ABSTRACT Grafting can be an ally in the vegetable’s soilless cultivation, being the objective of this work evaluate the growth and production, as well as to define the thermal sum and trophic limit of grafted and non-grafted tomato plants cultivated in substrate. The experiments were conducted in a protected environment in the city of Jaguari-RS, in two growing seasons in the years 2019 and 2020. Italian and Gaucho tomato cultivars were used, the rootstock was chosen for giving vigor and longevity to the plants. Yield data were obtained through weekly fruit harvesting, growth data through periodic collections of whole plants and the total biomass obtained at the end of the experiments. Grafted plants show greater vegetative growth regardless of the crop season; however, non-grafted plants are more productive in a growing cycle with restricted light and low temperatures. Grafted plants require a greater thermal sum to complete their phenological stages. The trophic limit for grafted and non-grafted plants of Italian and Gaucho tomato cultivars is 4.8 MJ/m2/day.

RESUMO A enxertia pode ser uma aliada no cultivo sem solo de hortaliças, sendo o objetivo deste trabalho avaliar o crescimento e a produção, assim como definir a soma térmica e o limite trófico de plantas enxertadas e não enxertadas de tomateiro cultivadas em substrato. Os experimentos foram conduzidos em ambiente protegido na cidade de Jaguari-RS, em duas safras de cultivo nos anos 2019 e 2020. Foram utilizadas cultivares de tomateiro do tipo italiano e gaúcho, o porta enxerto foi escolhido por conferir vigor e longevidade às plantas. Os resultados produtivos foram obtidos por meio da colheita semanal dos frutos, os dados de crescimento por meio de coletas periódicas de plantas inteiras e a biomassa total obtida ao final dos experimentos. As plantas enxertadas apresentam maior crescimento vegetativo independente da safra de cultivo, no entanto, as plantas não enxertadas são mais produtivas em ciclo de cultivo com restrição de luminosidade e baixas temperaturas. As plantas enxertadas exigem maior soma térmica para completar seus estádios fenológicos. O limite trófico para plantas enxertadas e de pé franco das cultivares de tomateiro do tipo italiano e gaúcho é de 4,8 MJ/m2/dia.

RESUMEN El objetivo de este trabajo fue evaluar el crecimiento y rendimiento de tres cultivares híbridos de pepino de conserva, Feisty, Kybria y Tony, cultivados en el sistema de canales con recirculación del lixiviado y empleando el sustrato cascarilla de arroz in natura nuevo y reutilizado después del cultivo de tomate (CAR). El ensayo se instaló en un invernadero ubicado al sur de Brasil, entre el octubre del 2016 y el enero del 2017. Donde se evaluó las siguientes variables: masa seca de hojas, tallo y frutos, número de hojas, índice de área foliar y rendimiento. No se encontraron interacciones significativas entre el cultivar y el sustrato. La CAR no afectó el crecimiento ni tampoco el rendimiento de las plantas, sin embargo, ocasionó el incremento del peso medio de los frutos de pepino y la disminución en el número de frutos cosechados. 'Kybria', seguida de 'Tony', presentaron mayor crecimiento de frutos y rendimiento en relación a 'Feisty', en el cual se observó mayor crecimiento vegetativo en detrimento del crecimiento de los frutos. Los rendimientos obtenidos fueron altos con valores de 4,85; 7,18 y 8,33 kg m-2, respectivamente para los híbridos Feisty, Tony y Kybria. Así, se puede considerar que la cascarilla de arroz, nueva y reutilizada, son excelentes para la producción del pepino de conserva en sistema de recirculación de solución nutritiva.

ABSTRACT The objective of this study was to evaluate the growth and yield of three pickling cucumber hybrid cultivars: Feisty, Kybria and Tony, using a fresh rice husk substrate and a rice husk substrate reused after tomato cultivation in a leachate recirculation system (CAR). This trial was installed in a greenhouse located in southern Brazil between October, 2016 and January, 2017. The following variables were evaluated: dry mass of leaves, stems and fruits, number of leaves, leaf area index and yield. No significant interactions were found between the cultivars and the substrates. The reused substrate did not affect the growth nor the yield of the plants; however, the CAR caused an increase in the average weight of the cucumber fruits and a decrease in the number of harvested fruits. 'Kybria', followed by 'Tony', presented a higher fruit growth and yield than 'Feisty', in which a greater vegetative growth was observed to the detriment of the fruit growth. The yields were high with values of 8.33, 7.18 and 4.85 kg m-2, respectively, for the hybrids: Feisty, Kybria and Tony. In conclusion, rice husks, new and reused, are excellent for the production of canned cucumbers in a nutrient recirculation system.