A B S T R A C TInfrared thermometry allows evaluating plants under water stress, by measuring the canopy temperature, without the need of physical contact with the leaves. The aim of this study was to determine the water stress index of the tomato crop for industrial processing (Hybrid 'BRS Sena'), as a function of irrigation depths applied by subsurface drip irrigation, in Southern Goiás, Brazil, in 2015 and 2016. The experiment was conducted in a randomized block design, with four replicates. The treatments consisted in five irrigation depths: 50, 75, 100, 125 and 150% of crop evapotranspiration. The water stress index of the tomato crop was evaluated using two methodologies, as a function of the canopy temperature, air temperature and other local meteorological parameters, as well as the relationship between water stress index and crop yield. Theoretical and empirical methods estimate CWSI similarly in tomato. In the hottest hours of the day, even under adequate soil moisture conditions, the 'BRS Sena' tomato showed CWSI above 0.2. CWSI is a good indicator to evaluate the water status of the tomato crop for industrial processing and to recommend the moment of irrigation. The higher the CWSI, the lower the yield of 'BRS Sena' tomato.Índice de estresse hídrico de tomateiro em função de lâminas de irrigação R E S U M OA termometria infravermelha permite avaliar o estresse hídrico das plantas através da medição da temperatura do dossel, sem necessidade de contato físico com as folhas. Objetivou-se neste trabalho determinar o índice de estresse hídrico do tomateiro industrial (híbrido BRS Sena) em função de lâminas de irrigação aplicadas por gotejamento subsuperficial, na região Sul de Goiás, nos anos 2015 e 2016. O delineamento experimental foi em blocos ao acaso, com quatro repetições. Os tratamentos consistiram de cinco lâminas de irrigação, iguais a 50, 75, 100, 125 e 150% da evapotranspiração da cultura. Avaliou-se o índice de estresse hídrico do tomateiro por meio de duas metodologias, em função da temperatura no dossel, temperatura do ar e demais parâmetros meteorológicos locais, e também a relação dos valores do índice de estresse hídrico com a produtividade da cultura. Os métodos teórico e empírico estimam de maneira semelhante o CWSI no tomateiro. Nas horas mais quentes do dia, mesmo em condições de umidade adequada no solo, o tomateiro BRS Sena apresentou CWSI acima de 0,2. O CWSI é um bom indicativo para avaliar o estado hídrico do tomateiro industrial e indicar o momento de realizar a irrigação. Quanto maior o CWSI, menor foi a produtividade do tomateiro BRS Sena.

Irrigation management is essential for tomato fruits yield and quality. Therefore, the aim of this study was to evaluate the yield of tomatoes for industrial processing, 'BRS Sena' hybrid, subjected to water depths and irrigation suspension periods before harvest, irrigated by subsurface drip irrigation, in Goiás, Brazil (17º 49' 19.5" S and 49º 12' 11.3" W), in 2015 and 2016. The experiments were conducted under a randomized complete block design, with four replications, in split plots. Five irrigation levels (50, 75, 100, 125 and 150% of crop evapotranspiration) were evaluated in the plots and five irrigation suspension periods (0, 7, 14, 21 and 28 days before harvest) were evaluated in the subplots. At 125 days after transplanting the seedlings, the yields of green, mature, rotten fruits and total yield, water productivity and percentages of green, mature and rotten fruits were evaluated. The highest total fruit yields (105.86 and 58.60 t ha -1 ) were obtained with water replacements ranging from 125.47 (615.09 mm) to 132.11 (564.00 mm) of crop evapotranspiration, in the first and second year of experiment, respectively. Growing plants under water deficit and excess increased the incidence of rotten fruits and decreased that of mature fruits. Pre-harvest irrigation suspension reduced crop yield and incidence of green fruits and increased the incidence of rotten fruits. The highest water productivity by the crop occurred under water deficit, management that may be interesting for regions with water restrictions.Produtividade do tomateiro em função de lâminas e períodos de suspensão da irrigação RESUMO: O manejo da irrigação é essencial para a produtividade e qualidade dos frutos de tomateiro. Objetivou-se neste estudo avaliar a produtividade do tomateiro para processamento industrial "Híbrido BRS Sena" submetido à lâminas e períodos de suspensão da irrigação antes da colheita, irrigado por um sistema de gotejamento subterrâneo, na região Sul de Goiás, Brasil (17º 49' 19,5" S e 49º 12' 11,3" O), nos anos de 2015 e 2016. Os experimentos foram instalados no delineamento em blocos ao acaso, com quatro repetições, em parcelas subdivididas. Nas parcelas avaliaram-se cinco níveis de irrigação (50, 75, 100, 125 e 150% da evapotranspiração da cultura) e nas subparcelas cinco períodos de suspensão da irrigação (0, 7, 14, 21 e 28 dias antes da colheita). Aos 125 dias após o transplantio das mudas avaliou-se a produtividade de frutos verdes, maduros, podres e total, a produtividade da água e as percentagens de frutos verdes, maduros e podres. As maiores produtividades totais de frutos (105,86 e 58,60 t ha -1 ) foram obtidas com reposições hídricas que variaram de 125,47 (615,09 mm) e 132,11% (564,00 mm) da evapotranspiração da cultura, nos dois experimentos, respectivamente. As plantas cultivadas sob déficit e excesso hídrico, aumentaram a incidência de frutos podres e diminuíram a de frutos maduros. A suspensão da irrigação antes da colheita diminuiu a produtividade da cultura, aumentou a incidência de frutos podres e di...

This study was carried out to evaluate the postharvest quality of processing tomato fruits, submitted to irrigation depths and periods of suspension of irrigation before harvest, irrigated by subsurface drip in Cerrado areas in the southern region of Goiás State, Brazil, in 2015 and 2016. The experiments were established under a randomized block design, with four replicates arranged in a split plots scheme. In the plots, five irrigation depths were evaluated (50, 75, 100, 125 and 150% of the crop evapotranspiration) and, in the subplots, five periods of suspension of irrigation (0, 7, 14, 21 and 28 days before harvest) were assessed. After harvesting, which occurred at 125 days after transplanting the seedlings, the average fruit mass, fruit shape (longitudinal and transversal diameter), total soluble solids content, titratable acidity, pH, firmness, pulp yield, and water productivity for pulp yield were evaluated. Irrigation deficit, with the replacement of less than 100% of crop evapotranspiration, allowed to save water but significantly reduced the size of the fruits and the production of concentrated pulp. The suspension of irrigation before harvest decreased pulp yield and fruit size. The highest water productivity for pulp yield of tomato fruits occurred under water deficit with 50% of crop evapotranspiration. Irrigation depths from 50 to 150% of crop evapotranspiration and suspension before harvest does not influence total soluble solids content, pH, and fruit firmness.

HIGHLIGHTS The number of flowers, the abortion rate, and the number of fruits per flower cluster directly influence processing tomato yield. Deficient or excessive irrigation levels impair flowering and increase the abortion of flowers of the processing tomato. Irrigation management is essential for the yield of processing tomato crops from the Brazilian Cerrado.

The slope of cultivation channels and types of nutrient solutions in hydroponics and aquaponics influence nutrient absorption and plant production. This research aimed to evaluate lettuce production under different channel slopes and nutrient solutions in hydroponic and aquaponic systems using the nutrient film technique (NFT). A randomized block design was used, with three replicates, in a 3 × 5 split-plot scheme, with three nutrient solutions (conventional hydroponic solution and two wastewaters from the tilapia fish diets, with 15 and 18% of crude protein) and five slopes (2, 4, 6, 8 and 10%) of cultivation channels (PVC tubes). The following variables were evaluated: fresh and dry mass of shoot and roots and the chemical elements of the solutions. In the tilapia feed, the nutrient solution with 18% of protein (wastewater) provides greater production and accumulation of nutrients (N and P) in the lettuce shoot. The slope of 8% on cultivation channels provides greater production of iceberg lettuce, cultivar Lucy Brown. The different slopes and nutrient solutions studied did not influence the potassium (K) accumulation in the lettuce shoot.