Growth and physiology of jelly palm (Butia capitata) grown under colored shade nets

ABSTRACT. Butia capitata (Mart.) Becc., commonly known as jelly palm, is a palm tree native to the Cerrado biome. It is considered an endangered species owing to intensive extractive exploitation of its fruits, with slow and uneven seminiferous propagation as an aggravating factor. Thereby, there are some bottlenecks related to jelly palm seedling production that needs to be optimized. Light quality and intensity is very important to seedling production, as it controls the metabolism of plants and consequently their growth and development. Thus, the aim of this work is to evaluate the effect of shade nets on the growth and physiological aspects of jelly palm seedlings. The experimental design was completely randomized, with five treatments, ten replicates and eight plants per replicate, totaling 400 plants. Experimental treatments consisted of the use of shade nets with 50% shading and different radiation intensity: white (985 µmol m-2 s-1), red (327 µmol m-2 s-1), black (433 µmol m-2 s-1), and silver (405 µmol m-2 s-1). Full sun (1000 µmol m-2 s-1) was used as the control treatment. Growth and physiological analyses of the plants were performed after six months of treatment. We concluded that the red shade net increases growth and biomass of Butia capitata plants. However, the use of shade nets had no effect on the tested physiological characteristics of this species. The red shade net is the most suitable for the production of Butia capitata seedlings in the southern region conditions of Minas Gerais State.摘要。布蒂亚椰子（Butia capitata (Mart.) Becc.）俗称果冻棕榈（jelly palm），是原产于塞拉多生物群系（Cerrado）的棕榈科植物。由于对其果实的过度采掘利用，该物种已被列为濒危物种，而其种子繁殖缓慢且不均一的特性进一步加剧了这一濒危现状。因此，果冻棕榈的种苗生产存在若干亟待优化的瓶颈环节。光质与光强对种苗生产至关重要，因其可调控植物代谢过程，进而直接影响植株的生长与发育进程。本研究旨在评估不同遮阳网对果冻棕榈种苗生长及生理特性的影响。本实验采用完全随机设计，设置5个处理组、10次重复，每重复定植8株植株，总计400株供试材料。实验处理为使用遮光率50%的不同类型遮阳网：白色（辐射强度985 µmol·m⁻²·s⁻¹）、红色（327 µmol·m⁻²·s⁻¹）、黑色（433 µmol·m⁻²·s⁻¹）及银色（405 µmol·m⁻²·s⁻¹），以全光照（辐射强度1000 µmol·m⁻²·s⁻¹）作为对照处理。待施加处理6个月后，对供试植株的生长及生理指标开展测定与分析。研究结果表明，红色遮阳网可显著促进布蒂亚椰子植株的生长与生物量积累，但各类遮阳网的使用对该物种的待测生理特性均无显著影响。在米纳斯吉拉斯州南部区域的种植条件下，红色遮阳网是果冻棕榈种苗规模化生产的最优选择。