Fungicide and Clay Treatments for Control of Powdery Mildew Influence Wine Grape Microflora

There is very little information on the interaction of wine grape microflora with fungicides used to control grape diseases. The objective of this study was to determine how fungicides used in a standard grape pest management program and an experimental clay being developed for control of powdery mildew affect grape microflora. Grape leaves and fruit were surveyed for bacteria, fungi and yeast six times over the growing season in 2000 after treatment with clay or fungicides. In 2001 only clay was studied for control of powdery mildew in `Chancellor' grapes. The total number of propagules present on untreated leaf and fruit tissue were 76% bacteria, 14% yeast, and 9% fungi. Fungicides used for grape disease control significantly reduced epiphytic fungi (P < 0.0001), bacteria (P = 0.03), and yeast (P = 0.0001) on grape berries and epiphytic fungi (P < 0.0001), and yeast (P = 0.03) on leaves. The clay treatment had no detectable effect on grape microflora because no significant differences were recorded between clay or untreated grape berries or leaves on any of the sampling dates. Over the growing season the fungicide spray program reduced incidence and severity of powdery mildew better than clay. Clay controlled powdery mildew on `Chancellor' fruit in 2000 and 2001.

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Palmolive® detergent controls apple, cherry, and grape powdery mildew

Canadian Journal of Plant Science ◽

10.4141/cjps09017 ◽

2009 ◽

Vol 89 (6) ◽

pp. 1139-1147 ◽

Cited By ~ 2

Author(s):

P L Sholberg ◽

J Boulé

Keyword(s):

Powdery Mildew ◽

Fungicide Resistance ◽

Plant Disease ◽

Growing Season ◽

Apple Orchard ◽

Pinot Noir ◽

Podosphaera Leucotricha ◽

Grape Berries ◽

Apple Leaves ◽

Spray Timing

Palmolive® detergent applied in water was compared with the standard fungicide treatment for control of powdery mildew on apple [Podosphaera leucotricha (Ell. & Ev.) E.S. Salmon], cherry [P. clandestina (Wall.:Fr.) Lév.], and grape [Erysiphe necator (Schw.) Burrill]. Initial tests in the greenhouse with apple and grape seedlings showed that Palmolive® was as effective as myclobutanil in preventing powdery mildew on leaves. In apple orchard trials conducted in 2004, 2005 and 2006 Palmolive® detergent prevented powdery mildew on leaves, but caused fruit russetting when used at a rate higher than 5 mL L-1 through the growing season. The 10 mL L-1 rate reduced foliar powdery mildew in an apple and cherry nursery and in Pinot noir grapes, but caused russetting on grape berries. Further studies to determine optimum rates and spray timing will be required before it can be used safely on grapes. Studies on activity of Palmolive® detergent on Cameo apple leaves showed that it had protectant, eradicant, and antisporulant properties comparable with myclobutanil if applied within 1 d before or after inoculation with P. leucotricha and had superior antisporulant properties when applied to 7-d-old lesions. Palmolive® detergent, if used appropriately, could be an important component of an IPM strategy for control of powdery mildew on apple, cherry, and grape because it presents very little risk for the development of fungicide resistance. Key words: Pest management, plant disease, orchard, vineyard

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Brix, pH and anthocyanin content determination in whole Port wine grape berries by hyperspectral imaging and neural networks

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2015.05.013 ◽

2015 ◽

Vol 115 ◽

pp. 88-96 ◽

Cited By ~ 23

Author(s):

Armando M. Fernandes ◽

Camilo Franco ◽

Ana Mendes-Ferreira ◽

Arlete Mendes-Faia ◽

Pedro Leal da Costa ◽

...

Keyword(s):

Neural Networks ◽

Hyperspectral Imaging ◽

Anthocyanin Content ◽

Wine Grape ◽

Port Wine ◽

Grape Berries ◽

Content Determination

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Developing an Empirical Yield-Prediction Model Based on Wheat and Wild Oat (Avena fatua) Density, Nitrogen and Herbicide Rate, and Growing-Season Precipitation

Weed Science ◽

10.1614/ws-05-018.1 ◽

2007 ◽

Vol 55 (6) ◽

pp. 652-664 ◽

Cited By ~ 9

Author(s):

N. C. Wagner ◽

B. D. Maxwell ◽

M. L. Taper ◽

L. J. Rew

Keyword(s):

Field Data ◽

Wheat Yield ◽

Growing Season ◽

Predictor Variables ◽

Data Sets ◽

Wild Oat ◽

Best Fitting ◽

Weed Infestation ◽

Growing Season Precipitation ◽

Better Than

To develop a more complete understanding of the ecological factors that regulate crop productivity, we tested the relative predictive power of yield models driven by five predictor variables: wheat and wild oat density, nitrogen and herbicide rate, and growing-season precipitation. Existing data sets were collected and used in a meta-analysis of the ability of at least two predictor variables to explain variations in wheat yield. Yield responses were asymptotic with increasing crop and weed density; however, asymptotic trends were lacking as herbicide and fertilizer levels were increased. Based on the independent field data, the three best-fitting models (in order) from the candidate set of models were a multiple regression equation that included all five predictor variables (R2= 0.71), a double-hyperbolic equation including three input predictor variables (R2= 0.63), and a nonlinear model including all five predictor variables (R2= 0.56). The double-hyperbolic, three-predictor model, which did not include herbicide and fertilizer influence on yield, performed slightly better than the five-variable nonlinear model including these predictors, illustrating the large amount of variation in wheat yield and the lack of concrete knowledge upon which farmers base their fertilizer and herbicide management decisions, especially when weed infestation causes competition for limited nitrogen and water. It was difficult to elucidate the ecological first principles in the noisy field data and to build effective models based on disjointed data sets, where none of the studies measured all five variables. To address this disparity, we conducted a five-variable full-factorial greenhouse experiment. Based on our five-variable greenhouse experiment, the best-fitting model was a new nonlinear equation including all five predictor variables and was shown to fit the greenhouse data better than four previously developed agronomic models with anR2of 0.66. Development of this mathematical model, through model selection and parameterization with field and greenhouse data, represents the initial step in building a decision support system for site-specific and variable-rate management of herbicide, fertilizer, and crop seeding rate that considers varying levels of available water and weed infestation.

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The Influence of Rooting Substrate and Growth Regulators Indol butyric Acid and Naphthalene Acetic Acid in the Number and Length of Adventitious Roots to Hardwood Cuttings in Blueberry cv. ‘Bluecrop’ (Vaccinium corymbosum L.)

Journal of Agricultural Studies ◽

10.5296/jas.v4i4.10013 ◽

2016 ◽

Vol 4 (4) ◽

pp. 28

Author(s):

Sabri Braha ◽

Petrit Rama

Keyword(s):

Growth Regulators ◽

Growing Season ◽

Vaccinium Corymbosum ◽

Naphthalene Acetic Acid ◽

Important Variation ◽

Physiological Processes ◽

One Year ◽

The Impact ◽

Better Than

The purpose of this research is to determine the impact of the turf-only substrate and turf–perlite in the ratio 2:1 and of growth regulators in the quality of adventive roots ( the number and length) of well lignified one-year old branches without fruit buds in the Bluecrop cultivar (Vaccinium corymbosum L.) taken at the end of the latent period before budding at the February 15 th during the -2015 growing season. In order to support the increase of the number of roots and their length the hardwood cuttings are treated with different IBA and NAA concentrations (1500, 3000, 4500 ppm), while a part of cuttings were untreated control. The number and the length of roots have increased in relation to the increase of concentration from 1500 to 3000 ppm followed by a decline of these values in concentrations over 3000 ppm. Respectively, the number of roots (8) and the higher values of root length (4.6 cm) are achieved in the turf–perlite substrate, IBA 3000 ppm (compared to the turf-only substrate). The presence of perlite helps the aeration of the substrate and supports biochemical and physiological processes which lead to the inducing of adventive roots. Regarding the number and length of roots an important variation for (p<0.05) was observed between different concentrations of IBA and NAA. In general the effect of IBA was a lot better than the effect of NAA.

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Host Barriers and Responses to Uncinula necator in Developing Grape Berries

Phytopathology ◽

10.1094/phyto.2004.94.5.438 ◽

2004 ◽

Vol 94 (5) ◽

pp. 438-445 ◽

Cited By ~ 35

Author(s):

Andrea Ficke ◽

David M. Gadoury ◽

Robert C. Seem ◽

Dale Godfrey ◽

Ian B. Dry

Keyword(s):

Cell Wall ◽

Powdery Mildew ◽

Wall Thickness ◽

Infection Process ◽

Cell Wall Thickness ◽

Antifungal Compound ◽

Uncinula Necator ◽

Grape Berries ◽

Pathogenesis Related ◽

Cuticle Thickness

Grape berries are highly susceptible to powdery mildew 1 week after bloom but acquire ontogenic resistance 2 to 3 weeks later. We recently demonstrated that germinating conidia of the grape powdery mildew pathogen (Uncinula necator) cease development before penetration of the cuticle on older resistant berries. The mechanism that halts U. necator at that particular stage was not known. Several previous studies investigated potential host barriers or cell responses to powdery mildew in berries and leaves, but none included observation of the direct effect of these factors on pathogen development. We found that cuticle thickness increased with berry age, but that ingress by the pathogen halted before formation of a visible penetration pore. Cell wall thickness remained unchanged over the first 4 weeks after bloom, the time during which berries progressed from highly susceptible to nearly immune. Autofluorescent polyphenolic compounds accumulated at a higher frequency beneath appressoria on highly susceptible berries than on highly resistant berries; and oxidation of the above phenolics, indicated by cell discoloration, developed at a significantly higher frequency on susceptible berries. Beneath the first-formed appressoria of all germinated conidia, papillae occurred at a significantly higher frequency on 2- to 5-day-old berries than on 30- to 31-day-old fruit. The relatively few papillae observed on older berries were, in most cases (82.8 to 97.3%), found beneath appressoria of conidia that had failed to produce secondary hyphae. This contrasted with the more abundantly produced papillae on younger berries, where only 35.4 to 41.0% were located beneath appressoria of conidia that had failed to produce secondary hyphae. A pathogenesis-related gene (VvPR-1) was much more highly induced in susceptible berries than in resistant berries after inoculation with U. necator. In contrast, a germin-like protein (VvGLP3) was expressed within 16 h of inoculation in resistant, but not in susceptible berries. Our results suggest that several putative barriers to infection, i.e., cuticle and cell wall thickness, antimicrobial phenolics, and two previously described pathogenesis-related proteins, are not principal causes in halting pathogen ingress on ontogenically resistant berries, but rather that infection is halted by one or more of the following: (i) a preformed physical or biochemical barrier near the cuticle surface, or (ii) the rapid synthesis of an antifungal compound in older berries during the first few hours of the infection process.

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Genetic Structure and Aggressiveness of Erysiphe necator Populations during Grapevine Powdery Mildew Epidemics

Applied and Environmental Microbiology ◽

10.1128/aem.01200-08 ◽

2008 ◽

Vol 74 (20) ◽

pp. 6327-6332 ◽

Cited By ~ 30

Author(s):

Josselin Montarry ◽

Philippe Cartolaro ◽

François Delmotte ◽

Jérôme Jolivet ◽

Laetitia Willocquet

Keyword(s):

Powdery Mildew ◽

Latency Period ◽

Growing Season ◽

Spore Production ◽

Erysiphe Necator ◽

Genetic Groups ◽

Grapevine Powdery Mildew ◽

Temporal Differentiation ◽

Group A ◽

Group B

ABSTRACT Isolates of the causal ascomycete of grapevine powdery mildew, Erysiphe necator, correspond to two genetically differentiated groups (A and B) that coexist on the same host. This coexistence was analyzed by investigating temporal changes in the genetic and phenotypic structures of E. necator populations during three epidemics. Group A was present only at the start of the growing season, whereas group B was present throughout all three epidemics. Group A was less aggressive in terms of germination and infection efficiency but was more aggressive than group B in terms of the latency period, lesion diameter, and spore production. Our results are consistent with a temporal differentiation of niches, preventing recombination, and suggest an association between the disease level and the frequencies of genetic groups.

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Enhanced Regional Monitoring of Wheat Powdery Mildew Based on an Instance-Based Transfer Learning Method

Remote Sensing ◽

10.3390/rs11030298 ◽

2019 ◽

Vol 11 (3) ◽

pp. 298 ◽

Cited By ~ 7

Author(s):

Linyi Liu ◽

Yingying Dong ◽

Wenjiang Huang ◽

Xiaoping Du ◽

Juhua Luo ◽

...

Keyword(s):

Powdery Mildew ◽

Transfer Learning ◽

Kappa Coefficient ◽

Learning Method ◽

Training Process ◽

Wheat Powdery Mildew ◽

Field Samples ◽

Monitoring Accuracy ◽

Sample Data ◽

Better Than

In order to monitor the prevalence of wheat powdery mildew, current methods require sufficient sample data to obtain results with higher accuracy and stable validation. However, it is difficult to collect data on wheat powdery mildew in some regions, and this limitation in sampling restricts the accuracy of monitoring regional prevalence of the disease. In this study, an instance-based transfer learning method, i.e., TrAdaBoost, was applied to improve the monitoring accuracy with limited field samples by using auxiliary samples from another region. By taking into account the representativeness of contributions of auxiliary samples to adjust the weight placed on auxiliary samples, an optimized TrAdaBoost algorithm, named OpTrAdaBoost, was generated to map regional wheat powdery mildew. The algorithm conducts this by: (1) producing uncertainty associated with each prediction based on the similarities, and calculating the representativeness contribution of all auxiliary samples by taking into account the overall uncertainty of the wheat powdery mildew map; (2) calculating the errors of the weak learners during the training process and using boosting to filter out the unreliable auxiliary samples by adjusting the weights of auxiliary samples; (3) combining all weak learners according to the weights of training instances to build a strong learner to classify disease severity. OpTrAdaBoost was tested using a dataset with 39 study area samples and 106 auxiliary samples. The overall monitoring accuracy was 82%, and the kappa coefficient was 0.72. Moreover, OpTrAdaBoost performed better than other algorithms that are commonly used to monitor wheat powdery mildew at the regional level. Experimental results demonstrated that OpTrAdaBoost was effective in improving the accuracy of monitoring wheat powdery mildew using limited field samples.

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Effectiveness of Starch Xanthide Formulations of Chloramben for Weed Control in Pumpkin (Cucurbita moschata)

Weed Science ◽

10.1017/s0043174500062275 ◽

1982 ◽

Vol 30 (2) ◽

pp. 169-174 ◽

Cited By ~ 8

Author(s):

Victor Raboy ◽

Herbert J. Hopen

Keyword(s):

Weed Control ◽

Sandy Soil ◽

Growing Season ◽

Silt Loam ◽

Cucurbita Moschata ◽

Release Rates ◽

Emulsifiable Concentrate ◽

Loam Soil ◽

In Parenthesis ◽

Better Than

The persistence and effectiveness in pumpkin [Cucurbita moschata(Puch.) Poir.] weed control of several starch xanthide (SX) and commercial formulations of the ammonium (NH3) salt and methyl (CH3) ester of chloramben (3-amino-2,5-dichlorobenzoic acid) were studied in the laboratory and field. The soluble concentrate (SC) of chloramben NH3salt and the emulsifiable concentrate (EC) of chloramben CH3ester controlled weeds throughout the growing season on a silt loam soil. SC chloramben NH3salt was not effective, and EC chloramben CH3ester was inconsistent in weed control on sandy soil. Manipulation of the SX formulation produced products with slow, uniform release rates. The release rates (crosslinking reagent in parenthesis) rank as follows, from fastest to slowest: SX(Ca2+) CH3ester = SX(H2O2) acid > SX(H2O2) CH3ester > SX(Fe3+) acid > SX(Fe3+) CH3ester. In trials on silt loam and sand, SX formulations did not control weeds better than EC chloramben CH3ester.

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Lupin grain yields and fertiliser effectiveness are increased by banding superphosphate below the seed

Australian Journal of Experimental Agriculture ◽

10.1071/ea9910357 ◽

1991 ◽

Vol 31 (3) ◽

pp. 357 ◽

Cited By ~ 24

Author(s):

RJ Jarvis ◽

MDA Bolland

Keyword(s):

Grain Yield ◽

Vegetative Growth ◽

Field Experiments ◽

Soil Surface ◽

Growing Season ◽

Lupinus Angustifolius ◽

Grain Yields ◽

P Content ◽

Better Than

Five field experiments with lupins (Lupinus angustifolius) measured the effectiveness, for production, of 4 superphosphate placements either: (i) drilled with the seed to a depth of 4 or 5 cm; (ii) applied to the soil surface (topdressed) before sowing; or (iii) banded 2.5-5 cm and 7.5-8 cm below the seed while sowing. Levels of applied phosphate (P) from 0 to 36 kg P/ha were tested. In all experiments lupin grain yield responded to the highest level of superphosphate applied. At this P level, the average grain yield from all trials was 1.16 t/ha for the deepest banded treatment. This was 0.38 t/ha (49%) better than P drilled with the seed, and 0.62 t/ha (115%) better than P topdressed. Relative to superphosphate drilled with the seed and regardless of the lupin cultivar or the phosphate status of the soil, the effectiveness of superphosphate was increased by 10-90% by banding below the seed, and decreased by 30-60% by topdressing. Increasing the levels of superphosphate drilled with the seed generally reduced the density of seedlings and reduced early vegetative growth, probably due to salt or P toxicity. However, during the growing season, the plants treated with high levels of superphosphate recovered, so that eventually yields of dried tops and grain responded to increasing superphosphate drilled with the seed. In each experiment there was a common relationship between yield and P content in lupin tissue, regardless of how the superphosphate was applied, suggesting that lupins responded solely to P, and other factors did not alter yield. We recommend that farmers band superphosphate 5-8 cm below the seed while sowing, rather than continue the present practices of either drilling the fertiliser with the seed, or topdressing it before sowing.

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