinnia (cv. Red California Giant) in response to growing seasons and irrigation levels. In a greenhouse located in Rio de Janeiro (Brazil), zinnia plants were grown in two cycles (autumn-winter and winter-spring) in pots with water replacement corresponding to 46, 64, 75 and 100% of their water requirement. Based on the stem length and diameter and on the flower diameter, there was variation in the quality of the stems produced in the growing seasons evaluated. All stems from the autumn-winter cycle were classified as A1 (high quality), while almost 9% of the stems from the winter-spring cycle were classified as A2 (medium quality). There was a linear growth trend in the production and quality of zinnia stems with the increase of the irrigation level in most cases, as well as significant effect of the growing seasons, with the best results of number of stems, fresh weight, length and diameter of the stem and flower diameter found in the autumn-winter cycle. The weather conditions of this cycle favor the production and quality of zinnia floral stems, and the replacement of 100% of the specie’s water requirement is recommended in both cultivation cycles. RESUMO A zínia (Zinnia elegans Jacq.) é uma planta de rápido crescimento e fácil cultivo que apresenta flores de variadas colorações. Essa espécie tem se tornado uma opção a ser introduzida comercialmente em vários países como flor de corte e sua qualidade floral é influenciada por diferentes técnicas de cultivo. Neste trabalho, nós avaliamos a produção e a qualidade de hastes florais de zínia (cv. Gigante da Califórnia Vermelha) em resposta a épocas de cultivo e níveis de irrigação. Em casa de vegetação localizada no Rio de Janeiro (Brasil), plantas de zínia foram cultivadas em dois ciclos (outono-inverno e inverno-primavera) em vasos com reposição de água correspondente a 46, 64, 75 e 100% da sua necessidade hídrica. Com base no comprimento e diâmetro de hastes e no diâmetro de flores, houve variação na qualidade das hastes florais produzidas nas épocas de cultivo avaliadas. Todas as hastes do ciclo outono-inverno foram classificadas como A1 (alta qualidade