Jeferson Luiz Dallabona Dombroski

Fruit, seed and seedling morphology of Jatropha elliptica Müll. Arg. (Euphorbiaceae).

The aim of this work was to describe the morphology of the fruit, the seed and the development of the seedling of Jatropha elliptica Mull. Arg. The fruits were collected in September and October (2002), in the Experimental Farm at Universidade Federal Mato Grosso, in Santo Antonio de Leverger-MT. 50 fruits and 50 seeds were utilized to describe the fruit and the seed morphology. For the characterization of the germination stages, four repetitions of 20 seeds were used, sowning upon blot paper, in clear plastic boxes, moisten with giberelic acid (400 ppm), kept in a germination chamber, at 30 oC and with an eight hours photoperiod, during 45 days. The fruit of J. elliptica is dry, with three cocas, a hard endocarp, and shows an explosive dehiscence. The seed is oval, albuminous, has a smooth testa and a marmoreal color, with a caruncule in the ventral part, a visible hilum in the base and the distinct longitudinal rafe. The germination is epigeous and phanerocotyledonal. The germination average time is from 13 to 25 days. It was possible to describe and to illustrate, in a distinct form, J. elliptica fruit, seed and seedling morphologies, which behaved in a sufficiently homogeneous and trustworthy way for the identification.

PRODUÇÃO DE MUDAS DE Enterolobium contortisiliquum E PARTIÇÃO DE ASSIMILADOS EM RESPOSTA À ADUBAÇÃO FOSFATADA E INOCULAÇÃO COM FUNGOS MICORRÍZICOS

This study aimed to evaluate the production of Enterolobium contortisiliquum (Vell.) Morong seedlings and assimilate partitioning under different levels of phosphorus, in the presence and absence of arbuscular mycorrhizal fungi. The experiment was conducted in randomized blocks in a 5x2 factorial design, with four replications represented by three plants each. The first factor consisted of P levels (0, 50, 100, 150 and 200 mg.Kg soil -1 ), using superphosphate fertilizer (P 2 O 5 ) as the phosphorus source. The second factor consisted of the presence or absence of arbuscular mycorrhizal fungi. At 98 days after sowing (DAS), plants were evaluated by non-destructive assessments of shoot height (APA), leaf number (NF) and stem diameter (DC). Then, chlorophyll content index (ICC), leaf dry matter (MSF), stem dry matter (MSC), shoot dry matter (MSPA) and root dry matter (MSR) analyses were conducted. Leaf area (AF), leaf weight ratio (RPF), specific leaf area (AFE), Dickson quality index (IQD) and shoot/root dry matter ratio (MSPA/R) were also determined. The P level of 100 mg.Kg -1 proved to be the most efficient one for the production of Enterolobium contortisiliquum seedlings in Mossoro, Rio Grande do Norte state, with no benefits in the use of mycorrhizal fungi until 98 DAS, promoting photoassimilate distribution between the organs of young seedlings favorable to the establishment in the field.

Desempenho agronômico de cultivares de batata-doce oriundas de ramas produzidas de forma convencional e in vitro - DOI:10.5039/agraria.v8i3a2353

Este trabalho teve como objetivo avaliar o desempenho agronomico de cultivares de batata-doce [ Ipomoea batatas L. (Lam.)] oriundas de ramas produzidas de forma convencional e in vitro, nas condicoes edafoclimaticas de Mossoro-RN. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 5 x 2, com quatro repeticoes. Os tratamentos consistiram da combinacao de cinco cultivares de batata-doce (ESAM 1, ESAM 2, ESAM 3, Branca do Rio de Janeiro e California) e duas formas de propagacao (convencional e in vitro). As caracteristicas avaliadas foram: Produtividades total, comercial e nao-comercial de raizes; massa de raizes comerciais; numero de raizes comerciais e total por planta; massa seca da parte aerea, de raizes e total. A propagacao in vitro proporcionou, em todas as cultivares de batata-doce maior numero e produtividade de raizes comerciais, sendo a cultivar ESAM 1 a que apresentou os maiores ganhos percentuais. As cultivares California e ESAM 2 foram as mais produtivas, respectivamente na propagacao convencional e in vitro.