Seeds of maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench.] were submitted to different osmotic potential levels induced by polyethylene glycol (PEG) with the objective of evaluating the effects of drought stress on seed germination and early seedling growth. Seeds were arranged in paper rolls and soaked in PEG solutions prepared with osmotic potentials 0.0 (control), -0.2, -0.4, and -0.8 MPa and kept into a seed germinator, at 25 °C for 18 days. A completely randomized design in a 2 × 4 factorial scheme with four replications of 50 seeds each was used. The results showed that by increasing of the osmotic potential level, germinated seed number, germination rate index, root and shoot length, shoot and root dry matter, and seedling vigor index (SVI) decreased, while mean germination time (MGT) and root: shoot ratio (RSR) increased in both crops. Additionally, the maize was more susceptible than sorghum to drought stress, with germination response declining more rapidly with decreasing osmotic potential. Sorghum crop tolerates water stress of up to -0.2 MPa, without reducing germination of the seeds; however, the growth of shoots and roots are inhibited. Drought stress limits the process of seed germination and early growth of maize seedlings.
Pasture areas have been decreasing over the years in Brazil, largely due to the expansion of agricultural areas, mainly in the Southeast region. Natural or planted pastures are subject to attack by insects that can become pests depending on their level of infestation and among them are the Scarabaeidae beetles. The scarce information on the species of this family existing in the region of Bálsamo (São Paulo) makes a study on the occurrence of these species necessary, thus generating data that can contribute to identification and information on possible existing pest species. During September 2018 to August 2019, collections of phytophagous Scarabaeidae species were done in pasture areas with a light trap. A total of 446 adults from the subfamilies Dynastinae, Melolonthinae and Rutelinae were collected. In Dynastinae the genera Bothynus, Coelosis, Cyclocephala, Chalepides and Actinobolus were collected, in Melolonthinae the genera Plectris and Liogenys and in Rutelinae the genera Anomala, Geniates, Leucothyreus, Lobogeniates, Byrsopolis and Trizogeniates were found. Among the species collected, some are described as pests in crops, including pastures, such as Liogenys suturalis Blanchard, which was the species that had the largest number of individuals during the collection period, being indicated as a species worthy of more detailed studies.
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