Photo-selective shade nets on the production and quality of sugarcane plantlets

ABSTRACT Brazil is the world’s largest producer of sugarcane (Saccharum officinarum L.) and research aimed at propagation has promoted higher quality in production. The objective of this study was to investigate the effect of the variation of micrometeorological elements on the survival and quality of pre-sprouted sugarcane plantlets. The study was carried out in a protected environment (UFRPE). Plantlets of the cultivar RB92579 were obtained by the technique of production of pre-sprouted plantlets. The protected environments were divided into four modules covered with low-density polyethylene plastic + photo-selective shade nets and one module without shade net. Micrometeorological data of global and photosynthetically active solar radiation, air temperature, substrate temperature, relative humidity and the solar radiation spectrum were recorded in each module. The experiment was conducted in a completely randomized design and the principal component analysis was used to verify the association between the cultivation modules, micrometeorological variables and crop variables. Anti-UV low-density polyethylene plastic + freshnet led to lower transmittance of global solar radiation, higher percentage of photosynthetically active radiation and lower plantlet mortality. Substrate temperature above 30.2 °C resulted in higher plantlet mortality. Larger spectrum in the red range led to the production of better quality plantlet. The use of freshnet shade net promoted adequate conditions for the cultivation of sugarcane plantlets and allows obtaining better quality plantlets. RESUMO O Brasil é o maior produtor mundial de cana-de-açúcar (Saccharum officinarum L.), e pesquisas voltadas à propagação têm proporcionado maior qualidade na produção. Objetivou-se averiguar o efeito da variação dos elementos micrometeorológicos na sobrevivência e qualidade de mudas pré-brotadas de cana-de-açúcar. A pesquisa foi realizada em ambiente protegido (UFRPE). As mudas da cultivar RB92579 foram obtidas pela técnica de produção de mudas pré-brotadas. Os ambientes protegidos foram divididos em quatro módulos cobertos com plástico polietileno de baixa densidade + malhas de sombreamento fotosseletivas e um módulo sem malha. Foram registrados os dados micrometeorológicos de radiação solar global e fotossinteticamente ativa, temperatura do ar e do substrato, umidade relativa do ar e o espectro de radiação solar em cada módulo. O experimento foi instalado em delineamento inteiramente casual