Clovis Pereira Peixoto

Genótipos de bananeira em três ciclos na Zona da Mata Mineira

The objective of this work was to evaluate during three cycles the main vegetative characteristics of the genotypes Prata Ana, Grande Naine, Caipira, Nam, Pioneira, FHIA-01, FHIA-18, PV03-44 and SH3640, aiming to incorporate new genotypes to commercial production systems. An experiment was carried out at Zona da Mata Mineira region during three crop cycles, in randomized block design, with nine treatments (genotypes) and three replications (cycles). Height, precocity, number of leaves, resistance to Yellow Sigatoka and plant suckers were evaluated. The variety Grande Naine had the lower height, while Prata Ana, FHIA-01 and SH3640, the larger diameter. The genotypes that presented higher precocity were Pioneira and FHIA-18. The varieties Nam and Caipira presented the highest numbers and precocity of suckers. The genotypes FHIA-01, FHIA-18 and SH3640 were superiors in relation to the characteristics evaluated.

Tamanho ótimo de parcela para experimentos com plantas de mamoeiro em casa de vegetação

Neste trabalho, objetivou-se a determinacao do tamanho otimo de parcelas em experimentos em casa de vegetacao com a cultura do mamoeiro. Foram conduzidos dois ensaios de uniformidade com as cultivares Golden, do grupo Solo, e com o hibrido Tainung No 1, do grupo Formosa. Os ensaios foram formados por plantas em sacos de polietileno, dispostas em 10 fileiras, com 10 plantas em cada fila. Entre o periodo do desbaste e do aparecimento da primeira flor funcional, foram feitas avaliacoes das variaveis: altura de planta, diâmetro de caule, numero de folhas, largura e comprimento de folha madura. Foram simulados diversos tamanhos e formas de parcelas, em que cada planta foi considerada primeiramente como uma unidade basica (parcela) ate 50 plantas por unidade basica. Para a estimacao do tamanho otimo de parcelas empregou-se o metodo da maxima curvatura modificado. Pode-se concluir que, para os materiais e variaveis estudadas, o tamanho de parcela otimo deve ser formada por oito plantas.

Avaliação agronômica em híbridos diplóides (AA) de bananeira

The aim of the present work was to characterize horticultural characteristics in (AA) banana diploid hybrids. The experiment was carried out at the experimental field of Embrapa Cassava and Tropical Fruits in randomized blocks with four replicates and 11 (AA) banana diploid hybrids were evaluated: (4279-06, TH03-01, 8987-01, 0323-03, 1318-01, 0116-01, 8694-20, 1304-06, 9179-03, 4223-06 and SH3263). Data of the agronomical characteristics evaluated were submitted to the analysis of variance and the averages of the genotypes grouped by the Scott-Knott test at 5% of probability. The SH3263 genotype presented favorable values to the breeding for number of hands per bunch, number of fruits per bunch, low yellow-sigatoka incidence during flowering and also lower number of days until bunch emission at harvest, greater weight of second hand and fruit length greater than 10 cm. The 0323-03 hybrid presented greater live leaf retention during bunch harvest and also the lowest score for yellow-sigatoka during the harvest. The high variability encountered enables the selection of (AA) diploids with potential use in breeding programs of this crop.

Seleção de híbridos diplóides (AA) de bananeira com base em três índices não paramétricos

The objective of the present study was to select diploids (AA) hybrids of banana based on three non-parametric indices as to guide the selection and increase the use of the variability present in the Banana Germplasm Bank of Embrapa Cassava and Tropical Fruits. Eleven hybrids were evaluated in random blocks with four replicates. The plots consisted of six plants spaced 2.5 m x 2.5 m whereas the border rows were from the Pacovan cultivar. The following characteristics were evaluated: plant height, pseudostem diameter, number of suckers, number of leaves during flowering, plant cycle from planting to bunch emission, presence of pollen, number of hands, number of fruits, fruit length and yellow-Sigatoka resistance. The average of these ten characteristics was used for calculating the multiplicative indices of sum of classification and genotype-ideotype distance. The two hybrids presenting best global performance SH3263 and 1318-01 ranked respectively, first and second by the multiplicative indices and sum of classification whereas the genotype-ideotype distance index ranked them first and fourth . Although in general, all three indexes presented good coherence between general performance of the hybrids and their classification, the multiplicative and sum of classification indexes provided a more adequate classification of these hybrids.

Avaliação de extratos das espécies Helianthus annuus, Brachiariabrizanthae Sorghum bicolor com potencial alelopático para uso como herbicida natural

This study aimed to evaluate the allelopathic potential of aqueous extracts of Brachiaria, sunflower, sorghum germination and early growth of lettuce (Lactuca sativa L.), in the attempt of employing these extracts as a natural herbicide. The study was conducted at the Laboratory of Plant Physiology of the Universidade Federal do Reconcavo da Bahia. A trial was arranged in a completely randomized design with 4 treatments and 6 replications. The treatments were extracts of Brachiaria, sunflower, sorghum, and, as a control, distilled water. The extracts were obtained by using 200 g of plant material in 1000 mL of distilled water. First, the lettuce seeds were distributed in a seedling box containing two sheets of germitest moistened paper with treatments, and then were taken to a germination chamber. The germination was daily monitored. The average germination time and the initial growth were evaluated after ten days, through the measuring of the aerial part length (APL) and the root system length (RSL). The data generated were subjected to analysis of variance and the means were compared by the Tukey test. Based on the results, the extracts of Brachiaria, sunflower and sorghum did not affect the germination of lettuce, but, on the other hand, the Brachiaria and sorghum increased the germination time. The extracts caused an increase in the aerial part and reduced the root system growth and the formation of normal seedlings. Since they caused inhibition on the growth of the lettuce root system, have also potential to be used as natural herbicides.

Perdas causadas pela ferrugem-asiática em cultivares de soja semeadas em diferentes épocas, no Oeste da Bahia

Yield loss caused by rust in soybean cultivars sown in different periods in the western region of Bahia, Brazil The objective of this work was to quantify the yield loss caused by Asian soybean rust in three cultivars sown in different periods in the western region of Bahia. The experiments were installed in Sao Desiderio, BA, in the growing seasons 2007/2008 and 2008/2009. The experimental design was carried out in random blocks with four replicates and subdivided plot scheme in time. The plot was represented by the rust control treatments (with and without chemical control) and the subplots represented by cultivars (Monsoy 8411, BRS Corisco and BRS Barreiras). The severity, number of leaves throughout the cycle and yield were evaluated. The logistic model was the one that better fitted the severity data whereas the polynominal exponential function Ln (y) = a + bx 1, 5