ABSTRACT The pearl millet is a potential feedstock for biomass production under sensitive areas to climate changes, as the southern coast of Brazil. Looking for the sustainability of small-scale vegetable farmers on that region, the aim of this study was to evaluate the effect of pearl millet as a cover crop on suppression of weeds during no-tillage cultivation of broccoli for two consecutive sea sons. The experimental design was a randomized block with four treatments and four replications in split-plot design over time. Soil covering with whole millet; milled millet; spontaneous weeds (fallow) and conventional planting were tested; by they could causes changes in the community of weeds, either in the occurrence of weed species and in the accumulation of their biomass with influence on the yield of broccoli. The weed species density average over the two seasons, from higher to lower, followed respectively: Cyperus rotundus, Eleusine indica, Galinsoga quadriradiata, Cynodon dactylon, Commelina erecta and Amaranthus lividus. It was verified that soil covering with pear millet has altered weeds population dynamic and their biomass, being efficient in suppress the emergence of weeds. At the second season, the soil covered with whole pearl millet increased the yield of broccoli in comparison to the conventional system, being a sustainable technique for family farmers.

RESUMEN El mijo perla es una especie potencial para la producción de biomasa en áreas sensibles a los cambios climáticos, como la costa sur de Brasil. Buscando la sostenibilidad de los pequeños productores de hortalizas en esa región, el objetivo de este estudio fue evaluar el efecto del mijo perla como cultivo de cobertura en la supresión de las malas hierbas durante el cultivo de brócoli cero labranza durante dos temporadas consecutivas. El diseño experimental fue un bloque aleatorio con cuatro tratamientos y cuatro repeticiones en el diseño de parcelas divididas a lo largo del tiempo. Suelo cubierto con mijo entero; mijo aplastado; malezas espontáneas (barbecho) y la siembra convencional se ensayaron para comprobar si podrían causar cambios en la comunidad de malezas, ya sea en la presencia de especies de malezas y en la acumulación de su biomasa con influencia en el rendimiento del brócoli. La densidad promedio de las especies de malezas durante las dos estaciones, siguió respectivamente: Cyperus rotundus, Eleusine indica, Galinsoga quadriradiata, Cynodon dactylon, Commelina erecta y Amaranthus lividus. Se verificó que la cobertura del suelo con mijo perla ha alterado la dinámica poblacional de las malezas y su biomasa, siendo eficaz para limitar la aparición de malezas. En la segunda temporada, el suelo cubierto con mijo perla entero aumentó el rendimiento del brócoli en comparación con el sistema convencional, siendo una técnica sostenible para los agricultores familiares.

Abstract Stevia (stevia rebaudiana Bertoni) is a species characterized by producing non-caloric substances with high sweetening potential. Among these substances, rebaudioside A and stevioside are produced in greater quantity. Plant density and harvesting time are factors that affects biomass and sweetening compounds yield in this species. The objective of this research was to evaluate the effect of plant densities and harvesting times on the productive and physiological characteristics of stevia in southern Brazil. The experimental design was in randomized blocks, in a split-plot scheme, with 9 treatments comparing the effect of three planting densities (166 667, 83 333 and 33 333 plants ha-1) in the plots and three harvesting periods (before, in the beginning and in full flowering) in the subplots. Harvesting at the beginning of flowering promoted higher dry leaf biomass yield and, when associated with the lowest planting density, promoted higher levels of rebaudioside A and stevioside. The lowest planting density resulted in greater leaves biomass accumulation, whereas the highest density promoted higher yields per area. Interaction between density of 166 667 plants ha-1 and the harvest at the onset of flowering promoted higher yields of rebaudioside A (43.22 kg ha-1) as well as higher rebaudioside A/stevioside ratio (0.60).

Epicormic shoots were induced in stumps and detached branches of adult Paulownia fortunei var. mikado plants to evaluate rooting potential. Stem cuttings obtained from shoots of stump were prepared with 12 cm in length and two leaves reduced to 78.5 cm² (10 cm diameter). Cuttings from shoots of branches were prepared with 8-10 cm in length, and two leaves reduced to 50 % of the original size. Anatomical analysis was performed to evaluate possible barriers to rhizogenesis. After disinfestation, indolebutyric acid (IBA) was applied (0, 500, 1,000, 1,500 and 2,000 mg L-1). Installation was made in plastic pots with a volume of 170 cm³ and 53 cm³, respectively for each type of cuttings, with fine vermiculite and carbonized rice hulls (1:1 v/v) as substrate. After 60 days in a greenhouse, cuttings from epicormic shoots of branches presented rooting (58.12 %) and the average length of the three longest roots/ cutting (4.76 cm) was higher than in cuttings from stumps. The highest number of roots/cutting (7.66) and percentage of cuttings with callus (27.50) was observed in cuttings from stumps. There were no anatomical barriers observed harming the roots formation in the two types of cuttings. The use of indolebutyric acid is not required to induce rooting.

Brotes epicórmicos fueron inducidos en cepas y ramas desprendidas de árboles maduros de Paulownia fortunei var. mikado (quiri) para evaluar el potencial de enraizamiento. Estacas provenientes de brotes de las cepas se prepararon con 12 cm de longitud y dos hojas reducidas a 78,5 cm² (10 cm de diámetro), estacas de brotes de ramas desprendidas se prepararon con 8-10 cm de longitud y dos hojas reducidas a 50 % del tamaño original. Se realizó un análisis anatómico para evaluar las posibles barreras para el enraizamiento. Después de la desinfección se aplicó ácido indolbutírico (IBA) (0, 500, 1.000, 1.500 y 2.000 mg L-1). La instalación se hizo en tubos de 170 cm³ y 53 cm³, respectivamente, para cada tipo de estaca, con vermiculita fina y cáscara de arroz carbonizado (1:1, v/v) como sustrato. Después de 60 días en el invernadero, estacas de brotes epicórmicos de ramas mostraron enraizamiento (58,12 %) y longitud media de las tres raíces más largas por estaca (4,76 cm) mayor que en estacas provenientes de cepas. Se observó un mayor número de raíces por estaca (7,66) y porcentaje de estacas con callo (27,50) en las estacas de brotes epicórmicos provenientes de cepas. No se observaron barreras anatómicas perjudiciales para la respuesta rizogénica en los dos tipos de estacas. No se requiere el uso de ácido indolbutírico para inducir el enraizamiento.

Propôs-se, com este trabalho, avaliar o fósforo extraível Mehlich-1 em um Latossolo Vermelho-Amarelo Distrófico típico, ácido, que recebeu lodo de esgoto alcalinizado (biossólido alcalinizado) adicionado com 0, 0,436, 0,872 e 1,745 dag kg-1 de P proveniente de três diferentes fontes e cultivado com feijoeiro (Phaseolus vulgaris cv. IPR Uirapuru) em casa de vegetação. Objetivou-se, também, quantificar o fósforo acumulado pelas plantas, a produção das plantas e o índice de eficiência agronômica relativa. Para o estabelecimento de tratamentos a dose recomendada foi de 45,85 kg ha-1 de P a partir dos tratamentos, exceto da testemunha (0 dag kg-1 de P). Esta dose de fósforo foi calculada para 2,5 kg deste Latossolo de Contenda, Paraná, contidos em vasos de 3 dm3 cultivados com 6 plantas de feijoeiro (cv. IPR Uirapuru). O fósforo adicionado em biossólido alcalinizado aumentou o fósforo extraível Mehlich-1 do solo, a acumulação de fósforo pelas plantas bem como a produção de grãos e a massa seca total das plantas de feijoeiro. O melhor nível de fósforo adicionado ao biossólido alcalinizado foi de 0,436 dag kg-1 de P proveniente de fosfato natural parcialmente acidulado Alvorada e superfosfato simples.

This study aimed to evaluate the extractable phosphorus Mehlich-1 in a distrophic Red-Yellow Latosol (Oxisol) which received alkaline sewage sludge (alkaline biosolid) along with 0, 0.436, 0.872 and 1.745 dag kg-1 of P from three different sources and cultivated with common bean (Phaseolus vulgaris cv. IPR Uirapuru) in greenhouse. It also aimed to quantify the phosphorus uptake by the plant, plant production and the relative agronomic effectiveness index. For the establishment of the treatment the recommended dose was 45.85 kg ha-1 of P from the treatments, except the control (0 dag kg-1 of P). This dose was calculated for 2.5 kg of this Oxisol from Contenda, Paraná State, Brazil, contained in recepients of 3 dm3 with 6 cultivated bean plants (cv. IPR Uirapuru). Phosphorus added in alkaline biosolid increased the extractable phosphorus (Mehlich-1) in soil and phosphorus accumulated in plants as well as the grain and total dry mass production of bean plants. The best level of phosphorus added to alkaline biosolid was 0.436 dag kg-1 of P from the partially acidulated phosphate rock Alvorada and single superphosphate.

O cultivo de camomila na região Sul do Brasil tem sido realizado utilizando-se como material genético a cultivar Mandirituba. Apesar da produção de capítulos florais e teor de óleos essenciais apresentado por esta cultivar ser considerado satisfatório, tem sido observada nas regiões produtoras a ocorrência de problemas fitossanitários que resultam em perdas significativas da produção. Este trabalho teve como objetivos comparar materiais genéticos de camomila provenientes da Holanda, Dinamarca e Mandirituba, e avaliar o efeito de diferentes densidades de semeadura no desenvolvimento das plantas, produção de capítulos, rendimento e qualidade do óleo essencial da cultivar Mandirituba, atualmente cultivada na região. Os experimentos foram conduzidos no município de Piraquara (PR). A extração do óleo essencial foi realizada por hidrodestilação em aparelho tipo Clevenger e a determinação da composição do óleo foi feita por cromatografia em fase gasosa acoplada ao espectrômetro de massa (GC/MS). Os materiais genéticos provenientes da Holanda e de Mandirituba apresentaram maior produção de biomassa seca de capítulos, em relação ao material genético da Dinamarca. A cultivar Mandirituba apresentou o maior rendimento de óleo essencial (4,71 mL g-1 ms), sendo também superior em relação à produtividade de óleo essencial (2,40 L ha-1). Os materiais procedentes da Dinamarca e de Mandirituba apresentaram composição do óleo essencial semelhantes. A densidade de plantio de 1,0 kg ha-1 da cultivar Mandirituba resultou em melhor desenvolvimento das plantas e maior produção de óleo essencial. Quantidades superiores a 3,0 kg ha-1 de sementes não resultaram em maior densidade de plantas tendo em vista a alta competição e percentual de plântulas mortas.

The cultivar Mandirituba is the only genetic material for chamomile cultivation in southern Brazil. Besides the limitations regarding floral buds and the yield of essential oil presented by this cultivar, phytosanitary problems have also been observed. The objectives of this work were to compare the genetic materials from the Netherlands, Denmark and Mandirituba and to evaluate the effect of seeding rate on floral heads development and essential oil production, yield and quality. The experiments were carried out at field conditions in Piraquara, Paraná state, Brazil. The essential oil extraction was obtained by hydrodistillation using a Clevenger apparatus and the oil composition was analyzed by gas chromatography coupled to mass spectrometry (GC/MS). The genetic materials from the Netherlands and Mandirituba presented statistically higher dry mass accumulation than the ones from Denmark. However the material from Mandirituba showed a great essential oil yield (4.7 mL g-1 ms) and productivity (2.40 L ha-1). The genetic material from Denmark and Mandirituba showed similar essential oil composition. The density of 1.0 kg ha-1 for cultivar Mandirituba resulted on great plant development and essential oil production. The use of 3.0 kg ha-1 of seeds did not increase plant density due to the high plant competition.