Ecologia da germinação de sementes e desenvolvimento de plantas de Platymiscium floribundum Vog. (Sacambu) - Fabaceae em viveiro e sob dossel de floresta ombrófila densa, São Paulo, SP

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Alterações histológicas e bioquímicas e potencial fisiológico de sementes de soja

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Testes de vigor em sementes de quiabeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Revestimento de sementes de milho superdoce

Pós-graduação em Agronomia - FCAV

Influência do Extrato Pirolenhoso no desenvolvimento e crescimento de plantas de milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho em laboratório e em campo de sementes de milho submetidas a diferentes tempos de envelhecimento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Doses de regulador vegetal em sistema de semeadura convencional e direta sobre a produtividade, teor de nutriente nas folhas e nas sementes e qualidade fisiológica das sementes de três cultivares de feijão

Pós-graduação em Agronomia - FEIS

Morphology and anatomy of the diaspores and seedling of Paspalum (Poaceae, Poales)

RESUMO O conhecimento relativo ao diásporo e ao desenvolvimento pós-seminal de Paspalum L. é importante para a conservação da biodiversidade dos campos, devido sua importância na representatividade e no melhoramento genético de pastagens. A morfologia do diásporo e do desenvolvimento pós-seminal de Paspalum dilatatum Poir. (rizomatosa); P. mandiocanum Trin. var. subaequiglume Barreto (estolonífera), P. pumilum Nees. (cespitosa decumbente) e P. urvillei Steud. (cespitosa ereta) foi descrita procurando distinguir as espécies com diferentes formas de crescimento, e levantar características úteis para a taxonomia. P. dilatatum se diferencia por apresentar diásporo oval, de maior tamanho que as demais, com cinco nervuras salientes e tricomas; P. urvillei por apresentar diásporo com uma nervura central mais desenvolvida do que as duas nervuras laterais e tricomas; P. mandiocanum var. subaequiglume por apresentar diásporo com tricomas apenas na margem; e P. pumilum por apresentar diásporo glabro. A cariopse envolve a semente que apresenta embrião diferenciado, disposto lateralmente; apresenta hilo elíptico em todas as espécies estudadas e rostelo em P. dilatatum e P. mandiocanum var. subaequiglume. O desenvolvimento pós-seminal é semelhante nas quatro espécies e se inicia com a germinação, que é marcada pela emergência da coleorriza, seguida pelo coleóptilo. Essas características são comuns às demais Poaceae já estudadas, indicando um padrão para a família e não diferenciam as formas de crescimento.

Discrimination of soybean seed lots by multivariate exploratory techniques

Physiological potential characterization of seed lots is usually performed by germination and vigor tests; however, the choice of a single test does not reflect such potential, once each test assesses seeds of differentiated mode. Multivariate techniques allow understanding structural dependence contained in each variable, as well as characterize groups of seed lots according to specific standards. The study aimed at evaluating variability among soybean seed lots and discriminate these lots by multivariate exploratory techniques as function of seed vigor. Experiment was performed with 20 soybean seed lots (10 lots cv. BRS Valiosa RR and 10 lots cv. M-SOY 7908 RR). Seed physiological potential was assessed by testing for: germination (standard, and under different water availability); vigor (accelerated aging and electrical conductivity); and field seedling emergence. Cluster analysis of seed lots, as well as Principal Component Analysis was performed using data obtained on all tests. Multivariate techniques allowed stratifying seed lots into two distinct groups. Principal Component Analysis showed that values obtained for variables: field seedling emergence, accelerated aging, and germination under different water availability were linked to BRS Valiosa RR; while to variables germination and electrical conductivity, were linked to M-SOY 7908 RR.

Dispersal of Cotesia flavipes in sugarcane field and implications for parasitoid releases

Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is a major sugarcane pest in Brazil. The management of infested areas is based on the release of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), a parasitoid of D. saccharalis larvae, but there are doubts about the effectiveness of C. flavipes, primarily regarding its rate of dispersal in sugarcane fields. Thus, the objective of this study was to evaluate the dispersal of C. flavipes in a sugarcane field and suggest a release method that provides higher parasitoid efficiency. The study was carried out in four areas of approximately 1 ha, in which stalk pieces containing 20 D. saccharalis larvae were distributed in a rectangular grid, and 12,000 C. flavipes adults were released at four points, that were 50 m apart and 25 m from the field border. Three days later, the D. saccharalis larvae were recovered and kept in the laboratory until they reached pupal stage or C. flavipes emergence. Parasitism varied from 13.2% to 42.8%. The random distribution of parasitized larvae was found in one assay. In three areas, the parasitized larvae showed an aggregated distribution, with a range of 15 to 25 m. Since the parasite's success is directly linked to parasitoid dispersion, it would be interesting to move the release points to 30 m from each other because the dispersal may happen in a 15 m radius.

Assessment of the physiological potential of spinach seeds (Tetragonia tetragonoides (Pall.) Kuntze)

The efficiency of vigor tests in assessing the physiological potential of seeds depends on their standardization for different species. In this context, the research aimed to study specific methodologies to evaluate the vigor of spinach seeds (Tetragonia tetragonoides). For this purpose, five lots of spinach seed cv. New Zealand were submitted to germination, first count of germination, seedling emergence in the field, accelerated aging (with and without use of saturated solution of NaCl at 41and 45 ºC for 24,48 and 72 hours), controlled deterioration (18,21 and 24% seed water content adjustments for 24 hours at 45 ºC) and electrical conductivity tests with variations inwater volume (25, 50 and 75 mL), seed quantity (25 and 50) and soaking period (1, 2, 4, 8,12, 16 and 24 hours) at 25 ºC. The first count test allowed obtaining preliminary information about seed vigor, and other tests in general showed similarity with seedling emergence in the field. Thus, it was concluded that traditional accelerated aging test 24 h /41 ºC and accelerated aging test with saturated salt solution for 24 h at 41 ºC and 45 ºC, and controlled deterioration test with 21% seed water content / 24 h / 45 ºC were all efficient for evaluating the physiological potential of spinach seeds.

Qualidade fisiológica de sementes de milho doce classificadas pela espessura e largura

Sweet maize seeds present lower physiologic quality, when compared to regular maize seeds, due to the influence of several features, such as the seed size and shape. Thus, this study aimed at evaluating the seed physiologic quality of two sweet maize cultivars (BR-401 and BR-402), separately classified according to thickness, by using slotted screen sieves (8/64 x 3/4, 9/64 x 3/4, 10/64 x 3/4, 11/64 x 3/4, 12/64 x 3/4 and 13/64 x 3/4), and width, with round screen sieves (17/64, 18/64, 19/64, 20/64, 21/64 and 22/64). For each cultivar, sorted lots were compared with the unrated batch, following a completely randomized design, in a 2x7 factorial scheme, with four replications. The biometric parameters evaluated were sieve retention, 100 seeds weight and water content. The physiologic quality was determined according to the first counting, germination, cold test, accelerated aging, electric conductivity and seedling emergence in the field. The classification with sieves improved the physiologic quality of sweet maize seeds. Seeds with intermediate thickness, for both cultivars, generally presented greater vigor. Concerning width, larger seeds, for the BR-401 cultivar, and intermediate seeds, for the BR-402 cultivar, showed better physiologic quality.

Qualidade de sementes de soja convencional e transgênica em função da dessecação das plantas com glyphosate

Pós-graduação em Agronomia (Agricultura) - FCA

Population Structure and Pathotype Diversity of the Wheat Blast Pathogen Magnaporthe oryzae 25 Years After Its Emergence in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Orbit based procedure for doublets of scalar fields and the emergence of triple kinks and other defects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)