Antonio Edson Brandão Da Silva

This study presents an analysis of the precipitation index at six experimental stations operated by the Pernambuco Water and Climate Agency (APAC) to monitor the behavior of this index in selected municipalities of the metropolitan region of Recife, Pernambuco: Jaboatão dos Guararapes, Olinda, Várzea/Recife, Lamepe ITEP/Recife, Jaboatão dos Guararapes - TIP, and Camaragibe. Daily precipitation data were collected between 1960 and 2020. The following states were identified for use in the Markov chain: no rain, light rain, light to moderate rain, moderate rain, moderate to heavy rain, and heavy rain. Additionally, the 180-day moving window method was applied. The transition probability matrix of the Markov chain for the states mentioned above was obtained. This information is essential for estimating the probability of adverse events in which heavy rains can impact the lives of thousands of inhabitants in the Metropolitan Region of Recife (RMR). Future work can utilize this study's estimated transition probability matrix to simulate rainfall scenarios and assess potential risks of flooding and landslides.

Nowadays, the development of low-cost technologies that help the rural producer in raising the productivity of crops with environmental concern is essential. From this, the objective of the present work was to evaluate doses of humic substances as an alternative for the production of squash seedlings. The research was developed at the University of the State of Bahia - UNEB, in Euclides da Cunha - Bahia, using the Moranga Exposure cultivar. The experimental design adopted was completely randomized with 3 compounds and 5 doses, with 15 treatments and 5 repetitions for each compound dose, in a 3x5 factorial scheme. The doses of humic substances used were 0, 0.5, 1.0, 2.0 and 4.0 mL/plant^-1. The following variables were analyzed: number of leaves, stem diameter, plant height, chlorophyll content, root length, shoot dry mass and root dry mass. Based on the results found, it was concluded that the dose of 0.5 mL/plant^-1 provided squash seedlings with a greater number of leaves (3.4), plant height (25.2 cm), stem diameter (0.68 mm), chlorophyll content (40.1 µg.cm^-2), root length (31.40 cm), shoot dry mass (1.78 g), root dry mass (0.35 g). It was also possible to observe that the dose of 4.0 mL/plant-1 and the absence of humic substances in the dose of 0 mL/plant^-1 had a limiting effect on the development of the culture. Thus, doses of 0.5 mL/plant^-1 are indicated for the production of squash seedlings in the semi-arid region.

A utilização de polímeros hidroretentores a nível de semiárido se constitui em uma prática recente que vem ganhando cada vez mais espaço na agricultura. A partir do exposto, o presente trabalho teve por objetivo avaliar a influência de diferentes turnos de rega e polímero hidroretentor na qualidade de frutos de melancia cultivada em condições semiáridas. O experimento foi conduzido na Universidade do Estado da Bahia em Euclides da Cunha – Bahia. O delineamento estatístico foi de blocos casualizados. Os tratamentos consistiram na adoção de três turnos de rega, sendo: 1D – diariamente; 2D – a cada 1 dia; 3D – a cada 2 dias. As variáveis analisadas foram: número de frutos (NF) e peso de frutos (PF). Com auxílio do software Sisvar® foi realizada a análise de variância (ANOVA) e as médias foram comparadas pelo teste Tukey ao nível de 5% de probabilidade. O polímero hidroretentor influenciou de forma significativa as variáveis, sendo responsável pelo maior número de frutos (1,83) e maior peso de frutos (9,14 kg). A partir dos resultados obtidos, observou-se a eficiência do polímero hidroretentor na produção de melancia no semiárido.