Greenhouse Data suggest that Growth Stage Impacts Phomopsis Stem Canker Severity Associated with Diaporthe gulyae on Sunflower (Helianthus annuus L.)

2021 ◽  
Author(s):  
Renan Guidini ◽  
Nathan Braun ◽  
Mammen Korah ◽  
Laura Marek ◽  
Febina Mathew
Keyword(s):  
Helianthus Annuus ◽  
Disease Severity ◽  
Growth Stage ◽  
Rating Scale ◽  
Stem Canker ◽  
Growth Stages ◽  
Post Inoculation ◽  
Resistance Response ◽  
Helianthus Annuus L ◽  
The Impact

Diaporthe gulyae Shivas et al. was initially described as causing Phomopsis stem canker of sunflower (Helianthus annuus L.) in the U.S. in 2010. In this study, the impact of growth stage on disease severity associated with D. gulyae in cultivated accessions was investigated. One hundred thirty-nine accessions were inoculated with a single isolate of D. gulyae using the mycelium contact inoculation method at V4-V6 (four to six true leaves) and R4-R6 (inflorescence to ray flower wilting) growth stages in the greenhouse. The experiment was conducted in a completely randomized design with six replications and repeated once. Disease severity was assessed at 14 days post-inoculation using a 0-to-5 rating scale. A significant interaction between growth stage and accessions (p<0.0001) was observed for disease severity [relative treatment effect (RTE)] caused by D. gulyae. Among the 139 accessions, 24, three, and two accessions had significantly lower RTE at V4-V6, R4-R6, and both growth stages respectively, based on 95% confidence intervals, when compared to the inbred susceptible check ‘HA 288’. This study suggests that accessions differ in their susceptibility to D. gulyae possibly because of changes in resistance response during host development. Future studies on sunflower-D. gulyae interaction are warranted for developing commercial hybrids with resistance to the causal fungus.

Dwarf sunflower response to row spacing, stand reduction, and defoliation at different growth stages

2003 ◽  
Vol 83 (2) ◽  
pp. 319-326 ◽  
Author(s):  
B. L. Johnson
Keyword(s):  
Helianthus Annuus ◽  
Oil Content ◽  
Growth Stage ◽  
Total Yield ◽  
Reciprocal Relationship ◽  
Yield Response ◽  
Yield Reduction ◽  
Row Spacing ◽  
Growth Stages ◽  
Helianthus Annuus L

Growth compensation of dwarf sunflower (Helianthus annuus L.) hybrids to low initial stands, later stand losses, or plant defoliation has not been reported regarding replanting decisions and crop insurance yield loss assessment. Three experiments were conducted to study the affect of stand reduction, defoliation, and row spacing on dwarf sunflower yield and quality when grown in eastern North Dakota. Experiment 1 evaluated stand reduction (0, 25, 50 and 75%) applied at growth stages (V4, R1 and R6) in 15, 45 and 76 cm spaced rows. Row spacing interactions with stand reduction and growth stage were not significant for yield indicating growth stage and stand reduction effects on yield response were independent of row spacing. In exp. 2, significant growth stage (V4, V8, R1, R2, R3, R5 and R6) by stand reduction (0, 12, 25, 37, 50, 62 and 75%) interaction showed stand reduction at vegetative growth stages not influencing yield, but as maturity progressed yield reductions became greater with increased stand reduction. Achene weight increased with increasing stand reduction at vegetative and early reproductive stages. A reciprocal relationship was noted between achene weight and achene oil content where oil content decreased as achene weight increased. Interaction of growth stage (R1 and R6) and defoliation (0, 25, 50, 75 and 100%) in exp. 3 indicated greater reduction in yield, test weight, 1000-achene weight, and achene oil conte nt as defoliatin increased at growth stage R6. Yield compensating ability of dwarf sunflower is dependent on type and level of damage and growth stage of occurrence, with total yield reduction considering all effects. Key words: Sunflower, Helianthus annuus L., row spacing, stand reduction, defoliation

scholarly journals Camptocormia in patients with multiple system atrophy at different disease durations: frequency and related factors

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ling Yu Zhang ◽  
Bei Cao ◽  
Qian-Qian Wei ◽  
Ru Wei Ou ◽  
Bi Zhao ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Disease Severity ◽  
Disease Duration ◽  
Rating Scale ◽  
Cox Regression ◽  
Age Of Onset ◽  
Older Age ◽  
Related Factors ◽  
Cox Regression Analysis ◽  
The Impact

Abstract Background Camptocormia is common in patients with multiple system atrophy (MSA). The current study was aimed at assessing the frequency of camptocormia and its related factors in MSA patients with different disease durations. Also, the impact of camptocormia on disability was evaluated. Methods A total of 716 patients were enrolled in the study. They were classified into three groups based on disease duration (≤ 3, 3–5, ≥ 5 years). Specific scales were used to evaluate the motor and non-motor symptoms. Disease severity was assessed using the Unified Multiple System Atrophy Rating Scale (UMSARS). The binary logistic regression model was used to explore the factors related to camptocormia. To analyze the impact of camptocormia on disability in patients with disease duration less than 5 years, propensity score matching (PSM) and stratified Cox regression analysis were used. Results In the current study, we found that the frequency of camptocormia was 8.9, 19.7 and 19.2% when the disease duration was ≤3, 3–5, ≥ 5 years, respectively. In the disease duration ≤3 years group, we found that MSA-parkinsonian subtype (MSA-P) (OR = 2.043, P = 0.043), higher total UMSARS score (OR = 1.063, P < 0.001), older age of onset (OR = 1.047, P = 0.042), and lower score on the frontal assessment battery (FAB) (OR = 0.899, P = 0.046) were associated with camptocormia. Only greater disease severity was associated with camptocormia in the group of patients with disease duration 3–5 years (OR = 1.494, P = 0.025) and in the group of patients with disease duration ≥5 years (OR = 1.076, P = 0.005). There was no significant impact of camptocormia on disability in patients with a disease duration of < 5 years (HR = 0.687, P = 0.463). Conclusion The frequency of camptocormia increased with prolonged disease duration. Disease severity was related to camptocormia at different stages of the disease. The MSA-P subtype, older age of onset, and lower FAB score were associated with camptocormia in the early stage of the disease.

scholarly journals Biological Control of the Weedy Plant (Rumex crispus) at the Seedling Growth Stage by the Green Dock Beetle (Gastrophysa viridula)

2019 ◽  
Vol 28 (1) ◽  
pp. 21-31
Author(s):  
Khalid S. Alshallash Khalid S. Alshallash
Keyword(s):  
Biological Control ◽  
Seedling Growth ◽  
Growth Stage ◽  
Biological Control Agent ◽  
Dry Weight ◽  
Control Agent ◽  
Growth Stages ◽  
Rumex Crispus ◽  
Shoot Number ◽  
The Impact

In four glasshouse experiments, the effectiveness of the adult green dock beetle Gastrophysa viridula (Coleoptera: Chrysomelidae), at the effective number of applied individuals, for use as a biological control agent of curled dock, Rumex crispus (Polygonaceae) were studied. The feeding of the beetle was investigated at four different numbers of beetle (0, 1, 2, 3) and at four seedling growth stages of the plant, defined by the average of leaf area per plant (1-1.22 , 2-4.45, 3-11.56, and 4-71.52 cm2/plant). Grazing by one, two or three dock beetles did not result in a significant reduction in dock dry weight or shoot numbers at the youngest growth stage. However, both at later seedling growth stages were significantly affected (P ? 0.0001), at any beetles number. The increase of beetle numbers caused nonsignificant increased effect, in some trials, confirming the impact of a single beetle. Three months after beetle grazing, dock seedlings of first, second and third growth stages were not able to regrow, however, some plants at the 4th growth stage, re-emerged. This suggested that the highest effect of beetle's feeding occurs on the early seedling stages. Statistical analysis showed a positive correlation (0.77) between dry weight and shoot number at all the four seedling growth stages, thus confirming the impact of the beetle on both the dry weight and shoot numbers. Combining beetle grazing with other control methods at older dock seedling stages could, therefore, provide better suppression

scholarly journals Evaluation of Rice Responses to the Blast Fungus Magnaporthe oryzae at Different Growth Stages

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Xinglong Chen ◽  
Yulin Jia ◽  
Bo Ming Wu
Keyword(s):  
Disease Severity ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Stage ◽  
Disease Index ◽  
Blast Disease ◽  
Growth Stages ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Different Growth Stages

Rice blast, caused by the fungus Magnaporthe oryzae, is the most damaging disease for rice worldwide. However, the reactions of rice to M. oryzae at different growth stages are largely unknown. In the present study, two temperate japonica rice cultivars, M-202 and Nipponbare, were inoculated synchronously at different vegetative growth stages, V1 to V10. Plants of M-202 at each stage from V1 to reproductive stage R8 were inoculated with M. oryzae race (isolate) IB-49 (ZN61) under controlled conditions. Disease reactions were recorded 7 days postinoculation by measuring the percentage of diseased area of all leaves, excluding the youngest leaf. The results showed that the plants were significantly susceptible at the V1 to V4 stages with a disease severity of 26.7 to 46.8% and disease index of 18.62 to 37.76 for M-202. At the V1 to V2 stages, the plants were significantly susceptible with a disease a severity of 28.6 to 39.3% and disease index of 23.65 to 29.82 for Nipponbare. Similar results were observed when plants of M-202 were inoculated at each growth stage with a disease severity of 29.7 to 60.6% and disease index of 21.93 to 59.25 from V1 to V4. Susceptibility decreased after the V5 stage (severity 4.6% and index 2.17) and became completely resistant at the V9 to V10 stages and after the reproductive stages, suggesting that plants have enhanced disease resistance at later growth stages. These findings are useful for managing rice blast disease in commercial rice production worldwide.

SIMULATION OF LEAF DAMAGE BY ARTIFICIAL DEFOLIATION AND ITS EFFECT ON SUNFLOWER (Helianthus annuus L.) PERFORMANCE / SIMULACION DEL DAÑO DE HOJA POR LA ELIMINACION ARTIFICIAL DE HOJAS Y SU EFECTO SOBRE LAS PERFORMANCES DEL GIRASOL / SIMULATION DE DÉTÉRIORIATION DES FEUILLES CAUSÉE PAR DEFOLIATION ARTIFICIELLE ET SON EFFET SUR LE TOURNESOL (Helianthus annuus L.)

Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 145-154
Author(s):  
M.A. Khan Shafiullah ◽  
M.A. Poswal ◽  
M.A. Rana ◽  
M.A. Baitullah
Keyword(s):  
Helianthus Annuus ◽  
Seed Yield ◽  
Agricultural Research ◽  
Leaf Damage ◽  
Yield Reduction ◽  
Atmospheric Conditions ◽  
Foliar Diseases ◽  
Yield Decline ◽  
Helianthus Annuus L ◽  
The Impact

SUMMARY Sunflower (Helianthus annuus L.) hybrid NK-212 was planted at National Agricultural Research Center, Islamabad, during 1992 and 1993 to assess the impact of various levels of simulated leaf damage, commonly caused by insects, hail or foliar diseases, on source and sink relationship. Insect attack, hail and foliar diseases often partially defoliate sunflowers and may become important factors limiting the production. Reduction in leaf area may also occur in the field as a consequence of pathogens or atmospheric conditions. Artificial defoliation was chosen as an experimental means to assess its effect on seed yield and plant behavior. It had also made possible to evaluate the effect of such a reduction at different phenological stages and to identify the leaves that contribute greatly to the seed yield. The leaves were clipped in various proportions from different parts of the plant, i.e., lower, middle and upper. The removal of upper 2/3 and 1/2 leaves caused a yield reduction of 29 and 55.8%, in 1992 and 37 and 44.8%, in 1993, respectively. In 1992, about 1% yield decline was recorded when the lower 1/3 leaves were removed and 6% yield decline with the removal of the lower 1/2 leaves. In 1993, the yield reduction was 26.7 and 39.2% due to removal of lower 1/3 and 1/2 leaves, respectively. This indicated that the upper leaves (source) contribute more towards seed yield (sink) than the lower ones. Correspondingly, the results indicated that insects and pests feeding on the upper portion of the sunflower plant can cause larger reduction in seed yield than those feeding on the lower leaves.

Effects of Low-Dose Flumioxazin and Metribuzin Postemergence Applications on Soybean

2018 ◽  
Vol 33 (1) ◽  
pp. 87-94
Author(s):  
Daniel O. Stephenson ◽  
Todd A. Spivey ◽  
Michael A. Deliberto ◽  
David C. Blouin ◽  
Brandi C. Woolam ◽  
...  
Keyword(s):  
Growth Stage ◽  
Low Dose ◽  
Yield Loss ◽  
Economic Loss ◽  
Growth Stages ◽  
Post Injury ◽  
Width Reduction ◽  
The Impact

AbstractAll herbicides will move off-target to sensitive crops when not applied correctly. Therefore, low-dose applications of flumioxazin and metribuzin were evaluated in soybean at the unifoliate, V2, and V4 growth stages. Rates evaluated were 12.5%, 25%, and 50% of the labeled use rates of 72 and 316 g ai ha−1 of flumioxazin and metribuzin, respectively. Flumioxazin injury was characterized by necrosis and visible height and width reduction. Injury increased with rate 3 d after treatment (DAT), with unifoliate, V2, and V4 soybean injured 15% to 30%, 18% to 27%, and 5% to 8%, respectively. Unifoliate and V4 soybean were injured more than V4 soybean 3 to 14 DAT, but injury decreased to <5% by 42 DAT. Soybean yields in the flumioxazin study were 92% to 96% of the nontreated, resulting in a yield loss of 196 to 393 kg ha−1 and a revenue loss of 71 to 141 US$ ha−1. Metribuzin injury was primarily chlorosis with necrosis and a visible reduction in soybean height and width. Soybean at the V2 growth stage was injured 14% more than V4 soybean 3 DAT, regardless of metribuzin rate. Injury to V2 and V4 soybean was similar 14 DAT, with injury of 21% to 40% across rates. Soybean injury when treated at the V2 and V4 growth stages was 6% to 29% 42 DAT compared to unifoliate soybean at 0 to 17%. Soybean yields in the metribuzin study yields were 96% to 98% of the nontreated. However, a 2% to 4% reduction equates to a loss of 90 to 180 kg ha−1 and a revenue loss of 32 to 65 US$ ha−1. Unifoliate and V2 soybean are more sensitive to a low dose of flumioxazin POST, and V2 and V4 soybean are more sensitive to a low dose of metribuzin POST. Injury and the impact on soybean growth could potentially cause economic loss for a soybean producer.

scholarly journals Determination of Growth Stage-Specific Crop Coefficients (Kc) of Sunflowers (Helianthus annuus L.) under Salt Stress

Water ◽  
2017 ◽  
Vol 9 (3) ◽  
pp. 215 ◽  
Author(s):  
Minghai Hong ◽  
Wenzhi Zeng ◽  
Tao Ma ◽  
Guoqing Lei ◽  
Yuanyuan Zha ◽  
...  
Keyword(s):  
Salt Stress ◽  
Helianthus Annuus ◽  
Growth Stage ◽  
Helianthus Annuus L ◽  
Crop Coefficients

scholarly journals The Infection Processes of Sclerotinia sclerotiorum in Basal Stem Tissue of a Susceptible Genotype of Helianthus annuus L.

2012 ◽  
Vol 40 (1) ◽  
pp. 143 ◽  
Author(s):  
Robab DAVAR ◽  
Reza DARVISHZADEH ◽  
Ahmad MAJD ◽  
Ardashir KHARABIAN MASOULEH ◽  
Yobert GHOSTA
Keyword(s):  
Helianthus Annuus ◽  
Sclerotinia Sclerotiorum ◽  
Host Cells ◽  
Post Inoculation ◽  
Plant Surface ◽  
Susceptible Genotype ◽  
Helianthus Annuus L ◽  
Fungal Hyphae ◽  
Infection Processes ◽  
Host Tissues

Sunflower, Helianthus annuus L., is a major oil seed crop widely cultivated throughout the globe. White mold, caused by necrotrophic pathogen Sclerotinia sclerotiorum (Lib.) de Bary, is a common and widespread pathogen of sunflower. The infection process of S. sclerotiorum was studied in the stem base of infected host tissues by light microscopy and Hemi-thin sectioning techniques. Host-pathogen interactions were examined at the plant surface and cellular level of a susceptible genotype (C146), 12, 24 and 48 h of post inoculation. The results showed that the appressoria were formed and the hyphal strands branched upon contact of pathogen with the host surface. Moreover a direct penetration of fungal hyphae was observed through the cuticle within 12h of inoculation. Microscopic observation of inoculated tissues after 24 hours revealed that fungal hyphae have developed both inter- and intra-cellular layer. Moreover, the fungal hyphae growth was incremental among and inside the host cells. The host cells were completely colonized by fungal mycelium 48 hour after inoculation, leading to a tissue collapse. The hyphae invaded the dead host tissues and emerged from the host tissue after extensive colonization. The present study has detailed the infection processes and pathogen development both at plant surface and inside the host tissues. The results of this study will be useful for engineering of disease-resistant genotypes and development of markers for screening pathogen resistance individuals.

scholarly journals Growth-Dependent Stable Carbon Isotope Fractionation by Basidiomycete Fungi: δ13C Pattern and Physiological Process

2002 ◽  
Vol 68 (10) ◽  
pp. 4956-4964 ◽  
Author(s):  
Matthew R. Henn ◽  
Gerd Gleixner ◽  
Ignacio H. Chapela
Keyword(s):  
Growth Medium ◽  
Fungal Biomass ◽  
Growth Stage ◽  
Stable Carbon Isotope ◽  
Axenic Culture ◽  
Growth Stages ◽  
Second Phase ◽  
C Isotopes ◽  
Low Concentrations ◽  
The Impact

ABSTRACT We grew 11 basidiomycetes in axenic culture to characterize their physiological capacities to fractionate stable C isotopes. Generally, δ13C values of the fungal biomass were (i) enriched in 13C relative to the growth medium, (ii) variable among the isolates, and (iii) dependent on the growth rate and growth stage of the fungi. We found a multiphasic dynamic of fractionation for Cryptoporus volvatus and Marasmius androsaceus during various growth stages. The first phase, P1, corresponded to the exponential growth stage and was characterized by an increasing enrichment in 13C content of the fungal biomass relative to the growth medium ranging between 4.6 and 6.9‰. The second phase, P2, exhibited a continual depletion in 13C of the fungal biomass, with the δ13C values of the fungal biomass asymptotically returning to the δ13C value of the growth medium at inoculation. The expression of the various fractionation phases was dependent on the amount of low-concentration micronutrients and growth factors added to the growth medium. The onset of P2 occurred at reduced concentrations of these elements. All of the sugars in the growth medium (sucrose, maltose, and glucose) were utilized for growth, indicating that the observed fractionation was not an artifact derived from the preferential use of 13C-rich maltose, which was found at low concentrations in the growth medium. In this study, we establish a framework with which to explore the impact of physiological fractionations by fungal interfaces on natural distributions of stable C isotopes.

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