Elisangela Clarete Camili

Vaporização de ácido acético para o controle pós-colheita de botrytis cinerea em uva 'Itália'

ABSTRACT – Two in vivo trials were carried out in order to evaluate the effect of acetic acid vapor (AA) as an alternative for postharvest control of gray mold (Botrytis cinerea) in ‘Italia’ grapes. The direct and indirect effect of AA over treated bunches before and after pathogen inoculation was evaluated. In trial 1, grape bunches were inoculated and after 4 h submitted to AA vapors (0.0, 0.25, 0.5, 1.0 or 2.0 mL) in hermetic chambers (200 L), at 25±1 oC / 70-80 % RH, for 30 min. In trial 2, grape bunches were vaporized or not with AA (1 mL 100 L -1 ) and after 24, 48, 72 or 96 h, inoculated with B. cinerea. For inoculation, in each bunch (10 per treatment) 10 berries were injured with a ±2 mm deep puncture and sprayed with a spore suspension (±10 5 conidia mL -1 ). After treatments, bunches were stored at 25±1 oC / 80-90 % RH and daily evaluated regarding rot incidence and severity. The in vitro effect of AA vapor on pathogen control was evaluated in order to verify if this agent would directly affect mycelia growth and B. cinerea conidia germination. In the in vivo trials, AA vapor control B. cinerea rot in ‘Italia’ grape in bunches inoculated before and after treatment with AA. Grapes inoculated 48 h after treatment with AA showed the lowest disease incidence index. In vitro AA has a direct effect on mycelia growth and conidia germination of B. cinerea.Index terms: Vitis vinifera L., gray mold, alternative control.

Métodos para o condicionamento fisiológico de sementes de milho

This study aimed to evaluated different methodologies and water potentials for priming of maize seeds, in order to increase vigor. The experiment was carried out following a completely randomized design, in a factorial scheme 4x3+1, with four water potentials (0.0, -0.4, -0.8 and -1.2 MPa), three priming methods (immersion in non-aerated solution, immersion in aerated solution, paper roll) and a control. After priming, the seeds were dried and evaluated for water content, percentage and first germination count, seedlings length and dry mass, cold test and vigor index. The water potential recommended for priming maize seeds, in polyethylene glycol 6000 is -0.4 MPa for 24 hours. The priming procedures in towel paper rolls improve the quality of maize seeds.

CARACTERÍSTICAS FÍSICAS E BROMATOLÓGICAS NA PREFERÊNCIA DE Callosobruchus maculatus (COLEOPTERA: BRUCHIDAE) A DIFERENTES VARIEDADES DE FEIJÃO-CAUPI

Cowpea is an herbaceous legume susceptible to several insects and diseases; and the beetle Callosobruchus maculatus is the main pest causing direct losses in the production of this crop. The objective of this work was to assess the physical and bromatological characteristics of beans of cowpea varieties (Bico-deOuro, BRS-Novaera, BRS-Guariba and BRS-Tumucumaque) preferred by C. maculatus. Adults of C. maculatus were obtained from a storage unit of cowpea beans. The physical and bromatological characteristics and attractiveness of cowpea beans to insects were evaluated in laboratory. The preferences for oviposition with no choice and attraction to cowpea beans by C. maculatus are not related to the high protein content or physical characteristics of the bean seed coat (thickness and fiber content), since the insects were more attracted to beans of the variety Bico-de-Ouro, which had low crude protein content, the thickest seed coat and high NDF content.

Germination and vigor of seeds of Magonia pubescens A. St.-Hil. submitted to storage and pre-imbibition in water

Timbó (Magonia pubescens A. St.-Hil.) is a species with ornamental potential, which can be used in composition of gardens, squares and especially in streets landscaping. It is also suitable for planting in degraded areas of permanent preservation. This work aimed to verify the effect of seed size, storage and pre-imbibition time on seed germination and vigor. The test design was completely randomized, in a plot scheme subdivided in time. The main plots were seed size (large and small), packaging (0.5 mm-thick transparent polyethylene and kraft paper bag), and time of imbibition in water (0, 12 and 24 hours); and as subplots, it was considerate the storage times (0, 3, 6, 9 and 12 months). The tests were carried out in five replications of ten seeds, and the evaluated variables were: water content of the seeds, percentage of germination (% G), mean germination time (MGT), shoot height (cm), collar diameter (mm), number of leaves, and fresh and dry mass of the aerial part (g). The size of the seed did not influence the germination percentage, but large seeds formed more vigorous seedlings. The storage did not affect seeds germination, nor the vigor of the seedlings. Seed preimbibition did not influence the percentage of germination, but the mean germination time decreased, and more vigorous seedlings were formed. In order to obtain more vigorous Timbó seedlings, the best option is to use large seeds. They can be stored for up to 12 months without losing vigor and pre-soaked to accelerate the beginning of germination, thus forming a more homogeneous lot of seedlings.

Allelopathic potential of Inga laurina leaf extract on lettuce seed germination

The aim of this study was to evaluate the allelopathic potential of Inga laurina leaves on the germination and growth of Lactuca sativa L. seedlings. The extract was obtained by blending 50 g of leaves in 500 ml of distilled water. Extracts were obtained by diluting the leaf homogenate in water to concentrations of 0 (control), 25, 50, 75 and 100%. The bioassay was conducted in a completely randomized design with five treatments and four repetitions of 50 seeds of L. sativa . The characteristics observed were germination and abnormal seedlings, germination rate, shoot length and root length, dry weight of seedlings and allelopathy index. There was no difference between extracts for germination ranging from 98%to 100%. The speed of germination rate and seedling root length decreased with increasing concentration and could be explained by second degree polynomial regression models with R 2 above 98%. The fresh mass increased with higher concentrations of the extract. The allelopathic index was negative, indicating inhibition, and increased with increasing extract concentration. The leaf extract of Inga laurina at different concentrations did not affect lettuce seed germination. Allelopathic potential was seen in the developmental characteristics of lettuce seedlings.

INSEGURANÇA NA QUALIDADE GENÉTICA DE SEMENTES DE ALFACE PRODUZIDAS NA AMÉRICA DO NORTE E DO SUL

Objetivou-se comparar a similaridade qualitativa das caracteristicas fenotipicas de plantas de alface cv. Marisa, desenvolvidas a partir de lotes de sementes produzidas nos Estados Unidos da America (EUA) e no Chile. O delineamento experimental foi em blocos ao acaso, com dois tratamentos (lotes de sementes provenientes dos EUA – Lote 1 e Chile – Lote 2) e seis repeticoes, sendo cada unidade experimental constituida por uma parcela de 3,0 x 1,2 m (3,6 m²) e a area util para avaliacao composta de 10 plantas de alface, excluindo-se as primeiras e as ultimas plantas de cada linha de cultivo.Avaliou-se nas mudas, 26 dias apos a semeadura, o numero de folhas; comprimento da maior raiz (cm); massa da materia seca da parte aerea (MS aerea) e das raizes (MS raizes) (g). No ponto de colheita, antes do corte das plantas, avaliou-se o diâmetro e a altura (cm) e; apos a colheita, avaliou-se a massa da materia fresca total da parte aerea (g planta -1 ); a massa da materia fresca comercial (g planta -1 ); o numero de folhas comerciais, contando-se aquelas maiores que 3 cm de comprimento, iniciando-se pelas folhas basais ate a ultima folha aberta; a massa da materia fresca do caule (g) e; o comprimento do caule (cm), apos a retirada das folhas. Verificou-se diferenca nas caracteristicas agronomicas avaliadas na fase de producao de mudas e no ponto de colheita, destacando-se aquelas provenientes de sementes dos EUA. DOI: 10.12957/ric.2015.19093

Produção e tolerância ao pendoamento de alface-romana em diferentes ambientes

O experimento foi conduzido na area experimental da Universidade do Estado de Mato Grosso, localizada no municipio de Caceres-MT, no periodo de maio a agosto de 2011, com o objetivo de avaliar a influencia de diferentes ambientes e espacamentos na producao e tolerância ao pendoamento de alface-romana cultivar Sophia. O delineamento experimental foi em blocos casualizados, arranjados em esquema fatorial 2 x 5, composto por dois espacamentos (30 x 30 cm e 25 x 25 cm) e cinco ambientes de cultivo (tela de sombreamento 30 e 50% , tela termorrefletora de 30 e 50% e ambiente aberto), perfazendo 10 tratamentos com quatro repeticoes cada. As parcelas experimentais foram constituidas por quatro linhas, com cinco plantas cada, totalizando 20 plantas por parcela. Consideraram-se como area util para avaliacao da producao as seis plantas centrais. As parcelas em que foi utilizado o espacamento 30 x 30 cm apresentavam 1,8 m2 cada, e as com o espacamento 25 x 25 cm, 1,5 m2 cada. As mudas foram transplantadas com 26 dias e a colheita realizada aos 46 dias apos o transplantio. Observou-se que o espacamento de 25 x 25 cm entre plantas e o ambiente aberto proporcionaram maior produtividade da alface-romana. Porem, o tempo para pendoamento das plantas no ambiente aberto foi menor que nos ambientes com as telas de sombreamento ou termorrefletora.