Investigation of Affecting Factors on Soybean (Glycine max L.) Pod Abnormality in Gorgan

Soybean pod abnormality is a kind of growth in which soybean plant accompanied with growth disorders including sever pod and flower abscission as well as leaves and pod morphological modifications. In an acute status, these kinds of plants stays green; therefore, the yield decreases and harvest time delay, dramatically. To investigate the reasons of pod distortion abnormality in Katul cultivar, a field assay based on roving method was performed. In the field experiment based on roving method 40 fields of Katul were selected randomly and traits like yield and yield component as well as managemental and climatic parameters were recorded in two successive growing years, 2015 and 2016. Result indicated that all field management factors didnot have any effect on PDS, except frequency of irrigation. In such a way that decreasing frequency of watering increased incidence of PDS significantly. Furthermore, percent of flower abscissions as well as shoot dry weight were increased; meanwhile, number of pod per plant, number of grain per pod, number of grain per plant, 1000-grain weight, harvest index, biological yield and grain yield dwindled extraordinary in PDS plants. Taken together, these results indicated that abiotic stresses such as heat and drought stresses as well as undesirable field irrigation might play an important role in soybean pod distortion abnormality incidence. In addition, interpreting of mineral nutrient indicated that well nutrition plants might decrease damage percentage of soybean pod abnormality.