Influence of continuous cropping on corn and soybean pathogens

Abstract

The objective of this study was to evaluate the influence of two tillage programs (conventional and no-tillage) and different rotations with soybeans and corn on the occurrence of Fusarium species. The work was conducted in the experimental field and Seed Laboratory at Iowa State University. The treatments were: tillage (no-tillage and conventional tillage), crop (corn and soybeans) and three different cropping sequences for corn and soybeans, respectively. Treatment with corn: (1) the first year after four years of soybeans (1C); (2) alternating corn and soybeans each year (C / SB); (3) Continuous corn (C). Treatment with soybeans; (1) the first year after four years of corn (1S); (2) alternating soybeans and corn each year (SB / C); (3) Continuous soybeans (S). Two plant counts were performed in two stages in soybean (VC and V3) and corn (V1 and V3). The root system of ten plants were collected in the vegetative stages V2 and V5 for soybeans and corn. The fungi were isolated from the roots, and the Fusarium species were identified based on the most distinctive morphological characteristics. Nine species were identified in both soybeans and corn, namely F. acuminatum, F. equiseti, F. graminearum, F. oxysporum, F. proliferatum, F. solani, F. subglutinans, F. verticillioides and F. virguliforme. There were no significant differences among the treatments concerning the Fusarium species composition, for both soybeans and corn. In soybeans Fusarium oxysporum was the most frequently observed saprophyte species, followed by F. solani. For corn the main trends in the data was the predominance in all treatments of F. solani, whose highest frequency was in the no-tillage system.

Dynamics of soil properties and fungal community structure in continuous-cropped alfalfa fields in Northeast China

“…4F). Some species of the fungal genus Cyphellophora are potential pathogens (Decock et al, 2003; Ma et al, 2018), and the relative abundance of OTU1311 was correlated significantly with some soil properties, such as soil TC, TN, TP and AP (Table S7), suggesting that continuous cropping may promote the proliferation of pathogens (Guo et al, 2011; Ranzi et al, 2017).…”

Soil Health Check-Up of Conservation Agriculture Farming Systems in Brazil

“…Production fields managed under soybean monocropping and without diversification with cover crops are more prone to Fusarium root rot [78]. This is one of the most important soybean soil diseases that occurs in many fields in the North and South America [79,80]. Soybean lateral roots with Fusarium root rot may die and, in consequence, reduce plant nutrients uptake and exudates production that could support a more diversified soil biota [81].…”

“…It is important to highlight that this genus was the most prevalent in LYE and MYE and was associated with a decrease in plant-growth-promoting organisms (Figure 7c). Ranzi et al [80], evaluating the soybean and maize in monocropping systems, were able to identify up to nine Fusarium species connected with the lack of crop diversity and high soil compaction.…”

Peer Review #1 of "Dynamics of soil properties and fungal community structure in continuous-cropped alfalfa fields in Northeast China (v0.1)"

“…Manuscript to be reviewed as soil TC, TN, TP and AP (Table S7), suggesting that continuous cropping may promote the proliferation of pathogens (Guo et al, 2011;Ranzi et al, 2017).…”