Nerison Luiz Poersch

Micromineral composition of common bean cultivars and its application in crop breeding

The objective of this investigation was to determine the micromineral composition of seeds of common bean cultivars grown at different locations, examine cultivar x location interactions, and identify cultivars for direct consumption or use in breeding programs. Iron, zinc, copper, manganese and boron concentrations mineral were determined for 19 cultivars obtained in the 2004/05 cropping year in two locations in Rio Grande do Sul State, Brazil. Iron (71.5 mg kg-1), followed by zinc (30.0 mg kg-1), manganese (18.9 mg kg-1), copper (9.5 mg kg-1) and boron (8.3 mg kg-1) were the main constituents. Significant cultivar x location interactions were detected for zinc content and grain yield. Cultivar Guateian 6662 presented high micromineral content, independently of location, being suitable for diet enrichment and cultivar improvement.

Efeito de períodos de semeadura e das condições de armazenamento sobre a qualidade de grãos de feijão para o cozimento

Appropriate preservation can maintain grain characteristics of recent harvested grains for larger period, assuring commercial value of the stored product. The objective of this study was to evaluate the effect of sowing periods on cooking quality of common bean grains of the TPS Nobre cultivar when stored under different temperatures, moisture content and storage times. A completely randomized design was applied, with three replications. The treatments were combinations of e three sowing periods, three storage environment and three storage times (0, 3 and 6 months). The results obtained showed that the percentage of normal and hard grains was influenced by storage environment and storage time. The highest percentage of hard grains were verified in the six month storage when storage occurred at 12oC of main air temperature and 45-50% of moisture content and with grains of the late sowing (10/21/03). The water imbibition and cooking time varied according to sowing periods, storage environment and storage time, characterizing genotype x environment interaction on the cooking quality of common bean. In conclusion, longer or shorter time of water imbibition and cooking may be necessary as function of the grain quality at harvesting or of the temperature and moisture content during storage.

Potencial de aumento do teor de ferro em grãos de feijão por melhoramento genético

BREEDING POTENTIAL FOR IRON CONTENT IN COMMON BEAN The development of common bean germplasm with higher iron content would be an interesting alternative to reduce the low in take of this mineral in Brazilians diet. The objectives of this research were to evaluate the existence of maternal effect in iron content and to analyse the inheritance of this trait. The F1, F1 reciprocal, F2, F2 reciprocal, F3, F3 reciprocal, backcross 1 and backcross 2 generations were performed among the cultivars Minuano x Diamante Negro and Diamante Negro x IAPAR 44. The iron content was ascertained by nitric-perchloric digestion and determination on the atomic absorption spectrophotometer. Genetic variability in grain iron content was revealed in two crosses, beyond expression of maternal effect . Estimates of heritability in the broad sense was of 76.36% and the narrow sense of 50.60% in the cross Minuano x Diamante Negro. The gain from selection was of 11.14% and it is able to increase in grain iron content in common bean by plant breeding. The selection performed in the early generation may be effective for development of common bean germplasm with higher iron content.

Padronização de metodologia para avaliação do tempo de cozimento dos grãos de feijão

Different times of dropping the plunger of the Mattson cooker were used to characterize cooking of common bean grains. The objective of this study was to standardize bean grains cooking methodology. A completely randomized design was used with three replications and 23 dry bean cultivars, evaluated for cooking during the year 2005. The drop time of each peg was considered (Peg1, Peg2,..., Peg25) - or cooking time of each bean grain - and drop mean time of the first pegs, i = 1, 2,...,25 peg (Pmean1, Pmean2,..., Pmean25). The results obtained permit to say that experimental precision was modified with criteria change for characterization common bean of cooking time. The use of peg drop mean time of Mattson cooker made possible a better discrimination between cultivars. The utilization of drop mean time of the thirteen first pegs of the 25 pegs conferred greater experimental precision, and is proposed as a criterion to characterize cooking of common bean grains.

Substratos para cultivo de feijoeiro em vasos com fertirrigação

The objective of this paper was to identify an appropriate substrate for common bean grown in flowerpots. The experiments were carried out in a green house during 2005, with the TPS Nobre common bean cultivar. Seven substrates were evaluated: Plantimax®, carbonized rice husks, vermiculite, sand, carbonized rice husks + 20% of Plantimax®, carbonized rice husks + 20% of vermiculite and carbonized rice husks + 20% of sand. The experimental design was completely randomized with five replications. The nutrients were supplied weekly to fertigation and the water was added to refill the consumed volume. The evaluated substrates had different chemical and physical characteristics. The commercial substrate Plantmax® was characterized by high cations capacity exchange (30.6 cmol c L-1) and the highest water storage capacity per volume unit, which contributed for the higher dry matter yield of the plants and for common bean grains yield components. Therefore, we concluded that commercial substrate Plantmax® is appropriate for the common bean cultivation in flowerpots with fertigation.