José George Ferreira Medeiros

FUNGOS ASSOCIADOS ÀS SEMENTES DE Enterolobium contortisiliquum : ANÁLISE DA INCIDÊNCIA, CONTROLE E EFEITOS NA QUALIDADE FISIOLÓGICA COM O USO DE EXTRATOS VEGETAIS

The fungi are main micro-organisms associated with seeds, may cause damages, both in the field but also post-harvest and during storage. In this last phase, deterioration can occur by the action of specific fungi, affecting their physiological quality. The use of plant extracts with antimicrobial properties are promising and environmentally friendly alternatives to replace the protection promoted by fungicide application. The objective of this work was to evaluate the effectiveness of extracts of Allamanda blanchetti e Momordica charantia in concentrations of 10, 100, 500 e 1000 ppm on mycoflora and germination in seeds of Enterolobium contortisiliquum. Seeds were collected in different municipalities in the state of Paraiba (Areia, Arara, Conde and Sobrado). The lots were tested for germination and sanity. The evaluation of the incidence of fungus was made from the visualization of fungi by the method of incubation blotter test. Was used the health test 100 seeds per treatment which were immersed in 20 mL of extracts for five minutes, incubated in then Petri dishes on double layer of filter paper. 200 seeds were used in the germination test, with four replications of 25 seeds per treatment, divided into germitest paper and germinated at temperatures of 30 ± 2°C. The experimental design was completely randomized. It was found in the seeds of Enterolobium contortisiliquum the following fungi: Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer, Penicillium sp., Curvularia lunata, Nigrospora sp. and Cladosporium sp. The extracts of Allamanda blanchetti and Momordica charantia at concentrations of 500 and 1000 ppm caused a reduction in the frequency of fungi. The extract of Momordica charantia at concentrations of 500 and 1000 ppm provided an increase in germination and first count, and reduce the percentage of dead seeds.

Thermotherapy in treating fennel seeds (Foeniculum vulgare Mill.): effects on health and physiological quality

Thermotherapy is a physical treatment consisting of the exposure of seeds to the action of heat over time. The aim was to assess the health and physiological quality of fennel seeds (Foeniculum vulgare Mill.), both freshly harvested and stored for three years, and submitted to thermotherapy. Two experiments were conducted. In the first, thermotherapy was carried out on freshly-harvested fennel seeds obtained under different cropping systems: T1 - Monocrop fennel treated with the insecticide, thiamethoxam; T2 - Monocrop fennel without the application of insecticide; T3 - Fennel intercropped with cotton and treated with insecticide; T4 - Intercropped fennel without the application of insecticide. In the second experiment, seeds were used which had been stored for three years and obtained from plants, both treated and untreated with insecticide. The seeds were exposed to dry heat for different periods (0, 3, 6, 9, 12 and 15 days) at 70 °C. The tests performed included: health, germination, first count, speed germination index, seedling length and dry weight. The cropping systems had no influence on the incidence of the fungus Alternaria sp. Stored fennel seeds coming from plants treated with insecticide, display better health and physiological quality. A period of 12 days of thermotherapy is effective in controlling the fungus Alternaria sp. without causing losses in the viability of the fennel seeds.