BOLETIM DA FACULDADE DE CIÊNCIAS AGRÁRIAS DO PARÁ, n. 11, dez. 1979

Abstract

1) Tagging of piramutaba Brachyplatystoma vaillantii (VAL., 1840) in the Amazonian basin with the use of a tag named "Anchor tag", made in U.S.A. The main purpose of tagging is to know the food and reproduction "homes", and the migratory ways. Also, the research looks to a knowledge of possible catch's efforts, and of the fish stock of the referred fish. The firts results revealed recaptures in the neighbourhood of the tagging's places, and at south, and at north of the same. The piramutaba was recaptured 5 days after liberation, and 30 km at north of the tagging place. Between 1978 and 1979 were tagged 9,296 piramutabas, and until Sept., 25, 1979 were recaptured 63 tagged piramutabas ( = 0,67% / total).

2) The behavior of okra varieties known as "Chifre de veado" ("Dee horn") (Hibiscus esculentus, L.) has been investigated under three different densities, namely, one," two and three plants per hole a part 1 meter in the row andd, 0,50 m between raws. The trial has been conducted near Belém, State of Pará, with a typical humid equatorial climate under two rainfall conditions namely 779 mm and 1878 mm. It was found that pod production showed no statystical sgnificant difference in relation to densities used and also that the higher yields are related to the higher rainfall conditions.

3) The pollen morphology of four (4) varieties of the genus Corchorus is studied for purpose to provide subsidiary element of the taxonomy of TILIACEAE. The employed material was fresh pollen of natural varieties of jute called "violet", "white", "smooth" and "solimões", that was removed from plant just before the anthesis. The technique of acetolisis was used for preparation of material. It was observed that variability between polar and equatorial diameters of each studied variety was very little. Although there is little variation between the studies diameters, however it was found out that only the white jute has the biggest pollen grain. Notwithstanding we deal with a stenopalinos genus nevertheless the features of the pollen have a great value in generic Identification. In spite of the little variability between the polar and equatorial diameters of different grains, however these ones gives data very important to be used in identification of varieties.