ABSTRACT The objective was to evaluate the quality of sunflower seeds classified according to their thickness and passed through the seeder-fertilizer dosing system under variation of the travel speed. A lot of M734 was classified by thickness passing the seeds through a set of oblong-hole sieves and two thicknesses were selected. A portion of the seeds with only the commercial classification was also reserved, named as non-classified. The biometric evaluation was done and the sowing was carried out at 5.0, 6.5, 8.0, 9.5 and 11.0 km h-1. The quality of the seeds was evaluated through: germination and first germination count, average time and percentage of emergence in sand, accelerated aging and tetrazolium test. The classification by thickness reduce the coefficient of variation of the length, width, thickness, and mass but seeds classification does not affect seed vigor and viability after sowing under speed variation. In the higher studied speed, the passage of seeds through the dosing mechanism reduces germination. The vigor is affected at 6.5 km h-1 speed by the accelerated aging test. According to the emergence in sand and tetrazolium test, speed variation does not affect the vigor and viability of sunflower seeds.

Resumo: Buchenavia tomentosa produz frutos com função ecológica para a fauna do Cerrado. Objetivou-se, neste trabalho, quantificar a germinação e o comportamento das sementes em condições térmicas e esclarecer a absorção de água pela estrutura de dispersão de B. tomentosa. Frutos maduros foram despolpados, o endocarpo removido, e as sementes utilizadas nos testes de germinação, às temperaturas de 10 a 45 °C. As sementes foram colocadas em rolos de papel e em seguida em câmaras de germinação sob doze horas de fotoperíodo. Modelos de germinação em temperaturas sub e supra ótimas foram obtidos por meio da taxa de germinação (Tg), a partir do tempo para germinação de 50% das sementes (t50). Índice de velocidade de germinação (GSI), medidas dos comprimentos e massas secas da parte aérea e raiz das plântulas em cada temperatura foram obtidos. A curva de embebição de água das sementes com ou sem endocarpo aderido foi avaliada, e outras amostras testadas quanto à emergência em areia. As temperaturas cardinais foram: temperatura base (Tb) de 9,23 °C; máxima (Tmax) de 44,6 °C; ótima (To) de 29,24 °C e soma térmica de 89,71 °C.days. As plântulas apresentaram maior comprimento das raízes e parte aérea e maior massa seca das raízes na temperatura ideal. O endocarpo retarda, mas não impede a absorção de água e emergência das sementes.

Abstract: Buchenavia tomentosa produces fruits with ecological function for Cerrado’s fauna. The aims of this paper were to quantify seed germination and behavior on thermal conditions and explain about water absorption of dispersal structure in B. tomentosa seeds. Ripe fruits were pulped, the endocarp removed, and seeds used in the germination tests at temperatures of 10 to 45 °C. Seeds were placed in rolls of filter paper and then placed in germination chambers, at twelve hours of photoperiod. Germination models at sub and supra optimal temperatures were made from the germination rate (Tg), from the time to germination of 50% of the seeds (t50). Germination speed index (GSI), measurements of shoot and root lengths and dry mass at each temperature were obtained. The water imbibition curve of seed with or without endocarp adhered and scarified or not was made and other samples were tested for emergence in sand. Cardinal temperatures were: base temperature (Tb) of 9.23 °C; maximum temperature (Tmax) of 44.6 °C; optimum temperature (To) of 29.24 °C and thermal time of 89.71 °C.days. Seedlings showed higher GSI, root and aerial part length and higher root dry mass at the optimal temperature. The endocarp retards, but does not prevent water absorption and emergence.

RESUMO Escolhas no manejo cultural, como a do cultivar e a do sistema de colheita, podem influenciar os índices dos parâmetros de qualidade da fibra do algodão. Objetivou-se, com este trabalho, analisar as características das fibras de dois cultivares de algodão submetidos a diferentes sistemas mecanizados de colheita (picker e stripper). O experimento foi conduzido na safra de 2012, com espaçamento de 0,45 m entre linhas, no município de Juscimeira, MT. Utilizou-se delineamento em blocos casualizados, em esquema de parcelas subdivididas, com dois fatores, sendo eles, A, nas parcelas (dois cultivares) e B, nas subparcelas (três sistemas de colheita - manual, picker e stripper), com cinco repetições. A qualidade da fibra foi determinada em amostras coletadas manualmente da planta e, após a colheita mecanizada, retiradas de dentro do cesto armazenador de cada colhedora. As análises das características das fibras foram realizadas em Laboratório de Classificação de Fibras, com o aparelho HVI (High Volume Instrument). As fibras do algodão colhido com o sistema manual, em seguida, sistema picker apresentam melhores características e melhor qualidade que as das fibras colhidas com stripper.

ABSTRACT Choices in crop management such as cultivar and harvesting system can influence fiber quality parameters. This study aimed to evaluate fiber characteristics of two cultivars in narrow row cotton submitted to different mechanized harvesting systems (picker and stripper). The experiment was conducted in season 2012, with 0.45 m, at Juscimeira - MT. It was used randomized block design in split plot with two factors, factor A in the plots (two cultivars) and factor B in the subplots (three harvesting systems - manual, picker and stripper), with five replications. The quality of the fiber was determined in manually collected samples of plants and after harvest, withdrawn inside the basket of each harvester. The analysis of the characteristics of fiber, were analyzed in Laboratory of Classification of Fiber in apparatus by HVI (High Volume Instrument). Fibers picked with manual, followed by picker system have characteristics and better quality compared to fibers harvested with stripper.

O objetivo deste trabalho foi avaliar a aplicação de nitrogênio em cobertura na cultura da mamona (Ricinus communis L.), em Campo Grande, MS. As doses de N foram 0, 30, 60 e 120 kg ha-1. A semeadura foi realizada em 27 de janeiro de 2006. O espaçamento entre linhas utilizado foi de 0,9 m e 0,45 m entre plantas. Foram realizadas as seguintes avaliações: altura e diâmetro de caule das plantas, número de cachos e de frutos por planta, matéria seca, produtividade e teor de óleo. A utilização de 80 kg ha-1 de N em cobertura aumentou a produtividade sem alterar o teor de óleo das sementes.

The development of castor plants (Ricinus communis L.) under nitrogen sidedressing fertilization was evaluated in a randomized block design, constituted by different level of nitrogen sidedressing fertilization (0, 30, 60 and 120 kg ha-1). The sowing was performed on January 27, 2006, comprising three lines of 4 m every plot. The spaces were 0.9 m between lines and 0.45 m between plants. Height and diameter plants, dry matter, yield and oil content were evaluated. The 80 kg ha-1 nitrogen sidedressing fertilization increases the yield and did not alter seed oil content.