scholarly journals Phosphorous acid for controlling Phytophthora taxon Agathis in kauri glasshouse trials

2013 ◽  
Vol 66 ◽  
pp. 242-248 ◽  
Author(s):  
I.J. Horner ◽  
E.G. Hough
Keyword(s):  
Untreated Control ◽  
Foliar Spray ◽  
Phosphorous Acid ◽  
Phytophthora Species ◽  
In Vitro Tests ◽  
Potential Treatment ◽  
Soil Application ◽  
Soil Inoculation ◽  
Trunk Injection

Phytophthora taxon Agathis (PTA) is a serious problem in Auckland and Northland kauri forests Phosphorous acid (phosphite) is a potential treatment for infected or threatened trees In vitro tests on phosphiteamended agar showed that PTA was more sensitive to phosphite than other Phytophthora species commonly controlled by this chemical Before progressing to forest trials phosphite efficacy was tested on PTAinoculated kauri seedlings in the glasshouse Twoyearold kauri seedlings were inoculated with PTA applied directly to trunk wounds or by soil application Phosphite was applied as a foliar spray as a trunk injection or as a soil drench either 5 days before or 5 days after inoculation All untreated control trees died whether trunk or soilinoculated With phosphite injection survival was 100 following PTA soil inoculation and 67 following trunk inoculation Foliar spray and soil drenchapplied phosphite treatments were less effective than trunk injection although some trees survived

scholarly journals Pathogenicity of four Phytophthora species on kauri in vitro and glasshouse trials

2014 ◽  
Vol 67 ◽  
pp. 54-59 ◽  
Author(s):  
I.J. Horner ◽  
E.G. Hough
Keyword(s):  
Plant Growth ◽  
Forest Soils ◽  
Phytophthora Cinnamomi ◽  
Phytophthora Species ◽  
The Other ◽  
Root Damage ◽  
Soil Inoculation

In kauri forest soils surveys Phytophthora taxon Agathis (PTA) P cinnamomi P multivora and P cryptogea were detected frequently In vitro and glasshouse studies determined that all four Phytophthora species produced lesions on excised kauri leaves and stems Lesion advance was significantly slower with P cinnamomi P multivora and P cryptogea than with PTA When 2yearold kauri seedlings were trunkinoculated lesion spread was rapid with PTA trunks were girdled and all trees died within 46 weeks Phytophthora cinnamomi P multivora and P cryptogea produced substantially smaller lesions than PTA no trees died and plant growth was only slightly suppressed Following soil inoculation with PTA all kauri seedlings died within 10 weeks There were no deaths following soil inoculation with P cinnamomi P multivora or P cryptogea although feeder root damage was observed and the respective pathogens were reisolated Results suggest that PTA is an aggressive pathogen and the other three species are weaker pathogens of kauri

scholarly journals Biocontrol of Rhizoctonia solani Root Rot of Chilli by Bacillus subtilis formulations under Pot Conditions

2016 ◽  
Vol 30 (2) ◽  
pp. 109 ◽  
Author(s):  
Ashwini Narasimhan ◽  
Srividya Shivakumar
Keyword(s):  
Bacillus Subtilis ◽  
Rhizoctonia Solani ◽  
Root Rot ◽  
Untreated Control ◽  
Disease Incidence ◽  
Foliar Spray ◽  
Dry Weight ◽  
Root Colonisation ◽  
Soil Application ◽  
Seed Application

The chilli crop suffers massive yield loss due to root rot caused by <em>Rhizoctonia solani</em>. An increase of 10 × 10<sup>5</sup> root colonizing units/cm was obtained as a result of <em>Bacillus subtilis</em> in vitro root colonisation assay post germination. Shelf life studies of the formulations revealed stable population level of the biocontrol agent upto 180<sup>th</sup> day (30°C - 1.6 × 10<sup>8</sup>; 4°C - 1.9 × 10<sup>8</sup>) in talc and upto 150<sup>th</sup> day in lignite (30°C - 1.5 × 10<sup>8</sup>; 4°C - 1.3 × 10<sup>8</sup>). Soil, seed, foliar spray and dip treatment methods of <em>B. subtilis</em> and chlorothalonil brought about a considerable enhancement of all biometric parameters and reduced disease incidence compared to the untreated control. In comparison to the untreated control (50 g and 21 g fresh and dry weight, respectively), highest plant fresh weight (76.84 g) and dry weight (34.17 g) was achieved by the Seed application method. Comparison of plant height revealed maximum values 70 cm (soil application) and 77 cm (dip treatment) with <em>B. subtilis</em> application which was analogous to chlorothalonil treatment (56.5 cm with soil application and 70.33 cm with dip treatment) which was considerably superior to the untreated control (58.2 cm with dip treatment and 61 cm with soil application, respectively). Root dip treatment showed considerable increase in root length with <em>B. subtilis</em> (33 cm) and chlorothalonil (28.5 cm) when compared to untreated control (15 cm). Growth promotion was better with Root dip application while disease control was achieved better with seed application. A 66% and 84% reduction in incitation of disease was noticed with soil and seed application methods, respectively.

Effect of fungicides applied as foliar sprays and trunk injections on nut rot of chestnuts caused by Phomopsis castanea in Victoria

1998 ◽  
Vol 38 (3) ◽  
pp. 295 ◽  
Author(s):  
W. S. Washington ◽  
V. Hood ◽  
F. Goubran ◽  
G. Hepworth ◽  
S. Stewart-Wade
Keyword(s):  
Cold Storage ◽  
Mycelial Growth ◽  
Storage Disease ◽  
Phosphorous Acid ◽  
Growing Season ◽  
Foliar Sprays ◽  
Trunk Injection

Summary. Fungicides applied in vitro, as foliar sprays and trunk injections were evaluated for the control of phomopsis nut rot, an important storage disease of chestnuts in Australia caused by Phomopsis castanea. Benomyl, imazalil, prochloraz and propiconazole were most effective in vitro against mycelial growth, with EC50 values <0.1 µg/mL. Iprodione was less effective with an EC50 value between 1 and 10 µg/mL, while chlorothalonil and phosphorous acid were ineffective with EC50 values >100 µg/mL. Up to 4 foliar sprays of benomyl, or phosphorous acid, applied to trees during the growing season reduced (P<0.05) the incidence of rotted nuts during cold storage in 2 out of 5 trials, or 1 out of 3 trials respectively. In one trial, nut rot was reduced from 42.6% in unsprayed trees to 23 or 23.6% in nuts from trees sprayed with benomyl or phosphorous acid respectively. Prochloraz sprays were not effective. At harvest kernel nut tissue from trees sprayed with benomyl, prochloraz or phosphorous acid showed residues of <0.03, 0.14 or from 16 to 145 µg/g respectively. Trunk injection with imazalil or phosphorous acid at flowering in December did not control the disease, although in 1 trial, phosphorous acid reduced rot levels in stored nuts from 51.1% in untreated trees to 41.8% (P = 0.088). Imazalil treatments caused leaf scorching and in some cases limb death above the point of injection. Occasional slight leaf scorching was associated with some phosphorous acid injections. Residue studies showed that phosphorous acid moved into nut tissue, but showed little lateral redistribution around the tree.

scholarly journals Effects of Soil-Applied and Trunk and Petiole-Injected Manganese on Manganese Content of Coconut Palm (Cocos nucifera)

2010 ◽  
Vol 36 (6) ◽  
pp. 272-274
Author(s):  
Timothy Broschat ◽  
Joseph Doccola
Keyword(s):  
Untreated Control ◽  
Cocos Nucifera ◽  
Manganese Content ◽  
Calcareous Soils ◽  
Coconut Palm ◽  
Manganese Deficiency ◽  
Soil Application ◽  
Trunk Injection ◽  
Effective Result ◽  
Mn Concentrations

Manganese deficiency is a common and potentially fatal disorder of palms growing in highly leached and calcareous soils. Soil applications of MnSO4 may not always be effective in treating this disorder due to rapid oxidation of Mn to less available forms. Trunk injection with MnSO4 (2.0 g Mn) was found to be more effective in increasing foliar Mn concentrations than soil application (192 g Mn) or petiole injections with 0.1 g Mn in a single hole, or 0.5 g Mn divided among four holes. In contrast to trunk injection, neither petiole injections nor soil application of MnSO4 increased foliar Mn concentrations above that of the untreated control palms. Trunk injections, while effective, result in permanent wounds that could potentially serve as entry sites for the trunk pathogen Thielaviopsis paradoxa, especially on young palms with minimal trunks.

Phytophthora Species Differ in Response to Phosphorous Acid and Mefenoxam for the Management of Phytophthora Root Rot in Rhododendron

Plant Disease ◽  
2020 ◽  
Author(s):  
Jerry E. Weiland ◽  
Carolyn F. Scagel ◽  
Niklaus J. Grünwald ◽  
E. Anne Davis ◽  
Bryan R. Beck
Keyword(s):  
Root Rot ◽  
Production Systems ◽  
Foliar Spray ◽  
Phosphorous Acid ◽  
Phytophthora Species ◽  
Phytophthora Root Rot ◽  
Application Method ◽  
Affect Control ◽  
Pathogen Diversity ◽  
Significant Disease

Phytophthora root rot, caused by many soilborne Phytophthora species, is a significant disease affecting the $42 million rhododendron nursery industry. Rhododendron growers have increasingly reported failure by two systemic fungicides, phosphorous acid and mefenoxam, to adequately control root rot. Both fungicides may be applied as a foliar spray or soil drench, but it is unknown how application method, fungicide chemistry, or pathogen diversity affects disease control. Therefore, two experiments were conducted to (i) determine whether differences in application method or fungicide chemistry affect control of root rot caused by P. cinnamomi and P. plurivora and (ii) evaluate the sensitivity of Phytophthora species and isolates from the rhododendron industry to each fungicide. Results demonstrated that soil drenches of either fungicide were more effective than foliar sprays for control of P. cinnamomi, but were ineffective for P. plurivora. Furthermore, Phytophthora species and isolates varied in sensitivity to phosphorous acid and mefenoxam, and there were multiple fungicide insensitive isolates, especially within P. plurivora. Differences in sensitivity were also observed among isolates from different nurseries and production systems, with some nurseries having less sensitive isolates than others and with container systems generally having less sensitive isolates than field systems. Our results provide three potential reasons for why fungicide control of Phytophthora root rot might fail: (i) the fungicide can be applied to the wrong portion of the plant for optimal control, (ii) there are differences in fungicide sensitivity among soilborne Phytophthora species and isolates infecting rhododendron, and (iii) fungicide insensitive isolates are present in the rhododendron nursery industry.

scholarly journals Quaternary Ammonium Compounds as New Sanitizers for Reducing the Spread of the Olive Knot Pathogen on Orchard Equipment

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1188-1193 ◽  
Author(s):  
K. A. Nguyen ◽  
H. Förster ◽  
J. E. Adaskaveg
Keyword(s):  
Quaternary Ammonium ◽  
Foliar Spray ◽  
Field Trials ◽  
Quaternary Ammonium Compounds ◽  
Organic Load ◽  
Short Exposure ◽  
In Vitro Tests ◽  
Bacterial Disease ◽  
Ammonium Compounds

Olive knot, caused by the wound pathogen Pseudomonas savastanoi pv. savastanoi, is a serious bacterial disease that can be disseminated by orchard equipment. Greenhouse studies confirmed that cutting tools contaminated during contact with olive knots are able to spread the pathogen to healthy olive tissue. Quaternary ammonium compounds (QACs) were assessed as sanitizing agents for contaminated equipment as a disease management strategy. In laboratory in vitro tests, QACs exhibited high toxicity against the bacterium over a broad pH range from 6 to 9 using short exposure periods (15 to 60 s) and low concentrations (5 µg/ml). QACs applied to contaminated hard surfaces in the presence of an organic load reduced bacterial recovery by ≥3.6 log10 CFU/ml. In field trials, sanitation of hedging equipment that was contaminated with the pathogen (2 × 107 CFU/ml) and used to prune olives, was successful and sometimes completely prevented new infections from occurring. Application of additional foliar spray treatments of copper or copper-kasugamycin mixtures after hedging significantly improved disease control. In laboratory and field studies, sodium hypochlorite was significantly less effective than QAC compounds in the presence of organic matter. A nonphenolic QAC formulation, however, was ineffective as a preventative treatment when applied prior to inoculation of olive wounds, whereas a copper hydroxide application was highly effective. Based on data from this research, a QAC formulation was registered for field use as a sanitizer for olive equipment in California in 2015.

Anti-Diabetic Activity of a Mineraloid Isolate, in vitro and in Genetically Diabetic Mice

2011 ◽  
Vol 81 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Joel Deneau ◽  
Taufeeq Ahmed ◽  
Roger Blotsky ◽  
Krzysztof Bojanowski
Keyword(s):  
Dna Microarrays ◽  
Human Fibroblasts ◽  
Diabetic Animal ◽  
In Vitro Tests ◽  
Diabetic Mice ◽  
Fossil Material ◽  
Expression Of Genes ◽  
Enhanced Expression ◽  
Genetically Diabetic Mice

Type II diabetes is a metabolic disease mediated through multiple molecular pathways. Here, we report anti-diabetic effect of a standardized isolate from a fossil material - a mineraloid leonardite - in in vitro tests and in genetically diabetic mice. The mineraloid isolate stimulated mitochondrial metabolism in human fibroblasts and this stimulation correlated with enhanced expression of genes coding for mitochondrial proteins such as ATP synthases and ribosomal protein precursors, as measured by DNA microarrays. In the diabetic animal model, consumption of the Totala isolate resulted in decreased weight gain, blood glucose, and glycated hemoglobin. To our best knowledge, this is the first description ever of a fossil material having anti-diabetic activity in pre-clinical models.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

In Vitro Thrombogenicity Tests of Factor IX Concentrates

1979 ◽  
Vol 42 (05) ◽  
pp. 1355-1367 ◽  
Author(s):  
C V Prowse ◽  
A Chirnside ◽  
R A Elton
Keyword(s):  
Factor Viii ◽  
Partial Thromboplastin Time ◽  
Generation Time ◽  
Activated Partial Thromboplastin Time ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Factor Viii Inhibitor ◽  
Factor Ixa ◽  
Viii Inhibitor

SummaryVarious factor IX concentrates have been examined in a number of in vitro tests of thrombogenicity. The results suggest that some tests are superfluous as in concentrates with activity in any of these tests activation is revealed by a combination of the non-activated partial thromboplastin time, the thrombin (or Xa) generation time and factor VIII inhibitor bypassing activity tests. Assay of individual coagulant enzymes revealed that most concentrates contained more factor IXa than Xa. However only a small number of concentrates, chiefly those that had been purposefully activated, contained appreciable amounts of either enzyme.

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