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.

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The measurement and mapping of transportation network vulnerability to natural hazards constitute subjects of global interest for a sustainable development agenda and as means of adaptation to climate change. During a flood, some elements of a transportation network can be affected, causing the loss of lives. Furthermore, impacts include damage to vehicles, streets/roads, and other logistics services - sometimes with severe economic consequences. The Network Science approach may offer a valuable perspective considering one type of vulnerability related to network-type critical infrastructures: the topological vulnerability. The topological vulnerability index associated with an element is defined as reducing the network’s average efficiency due to removing the set of edges related to that element. In this paper, we present the results of a systematic literature overview and a case study applying the topological vulnerability index for the highways in Santa Catarina (Brazil). We produce a map considering that index and areas susceptible to urban floods and landslides. Risk knowledge, combining hazard and vulnerability, is the first pillar of an Early Warning System and represents an important tool for stakeholders of the transportation sector in a disaster risk reduction agenda.

The sowing of the wheat crop is a delicate process given the reduced size of its seed. Errors in adjusting the depth of sowing of this crop may result in damage to the establishment and initial growth of the crop. This study aimed to evaluate the influence of the relationship between inoculation with Azospirillum brasilense, Stimulate ® treatment and sowing depth on emergence and initial growth of wheat plants. The experimental design was a randomized complete block design with four replications, in a 4 x 4 factorial scheme. The first factor consisted of the following treatments: i) seed inoculation with A. brasilense, ii) seed treatment with Stimulate ® , iii) inoculation of seeds with A. brasilense associated with the treatment of seeds with Stimulate ® and iv) without inoculation and seed treatment. The second factor was constituted by four sowing depths, being: 1.0; 3.0; 5.0 and 7.0 cm. The treatment of seeds with Stimulate ® favors the higher accumulation of dry mass of stem in wheat plants when sown in greater depths. Seeding at greater depths up to 7.0 cm resulted in the delayed emergence of seedlings, a smaller number of tillers and less dry matter accumulation in wheat plants. Azospirillum brasilense e Stimulate ® favorecem o crescimento inicial do trigo semeado em maiores profundidades?RESUMO: A semeadura da cultura do trigo é um processo delicado tendo em vista o tamanho reduzido de sua semente. Erros no ajuste da profundidade de semeadura desta cultura podem resultar em prejuízos para o estabelecimento e crescimento inicial da cultura. Este estudo teve por objetivo avaliar a influência da relação entre a inoculação com Azospirillum brasilense, o tratamento com Stimulate ® e a profundidade de semeadura sobre a emergência e o crescimento inicial de plantas de trigo. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições, em esquema fatorial 4 x 4. O primeiro fator foi constituído pelos seguintes tratamentos: i) inoculação de sementes com A. brasilense, ii) tratamento de sementes com Stimulate ® , iii) inoculação de sementes com A. brasilense associado ao tratamento de sementes com Stimulate ® e iv) sem inoculação e tratamento de sementes. O segundo fator foi constituído por quatro profundidades de semeadura, sendo: 1,0; 3,0; 5,0 e 7,0 cm. O tratamento de sementes com Stimulate ® favorece o maior acúmulo de massa seca de colmo em plantas de trigo quando semeado em maiores profundidades. A semeadura em maiores profundidades, até 7,0 cm, tem como consequência o atraso na emergência plântulas e, a redução do número de afilhos e acúmulo de massa seca em plantas de trigo.Palavras-chave: fixação biológica; bactéria diazotrófica; emergência; afilho; Triticum aestivum L.Does Azospirillum brasilense and Stimulate ® to improve the initial growth of wheat sown at greater depths?Rev. Bras.