Fusarium spp. are commonly isolated from soybean roots but the pathogenic activity of most species is poorly documented. Aggressiveness and yield impact nine were determined on in greenhouse (50 isolates) field microplot (19 experiments. Root rot severity shoot root dry weights compared at growth stages V3 or R1. systems scanned digital image analysis was conducted; measured microplots. Disease morphology impacts varied among within species. graminearum highly aggressive (root >90%),...

ABSTRACT Seed treatments are applied to soybean [ Glycine max (L.) Merr.] seeds control early season diseases and insects. Unsold, treated seed must be disposed in a different manner than untreated seed. To minimize disposal costs, it is necessary improve storage. The objective was determine the best storage environments that would deterioration of Twenty‐four varieties, lipid protein contents from four maturity groups, were either with fungicide or mixture plus insecticide stored three...

A 3-year survey was conducted in Iowa to characterize the distribution and frequency of species Fusarium associated with soybean roots. Ten plants were collected from each 40 57 fields year at V2 V5 R3 R4 growth stages. colonies isolated symptomatic symptomless roots identified based on cultural morphological characteristics. Species identification confirmed by amplification sequencing translation elongation factor (EF1-α) gene. Fifteen identified; oxysporum most frequently, accounting for...

The germination and sporulation of Colletotrichum acutatum were characterized over time on strawberry leaves (cv. Tristar) plastic coverslips incubated at 26°C under continuous wetness. Conidia germinated within 3 h after inoculation formed melanized appressoria with pores by 9 inoculation. Host penetration was not observed up to 7 days Production secondary conidia conidial hyphal phialides began 6 Secondary conidiation responsible for a threefold increase in the total number Primary hyphae...

Current management of sudden death syndrome (SDS) soybean, caused by Fusarium virguliforme, focuses on planting resistant varieties and improving soil drainage; however, these measures are not completely effective. A 6-year study evaluated the effects cropping system diversification SDS soybean yield. SDS, root health, yield, F. virguliforme density in were assessed a naturally infested field trial comparing 2-year consisting corn-soybean rotation synthetic fertilizer applications with 3-...

Fusarium oxysporum (Fo) is an important pathogen that reduces soybean yield by causing seedling disease and root rot. This study assessed the effects of pH temperature on Fo fungal growth disease. In in vitro assay, 14 isolates collected from symptomatic roots across Iowa 2007 were grown artificial culture media at five levels (4, 5, 6, 7, 8) incubated four temperatures (15, 20, 25, or 30°C). a rolled-towel seeds Fo-susceptible cultivar Jack inoculated with suspension pathogenic...

Strawberry leaves (cv. Tristar) inoculated with Colletotrichum acuta-tum conidia were incubated at 10, 15, 20, 25, 30, and 35°C under continuous wetness, 25°C six intermittent wetness regimes. The number of appressoria was quantified on excised leaf disks. In order to assess pathogen survival, frozen induce acervular development. Germination, secondary3 conidiation, appressorial development significantly (P ≤ 0.05) affected by temperature treatments. Under the optimum range for conidial...

Fusarium spp. are widespread soilborne pathogens that cause important soybean diseases such as damping-off, root rot, wilt, and sudden death syndrome. At least 12 species of Fusarium, including F. proliferatum, have been associated with roots, but their relative aggressiveness rot is not known pathogenicity has established for all reported (2). In collaboration Iowa State University extension specialists, roots were arbitrarily sampled from three fields in each 98 counties 2007 to 2009. Ten...

Sudden death syndrome (SDS) is one of the major yield-limiting soybean diseases in Midwestern United States. Effective management for SDS requires accurate detection fields. Since traditional scouting methods are time-consuming, labor-intensive, and often destructive, alternative to monitor large fields needed. This study explores potential using high-resolution (3 m) PlanetScope satellite imagery random forest classification algorithm. Image data from blue, green, red, near-infrared (NIR)...

Sudden death syndrome (SDS) of soybean is favored by planting in cool soil but epidemics can be severe even when occurs later the season into warmer soil. Our objective was to determine how temperature affects susceptibility plants exposed Fusarium virguliforme at different ages. Soybean were grown rhizotrons water baths 17, 23, and 29°C. Subsets inoculated 0, 3, 7, 13 days after (DAP) drenching with a conidial suspension. Root rot developed all severity decreased increasing plant age...

Soybean yield losses due to sudden death syndrome (SDS) have varied from year in Iowa since the disease was first reported 1993. An SDS epidemic 2010 resulted significant and raised numerous concerns by farmers agronomists regarding potential for future outbreaks. Since infection development is highly dependent on temperature soil moisture, our hypothesis that epidemics occur years with above-average rainfall below-average temperatures. To test this hypothesis, environmental conditions...

Isolates in the Fusarium oxysporum species complex (FOSC) from soybean range nonpathogenic to aggressive pathogens causing seedling damping-off, wilt, and root rot. The objective of this research was characterize genotype phenotype isolates within FOSC recovered predominantly roots seedlings. Sequence analyses translation elongation factor (tef1α) gene mitochondrial small subunit (mtSSU), polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis intergenic spacer...

During 2007 to 2009, symptomatic and asymptomatic soybean plants were collected from fields in 18 Iowa counties. Fusarium isolates recovered surface-sterilized root tissue on peptone PCNB agar (2). Single-spore transferred synthetic low nutrient (SNA) overlain with pieces (1 × 2 cm) of sterile filter paper, potato dextrose (PDA), placed the dark for 10 14 days morphological identification (4). Twenty-three identified as commune K. Skovg., O'Donnell & Nirenberg, previously F. oxysporum...

The ability to accurately detect and quantify Fusarium virguliforme, the cause of sudden death syndrome (SDS) in soybean, samples such as plant root tissue soil is extremely valuable for accurate disease diagnoses address research questions. Numerous quantitative real-time polymerase chain reaction (qPCR) assays have been developed this pathogen but their sensitivity specificity F. virguliforme not compared. In study, six qPCR were compared five independent laboratories using same set DNA...

Soybeans [Glycine max (L.) Merr.] are susceptible to many diseases including fungal such as soybean sudden death syndrome (SDS). Several studies reported SDS resistance quantitative trait loci (QTL) on the genome using different recombinant inbred line (RIL) populations and low density genetic linkage maps. High exclusively single nucleotide polymorphisms-based (SNP-based) maps were not yet in soybean. The objectives of this study (1) construct a high SNP-based map 'PI438489B' by 'Hamilton'...

Abstract Tectona grandis (teak) plantations are being produced with trees from genetic improvement programs, including clonal selection. However, limited information about inheritance of wood properties is available. For studying parameters T. and stem diameter two 10-yr-old trials were studied involving nominally 2 sites × 20 clones 3 replicates 1 ramet. Clonal variation was observed in: heartwood (HWP), pith (PP) bark (BP) percentages; green moisture content (IMC) density (GD); tangential...

In general, early detection and timely management of plant diseases are essential for reducing yield loss. Traditional manual inspection fields is often time-consuming laborious. Automated imaging techniques have recently been successfully applied to detect diseases. However, these methods mostly focus on the current state crop. This paper proposes a gated recurrent unit (GRU)-based model predict soybean sudden death syndrome (SDS) disease development. To SDS at quadrat level, proposed...

Soybean sudden death syndrome is characterized by root rot followed the development of foliar symptoms. However, it not known how time infection affects disease severity. plants were inoculated at 0, 4, 7, 14, 21, 28, and 35 days after planting (DAP) drenching potting media with conidia Fusarium virguliforme, then incubating in growth chambers 17°C for 7 24°C 31 days. Root severity symptoms assessed 18 38 inoculation (DAI). developed on all ages but seed stage (0 DAP) had highest (P < 0.01)...

Abstract Sudden death syndrome (SDS) of soybean is a concern in the major producing regions North and South America. The disease caused by soil-borne fungi genus Fusarium most recognized development interveinal chlorosis necrosis on leaves, premature defoliation. Yield losses associated with SDS can be economically devastating depending intensity timing onset. Our understanding about has greatly expanded since it was first described USA 1971, comprehensive review written 1997 Roy et al ....