RESUMONeste trabalho, objetivou-se avaliar o efeito de extratos e óleos essenciais de quatorze plantas medicinais e ou nativas, conhecidas popularmente no Norte de Minas Gerais, sobre a germinação de esporos e crescimento micelial do fungo Colletotrichum gloeosporioides. Foram utilizados no teste de inibição do crescimento micelial, os extratos aquosos de alecrim (Rosmarinus officinalis), erva baleeira (Cordia verbenacea), joá (Solanum sisymbriifolium), quebra-pedra (Phyllanthus corcovadensis), erva botão (Eclipta alba) e açafrão da índia (Curcuma longa) obtidos por meio do processo de infusão; óleo essencial de alecrim de vargem (Família Lamiaceae), alecrim pimenta (Lippia sidoides), alfavaca cravo (Ocimum gratissimum), lippia (Lippia citriodora), goiaba branca (Psidium guajava), capim santo (Cymbopogon citratus); óleo resina de copaíba (Copaifera langsdorffi); hidrolatos de alecrim de vargem, goiaba vermelha (Psidium guajava), lippia, capim santo, goiaba branca, alfavaca cravo; manipueira de (Manihot esculenta). Também foram testados esses mesmos hidrolatos e os óleos essenciais na germinação dos esporos do fungo. Termos para indexação:Controle alternativo, antracnose, maracujá, plantas medicinais ou nativas. ABSTRACTThe objective of the work was to evaluate the effect of extracts and essential oils of fourteen medicinal and or native plants popularly known in the North of Minas Gerais, on the germination of spores and the mycelial growth of Colletotrichum gloeosporioides fungus. The following were used in the mycelial growth inhibition test: the watery extracts of rosemary (Rosmarinus officinalis), Cordia verbenacea, Solanum sisymbriifolium, Phyllanthus corcovadensis, Eclipta alba, and Curcuma longa obtained through the infusion process; essential oils of "alecrim de vargem" (Lamiaceae Family), Lippia sidoides, Ocimum gratissimum, Lippia citriodora, white guava (Psidium guajava), lemongrass (Cymbopogon citratus); copaíba oil resin (Copaifera langsdorffi) as well as hydrolates of "alecrim de vargem", red guava (Psidium guajava), Lippia citriodora, lemongrass, white guava, Ocimum gratissimum; and cassava manipueira (Manihot esculenta). The same hydrolates and essential oils were also tested on the germination of the fungus spores. All the treatments were carried out in vitro, cultivating the fungus in PDA supplemented with 100µL of the vegetal compounds. In the germination inhibition test, all the essential oils prevented the germination of the fungus. However, the hydrolates did not have this effect. In the mycelial growth test, the essential oils of all of the plants completely inhibited the fungus growth, except the white guava oil. The watery extracts, the cassava manipueira, the oil resin and hydrolates were also not efficient in preventing the growth of the pathogen. These results indicate the fungitoxic potential of some essential oils of medicinal plants.

Resumo -O objetivo deste trabalho foi avaliar alterações fisiológicas durante a ontogênese de sementes das pimentas malagueta e biquinho, e determinar o melhor estádio para colheita. As flores em antese foram etiquetadas diariamente e os frutos foram colhidos aos 25, 40, 55, 70, 85 e 100 dias após a antese (DAA). Em cada época de maturação, as sementes foram avaliadas quanto a: teor de água, massa de matéria seca, germinação, primeira contagem de germinação, índice de velocidade de germinação e envelhecimento acelerado. O início do desenvolvimento das sementes foi caracterizado pelo acúmulo de matéria seca, e ocorreu até os 80 DAA, para pimenta malagueta, ou até os 70 DAA, para pimenta biquinho. Em sementes ortodoxas, como as da pimenteira, observa-se decréscimo no teor de água após elas atingirem máxima matéria seca. Aos 100 DAA, o teor de água foi de 14%, na pimenta malagueta, e de 15%, na pimenta biquinho. As sementes colhidas aos 25 e 40 DAA não germinaram. A percentagem de germinação aumentou entre os 40 e 70 DAA, e diminuiu a partir de então. A maturidade fisiológica das sementes de pimentas malagueta e biquinho ocorre aproximadamente aos 70 DAA, época ideal para colheita.Termos para indexação: Capsicum, envelhecimento acelerado, germinação, maturação, potencial fisiológico, vigor. Physiological quality of ''malagueta'' and ''biquinho'' pepper seeds during ontogenyAbstract -The objective of this work to evaluate the physiological changes during seed ontogeny of ''malagueta'' and ''biquinho'' pepper, and to determine the best stage for harvest. Flowers in anthesis were tagged daily, and fruits were collected at 25, 40, 55, 70, 85, and 100 days after anthesis (DAA). In each maturation time, seeds were evaluated for water content, dry weight, germination, first germination count, germination speed index, and accelerated aging. The beginning of seed development was characterized by dry matter accumulation, which occurred until 80 DAA for ''malagueta'' pepper and 70 DAA for ''biquinho'' pepper. In orthodox seeds, such as pepper, after reaching maximum dry matter, a decrease is observed in water content. At 100 DAA, water content was 14% for ''malagueta'' pepper and 15% for ''biquinho'' pepper. Seeds harvested at 25 and 40 DAA did not germinate. Germination percentage increased between 40 and 70 DAA, and decreased thereafter. Physiological maturity of ''malagueta'' and ''biquinho'' peppers occurs at approximately 70 DAA, which is the ideal time for harvest.

Mulch and organic fertilizer in the production of lettuce and weed controlThis study aimed to assess the effects of mulch and organic fertilization on soil temperature and moisture, the incidence of weeds and yield of lettuce. The experimental design was a randomized block in a 3 x 3 factorial, including tifton, napier grass and lack of covering combined with cattle manure, chicken manure and no fertilizer. We analyzed the variables temperature and soil moisture, number of leaves produced per lettuce head, fresh weight and dry weight of lettuce shoots and weeds, and the phytosociological survey of infesting weed. Plants fertilized with chicken manure had greater fresh and dry weights compared to unfertilized plants. The application of tifton provided increased dry weight of lettuce, which may be associated with the lower temperature of plots that received this material as mulch. The species Commelina benghalensis was the most relevant weed in the organic cultivation. The application of organic fertilizers and mulch with grass was not able to suppress weeds and maintain soil moisture in areas of cultivation of lettuce.

RESUMO -Apesar das variedades crioulas favorecerem a autonomia no processo produtivo na agricultura familiar, tem-se observado o seu abandono ao elevar-se o nível tecnológico empregado na lavoura, acreditando-se que apenas os cultivares modernos apresentam retorno econômico. Dessa forma, o objetivo deste trabalho foi verificar a influência de diferentes sistemas tecnológicos de manejo sobre os caracteres agronômicos de milho, provenientes de duas variedades crioulas ('Argentino' e 'BR da Várzea') e de dois híbridos. Os sistemas de manejo foram classificados como baixo, médio e alto nível tecnológico. O experimento foi conduzido em esquema fatorial 4x3 (quatro genótipos de milho e três sistemas tecnológicos de manejo), em delineamento em blocos completos casualizados, em faixas, com três repetições. Avaliaram-se a emergência, a incidência de Spodoptera frugiperda (lagarta-do-cartucho), a precocidade e a sincronia do florescimento, plantas acamadas, o diâmetro do colmo, a altura da planta e da inserção da espiga, o estande final e a produtividade. O desempenho agronômico das variedades crioulas foi maximizado pelo incremento tecnológico, tanto quanto os híbridos. Práticas de manejo acessíveis, como a utilização de adubação orgânica e o controle alternativo de pragas, são capazes de maximizar a produção de grãos de milho. ABSTRACT -Despite landrace varieties favouring autonomy in the production process in family farming, their use has been neglected with the rise in the level of technology employed in agriculture, where it is believed that only modern cultivars present an economic return. The objective of this study therefore was to investigate the influence of different technological management systems on the agronomical characteristics of maize from two landrace varieties ('Argentine' and 'BR da Várzea') and from two hybrids. The management systems were classified as being of a low, medium and high technological level. The experiment was carried out in a 4x3 factorial (four maize genotypes and three technological management systems) in a complete randomized block design, in strips and with three replications. The following were evaluated: emergence, incidence of Spodoptera frugiperda (armyworm), flowering precocity and synchrony, plant bedding, stem diameter, plant and ear height, final growth and productivity. The agronomical performance of both the landrace varieties and the hybrids were maximized by technological advances. Affordable management practices, such as the use of organic fertilizers and alternative pest-control, are able to maximize the production of maize. Palavras

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