scholarly journals Effect of Fungicide Application and Cultivar on Soybean Green Stem Disorder

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1212-1220 ◽  
Author(s):  
C. B. Hill ◽  
C. R. Bowen ◽  
G. L. Hartman
Keyword(s):  
Field Experiments ◽  
Macrophomina Phaseolina ◽  
Primary Objective ◽  
Delayed Senescence ◽  
Fungicide Application ◽  
Soybean Cultivars ◽  
Plant Maturity ◽  
Soybean Plants ◽  
Insect Interactions ◽  
Green Stem

Green stem disorder of soybean (Glycine max) has increasingly become a nuisance for soybean producers. The disorder is distinguished from other manifestations of delayed plant maturity by the delayed senescence of stems only, with normal pod ripening and seed maturation. The primary objective of the first study was to determine whether green stem disorder increased with a fungicide treatment. Field cages to isolate soybean plants to prevent insect interactions were used and treatments included maturity group (MG) II insensitive and sensitive soybean cultivars with or without fungicide applications. A secondary objective was to determine fungi potentially associated with the disorder. The results indicated significant elevation of the incidence of green stem disorder when using a fungicide. Species of Diaporthe or Phomopsis and Macrophomina phaseolina were more frequent in stems without the disorder, whereas species of Colletotrichum were found mostly in stems with the disorder. In another study, field experiments were conducted without cages in replicated field plots to compare the effects of fungicides with different chemistries and timing of fungicide application on incidence of green stem disorder using green stem disorder MG II- and MG III-sensitive and insensitive soybean cultivars. There was a significant increase in percentage of green stem disorder due to fungicide application, depending on fungicide chemistry, timing of application, year, location, and cultivar sensitivity to green stem disorder. Generally, Headline and Headline-Domark applications resulted in higher incidence of green stem disorder than Domark alone or the nonsprayed control, with over 50% incidence in many cases. Higher percent green stem disorder was significantly (P < 0.05) associated with higher yields in 11 of the 28 trials. From the results of this research, soybean producers should be aware of the possible risk that fungicide application may have in increasing incidence of green stem disorder. In addition, producers can help manage green stem disorder by selecting soybean cultivars reported to be consistently insensitive to the disorder.

scholarly journals Co-inoculation with Azospirillum brasilense in soybean cultivars subjected to water déficit

2020 ◽  
Vol 24 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Alessandra M. de L. Naoe ◽  
Joênes M. Peluzio ◽  
Leonardo J. M. Campos ◽  
Lucas K. Naoe ◽  
Roberta A. e Silva
Keyword(s):  
Grain Yield ◽  
Water Deficit ◽  
Bradyrhizobium Japonicum ◽  
Azospirillum Brasilense ◽  
Field Experiments ◽  
Crop Evapotranspiration ◽  
Plant Genotype ◽  
Soybean Cultivars ◽  
Sowing Dates ◽  
Soybean Plants

ABSTRACT This study aimed to verify the effect of co-inoculation, association between Azospirillum brasilense and Bradyrhizobium japonicum bacteria, on soybean plants subjected to water deficit at two sowing dates. Two field experiments were conducted at the Universidade Federal de Tocantins, campus of Palmas, Brazil, in 2016. The experimental design was randomized blocks in a split-split-plot arrangement with four repetitions, where the plots consisted of two irrigation depths (100 and 25% of crop evapotranspiration - ETc), the subplots was composed of two methods of inoculant application (inoculation with Bradyrhizobium japonicum and co-inoculation with Azospirillum brasilense + Bradyrhizobium japonicum) and the sub-subplots comprised two soybean cultivars (TMG 132 and ANTA 82). The cultivars responded differently to the sowing dates. Co-inoculation did not influence grain yield under full irrigation conditions (100% ETc), in neither cultivar evaluated. However, under the water deficit condition (25% ETc), the grain yield of the cultivar TMG 132 increased 77.20%, indicating that there are different responses of interaction between Azospirillum brasilense, plant genotype and sowing dates.

scholarly journals Analysis of Grain Yield Differences Among Soybean Cultivars under Maize–Soybean Intercropping

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 110 ◽  
Author(s):  
Xingcai Wang ◽  
Xiaoling Wu ◽  
Guohui Ding ◽  
Feng Yang ◽  
Taiwen Yong ◽  
...  
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Photosynthetic Capacity ◽  
Photosynthetic Parameters ◽  
Total Biomass ◽  
Area Index ◽  
Soybean Cultivars ◽  
Significant Difference ◽  
Reproductive Biomass ◽  
Soybean Plants

Shading created by intercropping reduces the photosynthetic capacity of soybean plants but also directly affects the pod setting process of soybean. However, which of the changed aspects induce the yield differences in intercropped soybean cultivars is still unknown. Four soybean cultivars with similar yield and growth and development processes in monoculture were selected by a pre-experiment. Field experiments were carried out from 2015 to 2017 to investigate the leaf photosynthetic parameters, total biomass, reproductive characteristics, yield and yield components of soybean. The yield of soybean cultivars was significantly decreased in intercropping systems and the yield of cultivars (cvs.) ZH39 and QH34 were considerably higher than those of cvs. HD19 and HD20. Besides, the pod and seed number and harvest index were also reduced by intercropping and the yield components of cvs. ZH39 and QH34 in intercropping were significantly higher than those of cvs. HD19 and HD20, other than the seed size. Although the parameters of leaf photosynthetic capacity (leaf area index, net photosynthetic rate, and chlorophyll content) of soybean were changed by intercropping, there was no significant difference among cultivars. Additionally, the CGRR1–R5 (crop growth rate between R1 and R5) of intercropped soybean was lower than that of monoculture, while no significant differences were observed in different cultivars. The reproductive biomass at R5 was significantly different among soybean cultivars, and the reproductive partitioning and seed set efficiency of different cultivars were varied by the reproductive biomass at R5. Therefore, high-yielding cultivars in intercropping can achieve higher yield due to more reproductive structures survived at R5.

scholarly journals Multiple Mid-Atlantic Field Experiments Show No Economic Benefit to Fungicide Application When Fungal Disease Is Absent in Winter Wheat

2011 ◽  
Vol 101 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Randy Weisz ◽  
Christina Cowger ◽  
Gaylon Ambrose ◽  
Andrew Gardner
Keyword(s):  
Winter Wheat ◽  
Economic Benefit ◽  
Field Experiments ◽  
Block Design ◽  
Fungal Disease ◽  
Yield Response ◽  
Cumulative Probability ◽  
Delayed Senescence ◽  
Yield Increase ◽  
Fungicide Application

Strobilurin fungicides produce intensified greening and delayed senescence in plants, and have been claimed to enhance yields of field crops in the absence of disease. To help evaluate this claim, available publicly sponsored tests of fungicides on soft red winter wheat in Virginia and North Carolina (n = 42) were analyzed for the period 1994 to 2010. All tests were replicated and had a randomized complete block, split-plot, or split-block design. Each test included 1 to 32 cultivars and one to five fungicides (two strobilurins, one triazole, and two strobilurin-triazole mixtures). There was a total of 311 test–cultivar–fungicide treatment comparisons, where a comparison was the reported yield difference between sprayed and unsprayed treatments of a given cultivar in a given test. Parameters used to calculate the economic benefit or loss associated with fungicide application included a grain price range of $73.49 to 257.21 Mg–1 ($2 to 7 bu–1), a total fungicide application cost of $24.71 to 74.13 ha–1 ($10 to 30 acre–1), and a 0.14 to 0.21 Mg ha–1 (2.3 to 3.4 bu acre–1) loss in yield from driving over wheat during application (with a sprayer 27.4 or 18.3 m [90 or 60 feet] wide, respectively). The yield increase needed to pay for a fungicide application at each combination of cost and price was calculated, and the cumulative probability function for the fungicide yield-response data was modeled. The model was used to predict the probability of achieving a break-even yield, and the probabilities were graphed against each cost–price combination. Tests were categorized as “no-disease” or “diseased” based on reports of the researchers rating the tests. Subsets of the data were analyzed to assess the profitability of the triazole fungicide and the strobilurin-containing fungicides separately in no-disease versus diseased experiments. From the results, it was concluded that, with routine fungicide application based solely on wheat growth stage, total fungicide application costs had to be <$24.71 ha–1 ($10 acre–1) in order to average a ≥50% probability of breaking even or making a profit (compared with not spraying). By contrast, if fungicides were applied when fungal disease was present, total application costs of ≤$47 ha–1 ($19 acre–1) for strobilurins and ≤$72 ha–1 ($29 acre–1) for propiconazole alone were associated with a ≥50% probability of breaking even or making a profit at a wheat price of $184 Mg–1. The results do not support the application of strobilurin or triazole fungicides to mid-Atlantic wheat crops for “plant health” in the absence of disease. Rather, they support basing the decision to apply fungicide on observation of disease, if an economic return for the input is desired.

scholarly journals Selectivity of pre-and post-emergence herbicides to very-early maturing soybean cultivars

2019 ◽  
Vol 9 (4) ◽  
pp. 649-658 ◽  
Author(s):  
Felipe Guilherme Ferreira Fornazza ◽  
Jamil Constantin ◽  
Fellipe Goulart Machado ◽  
Rubem Silvério de Oliveira Jr. ◽  
Gustavo Delabio Da Silva ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Herbicide Application ◽  
Short Cycle ◽  
Soybean Cultivars ◽  
Combined Use ◽  
Early Maturing ◽  
Chlorimuron Ethyl ◽  
Soybean Plants

The combination of pre- and post-emergence herbicides may affect their selectivity to soybean plants, especially to short-cycle cultivars. The objective of this work was to evaluate the selectivity of pre- and post-emergence herbicides to very-early maturing soybean cultivars. Two field experiments were conducted, one in Mandaguaçu, Paraná (E1) and other in Rio Verde, Goiás (E2), Brazil, using a 4×7 factorial arrangement. The treatments consisted of four pre-emergence herbicide managements (S-metolachlor at 1440 g ha-1, diclosulam at 25.2 g ha-1, sulfentrazone at 300 g ha-1, and no herbicide application); and seven post-emergence herbicide managements (lactofen at 120 g ha-1, chlorimuron-ethyl at 12.5 g ha-1, bentazon at 720 g ha-1, lactofen at 120 g ha-1 + chlorimuron-ethyl at 12.5 g ha-1, glyphosate at 900 g a. e. ha-1, two sequential glyphosate applications at 720 g a. e. ha-1 each, and no herbicide application). The early-maturing soybean cultivars evaluated showed sensitivity to the herbicides used. The combined use of pre- and post-emergence herbicides increased the occurrence of injuries in the plants. Diclosulam and sulfentrazone were the least selective pre-emergence herbicides. All herbicide combinations used affected soybean grain yield in E1; lactofen, chlorimuron, and bentazon presented the least selectivity in E2.

scholarly journals Toxin Production in Soybean (Glycine max L.) Plants with Charcoal Rot Disease and by Macrophomina phaseolina, the Fungus that Causes the Disease

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 645 ◽  
Author(s):  
Hamed K. Abbas ◽  
Nacer Bellaloui ◽  
Cesare Accinelli ◽  
James R. Smith ◽  
W. Thomas Shier
Keyword(s):  
Culture Media ◽  
Leaf Disc ◽  
Toxin Production ◽  
Macrophomina Phaseolina ◽  
Economic Losses ◽  
Limit Of Quantification ◽  
Charcoal Rot ◽  
Wide Range ◽  
Soybean Plants ◽  
Rot Disease

Charcoal rot disease, caused by the fungus Macrophomina phaseolina, results in major economic losses in soybean production in southern USA. M. phaseolina has been proposed to use the toxin (-)-botryodiplodin in its root infection mechanism to create a necrotic zone in root tissue through which fungal hyphae can readily enter the plant. The majority (51.4%) of M. phaseolina isolates from plants with charcoal rot disease produced a wide range of (-)-botryodiplodin concentrations in a culture medium (0.14–6.11 µg/mL), 37.8% produced traces below the limit of quantification (0.01 µg/mL), and 10.8% produced no detectable (-)-botryodiplodin. Some culture media with traces or no (-)-botryodiplodin were nevertheless strongly phytotoxic in soybean leaf disc cultures, consistent with the production of another unidentified toxin(s). Widely ranging (-)-botryodiplodin levels (traces to 3.14 µg/g) were also observed in the roots, but not in the aerial parts, of soybean plants naturally infected with charcoal rot disease. This is the first report of (-)-botryodiplodin in plant tissues naturally infected with charcoal rot disease. No phaseolinone was detected in M. phaseolina culture media or naturally infected soybean tissues. These results are consistent with (-)-botryodiplodin playing a role in the pathology of some, but not all, M. phaseolina isolates from soybeans with charcoal rot disease in southern USA.

scholarly journals Effect of Nitrogen Fertilisation and Inoculation with Bradyrhizobium japonicum on the Fatty Acid Profile of Soybean (Glycine max (L.) Merrill) Seeds

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 941
Author(s):  
Ewa Szpunar-Krok ◽  
Anna Wondołowska-Grabowska ◽  
Dorota Bobrecka-Jamro ◽  
Marta Jańczak-Pieniążek ◽  
Andrzej Kotecki ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Bradyrhizobium Japonicum ◽  
Field Experiments ◽  
Fatty Acid Content ◽  
Soybean Seeds ◽  
Oilseed Crop ◽  
Soybean Cultivars

Soybean is a valuable protein and oilseed crop ranked among the most significant of the major crops. Field experiments were carried out in 2016–2019 in South-East Poland. The influence of soybean cultivars (Aldana, Annushka), nitrogen fertilizer (0, 30, 60 kg∙ha−1 N) and inoculation with B. japonicum (control, HiStick® Soy, Nitragina) on the content of fatty acids (FA) in soybean seeds was investigated in a three-factorial experiment. This study confirms the genetic determinants of fatty acid composition in soybean seeds and their differential accumulation levels for C16:0, C16:1, C18:1n9, C18:2, C18:3, and C20:0 as well saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Increasing the rate from 30 to 60 kg ha−1 N did not produce the expected changes, suggesting the use of only a “starter” rate of 30 kg ha−1 N. Inoculation of soybean seeds with a strain of Bradyrhizobium japonicum (HiStick® Soy, BASF, Littlehampton, UK and Nitragina, Institute of Soil Science and Plant Cultivation–State Research Institute, Puławy, Poland) is recommended as it will cause a decrease in SFA and C16:0 acid levels. This is considered nutritionally beneficial as its contribution to total fatty acids determines the hypercholesterolemic index, and it is the third most accumulated fatty acid in soybean seeds. The interaction of cultivars and inoculation formulation on fatty acid content of soybean seeds was demonstrated. An increase in the value of C16:0 content resulted in a decrease in the accumulation of C18:1, C18:2, and C18:3 acids. The content of each decreased by almost one unit for every 1% increase in C16:0 content. The dominant effect of weather conditions on the FA profile and C18:2n6/C18:3n3 ratio was demonstrated. This suggests a need for further evaluation of the genetic progress of soybean cultivars with respect to fatty acid composition and content under varying habitat conditions.

scholarly journals Delayed Senescence in Soybean: Terminology, Research Update, and Survey Results from Growers

2016 ◽  
Vol 17 (2) ◽  
pp. 76-83 ◽  
Author(s):  
C. J. Harbach ◽  
T. W. Allen ◽  
C. R. Bowen ◽  
J. A. Davis ◽  
C. B. Hill ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Biotic Factors ◽  
Delayed Senescence ◽  
Plant Parts ◽  
Whole Plant ◽  
Research Findings ◽  
Survey Results ◽  
Soybean Plants ◽  
Grower Survey ◽  
Specific Symptoms

The terms used to describe symptoms of delayed senescence in soybean often are used inconsistently or interchangeably and do not adequately distinguish the observed symptoms in the field. Various causes have been proposed to explain the development of delayed senescence symptoms. In this article, we review published reports on delayed senescence symptoms in soybean, summarize current research findings, provide examples of terms related to specific symptoms, and present an overview of the results of a multi-state survey directed to soybean growers to understand their concerns about delayed soybean senescence. Some of these terms, such as green bean syndrome and green stem syndrome, describe symptoms induced by biotic factors, while other terms describe symptoms associated with abiotic factors. Some delayed senescence terms involve the whole plant remaining green while other terms include just the stem and other plant parts such as pods. In the grower survey, 77% reported observing soybean plants or plant parts that remained green after most plants in the field were fully mature with ripe seed. Most respondents attributed these symptoms to changes in breeding and choice of cultivars. At the end of this article, we standardized the terms used to describe delayed senescence in soybean. Accepted for publication 23 March 2016. Published 15 April 2016.

scholarly journals Stalk Rot Fungi Affect Leaf Greenness (SPAD) of Grain Sorghum in a Genotype- and Growth-Stage-Specific Manner

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2062-2068 ◽  
Author(s):  
Y. M. A. Y. Bandara ◽  
D. K. Weerasooriya ◽  
T. T. Tesso ◽  
C. R. Little
Keyword(s):  
Field Experiments ◽  
Developmental Stages ◽  
Macrophomina Phaseolina ◽  
Remarkable Feature ◽  
Physiological Maturity ◽  
Stalk Rot ◽  
The Difference ◽  
Total Seed ◽  
Disease Pressure ◽  
Spad Readings

Stalk rots are among the most prevalent and destructive sorghum diseases worldwide. Although experimental evidence is limited, delayed postflowering senescence due to the staygreen trait is accepted as a physiological means of stalk rot resistance. Staygreen has been shown to be correlated with chlorophyll content (as measured by a soil and plant analytical development [SPAD] meter). Field experiments were conducted to test the effects of Fusarium stalk rot and charcoal rot on SPAD readings at three developmental stages, to test whether staygreen genotypes are more resilient to stalk-rot-mediated chlorophyll degradation, and to examine the relationships between SPAD and stalk rot resistance and tolerance when plants were inoculated with causal organisms. Staygreen and nonstaygreen lines (two) and hybrids (two) established in the field were inoculated with Fusarium thapsinum, F. proliferatum, F. andiyazi, and Macrophomina phaseolina at 14 days after flowering. SPAD readings were obtained at soft-dough, hard-dough, and physiological maturity. Most pathogens significantly reduced the SPAD of the genotypes over the mock-inoculated control at three developmental stages. The stalk-rot-resistant and staygreen check line, SC599, showed a remarkable feature of negative senescence from soft dough to physiological maturity under disease pressure. Disease severity was significantly and negatively correlated with SPAD at all developmental stages, revealing the potential impact of the staygreen trait on stalk rot resistance. The difference between control and pathogen-treated total seed weight per panicle (i.e., tolerance) was significantly and positively correlated with the difference between control and pathogen-treated SPAD at physiological maturity, demonstrating the ability of staygreen trait to enhance stalk rot tolerance under disease pressure.

scholarly journals Effects of Integrating Cultivar Resistance and Fungicide Application on Fusarium Head Blight and Deoxynivalenol in Winter Wheat

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 554-560 ◽  
Author(s):  
Stephen N. Wegulo ◽  
William W. Bockus ◽  
John Hernandez Nopsa ◽  
Erick D. De Wolf ◽  
Kent M. Eskridge ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
Economic Losses ◽  
Cultivar Resistance ◽  
Head Blight ◽  
Resistant Cultivars ◽  
Fungicide Application ◽  
Fungicide Efficacy ◽  
Moderately Resistant

Fusarium head blight (FHB) or scab, incited by Fusarium graminearum, can cause significant economic losses in small grain production. Five field experiments were conducted from 2007 to 2009 to determine the effects on FHB and the associated mycotoxin deoxynivalenol (DON) of integrating winter wheat cultivar resistance and fungicide application. Other variables measured were yield and the percentage of Fusarium-damaged kernels (FDK). The fungicides prothioconazole + tebuconazole (formulated as Prosaro 421 SC) were applied at the rate of 0.475 liters/ha, or not applied, to three cultivars (experiments 1 to 3) or six cultivars (experiments 4 and 5) differing in their levels of resistance to FHB and DON accumulation. The effect of cultivar on FHB index was highly significant (P < 0.0001) in all five experiments. Under the highest FHB intensity and no fungicide application, the moderately resistant cultivars Harry, Heyne, Roane, and Truman had less severe FHB than the susceptible cultivars 2137, Jagalene, Overley, and Tomahawk (indices of 30 to 46% and 78 to 99%, respectively). Percent fungicide efficacy in reducing index and DON was greater in moderately resistant than in susceptible cultivars. Yield was negatively correlated with index, with FDK, and with DON, whereas index was positively correlated with FDK and with DON, and FDK and DON were positively correlated. Correlation between index and DON, index and FDK, and FDK and DON was stronger in susceptible than in moderately resistant cultivars, whereas the negative correlation between yield and FDK and yield and DON was stronger in moderately resistant than in susceptible cultivars. Overall, the strongest correlation was between index and DON (0.74 ≤ R ≤ 0.88, P ≤ 0.05). The results from this study indicate that fungicide efficacy in reducing FHB and DON was greater in moderately resistant cultivars than in susceptible ones. This shows that integrating cultivar resistance with fungicide application can be an effective strategy for management of FHB and DON in winter wheat.

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