Research Objective
To assess the impact of two strobilurins on disease severity, greening/maturation, lodging, harvestability and yield under field conditions; to quantify and compare the secondary effects of two strobilurins on plant development and yield under controlled environmental conditions; to screen populations of important pulse crop pathogens in Saskatchewan for insensitivity to two strobilurin fungicides; and, if insensitivity is found in M. pinodes, A. lentis or C. lentis, to develop a reliable and efficient screening method for insensitivity to strobilurin fungicides.
The results of the field studies showed that although the strobilurin fungicides were as effective, or better in preventing disease as a non strobilurin fungicide, biomass and seed yield parameters of strobilurin treated plots of all the three pulse crops were not significantly different from those that received a non strobilurin fungicide. Important physiological parameters were not affected by the strobilurins in comparison with the non strobilurin fungicide or the water control in most situations. The greenhouse data was also consistent with these findings of the field experiments. Based on these results there is no strong evidence for positive or negative secondary effects of strobilurins on the physiology of pulse crops other than through the control of disease in Saskatchewan. Considering the high value of these fungicide in their function for disease control, and the high risk of losing this function due to the development of insensitivity in pathogen populations, it cannot be recommended to use strobilurins for blanket applications to achieve any perceived yield benefit unrelated to disease in situations where disease pressure does not require this. Results are based on a single application of strobilurins whereas two applications are allowed based on the labels of the fungicides. Therefore, further studies determine whether two applications would elicit any secondary effects in pea, lentil and chickpea.