Luzia Ferreira da Silva

Interceptação da chuva por duas espécies arbóreas em áreas verdes urbanas

O processo de interceptacao da agua da chuva foi analisado em duas especies de maior frequencia na arborizacao urbana, visando a obter a quantidade de interceptacao (I) ou perda por interceptacao, precipitacao interna (PI), escoamento pelo tronco (Et) e precipitacao total (PT). As especies escolhidas foram Caesalpinia pluviosa DC. (Fabaceae: Caesalpinoideae) ou sibipiruna e Tipuana tipu O. Kuntze (Fabaceae: Faboideae) ou tipuana, com mais de 50 anos de idade, sendo tres individuos isolados e tres em grupo de cada especie, plantadas no campus da ESALQ/USP onde o experimento foi realizado, durante o periodo de janeiro a fevereiro de 2007. As medicoes foram coletadas por meio de baldes de sete litros de capacidade de agua, tanto na extremidade como no centro da copa. A PI apresentou alta correlacao com a quantidade de PT, no centro da copa, em tipuana e na extremidade, em sibipiruna. O Et e a I tiveram baixa correlacao com a quantidade de PT, nas duas especies. As porcentagens medias de interceptacao foram maiores na extremidade da copa nos individuos de sibipiruna, com 60,6%, e no centro da tipuana, com 59,40%. Desse modo, as duas especies interceptaram ate 60% das aguas da chuva, o que propiciou grande potencial para serem plantadas no ambiente urbano.

Physiological blockage in plants in response to postharvest stress

Flowers have been designed primarily for cutting because of the diversity of shapes, colors and also durability. However, ornamental plants are used in floral arrangements in vases and have limited shelf-life. Thus, this study showed that one of the factors contributing to this limitation is the physiological blockage that occurs in plants in response to stress imposed by harvest. Key words: Flowers, stress, physiological blockage, harvest.

Aclimatização de mudas de cana-de-açúcar em ambiente protegido sob dois tipos de malhas de sombreamento

This study aimed to analyse the global solar radiation, temperature and their effects on the growth and development of seedlings of sugarcane under acclimatization in two types of coverages in a protected environment. The study was conducted in the experimental area at the Center for Strategic Technologies in the Northeast - Igarassu, PE. The greenhouse was covered with white polyethylene and divided into two: one associated with the thermal reflector mesh and another associated with black mesh. The studied variables were: weather (solar radiation, air temperature) and biometric (stem length, stem diameter, leaf length, leaf number, plant height and leaf area). For biometric monitoring, 12 randomly selected trays with four tubes per tray per treatment were used. The experimental design was completely randomized, using the Tukey test (p < 0.05) for comparison between means. The environment under thermal reflector mesh provided the best results for seedling development because of greater availability of solar radiation in the production environment.

Erratum to: The effects of two preservatives on peroxidase activity and total protein content in Strelitzia reginae during cold storage

This study aimed to assess changes in peroxidase activity and total protein content of cut flowers of Strelitzia reginae that were treated with the chemical preservatives 8-hydroxyquinoline citrate (8-HQC) or chlorine during cold storage. The bases of the cut flowers were immersed in 1.5 L of tap water with 48 h pulsing treatments (a control with no chemical preservatives (0 mg·L-1, 100 mg·L-1 chlorine, 250 mg·L-1 8-HQC or 500 mg·L-1 8-HQC) during cold storage at 10.5°C and 90% relative humidity. The solutions were then replaced with tap water and the cut flowers remained in cold storage for 12 days. For biochemical characterization of peroxidase activity and total protein content, tissue samples (sepals, petals, stems, and bracts) were collected and analyzed at 0, 4, 8, and 12 days after treatment. There was an increase in peroxidase activity in petals, stems, and bracts and a decrease in total protein content, regardless of the treatment used. In this experiment, therefore, differences in peroxidase activity and total protein content due to treatments with 8-HQC or chlorine were not identified.