Influence of Colletotrichum truncatum on the Physiological and Chemical Quality in Different Varieties of Soy Seed

The literature highlights that a severe infection by the fungus Colletotrichum truncatum may be capable of inflicting considerable damage to seeds after harvest, potentially affecting their chemical composition and physiological quality. Taking into account that currently there is no categorization in terms of susceptibility and tolerance on this pathogen, the present work is presented with the main objective of “Evaluate the influence of Pathogenicity of C. truncatum on the physiological quality (germination, vigor, viability) and biochemical components in different varieties of soybean seeds (Glycine max)” most planted in the region. The work was carried out in the Agrotec laboratory, located in the Municipality of San Alberto (Alto Paraná), using a completely randomized experimental design, with AxB factorial arrangement, where A indicates ten most planted soybean varieties in the region and B with or without artificial inoculation of Colletotrichum truncatum, with twenty treatments and four repetitions. The variables evaluated were: germination, vigor, viability and chemical composition. The data were subjected to analysis of variance and the Tukey test at 5% error. The results showed a significant statistical difference, accepting the alternative hypothesis proposed “The pathogenicity of Colletotrichum truncatum influences the physiological quality (germination, vigor, viability) and biochemical components (saturated and unsaturated fatty acids) in different varieties of soybean seeds (Glycine max)”.

Influence of Climatic Parameters on Soybean Subjected to Low Nitrogen Application Rates in Southern Guinea Savanna of Oyo State, Nigeria

The variability in weather patterns consequent upon climate change constitutes a critical factor influencing soil N availability and the performance of crops. This paper aimed at evaluating the effects of climatic factors on soybean subjected to low N rates under rain-fed situation in the southern Guinea agro-ecology of Oyo State, Nigeria. A 2-year field experiment involving two soybean varieties (TGx1485-1D and TGx1448-2E) and five low rates of N fertilizer application (0, 5, 15, 25, 35 kg/ha) using Urea applied by banding 7 days after planting was arranged in a 5 × 2 split-plot with three replications. N rates constitute the main plot while variety constitutes the sub-plot. Parameters measured include dry shoot weight, shoot N accumulation, and grain yield. Data were subjected to GENSTAT statistical package for analysis, and means separated with Duncan Multiple Range Test (DMRT) at 5% level of probability. Climatic parameters of rainfall, temperature, and potential evapotranspiration data were collected from the surface observatory of the National meteorological agency (NIMET) and subjected to Excel package for computation and graphics. The dry shoot weight increases as N rate increases up to 25 kg/ha, but declines at 35 kg/ha application rate, however, TGx1448-2E produced a higher dry shoot weight (2.9 t/ha) than TGx1485-1D (2.8 t/ha). Low N rates had no significant effects on shoot N accumulation and there was no significant difference in varietal response. Low N rate did not affect grain yield, but the TGx1448-2E had a greater yield of 1.5 t/ha than TGx1485-1D (1.30 t/ha). Annual rainfall amounts were 935.5 mm and1475.8 mm in 2009 and 2010 respectively. Potential evapotranspiration (PET) values were 1676.5 mm and 1676.8 mm in 2009 and 2010 respectively. Temperature values range from 24˚C to 29.8˚C in both years and the mean monthly temperature for 2009 was 26.5˚C and 27.1˚C for 2010. The application of N fertilizer to soybean requires appropriate timing for effective use. Climatic parameters such as rainfall, temperature, and evapotranspiration have dire consideration for fertilizer use and efficiency.