Abstract This study aimed to assess cassava root and stem yield at different spacings and four transplanting seasons of seedlings produced by an adaptation of the rapid multiplication method. The experimental design was a randomized block design with three replications in a factorial (4 × 5) arranged in strips. Treatments consisted of the combinations of growing seasons (November 9 and 24 and December 3 and 26) and spacings (0.6 × 0.6, 0.8 × 0.8, 0.8 × 0.6, 1.0 × 0.6, and 1.0 × 0.8 m). The percentage of survival, main stem branching height, number of branches, base, middle, and upper diameter, mean diameter, stem length, number of buds per stem and hectare, root length and diameter, root fresh matter per plant and hectare, and number of roots per plant were measured at harvest. Seedling transplanting performed up to November 24 favored the expression of stem and root yield. The spacing of 1.0 × 0.6 m was the most suitable for stem yield traits.

RESUMO A lavanda (Lavandula dentata) possui diversas aplicações medicinais, tanto in natura como após processamento industrial. O incremento à produtividade pode ser obtido por meio da propagação massal, ampliando a possibilidade de obtenção de matéria prima para a produção de óleo essencial. O objetivo deste trabalho foi desenvolver um protocolo de micropropagação a partir de explantes obtidos de sementes. Foram avaliados aspectos da germinação, multiplicação, alongamento e enraizamento in vitro e, em seguida, o processo de aclimatização das mudas. A germinação in vitro de lavanda pôde ser obtida apenas com a utilização do meio composto por ágar e água. Para a multiplicação, o uso de meio MS (Murashige & Skoog, 1962) acrescido de 5,0 µM de 6-benzilaminopurina ao meio nutritivo é o mais apropriado. Para o alongamento e enraizamento, a utilização de reguladores de crescimento é dispensável. A aclimatização pode ser obtida diretamente com a transferência do explante para sacos plásticos com substrato, mantidos em casa de vegetação. Foi possível desenvolver um protocolo para o cultivo in vitro (estabelecimento, multiplicação, alongamento, enraizamento e aclimatização) de lavanda a partir de explantes de sementes.

ABSTRACT Lavender (Lavandula dentata) has several medicinal applications, both in the fresh form and after industrial processing. Productivity increase could be obtained through the mass propagation, expanding the possibility of obtaining raw material for production of essential oil. The objective of this work was to develop a micropropagation protocol from explants obtained from seeds. Aspects of in vitro germination, multiplication, elongation and rooting were evaluated and, in sequence, the acclimatization process as well. The in vitro germination of lavender seeds can be obtained using a medium composed of agar and water. For multiplication, the use of MS medium (Murashige & Skoog, 1962) added with 5.0 µM 6-benzylaminopurine to the nutrient medium is the most appropriate. For elongation and rooting, the use of growth regulators is unnecessary. Acclimatization can be obtained directly by transferring the explant to plastic bags with substrate, kept in a greenhouse. It was possible to develop a protocol for the in vitro cultivation (establishment, multiplication, elongation, rooting and acclimatization) of lavender from explants of seed origin.

A utilização de espécies vegetais para cobertura do solo capazes de fornecer nutrientes e proteção ao solo é importante para a sustentabilidade dos sistemas agrícolas. O objetivo deste trabalho foi avaliar a produção de massa verde e seca, o teor e o acúmulo de nutrientes em plantas de cobertura de verão. O delineamento experimental foi de blocos casualizados, com sete tratamentos (capim-sudão, crotalária, feijão-de-porco, guandu-anão, trigo-mourisco, mucuna-preta e pousio) e seis repetições. Avaliou-se a produção de massa fresca e seca, teor e acúmulo de macronutrientes e micronutrientes na parte aérea das plantas de cobertura. Os maiores teores de nutrientes foram obtidos com o cultivo de leguminosas. A crotalária e o feijão-de-porco apresentaram por seu lado maior produção de massa seca e acúmulo de macronutrientes e micronutrientes.

The utilization of plant species for ground cover in order to supply nutrients and protect the soil is important for the sustainability of agricultural systems. The objective of this study was to evaluate the production of fresh and dry matter, and the content and accumulation of nutrients in summer cover crops. The experimental design was of randomized blocks, with seven treatments (sudan grass, crotalaria, jack beans, pigeon pea, buckwheat, velvet bean and fallow) and six replications. The parameters evaluated in the cover crops were the fresh and dry matter yield and the content and accumulation of macronutrients and micronutrients in the above-ground biomass of the plants. The highest levels of nutrients were obtained in the legume crops. The crotalaria and jack beans had both higher dry matter yield and accumulation of macronutrients and micronutrients.