scholarly journals Calcium chloride against black spot on apples

2010 ◽  
Vol 63 ◽  
pp. 279-279
Author(s):  
K.S.H. Boyd-Wilson ◽  
R.C. Butler ◽  
M. Walter
Keyword(s):  
Calcium Chloride ◽  
Venturia Inaequalis ◽  
Disease Incidence ◽  
Black Spot ◽  
Growing Season ◽  
High Rate ◽  
Water Control ◽  
Veterinary Medicines ◽  
Foliar Damage ◽  
Apple Production

Calcium chloride which is classified as generally recognised as safe (GRAS) under the Agricultural Compounds and Veterinary Medicines Regulations 2001 has potential for use in an organic apple production system against black spot (Venturia inaequalis) The effectiveness of calcium chloride on control of black spot was evaluated in a field trial over the 2007/2008 growing season Calcium chloride was applied 10 times over the season at the commerciallyrecommended rate of 033 kg product/100 litres or at 2 kg/100 litres (the latter treatment was halved after two applications due to foliar damage) At harvest fruit treated with the high rate of calcium chloride had a lower disease incidence of 41 than the water control which had 97 incidence (P

scholarly journals Treatment of overwintering apple leaves to reduce primary inoculum of apple black spot

2003 ◽  
Vol 56 ◽  
pp. 95-99
Author(s):  
K. Tshomo ◽  
I.J. Horner ◽  
M. Walter ◽  
A. Stewart ◽  
M.V. Jaspers
Keyword(s):  
Venturia Inaequalis ◽  
Black Spot ◽  
Field Trials ◽  
Water Control ◽  
Primary Inoculum ◽  
Apple Leaves ◽  
Fungal Isolates ◽  
Glass Slides ◽  
Ascospore Production ◽  
Nutrient Amendments

Field trials were conducted in Hawkes Bay and Lincoln into methods of treating overwintering apple leaves to reduce ascospore production by the apple black spot pathogen Venturia inaequalis The leaf treatments comprised three levels of nutrient amendments (including a water control) and five levels of saprophytic fungal isolates (including a nofungus control) in a factorial design Leaves were left to overwinter on the orchard floor and in spring the V inaequalis ascospores released were trapped on glass slides and counted Ascospore numbers were reduced (Plt;005) by the leaf amendment urea which alone caused 73 reduction but not by the BioStarttrade; product The effect of fungal isolates was not significant (P012) although when combined with the water treatment the isolates Chaetomium Phoma and Epicoccum spp and Trametes versicolor reduced numbers of ascospores by 33 27 15 and 28 respectively compared to the nofungus control When combined with urea the Chaetomium isolate reduced ascospore numbers by 92 and 82 compared to the nil fungus/water control treatments in Hawkes Bay and Lincoln respectively indicating that this treatment has potential for reducing primary inoculum of apple black spot

scholarly journals Effect of pruning on disease incidence of apple scab and powdery mildew in integrated and organic apple production

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Powdery Mildew ◽  
Production System ◽  
Production Systems ◽  
Venturia Inaequalis ◽  
Disease Incidence ◽  
Apple Scab ◽  
Organic Production ◽  
Environmentally Benign ◽  
Apple Cultivars ◽  
Apple Production

In a three-year study, the effect of two winter pruning treatments (strong and weak) on apple scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha) was evaluated on six apple cultivars (`Rewena', `Elstar', 'Liberty', 'Gala', 'Pilot' and `Jonica') in two environmentally-benign apple production systems (integrated and organic). Results on apple scab showed that compared to the integrated production system, the pathogen caused significantly more infection on the leaves of cvs. `Elstar', 'Gala' and `Jonica' in the organic production system. The effect of pruning treatments on apple scab was mainly detectable on the cultivars susceptible to the disease such as cvs. 'Gala' and `Jonica'. The weak pruning correlated with a higher level of apple scab infection than the strong pruning, especially in the organic production system. Primary mildew infection was very low in both protection systems (below 2 %), therefore, effect of pruning on primary mildew infection could not be analysed. Low secondary mildew incidence was detected in the organically treated orchard part; however, incidence of powdery mildew was significantly higher (P> 0.05) on cvs. 'Elstar', 'Pilot' and `Jonica' in the integrated orchard part compared to cvs. 'Gala', 'Rewena' and 'Liberty'. The highest incidence of mildew was on cv. 'Elstar'. Pruning had very low effect on incidence of secondary mildew infection on leaves.

scholarly journals The Influence of Preharvest Calcium Applications on Postharvest Quality and Yield of `Sweet Charlie' Strawberry

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 853D-853
Author(s):  
Camille Esmel* ◽  
John R. Duval ◽  
E.H. Simonne ◽  
Steven A. Sargent
Keyword(s):  
Cell Wall ◽  
Calcium Chloride ◽  
Calcium Sulfate ◽  
Foliar Spray ◽  
Growing Season ◽  
The United States ◽  
Soluble Solids ◽  
Postharvest Quality ◽  
Water Control ◽  
Yield Data

Strawberries are a high value commodity with a short shelf life. Florida is the largest producer of winter strawberries in the United States with 2,790 hectares of production, 90% are located in Hillsborough County. Many Florida growers apply additional calcium (Ca) as a foliar spray despite the lack of conclusive evidence of an increase in fruit quality or yield. It is believed that additional Ca will improve cell wall integrity through Ca linkages with pectins with in the cell wall and increase fruit firmness. Preharvest applications of calcium chloride have shown to delay the ripening of strawberry fruit and mold development. The objectives of this two year study were to determine the effects of Ca on yield, growth, and postharvest quality of strawberry when applied to the soil or as a foliar spray. `Sweet Charlie' strawberry plants were grown on a Seffner fine sand in Dover, Fla. The experimental design was a split-block replicated four times with soil and foliar Ca applications. Main plots consisted of a broadcast preplant incorporation of gypsum (calcium sulfate) 0 kg·ha-1, 36.7 kg·ha-1, and 73.4 kg·ha-1. Sub-plots consisted of foliar applications of 400 mg·L-1 Ca from calcium sulfate, 400 and 800 mg·L-1 Ca from calcium chloride and a water control applied weekly throughout the 2002-03 and 2003-04 growing season. Yield data was collected twice weekly through out the growing season. Fruits were graded for quality based upon size, visual appearance of pathogens degradation, frost/water damage, and misshapen form. Calcium content was determined for leaves, fruit, and calyxes in January and March. Postharvest quality evaluations of pH, titratable acidy, soluble solids, and firmness (Instron 4411) were determined in January and March.

scholarly journals Effect of Compost Amendments on Disease Severity and Yield of Tomato in Conventional and Organic Production Systems

Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 156-161 ◽  
Author(s):  
P. A. Abbasi ◽  
J. Al-Dahmani ◽  
F. Sahin ◽  
H. A. J. Hoitink ◽  
S. A. Miller
Keyword(s):  
Disease Severity ◽  
Production Systems ◽  
Disease Incidence ◽  
Organic Production ◽  
Fruit Rot ◽  
High Rate ◽  
Bacterial Spot ◽  
Marketable Yield ◽  
Tomato Production ◽  
Compost Amendments

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.

scholarly journals Analyses of temporal dynamics of brown rot development on fruit in organic apple production

2003 ◽  
Vol 9 (3-4) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Power Function ◽  
Yield Loss ◽  
Temporal Dynamics ◽  
Disease Incidence ◽  
Brown Rot ◽  
Mathematical Function ◽  
Apple Orchards ◽  
Apple Production ◽  
Fruit Disease ◽  
Fruit Harvest

In a two-year study, yield loss and temporal dynamics of brown rot development caused by Monilinia fructigena (Aderh. & Ruhl.) Honey were quantified and analysed in two organic apple orchards (Debrecen—Pallag and Debrecen—Józsa). The first infected fruits were observed at the beginning of August in both years and both locations, except for one occasion when the first infected fruit was found at the end of July. Temporal disease development was continuous up to harvest time in both years and locations. In the two years, pre-harvest yield loss on the trees amounted between 8.9% and 9.3% at Debrecen-Pallag and between 9.7% and 10.8% at Debrecen—Jozsa by fruit harvest. Incidence of infected fruits on the orchard floor ranged from 32.4% to 43.2% and from 53.3% to 61.9%, at Debrecen—Pallag and Debrecen—Józsa, respectively, by fruit harvest. Analyses of temporal disease progress showed that the best-fitted mathematical function was the power function in both orchards and years. Both parameters of the power function clearly demonstrated that incidence of brown rot on fruit increased faster on the orchard floor than on the tree. Moreover, the disease increase was faster at Debrecen—Józsa in most cases than at Debrecen—Pallag. Our results indicated that the strategy of disease management, the ripeness of the fruit and the presence of a wounding agent played an important role in the yield loss and in the temporal development of fruit disease incidence caused by M. fructigena in organic apple orchards. Biological and practical implications of the results are discussed.

scholarly journals Combined Influence of Chitosan and Calcium Chloride on Fusarium Dry Rot Disease Under Field Conditions

2020 ◽  
Vol 14 (1) ◽  
pp. 339-344
Author(s):  
Sabah R. Mohammed ◽  
Ivan D. Eskov ◽  
Elsayed M. Zeitar
Keyword(s):  
Plant Height ◽  
Calcium Chloride ◽  
Tuber Yield ◽  
Foliar Application ◽  
Growth Parameters ◽  
Disease Incidence ◽  
Field Conditions ◽  
Dry Rot ◽  
Fusarium Dry Rot ◽  
Rot Disease

Background: Fusarium dry rot disease caused by Fusarium sambucinum Fuckel (F. sambucinum) can infect the potato tubers in the field and during storage. Yield losses by F. sambucinum reach 60%. Traditional methods to control Fusarium dry rot are fungicides application, which led to developing many isolates resistant to these fungicides. Objective: The aim of this study is to evaluate the effect of calcium chloride (CaCl2) and chitosan, alone or in combination, on plant development, tuber yield, and Fusarium dry rot disease incidence under field conditions. Methods: Soil inoculated with F. sambucinum before planting. We treated the seed tubers with CaCl2 (0.5 or 1%), chitosan 0.5%, or both. The foliage was sprayed twice with CaCl2 (0.5 or 1%), 0.1% chitosan, or both. During the vegetation period, growth parameters, such as germination (%), plant height (cm), and branches number per plant, were measured. At harvest, we calculated the total and the marketable number of tubers and tuber yield. In addition, during storage, we assessed the incidence of Fusarium dry rot disease on tubers. Results: Results revealed that combined pre-planting application with 1% CaCl2 and 0.5% chitosan with 2 hours intervals, then spraying foliar with 1% CaCl2 and 0.1% chitosan twice with ten days intervals starting at 40 days after planting resulted in: a) increasing the germination, enhancing the growth parameters such as plant height and branches number per plant; b) enhancing the marketable tuber yield by 75.2 and 97.6% in Sante and Kolobok varieties, respectively; c) reducing Fusarium dry rot disease incidence by 61.9-72.7%. Conclusion: The work highlighted that the combined pre-planting and foliar application of CaCl2 and chitosan might be recommended for potato producers to reduce the incidence of Fusarium dry rot disease and augment yields.

scholarly journals Symptomatic intracranial arterial disease: incidence, natural history, diagnosis, and management

2011 ◽  
Vol 30 (6) ◽  
pp. E14 ◽  
Author(s):  
Ananth K. Vellimana ◽  
Andria L. Ford ◽  
Jin-Moo Lee ◽  
Colin P. Derdeyn ◽  
Gregory J. Zipfel
Keyword(s):  
Natural History ◽  
Medical Therapy ◽  
Endovascular Therapy ◽  
Medical Management ◽  
Surgical Intervention ◽  
Disease Incidence ◽  
Arterial Disease ◽  
High Rate ◽  
Diagnosis And Management ◽  
Ischemic Events

Symptomatic intracranial arterial disease is associated with a high rate of recurrent ischemic events. The management of this condition is controversial, with some advocating medical therapy as a sole means of treatment and others recommending endovascular therapy in addition to best medical management. In rare cases, surgical intervention is considered. A thorough review of the available literature was performed, and treatment recommendations based on these data are provided.

The control of apple scab (Venturia inaequalis) with some recently developed fungicides

1964 ◽  
Vol 4 (12) ◽  
pp. 55
Author(s):  
J Kuiper ◽  
BS Janes
Keyword(s):  
Venturia Inaequalis ◽  
Apple Scab ◽  
Black Spot ◽  
Field Trials ◽  
The Other ◽  
Single Trial

In field trials, dodine (n-dodecylguanidine acetate) controlled apple scab or black spot, Venturia inaequalis (Cke.) Wint., more effectively than several other fungicides at commonly used concentrations. The other fungicides in decreasing order of effectiveness were :-glyodin (2-heptadecyl-2-imidazoline acetate), thiram (tetramethylthiuram disulphide) and tecoram (bis-(dimethyldithiocarbamoyl)-ethylenebisdithiocarbamate). In a single trial, glyodin was superior to 2-heptadecyl-2-imidazoline. No phytotoxicity was observed in the trials.

scholarly journals The Influence of Spray Adjuvants on Exacerbation of Citrus Bacterial Spot

Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1305-1310 ◽  
Author(s):  
T. R. Gottwald ◽  
J. H. Graham ◽  
T. D. Riley
Keyword(s):  
Disease Incidence ◽  
Bacterial Spot ◽  
Water Control ◽  
Xanthomonas Axonopodis ◽  
Control Lesion ◽  
Simulated Wind ◽  
Citrus Spp ◽  
Spray Adjuvants

The effect of adjuvants on the spread of Xanthomonas axonopodis pv. citrumelo applied to nursery plots of citrus (Citrus spp.) rootstock trees in simulated wind-blown rain was studied. Commercial adjuvants tested included a penetrant-surfactant, the penetrant or surfactant components of the penetrant-surfactant alone, an antitranspirant, a surfactant, or 1 of 3 formulations of a spreader-binder. Individual rows were treated with the adjuvants or water alone as a control. Bacterial dispersal gradients in all rows were similar and extended the entire 7 m of the nursery rows. Disease incidence, number of lesions per plant, and lesion diameters were determined at selected assay points in each row 28 days after the event. The penetrant-surfactant and its surfactant component significantly increased the total number of lesions per plant and mean lesion diameters compared to the water control. The disease gradient slopes associated with the penetrant-surfactant and its surfactant component were significantly flatter and more extensive than the water control. The penetrant component of the penetrant-surfactant, the antitranspirant, and two spreader-binders adjuvants did not significantly alter the disease gradient compared to the water control. Lesion sizes and numbers were also increased by a surfactant product and the surfactant component of the penetrant-surfactant, but not by the penetrant component of the penetrant-surfactant, the antitranspirant, or the three spreader-binder formulations. These results suggest that surfactants which induce stomatal flooding may enhance infection and exacerbate citrus bacterial epidemics.

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