Silicon and manganese on rice resistance to blast

Blast, caused by the fungus Pyricularia oryzae, is the most important fungal disease of rice. The effect of silicon (Si) and manganese (Mn), and their interaction, on rice resistance to blast was investigated. Rice plants (cultivar "Metica 1") were grown in hydroponic solution with 0 or 2 mmol L-1 of Si and with 0.5, 2.5, and 10 mmol L-1 of Mn. Sixty-day-old plants were inoculated with a conidial suspension of P. oryzae and the incubation period (IP), the number of lesions (NL) per cm² of leaf area, the lesion size (LS), and blast severity were evaluated. Blast severity was scored at 48, 72, 96, and 144 hours after inoculation and data were used to obtain the area under blast progress curve (AUBPC). Silicon concentration was significantly higher in leaf tissues of plants supplied with this element than on its absence, regardless of Mn rates. There was no significant difference in Si concentration among the Mn rates for both - Si and +Si treatments. The Mn concentration was significantly higher in the tissues of plants from the - Si treatment as compared to plants of the +Si treatment, but only at the rate of 10 mmol L-1 of Mn. There was a significant increase in Mn concentration as the rates of this micronutrient increased from 0.5 to 10 mmol L-1 regardless of the Si treatments. The IP significantly increased in the +Si treatment. The Mn rates had no effect on the IP regardless of the Si treatments. The NL was significantly lower in the presence of Si regardless of the Mn rates. The Mn rates had no effect on NL regardless of the Si treatments. The addition of Si to the nutrient solution significantly reduced both LS and AUBPC regardless of Mn rates. However, in the absence of Si, the values for LS and AUBPC were significantly lower at the Mn rate of 10 µmol L-1 as compared to the rate of 0.5 µmol L-1. Overall, the results from this study showed the potential of Si to decrease blast development on rice regardless of the foliar concentration of Mn.

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Comparative Performance of Sanitizers in Managing Plant-to-plant Transfer and Postharvest Infection of Calonectria pseudonaviculata and Pseudonectria foliicola on Boxwood

Plant Disease ◽

10.1094/pdis-03-21-0481-re ◽

2021 ◽

Author(s):

Ravi Bika ◽

Warren Copes ◽

Fulya Baysal-Gurel

Keyword(s):

Shelf Life ◽

Disease Severity ◽

Ammonium Compound ◽

Conidial Suspension ◽

Rooted Cuttings ◽

Disease Progress ◽

Progress Curve ◽

Significant Difference ◽

Plant Transfer ◽

Blight Disease

Calonectria pseudonaviculata and Pseudonectria foliicola causing the infamous ‘boxwood blight’ and ‘Volutella blight’, respectively, are a constant threat to the boxwood production and cut boxwood greenery market. Both pathogens cause significant economic loss to all parties (growers, retailer, and customers) in the horticultural chain. The objective of this study was to evaluate efficacy of disinfesting chemicals [quaternary ammonium compound (QAC), peroxy, acid, alcohol, chlorine, cleaner] in preventing plant-to-plant transfer of C. pseudonaviculata and P. foliicola via cutting tools, as well as reduction of postharvest boxwood blight and Volutella blight disease severity in harvested boxwood greenery. First, an in vitro study was conducted to select products and doses that completely or near-completely inhibited conidial germination of C. pseudonaviculata and P. foliicola. The selected treatments were also tested for their ability to reduce plant-to-plant transfer of C. pseudonaviculata and P. foliicola and manage postharvest boxwood blight and Volutella blight in boxwood cuttings. For the plant-to-plant transfer study, Felco 19 shears were used as a tool for mechanical transfer of fungal conidia. The blades of Felco 19 shears were exposed to a conidial suspension of C. pseudonaviculata or P. foliicola by cutting a 1 cm diameter cotton roll that had been dipped into a fungal suspension. Disease-free boxwood rooted cuttings (10 cm height) were pruned with the contaminated shears. The Felco 19 shears were equipped with a mounted miniature sprayer connected to a pressurized reservoir of treatment solution that automatically sprayed the blade and plant surface while cutting. The influence of accumulated sap on the shear blade was studied through 1- or 10-cut pruning variable on test plants and screened for the efficacy of treatments. Then, the boxwood rooted cuttings were transplanted and incubated in room conditions (21 °C, 60% RH) with 12 h of fluorescent light; data evaluation on disease severity was done weekly for a month. Disease progress [area under disease progress curve (AUDPC)] was calculated. In another study, postharvest dip application treatments were used for the management of postharvest boxwood blight or Volutella blight on boxwood cuttings. The harvested boxwood cuttings were inoculated with a conidial suspension of C. pseudonaviculata or P. foliicola, then dipped into treatment solution 3 days afterwards. The treated boxwood cuttings were kept in room conditions, and boxwood blight or Volutella blight disease severity as well as marketability (postharvest shelf life) assessed every 2 days for 1 week. A significant difference between treatments was observed for reduction of boxwood blight or Volutella blight severity and AUDPC. The treatments (ODD + DoD + DdD + DB)AC [Simple Green D Pro 5], 2 propanol + DDAC (0.12%) [KleenGrow], and DBAC + DEAC [GreenShield] were the most effective in reducing the plant to plant transfer of boxwood blight and Volutella blight when pruned with contaminated Felco 19 shears. In addition to the three effective treatments above, acetic acid (2.5%) [Vinegar], 2-propanol + DDAC (0.06%), sodium hypochlorite (Clorox) and potassium peroxymonosulfate + NaCl (2%) [Virkon] were effective in reducing postharvest boxwood blight whereas DBAC + DBAC [Lysol all-purpose cleaner], ethanol [70% (Ethyl alcohol)] and DDAC +DBAC [Simple Green D Pro 3 plus] were effective in reducing Volutella blight disease severity and AUDPC, and also maintained better quality and longer postharvest shelf life of boxwood cuttings when applied as a dip treatment. The longer postharvest shelf life of boxwood cuttings noted may be attributed to reduced disease severity and AUDPC resulting in healthy boxwood cuttings.

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Effect of Temperature on the Incubation Period and Leaf Colonization in Bacterial Blight of Anthurium

Phytopathology ◽

10.1094/phyto.1999.89.11.1007 ◽

1999 ◽

Vol 89 (11) ◽

pp. 1007-1014 ◽

Cited By ~ 11

Author(s):

R. Fukui ◽

H. Fukui ◽

A. M. Alvarez

Keyword(s):

Linear Relationship ◽

Leaf Area ◽

Incubation Period ◽

Xanthomonas Campestris ◽

Resistant Cultivar ◽

Effect Of Temperature ◽

Susceptible Cultivar ◽

Degree Days ◽

Degree Day ◽

Leaf Tissues

Effect of temperature on leaf colonization in anthurium blight was studied using a bioluminescent strain of Xanthomonas campestris pv. dieffenbachiae. In a susceptible cultivar, colonization of leaf tissues (monitored by detection of bioluminescence) and symptom development (assessed visually) advanced rapidly at higher temperatures. For a susceptible cultivar, there was a linear relationship between degree-days and percent leaf area colonized by the pathogen, indicating that leaf colonization in a susceptible cultivar was a direct function of the cumulative effect of temperature. The degree-day intercept of the regression line represented the time from inoculation to detection of bioluminescence, and the slope indicated the increase of leaf colonization per degree-day. There also was a linear relationship between the logarithm of degree-days and the logarithm of percent leaf area showing visible symptoms in a susceptible cultivar. The degree-day intercept of this relationship represented the incubation period (about 500 degree-days). The degree-days required to detect bioluminescence was not considerably different between susceptible and resistant cultivars. However, the subsequent rates of leaf colonization were significantly lower for a resistant cultivar than for a susceptible cultivar in all temperature regimes. The results suggest that multiplication of the pathogen in the leaf tissues is optimized in the susceptible cultivar. In contrast, in the resistant cultivar, the defense mechanisms overshadow the temperature effect. The differential response to temperatures may be an additional indicator of cultivar susceptibility.

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The Influence of Silicon on Components of Resistance to Blast in Susceptible, Partially Resistant, and Resistant Cultivars of Rice

Phytopathology ◽

10.1094/phyto.2001.91.1.63 ◽

2001 ◽

Vol 91 (1) ◽

pp. 63-69 ◽

Cited By ~ 89

Author(s):

K. W. Seebold ◽

T. A. Kucharek ◽

L. E. Datnoff ◽

F. J. Correa-Victoria ◽

M. A. Marchetti

Keyword(s):

Leaf Area ◽

Incubation Period ◽

Calcium Silicate ◽

Magnaporthe Grisea ◽

Upland Rice ◽

Lesion Size ◽

Diseased Leaf ◽

Infection Efficiency ◽

Components Of Resistance ◽

Diseased Leaf Area

The application of silicon (Si) fertilizers reduces the severity of blast, caused by Magnaporthe grisea, in irrigated and upland rice; however, little research has been conducted to examine the epidemiological and etiological components of this reduction. Four cultivars of rice with differential susceptibilities to race IB-49 of M. grisea were fertilized with three rates of a calcium silicate fertilizer and inoculated with the pathogen to test the effects of Si on the following components of resistance to blast: incubation period, latent period, infection efficiency, lesion size, rate of lesion expansion, sporulation per lesion, and diseased leaf area. For each cultivar, the incubation period was lengthened by increased rates of Si, and the numbers of sporulating lesions, lesion size, rate of lesion expansion, diseased leaf area, and number of spores per lesion were reduced. Lesion size and sporulation per lesion were lowered by 30 to 45%, and the number of sporulating lesions per leaf and diseased leaf area were significantly reduced at the highest rate of Si. The net effect of Si on these components of resistance is an overall reduction in the production of conidia on plants infected with M. grisea, thereby slowing the epidemic rate of blast.

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Effect of root and leaf applications of soluble silicon on blast development in rice

Bragantia ◽

10.1590/brag.2013.032 ◽

2013 ◽

Vol 72 (3) ◽

pp. 304-309 ◽

Cited By ~ 16

Author(s):

Isaias Severino Cacique ◽

Gisele Pereira Domiciano ◽

Wiler Ribas Moreira ◽

Fabrício Ávila Rodrigues ◽

Maria Fernanda Antunes Cruz ◽

...

Keyword(s):

Calcium Silicate ◽

Lesion Size ◽

Fungal Disease ◽

Pyricularia Oryzae ◽

Leaf Epidermis ◽

X Ray ◽

Progress Curve ◽

Leaf Tissues ◽

Rice Leaves ◽

Soluble Silicon

Blast, caused by Pyricularia oryzae, is the most important fungal disease of rice worldwide. This study aimed to compare root and foliar supply of soluble silicon (Si) on rice resistance to blast. The application of soluble Si to the roots increased Si concentration in leaf tissues as compare to plants grown in soil amended with calcium silicate. There was no increase in leaf Si concentration after soluble Si spray, regardless if the leaves were washed or not before analysis. X-ray microanalysis revealed that Si deposition was very similar on the leaf epidermis of plants sprayed with soluble Si, root amended with soluble Si or grown in soil amended with calcium silicate. The lesion size, the number of lesions per cm² of leaf and the area under blast progress curve were reduced for rice plants grown in soil that received the application of soluble Si or was amended with calcium silicate. The results of this study showed that the supply of soluble Si to the roots or its spray onto to the rice leaves can decrease blast symptoms.

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Effect of Host Genotype on Incubation Period, Receptivity, Lesion Diameter, and Leaf Area Damage of Didymella arachidicola on Peanut1

Peanut Science ◽

10.3146/i0095-3679-14-2-10 ◽

1987 ◽

Vol 14 (2) ◽

pp. 90-94

Author(s):

P. Subrahmanyam ◽

D. H. Smith

Keyword(s):

Leaf Area ◽

Incubation Period ◽

Correlation Coefficients ◽

Field Trials ◽

Infected Leaf ◽

Host Genotype ◽

Lesion Diameter ◽

Leaf Tissues ◽

Glasshouse Screening ◽

Disease Epidemics

Abstract The effect of host genotype on incubation period, receptivity, lesion diameter and leaf area damage of Didymella arachidicola on nine peanut (Arachis hypogaea L.) genotypes was investigated under monocyclic infection in the glasshouse. The genotypes, Florunner. P 84/5/256, C 347/5/6, C 346/5/8 and P 105/3/7, resistant to the pathogen in field trials, had a longer incubation period, reduced receptivity, lesion diameter, and percentage leaf area damage, than susceptible genotypes. Among the susceptible genotypes, Tamnut 74 had the shortest incubation period, and highest receptivity, the largest lesion diameter, and percentage leaf area damage. The other susceptible genotypes. Egret, 38/7/20, and P 84/5/112, were intermediate for these variables. Production of pycnidia and pseudothecia of the pathogen could not be demonstrated in infected leaf tissues of any of the genotypes studied. There was significant interaction between plant age and disease development. Younger plants had a shorter incubation period, higher receptivity, larger lesion diameter, and percentage leaf area damage than older plants. Correlation coefficients among incubation period, receptivity, lesion diameter, and leaf area damage were highly significant. The possible role of these variables in disease epidemics and their use in glasshouse screening of peanut germplasm for resistance to D. arachidicola are discussed.

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Irrigation of Geraniums with an Automatic Controlled Water Table System

HortScience ◽

10.21273/hortsci.33.3.522d ◽

1998 ◽

Vol 33 (3) ◽

pp. 522d-522 ◽

Cited By ~ 1

Author(s):

J.W. Buxton ◽

D.L. Ingram ◽

Wenwei Jia

Keyword(s):

Water Potential ◽

Leaf Area ◽

Water Table ◽

Nutrient Solution ◽

Irrigation System ◽

Central Area ◽

Dry Weight ◽

Trickle Irrigation ◽

Run Off ◽

Optimum Water

Geraniums in 15-cm pots were irrigated automatically for 8 weeks with a Controlled Water Table (CWT) irrigation system. Plants were irrigated with a nutrient solution supplied by a capillary mat with one end of the mat suspended in a trough below the bottom of the pot. The nutrient solution remained at a constant level in the trough. Nutrient solution removed from the trough was immediately replaced from a larger reservoir. The vertical distance from the surface of the nutrient solution and the bottom of the pot determined the water/air ratio and water potential in the growing media. Treatments consisted of placing pots at 0, 2, 4, and 6 cm above the nutrient solution. Control plants were irrigated as needed with a trickle irrigation system. Geraniums grown at 0,2 and 4 CWT were ≈25% larger than the control plants and those grown at 6 CWT as measured by dry weight and leaf area. Roots of plants grown at 0 CWT were concentrated in the central area of the root ball; whereas roots of plants in other treatments were located more near the bottom of the pot. Advantages of the CWT system include: Plant controlled automatic irrigation; no run off; optimum water/air ratio.

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Combining Microfractures, Autologous Bone Graft, and Autologous Matrix-Induced Chondrogenesis for the Treatment of Juvenile Osteochondral Talar Lesions

Foot & Ankle International ◽

10.1177/1071100716687367 ◽

2017 ◽

Vol 38 (5) ◽

pp. 485-495 ◽

Cited By ~ 17

Author(s):

Riccardo D’Ambrosi ◽

Camilla Maccario ◽

Chiara Ursino ◽

Nicola Serra ◽

Federico Giuseppe Usuelli

Keyword(s):

Bone Graft ◽

Repeated Measures ◽

Osteochondral Lesion ◽

Young Patients ◽

Case Series ◽

Autologous Bone Graft ◽

Lesion Size ◽

Level Of Evidence ◽

Significant Difference ◽

Autologous Bone

Background: The purpose of this study was to evaluate the clinical and radiologic outcomes of patients younger than 20 years, treated with the arthroscopic-talus autologous matrix-induced chondrogenesis (AT-AMIC) technique and autologous bone graft for osteochondral lesion of the talus (OLT). Methods: Eleven patients under 20 years (range 13.3-20.0) underwent the AT-AMIC procedure and autologous bone graft for OLTs. Patients were evaluated preoperatively (T0) and at 6 (T1), 12 (T2), and 24 (T3) months postoperatively, using the American Orthopaedic Foot & Ankle Society Ankle and Hindfoot (AOFAS) score, the visual analog scale and the SF-12 respectively in its Mental and Physical Component Scores. Radiologic assessment included computed tomographic (CT) scan, magnetic resonance imaging (MRI) and intraoperative measurement of the lesion. A multivariate statistical analysis was performed. Results: Mean lesion size measured during surgery was 1.1 cm3 ± 0.5 cm3. We found a significant difference in clinical and radiologic parameters with analysis of variance for repeated measures ( P < .001). All clinical scores significantly improved ( P < .05) from T0 to T3. Lesion area significantly reduced from 119.1 ± 29.1 mm2 preoperatively to 77.9 ± 15.8 mm2 ( P < .05) at final follow-up as assessed by CT, and from 132.2 ± 31.3 mm2 to 85.3 ± 14.5 mm2 ( P < .05) as assessed by MRI. Moreover, we noted an important correlation between intraoperative size of the lesion and body mass index (BMI) ( P = .011). Conclusions: The technique can be considered safe and effective with early good results in young patients. Moreover, we demonstrated a significant correlation between BMI and lesion size and a significant impact of OLTs on quality of life. Level of Evidence: Level IV, retrospective case series.

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No Difference in Outcomes Following Osteochondral Allograft with Fresh Precut Cores Compared to Hemi-Condylar Allografts

Cartilage ◽

10.1177/19476035211021911 ◽

2021 ◽

pp. 194760352110219

Author(s):

Danielle H. Markus ◽

Anna M. Blaeser ◽

Eoghan T. Hurley ◽

Brian J. Mannino ◽

Kirk A. Campbell ◽

...

Keyword(s):

Patient Reported Outcomes ◽

Knee Injury ◽

Lesion Size ◽

Osteochondral Allograft ◽

Osteochondral Lesions ◽

Radiographic Outcomes ◽

Significant Difference ◽

Patient Reported ◽

The Mean

Objective The purpose of the current study is to evaluate the clinical and radiographic outcomes at early to midterm follow-up between fresh precut cores versus hemi-condylar osteochondral allograft (OCAs) in the treatment of symptomatic osteochondral lesions. Design A retrospective review of patients who underwent an OCA was performed. Patient matching between those with OCA harvested from an allograft condyle/patella or a fresh precut allograft core was performed to generate 2 comparable groups. The cartilage at the graft site was assessed with use of a modified Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system and patient-reported outcomes were collected. Results Overall, 52 total patients who underwent OCA with either fresh precut OCA cores ( n = 26) and hemi-condylar OCA ( n = 26) were pair matched at a mean follow-up of 34.0 months (range 12 months to 99 months). The mean ages were 31.5 ± 10.7 for fresh precut cores and 30.9 ± 9.8 for hemi-condylar ( P = 0.673). Males accounted for 36.4% of the overall cohort, and the mean lesion size for fresh precut OCA core was 19.6 mm2 compared to 21.2 mm2 for whole condyle ( P = 0.178). There was no significant difference in patient-reported outcomes including Visual Analogue Scale, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, and Tegner ( P > 0.5 for each), or in MOCART score (69.2 vs. 68.3, P = 0.93). Conclusions This study found that there was no difference in patient-reported clinical outcomes or MOCART scores following OCA implantation using fresh precut OCA cores or size matched condylar grafts at early to midterm follow-up.

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Photosynthesis of Blueberry Leaves as Affected by Septoria Leaf Spot and Abiotic Leaf Damage

Plant Disease ◽

10.1094/pdis.2004.88.4.397 ◽

2004 ◽

Vol 88 (4) ◽

pp. 397-401 ◽

Cited By ~ 22

Author(s):

I. Roloff ◽

H. Scherm ◽

M. W. van Iersel

Keyword(s):

Leaf Area ◽

Disease Severity ◽

Leaf Spot ◽

Abiotic Factors ◽

Lesion Size ◽

Leaf Conductance ◽

Yield Potential ◽

Leaf Spots ◽

Virtual Lesion ◽

Septoria Leaf Spot

Leaf spots caused by fungal pathogens or abiotic factors can be prevalent on southern blueberries after harvest during the summer and fall, yet little is known about how they affect physiological processes that determine yield potential for the following year. In this study, we measured CO2 assimilation and leaf conductance on field-grown blueberry plants affected by Septoria leaf spot (caused by Septoria albopunctata) or by edema-like abiotic leaf blotching. Net assimilation rate (NAR) on healthy leaves varied between 6.9 and 12.4 μmol m-2 s-1 across cultivars and measurement dates. Infection by S. albopunctata had a significant negative effect on photosynthesis, with NAR decreasing exponentially as disease severity increased (R2 ≥0.726, P < 0.0001). NAR was reduced by approximately one-half at 20% disease severity, and values approached zero for leaves with >50% necrotic leaf area. There was a positive, linear correlation between NAR and leaf conductance (R2 ≥ 0.622, P < 0.0001), suggesting that the disease may have reduced photosynthesis via decreased CO2 diffusion into affected leaves. Estimates of virtual lesion size associated with infection by S. albopunctata ranged from 2.8 to 3.1, indicating that the leaf area in which photosynthesis was impaired was about three times as large as the area covered by necrosis. For leaves afflicted by edema-like damage, there also was a significant negative relationship between NAR and affected leaf area, but the scatter about the regression was more pronounced than in the NAR-disease severity relationships for S. albopunctata (R2 = 0.548, P < 0.0001). No significant correlation was observed between leaf conductance and affected area on these leaves (P = 0.145), and the virtual lesion size associated with abiotic damage was significantly smaller than that caused by S. albopunctata. Adequate carbohydrate supply during the fall is critical for optimal flower bud set in blueberry; therefore, these results document the potential for marked yield losses due to biotic and abiotic leaf spots.

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Nitrogen for growth of stock plants and production of strawberry runner tips

Bragantia ◽

10.1590/s0006-87052012005000027 ◽

2012 ◽

Vol 71 (3) ◽

pp. 394-399 ◽

Cited By ~ 3

Author(s):

Djeimi Isabel Janisch ◽

Jerônimo Luiz Andriolo ◽

Vinícius Toso ◽

Kamila Gabriele Ferreira dos Santos ◽

Jéssica Maronez de Souza

Keyword(s):

Leaf Area ◽

Nutrient Solution ◽

Dry Matter ◽

Nitrogen Concentration ◽

Growth Period ◽

Dry Matter Partitioning ◽

Area Index ◽

Camino Real ◽

Nitrogen Concentrations ◽

Crown Roots

The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control), 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested) were collected weekly and counted during the growth period. The number of leaves, dry matter (DM) of leaves, crown and root, specific leaf area and leaf area index (LAI) was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.

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