BOLETIM DA FACULDADE DE CIÊNCIAS AGRÁRIAS DO PARÁ, n. 13, 1983

Abstract

1) In order to verify the effect of foliar fertilization on the development of the seedlings in the nursery as a suplementai mannuring in the soil, a trial was conducted under Belém-Pará conditions precisely at the Experimental Field of Convênio EMBRAPA/FCAP. The results after six months after planting haven't shown any advantage to foliar fertilization when compared with control (in the soil).

2) Preliminary trial was conducted in order to compare the effects caused by the application of tablets with slow liberation of nutrientes with conventional fertilization in the production of rubber tree budded stumps inside polybags. Results showed that twelve months in those çonditions, the tablet fertilization çould become an efficient way of fertilization because of its economical and agronornical advantages.

3) It was made puncture tapping in two Exploratory Trial in hevea rubber and it was utilized the clonal material IAN 717 with 14 years age. The first trial objected to test four E th rei concentrations and disposition of punctures in tapping band. The second, objected to test two differents tapping band height, in relation to soldering budding. In results, it was observed that in clone IAN 717, have increase of production in funtion to increase of stimulant concentration, farther the puncture tapping with Ethrel 2,5% was similar to half-spiral tapping without stimulation. Still observed a different behavior that clone in relation to productivity, in accord with tapping band height. The bands of 60 cm lenght with basal part distant from soldering budding about 90 cm was batter in production than the bands with basal part distant from soldering budding 40 cm. Deserve distinction, the facility that technique, for its simplicity, don't get necessary skill of tapping.

4) Exploratory trial established in Belém (FCAP) was made with purpose to study the behavior that new herbicide in relation to effect in weed control, and rubber seedlings fitotoxicity. The Ustilan was tested in two dosages (2 and 4 kg/ha) and several mannersof aplication. In obtained results, was observed that the Ustilan proportinated a good weed control, in pre-planting as well as in pre-emergence and post-emergence, but in pre-emergence it was better. In relation to fitotoxicity, the herbicide showed enough fitotoxic when it reach chlorophyllous parts of the plant.

5) A list of occurring pests in ruber-tree (Hevea brasiliensis) plantation, in Pará State, is presented and the lines of specific actions of entomologic researches for this culture, constant of National Program of Rubber-tree Research are also related, achieved observations in field and laboratory are also described about importance, biological features, natural enemies and chemical control of following pests: Erinnyis ello (Lepidoptera-Sphingidae), Premolis semirufa (Lepidoptera - Arctiidae) and Aleurodicus cocois (Homoptera Aleyrodidae).