ABSTRACT Sugarcane has a great economic interest in Brazil, so it needs technologies to increase its yield strength, especially for seedling production. This study aimed to ascertain the influence of shading nets on early growth and development of pre-sprouted sugarcane seedlings. An experiment was conducted in a protected environment, in the Rural Federal University of Pernambuco (UFRPE), in Recife-PE, Brazil. The protected environments were covered with anti-UV low-density polyethylene plastic plus: Solpack® red ultranet net, Solpack® white net, Solpack® freshnet net, and without shade net, and five replications each. The experiment was carried out in a completely randomized design, and multivariate principal component analysis (PCA) was used to verify associations among cultivation modules, micrometeorological factors, and seedling growth parameters. Anti-UV low-density polyethylene + shade net improved seedling growth and development up to 27 days after planting. Higher substrate temperatures benefited early growth of seedlings. After 27 days of planting, sugarcane seedlings required higher air temperatures, as well as increased global and photosynthetically active solar radiation.

ABSTRACT This research was carried out in Recife, PE, Brazil, and aimed to assess the variation of the surface temperature of trays and substrate in the production of lettuce seedlings and its influence on the final product. Trays consisted of expanded polystyrene, conventional polyvinyl chloride, polyvinyl chloride painted white, and polyvinyl chloride painted gray. Two cultivars (Solaris and Vanda) were used to register crop biometric variables from seedling stage to the final product (46 days). Tray and substrate temperatures were recorded by means of an infrared thermal imager. The experimental design was a completely randomized design in a 4 × 2 factorial scheme with three replications. The conventional polyvinyl chloride tray presented the highest surface temperature. The substrate temperature in the styrofoam tray was higher when compared to the others. The white tray showed the lowest values of substrate temperature, providing a better seedling development. Seedling quality and the most important agronomic characteristics for commercialization were obtained in the white tray, being the best alternative for lettuce cultivation.