scholarly journals Effects of a biocontrol agent of apple powdery mildew (Podosphaera leucotricha) on the host plant and on non-target organisms: an insect pest (Cydia pomonella) and a pathogen (Venturia inaequalis)

2008 ◽  
Vol 18 (2) ◽  
pp. 121-138 ◽  
Author(s):  
Aude Alaphilippe ◽  
Yigal Elad ◽  
Dalia Rav David ◽  
Sylvie Derridj ◽  
Cesare Gessler
2018 ◽  
Vol 10 (1) ◽  
pp. 5-19
Author(s):  
Tamás Hochbaum ◽  
Marietta Petróczy ◽  
Márta Ladányi ◽  
Géza Nagy

Abstract Though profitable crop production can be more simply achieved by using synthetic pesticides, the research of alternative plant protection solutions is necessary. The effect of the volatile oils of cinnamon, thyme, and a copper ingredient fertilizer were tested for their activity against apple scab and powdery mildew in apple orchards in 2014 and 2017. Oils applied alone or in combination were effective against apple scab in 2014 and in 2017 and against powdery mildew on leaves in 2017. The copper ingredient fertilizer product improved the efficacy of the oils. The results of these trials show that the tested volatile oils are suitable candidates for further research and for the development of organic fungicides against the diseases of apple.


1998 ◽  
Vol 38 (6) ◽  
pp. 625 ◽  
Author(s):  
W. S. Washington ◽  
O. N. Villalta ◽  
J. Ingram ◽  
D. Bardon

Summary. Twenty apple cultivars were assessed over 3 seasons for their susceptibility to natural infection with scab (caused by Venturia inaequalis) and powdery mildew (caused by Podosphaera leucotricha). It was evident that a number of important commercial cultivars are highly susceptible to leaf scab (average incidence of leaf scab: Pink Lady, 40.2% of leaves; Lady William, 37.1%; Braeburn, 20.0%; and New Jonagold, 18.7%) and powdery mildew (average incidence of leaf mildew: New Jonagold, 23.0%; Pink Lady, 17.8%). There was a high level of resistance to leaf scab in the cultivars Florina-Quérina, Redfree and Jonafree (all less than 1% incidence on leaves) and to powdery mildew in the cultivar Earlidel (no infection observed). The cultivars Jonathan, Bonza and Red Elstar showed a useful level of resistance to scab (average incidence of leaf scab between 1.6 and 3.2%), while the cultivars Red Fuji, HiEarly and Redfree all showed some resistance to powdery mildew (average incidence of mildew between 2.6 and 5.9%). Observations made on the low and variable numbers of fruit produced by some trees in their third year after planting showed that Pink Lady and Lady William were highly susceptible to fruit scab (67.6 or 57.6% scabbed fruit respectively). Twig infection by scab was also observed on shoots of the current season’s growth of Pink Lady.


2015 ◽  
Vol 60 (4) ◽  
pp. 381-393 ◽  
Author(s):  
Milovan Velickovic ◽  
Jelena Golijan

This paper implies current and economically significant diseases and pests of an apple and pear, i.e. problems of integral protection of these species of fruits in our country. Measures for their prevention are recommended regarding an adequate period. Special consideration is given to the diseases such as Venturia pyrina, Venturia inaequalis, Monilinia fructigena, Podosphaera leucotricha and Chondrostereum purpureum, as well as to pests such as Cydia pomonella, Cacopsylla pyri, Cacopsilla pyrisuga, Eryiophidae, Panonychus ulmi and Aphididae. The demand and importance of mass implementation of the concept of integral production in terms of obtaining biologically more valuable and ecologically safer fruits, i.e. preservation of the environment and health have been implied.


Author(s):  
Ran Wang ◽  
Yuan Hu ◽  
Peiling Wei ◽  
Cheng Qu ◽  
Chen Luo

Abstract Odorant binding proteins (OBPs) of insects play a critical role in chemical perceptions and choice of insect host plant. Bemisia tabaci is a notorious insect pest which can damage more than 600 plant species. In order to explore functions of OBPs in B. tabaci, here we investigated binding characteristics and function of odorant-binding protein 3 in B. tabaci (BtabOBP3). The results indicated that BtabOBP3 shows highly similar sequence with OBPs of other insects, including the typical signature motif of six cysteines. The recombinant BtabOBP3 protein was obtained, and the evaluation of binding affinities to tested volatiles of host plant was conducted, then the results indicated that β-ionone had significantly higher binding to BtabOBP3 among other tested plant volatiles. Furthermore, silencing of BtabOBP3 significantly altered choice behavior of B. tabaci to β-ionone. In conclusion, it has been demonstrated that BtabOBP3 exerts function as one carrier of β-ionone and the results could be contributed to reveal the mechanisms of choosing host plant in B. tabaci.


2012 ◽  
Vol 51 (9) ◽  
pp. 1633-1638 ◽  
Author(s):  
Martin Hirschi ◽  
Christoph Spirig ◽  
Andreas P. Weigel ◽  
Pierluigi Calanca ◽  
Jörg Samietz ◽  
...  

AbstractMonthly weather forecasts (MOFCs) were shown to have skill in extratropical continental regions for lead times up to 3 weeks, in particular for temperature and if weekly averaged. This skill could be exploited in practical applications for implementations exhibiting some degree of memory or inertia toward meteorological drivers, potentially even for longer lead times. Many agricultural applications fall into these categories because of the temperature-dependent development of biological organisms, allowing simulations that are based on temperature sums. Most such agricultural models require local weather information at daily or even hourly temporal resolution, however, preventing direct use of the spatially and temporally aggregated information of MOFCs, which may furthermore be subject to significant biases. By the example of forecasting the timing of life-phase occurrences of the codling moth (Cydia pomonella), which is a major insect pest in apple orchards worldwide, the authors investigate the application of downscaled weekly temperature anomalies of MOFCs for use in an impact model requiring hourly input. The downscaling and postprocessing included the use of a daily weather generator and a resampling procedure for creating hourly weather series and the application of a recalibration technique to correct for the original underconfidence of the forecast occurrences of codling moth life phases. Results show a clear skill improvement of up to 3 days in root-mean-square error over the full forecast range when incorporating MOFCs as compared with deterministic benchmark forecasts using climatological information for predicting the timing of codling moth life phases.


Author(s):  
J. N. Kapoor

Abstract A description is provided for Podosphaera leucotricha. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Malus spp., chiefly on M. pumila (apple), peach (Prunus persica), quince (Cydonia ualgaris) and Photinia spp. also attacked (Hirata, 1966). Also reported on almond fruit (43, 2544). DISEASE: Powdery mildew of apple. GEOGRAPHICAL DISTRIBUTION: Africa (? Kenya, Rhodaia, South Africa, Tanzania); Asia (China, India, Israel, Japan, U.S.S.R.); Australia and New Zealand, Europe (widely distributed) North America (Canada and U.S.A.); South America (Argentina, Brazil, Chile, Colombia, Peru). (CMI map 118). TRANSMISSION: Overwinters on host as dormant mycdium in blossom buds. The role of deistothecia in overwintering is doubtful. Spread by wind-borne conidia (Anderson, 1956).


2011 ◽  
Vol 50 (No. 2) ◽  
pp. 65-69 ◽  
Author(s):  
J. Blažek

Incidences of powdery mildew were repeatedly evaluated for two years on 1 420 young seedlings of 20 progenies (of different levels of mildew susceptibility) in a green house, and then for 10 years on 642 seedlings in an orchard. Part of the seedlings in the orchard were pre-selected for the characteristic and others not. Except for the first scoring done in the first year, there was no correlation between mildew incidence on individual seedlings in the green house and their mean performance in the orchard. The seedlings with scores above 6 (resistant or tolerant) at the first stage of evaluation in the green house, however, yielded four times more desirable seedlings after final selection in the orchard than the mean of the total. The progenies that had a better healthy state as a whole yielded more partially resistant genotypes than those with low mean scores. Therefore, the progenies that most rapidly develop infestation on the whole lot should be discarded, whereas those that retain a healthy state longer should be subjected to individual selection according to the previous item.


2009 ◽  
Vol 15 (1-2) ◽  
Author(s):  
I. J. Holb

In this review, some important features of biology and epidemiology are summarised for apple powdery mildew (Podosphaera leucotricha). In the first part of the review, the geographical distribution or the pathogen are discussed, then the morphology and taxonomy of the causal organism are described. Disease symptoms or apple powdery mildew are also shown and then host susceptibility/resistance is discussed in relation to durability of resistance. In the second part of this review, the general disease cycle of powdery mildew on apple are demonstrated and some basic features of powdery mildew epidemiology (such response of the pathogen to temperature, relative humidity, and rain as well as spore production, spore dispersal, diurnal patterns and temporal dynamics of the pathogen/disease) are also given on apple host.


2020 ◽  
Vol 23 (2) ◽  
pp. 1-6
Author(s):  
Helben Ismat Mohammaed ◽  
Mohammed Saeed Mirza ◽  
Feyroz Ramadan Hassan

Beauveria bassiana is an important entomopathogenic fungus that used as a biocontrol agent of insect pests. Maintaining and preserving B. bassiana cultures is essential for the effective evaluation of its potential as microbial agent against insect pest, for biodiversity studies and also for exchange of fungal material between laboratories. In the present work we evaluated the suitability of four preservation materials based on gelatin and rice to maintain the viability of B. bassiana to be used as baits for insect’s control. The gelatin amended with sugar recorded the maximum viability after 70 days of storage as 98.3% compared to 63.3% on rice media. Effective control of 80% of the ants was observed after 10 days of feeding on gelatin amended with sugar and rice bait. The results demonstrated that treatment with formulations containing conidia of B. bassiana presents insecticidal activity against ant in addition of acting as preservation materials.


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