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Water stress can affect the yield in tomato crops and, despite this, there are few types of research aiming to select tomato genotypes resistant to the water stress using physiological parameters. This experiment aimed to study the variables that are related to the gas exchanges and the efficiency in water use, in the selection of tomato genotypes tolerant to water stress. It was done in a greenhouse, measuring 7 x 21 m, in a randomized complete block design, with four replications (blocks), being five genotypes in the F2BC1 generation, which were previously obtained from an interspecific cross between Solanum pennellii versus S. lycopersicum and three check treatments, two susceptible [UFU-22 (pre-commercial line) and cultivar Santa Clara] and one resistant (S. pennellii). At the beginning of flowering, the plants were submitted to a water stress condition, through irrigation suspension. After that CO2 assimilation, internal CO2, stomatal conductance, transpiration, leaf temperature, instantaneous water use efficiency, intrinsic efficiency of water use, instantaneous carboxylation efficiency, chlorophyll a and b, and the potential leaf water (Ψf) were observed. Almost all variables that were analyzed, except CO2 assimilation and instantaneous carboxylation efficiency, demonstrated the superiority of the wild accession, S. pennellii, concerning the susceptible check treatments. The high photosynthetic rate and the low stomatal conductance and transpiration, presented by the UFU22/F2BC1#2 population, allowed a better water use efficiency. Because of that, these physiological characteristics are promising in the selection of tomato genotypes tolerant to water stress.

The larvicidal potential of the crude ethanolic extracts (CEE) of the stem peel of Sapindus saponaria was evaluated against Rhipicephalus sanguineus. Lethal concentrations (LC), were calculated by preparing CEE solutions at different concentrations in distilled water. Larvae fasted for 14-21 days were utilized in the bioassays, after incubation of engorged females collected from infested environments frequented by dogs in several neighborhoods of Goiânia, GO. Bioassays were performed in a specially constructed biological chamber for testing botanical acaricides, acclimatized to 27±1ºC, RH>80%. The larvae were counted on filter paper envelopes impregnated with the solutions or distilled water and larval mortality observed after 48h. S. saponaria showed good larvicidal activity (LC50 and LC99 of 1994 and 3922ppm, respectively) and the results demonstrated its potential as a botanical acaricide and an alternative control measure for R. sanguineus. Avaliou-se a potencialidade larvicida do extrato-bruto etanólico (EBE) da casca do caule de Sapindus saponaria sobre Rhipicephalus sanguineus. Para o cálculo das concentrações letais (CL) foram preparadas soluções com diferentes concentrações do EBE dissolvido em água destilada. Foram utilizadas larvas em jejum com 14 a 21 dias, obtidas pela incubação de teleóginas, coletadas em ambientes infestados, freqüentados por cães de vários bairros de Goiânia. Os bioensaios foram realizados em uma câmara biológica para testes com acaricidas botânicos, climatizada a 27±1ºC e UR>80%. As larvas foram contidas em envelopes de papel filtro impregnados com as soluções (grupo teste) ou com água destilada (grupo-controle) e a mortalidade larval foi observada após 48h. S. saponaria demonstrou atividade larvicida satisfatória (CL50 e CL99 respectivamente de 1994 e 3922ppm) e os resultados demonstraram seu potencial como acaricida botânico e medida alternativa para o controle de R. sanguineus.