The establishment of appropriate standards related to the physiological and morphological aspects of the seeds are fundamental procedures to help the nurserymen and seed producers in determining the maturity and the appropriate moment of collection of the fruits. In this sense, the objective of this research is to evaluate the physiological maturation of seeds of Parapiptadenia rigida by means of germination and vigor tests, based on the color of the pods. The seeds were collected in June 2017, from three matrices located in the municipality of Marechal Cândido Rondon, Paraná, Brazil. The pods were classified in four stages of maturation, according to the Chart of colors model “Munsell colors chart” for plants tissues, and measured the biometric parameters. The parameters observed to evaluate the germinative potential are: first germination count, germination velocity index, emergency velocity index, and fresh and dry matter masses of seedlings. The experimental design was completely randomized, with five maturation stages and four replicates of 25 seeds each. The averages were compared using the Tukey test at a 5% probability. The germination test showed that the increase in physiological potential of P. rigida seeds is associated with the progresses of pod maturation. Therefore, the vigor test demonstrated that the physiological maturation of the species is simultaneous with the change of coloration and maturation of the pods.

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Hovenia dulcis is a pioneering species, fast growing and considered exotic and invasive. The species has multiplicity of uses and reproduces by seeds. In this sense, it is extremely important to know the physiological maturity of H. dulcis seeds. The objective of the research was to determine if the maturation of H. dulcis seeds is achieved concomitantly with the physiological maturation of the false fruit. Seeds were obtained from seven adult trees located in Marechal Cândido Rondon, PR. The fruits were classified in five maturation stages, determined according to color chart. In order to verify the effects of the maturation stages of the false fruit on the physiological maturity seeds biometric characteristics, moisture content, germination, vigor and seedling development were evaluated. Seeds of H. dulcis presented evolution of maturation at the same time as the false fruit. For the evaluated parameters, seeds classified as stage 1 (7.5 YR 5/8) showed the best results for seed germination and seedling development, in contrast to those classified as stage 5 (2.5 YR 3/4), which presented low germination and delay in the development of seeds and seedlings.

The objective of this study is to identify and quantify the floristic composition of the weed community in the rice crop waterlogged in the municipality of Arari-MA. The botanical material was obtained in three areas by randomly a hollow rectangle of 0.50 m × 0.30 m by forty five times in each plot. The aerial parts of weeds were harvested, identified, counted and oven dried with forced air ventilation at 333.15 K to 343.15 K. These data were used to determine the phytosociological parameters and the Shannon-Wiener diversity index was also calculated. A total of 6607 plants were collected, being 4115 (62.28%) in the vegetative phase and 2492 (37.72%) in the reproductive phase. The monocotyledonous group obtained the largest number of plants, 2882 in the vegetative phase and 1535 in the reproductive phase. The Cyperaceae family recorded nine species and four genera and the Poaceae, seven and four species in the vegetative and reproductive phases, respectively. The species of higher IVI in the vegetative phase was E. sellowiana in the area A1 with 82.86%, and in the reproductive F. dichotoma with IVI of 90.49% in the area A3. The individuals density and species richness were higher in the vegetative phase of the culture and the monocotyledonous group predominated with the Cyperaceae and Poaceae families, and the weed diversity among the areas was low.

The objective of this work was to verify the responses in agronomic and physiological characters of lettuce seedlings when submitted to different doses of humic acids and the presence or absence of inoculation of the bacterium Azospirillum brasilense. The experiment was carried out at the Protected Cultivation Station and Biological Control Teacher Mário César Lopes, belonging to the Experimental Stations Nucleus of the State University of the West of Paraná. The experimental design was a randomized block design, in a 5 × 2 factorial scheme, with four repetitions, totaling 40 plots. The first factor consisted of five solutions containing humic acid (100%, 75%, 50%, 25% and 0%) and the second factor was the presence or absence of the diazotrophic bacterium Azospirillum brasilense obtained by commercial product. Germination tests were carried out in addition to the determination of agronomic characters such as the number of fully expanded leaves, plant height, stem diameter, main root length, shoot dry mass, root dry mass, total dry mass, and Dickson quality index. The association of diazotrophic bacteria and humic acids did not influence the emergency rate, mean emergence time, mean speed of emergency, emergence speed index, plant height, and root length of lettuce seedlings. The dilutions of humic acids, regardless of inoculation with bacteria diazotrophic favored the development of the number of leaves, stem diameter and Dickson quality index. Inoculation of lettuce seeds with diazotrophic bacteria associated with the addition of humic acids, favored the development of the dry mass of root and total dry matter.