scholarly journals Major cucumber diseases and the crop immunity

2021 ◽  
Vol 11 (1) ◽  
pp. 46-54
Author(s):  
S.V. Bondarenko ◽  
S.V. Stankevych ◽  
A.V. Matsyura
Keyword(s):  
Downy Mildew ◽  
Economic Effect ◽  
Product Variety ◽  
Agricultural Science ◽  
Integrated Systems ◽  
Pseudoperonospora Cubensis ◽  
Vegetable Crops ◽  
Economic Traits ◽  
Open Ground ◽  
Commercial Yield

In Ukraine, cucumber (Cucumis sativus Linneus) annually occupies about 20 % of the total area of all vegetable crops sown in the open ground or 52.6 thousand hectares. The main reason that significantly reduces the quantitative and qualitative indicators of this vegetable crop's main valuable economic traits is the high incidence of commercial crops with diseases, especially downy mildew (Pseudoperonospora cubensis (Berk and M.A. Curtis) Rostovtsev). Since 1985 in Ukraine, this cucumber disease in the open ground on nonresistant varieties has continuously had intense development, in some years the development – by the type of epiphytotic. Simultaneously, the shortage of commercial yield of this vegetable crop due to the defeat of this disease under the field conditions can reach the level of 50–80 % or more, seed loss – 25–70 %. One of the main reasons for significant losses of commercial yield and seeds of gherkin cucumber under the conditions of its cultivation in the open ground is recognized as the high susceptibility of samples to some diseases, particularly downy mildew (Pseudoperonospora cubensis (Berk. and M.A. Curtis) Rostovtsev). Unfortunately, this problem has remained relevant for Ukraine over the past few decades. So, obtaining the initial material of a gherkin cucumber with a harmonious combination in the genotypes of a complex of various valuable economic characteristics (yield, quality, resistance to diseases, chemical substances content, suitability for various types of processing) and creating a modern competitive, innovative product (variety, hybrid) on its basis remains a relevant and priority task for domestic agricultural science at present. At the same time, scientists have proved that introducing complex (integrated) systems into production, which expect the biologization of protection with its transfer to an ecological and economic basis, is recognized as the most promising today. We suggested using resistant varieties (hybrids) in such integrated systems that provide the highest economic effect.

CONSTRUCTING A DEMONSTRATION VEGETABLE GARDEN

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 671f-671
Author(s):  
M. Marutani ◽  
R. Quitugua ◽  
C. Simpson ◽  
R. Crisostomo
Keyword(s):  
Weed Control ◽  
Cultural Practices ◽  
Irrigation System ◽  
Agricultural Science ◽  
Drip Irrigation System ◽  
Vegetable Crops ◽  
University Campus ◽  
Crop Cover ◽  
Different Types ◽  
The University

A demonstration vegetable garden was constructed for students in elementary, middle and high schools to expose them to agricultural science. On Charter Day, a University-wide celebration, students were invited to the garden on the University campus. The purpose of this project was twofold: (1) for participants to learn how to make a garden and (2) for visitors to see a variety of available crops and cultural techniques. Approximately 30 vegetable crops were grown. The garden also presented some cultural practices to improve plant development, which included weed control by solarization, mulching, a drip irrigation system, staking, shading and crop cover. Different types of compost bins were shown and various nitrogen-fixing legumes were displayed as useful hedge plants for the garden.

The zoospore of Pseudoperonospora cubensis, the causal agent of cucurbit downy mildew

1989 ◽  
Vol 8 (5) ◽  
pp. 511-516 ◽  
Author(s):  
Lene Lange ◽  
Ulla Edén ◽  
Lauritz W. Olson
Keyword(s):  
Downy Mildew ◽  
Causal Agent ◽  
Pseudoperonospora Cubensis ◽  
Cucurbit Downy Mildew

scholarly journals Diagrammatic scale to assess downy mildew severity in melon

2009 ◽  
Vol 27 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Sami J Michereff ◽  
Marissônia A Noronha ◽  
Gaus SA Lima ◽  
Ígor CL Albert ◽  
Edilaine A Melo ◽  
...  
Keyword(s):  
Linear Regression ◽  
Leaf Area ◽  
Downy Mildew ◽  
Pseudoperonospora Cubensis ◽  
Northeast Brazil ◽  
Simple Linear Regression ◽  
Standard Methods ◽  
Accuracy And Precision ◽  
Severity Levels ◽  
Diagrammatic Scale

The downy mildew, caused by Pseudoperonospora cubensis, is an important melon disease in Northeast Brazil. Considering the lack of standard methods for its assessment, a diagrammatic scale was developed with 2, 4, 8, 16, 32, 64, 82, and 96% of affected leaf area. The scale was then checked for its accuracy, precision, and reproducibility in estimating downy mildew severity. The diagrammatic scale was validated by eight disease raters; using 50 leaves with different severity levels, previously measured using the software Assess®. Two evaluations were performed on the same set of leaves, but in a different sequence order, by the same raters, within a 15-day interval. The accuracy and precision of each rater was determined by simple linear regression between the actual and the estimated severity. The scale provided good levels of accuracy (means of 87.5%) and excellent levels of precision (means of 94%), with absolute errors concentrated around 10%. Raters showed great repeatability (means of 94%) and reproducibility (>90% in 90.3% of cases) of estimates. Therefore, we could conclude that the diagrammatic scale presented here was suitable for evaluating downy mildew severity in melon.

scholarly journals Cucumber breeding lines are a prospective material for creating new varieties for open ground in southern Russia

2021 ◽  
pp. 65-67
Author(s):  
O. P. Kigashpaeva ◽  
A. V. Gulin ◽  
L. P. Lavrova
Keyword(s):  
Import Substitution ◽  
Economic Traits ◽  
Scientific Center ◽  
Breeding Lines ◽  
Fruit Setting ◽  
Open Ground ◽  
New Varieties ◽  
Southern Russia ◽  
Predominantly Female ◽  
Academy Of Sciences

The varieties and hybrids of cucumbers cultivated in the Astrakhan region are insufficiently productive and are largely affected by a number of diseases. The introduction of innovative developments into production, in particular, new varieties and hybrids of domestic selection, largely solves the problem of import substitution and food security. The goal is to use promising breeding lines and their offspring as genetic sources and donors when creating new varieties and hybrids for open field conditions in southern Russia.Methods. Experiments were carried out in the fields of Precaspian agrarian federal scientific center of the Russian academy of sciences, according to the methods used in the Astrakhan region. Within three years, 47 collection samples were tested.Results. The article presents the results of studying the 12 most promising ones, distinguished by a complex of valuable economic traits, in particular by yield, amicability of fruit setting, which are of interest for further breeding work. According to the results of the data obtained, we can say that the best were the lines: 13-88RZ, 13-101RZ, Gherkins, KRASTAVAC, Courage, Zina, they can be used to create new varieties and hybrids of cucumber as donors of a predominantly female type of flowering, harmonious yield.

scholarly journals Host Preference of Mating Type in Pseudoperonospora cubensis, the Downy Mildew Causal Agent of Cucurbits

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 292-292 ◽  
Author(s):  
Y. Cohen ◽  
A. E. Rubin ◽  
M. Galperin
Keyword(s):  
Downy Mildew ◽  
Mating Type ◽  
Host Preference ◽  
Practical Implication ◽  
Natural Infection ◽  
Primary Source ◽  
Pseudoperonospora Cubensis ◽  
Close Proximity ◽  
Detached Leaves ◽  
Classical Genetics

The A2 mating type of Pseudoperonospora cubensis was first discovered in Israel in May 2010 on butternut gourd (Cucurbita moschata) (1). We monitored the occurrence of the A2 mating type of P. cubensis in isolates collected during May 2010 through September 2012 from downy mildew-infected cucurbit crops growing along the coastal plain of Israel. Mating type was determined by oospore production in melon leaf discs co-inoculated with sporangia of a test isolate mixed with sporangia of A1 or A2 tester isolates (2). The A1 and A2 tester isolates were maintained at 14°C (14 h light/day) by repeated inoculation of detached leaves of cucumber and pumpkin, respectively. The 29 isolates that were collected from cucumber (Cucumis sativum) were all A1. Of the 33 isolates collected from pumpkin (Cucurbita maxima), squash (C. pepo), or butternut gourd (C. moschata), 88% were A2 and 12% were A1. The host preference of mating type in P. cubensis was monitored at Bar-Ilan University farm during April to July 2012, among about 800 plants of eight cucurbit species (~100 plants per species) that were grown side-by-side in three adjacent net-houses (two 6 × 50 m and one 6 × 100 m) and exposed to natural infection. Downy mildew developed on cucumber, melon, pumpkin, squash, and butternut gourd, but not on watermelon, sponge gourd (Luffa cylindrica), or Momordica balsamina. Three-hundred and three isolates of P. cubensis were collected and tested for mating type: 123 from cucumber, 53 from melon, 30 from pumpkin, 48 from butternut gourd, and 41 from squash. The cucumber isolates expressed A1, A2, and A1A2 at a ratio of 94.3%, 3.3%, and 2.4%, respectively; the melon isolates 58.5%, 26.4%, and 15.1%; the pumpkin isolates 0%, 96.7%, and 3.3%; the butternut isolate 7.3%, 87.3%, and 5.5%; and the squash isolates 2.4%, 97.6%, and 0%, respectively. A1A2 isolates produce oospores when crossed with either A1 or A2 tester isolates. This is the first evidence suggesting a preference of A1 isolates to Cucumis spp. and of A2 isolates to Cucurbita spp. similar preference was recently observed among Chinese isolates of this pathogen (unpublished data). The mechanism(s) controlling this preference is not known. Classical genetics is currently employed to P. cubensis in order to understand if it derives from true linkage. The practical implication for downy mildew management is that growing cucumber/melon in close proximity to pumpkin/squash/butternut gourd should be avoided as it may enhance oospore production in nature. Oospores in soil were recently shown to serve as a primary source of downy mildew infection in cucumber (3). References: (1) Y. Cohen, A. E. Rubin, and M.Galperin. Plant Dis. 95:874, 2011; (2) Y. Cohen and A. E. Rubin. Eur. J. Plant Pathol. 132:577, 2012; (3) Y. J. Zhang et al. J. Phytopathol. 160:469, 2012.

scholarly journals Fungicides for Control of Downy Mildew on Pickling Cucumber in Michigan

2019 ◽  
Vol 20 (3) ◽  
pp. 165-169 ◽  
Author(s):  
Katelyn E. Goldenhar ◽  
Mary K. Hausbeck
Keyword(s):  
Downy Mildew ◽  
Untreated Control ◽  
Field Studies ◽  
Pseudoperonospora Cubensis ◽  
Relative Area ◽  
Disease Progress Curve ◽  
Cucurbit Downy Mildew ◽  
Disease Progress ◽  
Pickling Cucumber ◽  
Progress Curve

Michigan growers rely on fungicides to limit cucurbit downy mildew (CDM), incited by Pseudoperonospora cubensis; resistance of the pathogen to fungicides is a concern. We evaluated fungicides against CDM in Michigan field studies from 2015 to 2017. According to the relative area under the disease progress curve (rAUDPC), in 2015, mandipropamid, propamocarb, fluxapyroxad/pyraclostrobin, copper octanoate, and dimethomorph resulted in disease levels similar to the control. These treatments, along with cymoxanil, were similar to the control in 2016. Fungicides that were ineffective during 2015 and 2016 did not limit CDM in 2017. Famoxadone/cymoxanil and fluopicolide did not limit CDM in 2017. Each year, the following treatments were similar for disease based on rAUDPC data: oxathiapiprolin applied alone or premixed with chlorothalonil or mandipropamid, ametoctradin/dimethomorph, fluazinam, mancozeb/zoxamide, cyazofamid, and ethaboxam. An exception occurred in 2017, when ethaboxam was less effective than fluazinam, oxathiapiprolin/chlorothalonil, and oxathiapiprolin/mandipropamid. Mancozeb and chlorothalonil treatments were similar in 2015 and 2017, according to rAUDPC data. In 2017, yields were increased for oxathiapiprolin/chlorothalonil, oxathiapiprolin/mandipropamid, mancozeb, ametoctradin/dimethomorph, mancozeb/zoxamide, ethaboxam, cyazofamid, chlorothalonil, and fluazinam compared with the untreated control.

Downy mildew of Cucurbits (Pseudoperonospora Cubensis): the Fungus and its hosts, distribution, epidemiology and control

1980 ◽  
Vol 8 (2) ◽  
pp. 109-147 ◽  
Author(s):  
J. Palti ◽  
Y. Cohen
Keyword(s):  
Downy Mildew ◽  
Pseudoperonospora Cubensis ◽  
And Control

scholarly journals Relationship Between Loci Conferring Downy Mildew and Powdery Mildew Resistance in Melon Assessed by Quantitative Trait Loci Mapping

2005 ◽  
Vol 95 (5) ◽  
pp. 556-565 ◽  
Author(s):  
L. Perchepied ◽  
M. Bardin ◽  
C. Dogimont ◽  
M. Pitrat
Keyword(s):  
Quantitative Trait Loci ◽  
Powdery Mildew ◽  
Downy Mildew ◽  
Resistance Genes ◽  
Quantitative Trait ◽  
Pseudoperonospora Cubensis ◽  
Podosphaera Xanthii ◽  
Resistance Qtl ◽  
Trait Loci ◽  
Artificial Inoculations

Partial resistance to downy mildew (Pseudoperonospora cubensis) and complete resistance to powdery mildew (Podosphaera xanthii races 1, 2, 3, and 5 and Golovinomyces cichoracearum race 1) were studied using a recombinant inbred line population between ‘PI 124112’ (resistant to both diseases) and ‘Védrantais’ (susceptible line). A genetic map of melon was constructed to tag these resistances with DNA markers. Natural and artificial inoculations of Pseudoperonospora cubensis were performed and replicated in several locations. One major quantitative trait loci (QTL), pcXII.1, was consistently detected among the locations and explained between 12 to 38% of the phenotypic variation for Pseudoperonospora cubensis resistance. Eight other Pseudoperonospora cubensis resistance QTL were identified. Artificial inoculations were performed with several strains of four races of Podosphaera xanthii and one race of G. cichoracearum. Two independent major genes, PmV.1 and PmXII.1, were identified and shown to be involved in the simple resistance to powdery mildew. Three digenic epistatic interactions involving four loci were detected for two races of Podosphaera xanthii and one race of G. cichoracearum. Co-localization between PmV.1, resistance genes, and resistance genes homologues was observed. Linkage between the major resistance QTL to Pseudoperonospora cubensis, pcXII.1, and one of the two resistance genes to powdery mildew, PmXII.1, was demonstrated.

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