Renata da Silva Brant

Crescimento, teor e composição do óleo essencial de melissa cultivada sob malhas fotoconversoras

The use of color shading nets for cultivation of some ornamentals and vegetables has become common. Thus, observing the great influence of the solar radiation on the plant physiology, the objective of this research was to evaluate the the quantity and quality effects of spectral light transmitted through color shading nets (Chromatinet®) in Melissa officinalis L., including physiological aspects as:growth ,content and chemistry composition. Four treatments and five replications were disposed in a completely randomized design, being each experimental unit composed by four pots (one plant per pot). The treatments were lemon balms plants cultivated under full sunshine, black shading net (50%), red shading net (50%) and blue shading net (50%). The characteristics evaluated were: plants height; dry phytomass of leaves, stems, aerial part, roots and total; root/aerial part ratio; total leaf area; leaf area ratio; leaf weight ratio; specific leaf area; content, yield and composition of the essential oil. The utilization of nets favored the growth organs dry phytomass yield, independently of the color, in comparison with total sun light. Plants under red shading had lower content of essential oil and yield, but they showed the higher content of citral.

Adubação orgânica na produção de biomassa de plantas, teor e qualidade de óleo essencial de orégano (Origanum vulgare L.) em cultivo protegido

Origanum vulgare L., known as oregano or wild marjoram, is an aromatic plant widely used in cookery. In Brazil, there are few studies with this species aimed at improving the cultivation techniques. The present study was carried out to evaluate the effect of different levels of cattle and chicken organic manure on plant growth, chlorophyll content, besides essential oil content, yield and quality of oregano grown in a greenhouse. Two assays were carried out, one of them used cattle manure and the other, chicken manure (Hen). Oregano (Origanum vulgare L.) plants were grown in 10L-pots and subjected to the following treatments: Assay I: Cattle manure: 1) Soil without fertilization (control); 2) Soil + 3.0 kg m-2 cattle manure; 3) Soil + 6.0 kg m-2 cattle manure; 4) Soil + 9.0 kg m-2 cattle manure; and 5) Soil + 12.0 kg m-2 cattle manure; Assay II: Chicken manure: 1) Soil without fertilization (control); 2) Soil + 1.5 kg m-2 chicken manure; 3) Soil + 3.0 kg m-2 chicken manure; 4) Soil + 4.5 kg m-2 chicken manure; and 5) Soil + 6.0 kg m-2 chicken manure. The experimental design for both assays was in randomized blocks with four replicates and four pots per plot. Cattle and chicken manure levels significantly influenced oregano plant growth besides essential oil yield and chemical composition.

Espaçamento entre fileiras e densidade de semeadura do sorgo forrageiro para a região norte de Minas Gerais

Em razao da sua resistencia a seca, o sorgo forrageiro na forma de silagem e considerado um dos cultivos mais comuns para a alimentacao de ruminantes em propriedades da regiao Norte de Minas Gerais. Para um melhor manejo cultural do sorgo, objetivou-se, neste trabalho, avaliar tres densidades de plantas e tres espacamentos entre fileiras na condicao climatica do semiarido. Para isso, foram conduzidos experimentos, em dois anos agricolas. Em cada ano foram instalados experimentos em areas contiguas, utilizando se, respectivamente, os espacamentos entre linhas de 50 cm, 70 cm e 90 cm. Cada experimento foi conduzido sob o delineamento experimental de blocos casualizados em esquema fatorial 4 x 3, com tres repeticoes, sendo quatro cultivares e tres densidades de semeadura. A viabilidade da reducao do espacamento entre fileiras no sorgo forrageiro e dependente da cultivar em funcao da condicao climatica. O aumento da densidade de semeadura proporciona reducao na produtividade de materia seca.