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.

摘要：巴西是全球最大的甘蔗（Saccharum officinarum L.）生产国，针对种苗繁育的研究已有效推动甘蔗生产品质提升。本研究旨在探究微气象要素变化对预发芽甘蔗幼苗（pre-sprouted sugarcane plantlets）存活状况与品质的影响。本研究于UFRPE的保护地环境中开展。供试品种为RB92579，通过预发芽种苗生产技术获得幼苗。该保护地被划分为4个覆盖抗紫外线低密度聚乙烯塑料（Anti-UV low-density polyethylene plastic）与光选择性遮阳网的模块，以及1个无遮阳网的模块。各模块均记录了全球太阳辐射、光合有效辐射（photosynthetically active radiation）、空气温度、基质温度、相对湿度及太阳辐射光谱等微气象数据。实验采用完全随机设计，借助主成分分析（Principal Component Analysis）验证栽培模块、微气象变量与作物变量间的关联。结果表明，搭配抗紫外线低密度聚乙烯塑料与Freshnet遮阳网的模块，其全球太阳辐射透过率更低，光合有效辐射占比更高，幼苗死亡率更低；基质温度高于30.2℃时，幼苗死亡率显著升高；红光波段占比更高的光谱环境可培育出品质更优的甘蔗幼苗。综上，采用Freshnet遮阳网可为甘蔗幼苗栽培提供适宜环境，助力获得品质更佳的种苗。