Federal University of Roraima

About: Federal University of Roraima is a based out in . It is known for research contribution in the topics: Population & Thermogravimetry. The organization has 981 authors who have published 1218 publications receiving 7849 citations. The organization is also known as: Federal University of Roraima.

Path analysis of soybean yield in the micro region of Alto Médio Gurguéia

Abstract: The objective of this work was to evaluate, by using path analysis, the influence of some agronomic characters on soybean yield. An experiment was conducted in cerrado soil, in Serra do Quilombo, Bom Jesus, Southern of Piaui State, from december 2007 to april 2008, in an Oxisol. The experimental design was randomized blocks, with treatments consisting of six levels of phosphorus (0, 40, 60, 100, 120 and 140 kg P2O5 ha-1) with four replications. Some characteristics were evaluated: plant height, height of first pod insertion, number of nodes per plant, number of string beans per plant, 100 grains weight, dry weight and total grain production per plant. The number of pods per plant was the yield component that showed the greatest direct effect on dry matter and total grain production per plant. The number of nodes per plant had a strong indirect effect on dry matter production. The variable height of first pod insertion showed lower correlation with the other variables.

Yield of sweet potato as a function of organic fertilization and intercropping with Crotalaria juncea

Abstract: In the northern region of Brazil, information for the sweet potato regarding suitable soil management, especially organic fertilisation and intercropping with species of green manure, are still in the early stages The aim of this research therefore, was to evaluate the effect of poultry litter on the yield of sweet potato roots grown under a monocrop system and when intercropped with sunn hemp (Crotalaria juncea) under the soil and climate conditions of the State of Roraima The experiment was carried out in the field from August to December of 2014, in the Sector for Olericulture of the School of Agricultural Technology, on the Murupu Campus of UFRR in the town of Boa Vista, Roraima A randomised block experimental design was used, with three replications, in a (5 × 2) + 1 factorial scheme, representing five doses of poultry litter (0, 5, 10, 15 and 20 t ha-1), with sweet potato as both a monocrop and intercropped with sunn hemp, and one additional treatment with organic and mineral fertiliser Slips of the Granfina variety of sweet potato were used for planting Seeds of sunn hemp were sown in double rows between the rows of sweet potato 30 days after planting the slips, with the first cutting carried out 90 days after sowing The addition of poultry litter to the soil increased the total production of sweet potato roots for the crop planted in Roraima, whether intercropped or not with sunn hemp Despite the benefits to sweet-potato yield from the addition of poultry litter and the intercrop with sunn hemp, total productivity was greater in the additional treatment that received organic and mineral fertiliser

Weed Interference in Semi-Erect and Semi-Prostate Cowpea Cultivars

Abstract: This study aimed to determine weed interference periods in semi-erect and semi-prostrate cowpea cultivars. Two simultaneous experiments were conducted with the cowpea cultivars BRS Guariba (semi-erect) and BRS Arace (semi-prostrate). The experimental design was a randomized block design with four replications in a 7 × 2 factorial scheme, seven periods × two weed management (control and coexistence). Control and coexistence periods consisted of 0, 0-8, 0-16, 0-24, 0-32, 0-45, and 0-60 days after emergence (DAE) for the semi-erect cultivar and 0, 0-8, 0-16, 0-24, 0-32, 0-45, and 0-64 DAE for the semi-prostrate cultivar. Competition throughout the cycle reduced productivity by up to 39.81% for BRS Guariba and 37.27% for BRS Arace. The cultivars BRS Guariba and BRS Arace presented critical period of interference prevention of 9 to 41 DAE and 15 to 32 DAE, respectively. The semi-prostrate cultivar BRS Arace was more competitive with weeds, requiring a shorter control period to express maximum productivity.

Teacher Behavior Checklist: Psychometric Evidence in Teacher Evaluation by Brazilian University Students

Abstract: Performance evaluations help university teachers to improve teaching, especially when based on internationally recognized criteria. This study aimed to carry out a cross-cultural adaptation of the Teacher Behavior Checklist (TBC) for Brazilian students to evaluate their teachers (Study 1) and investigate its psychometric evidence (Study 2). In Study 1, evidence was favorable to the use of TBC for teacher evaluation by the student. In Study 2, 714 public university students participated (Average age = 24.3 years; SD = 6.85), 57.2% women. The TBC was applied collectively in the classroom. The results corroborated the two-factor model according to the instrument’s original version, demonstrating an evidence of validity. Evidence of reliability has been documented (alpha = 0.92; Test-Retest = 0.75). This study presented an adequate instrument for the teacher formative evaluation and expanded Brazil’s insertion in international research on effective teaching.