Cultural, Morphological and Pathogenic Variability in Alternaria cyamopsidis Causing Alternaria Blight of Clusterbean in Rajasthan

Background: Alternaria cyamopsidis (Rang. and Rao) causes Alternaria blight of clusterbean and it is one of the significant disease of clusterbean. Studies were conducted to compare the Cultural, morphological and pathogenic variability among ten isolates of Alternaria cyamopsidis from clusterbean, in five districts of Rajasthan viz., Bikaner, Barmer, Churu, Hanumangarh and Jaipur. Methods: During 2016-17 exhaustive survey was conducted in clusterbean growing areas of Rajasthan and collected diseased samples of clusterbean caused by Alternaria. All the samples were processed for isolation, purification and their pathogenicity was proved in cagehouse and laboratory and standard methods were adopted for cultural and morphological variability study. Result: All the isolates showed variation in their morphological characters, i.e., colony color and shape; conidial number, size, width, length, shape and septation on PDA. Out of ten isolates two isolate, viz., AlcyJp1 and AlcyJp2 showed maximum colony diameter 89.50 and 86.30 mm, respectively. All the isolates varied in their spore length and width and virulent on the tested variety of clusterbean for virulence. AlcyJp1 was the most virulent and produced maximum (65.50%) disease intensity, followed by AlcyJp2 isolate (61.22%).

Epidemiological models based on meteorological variables to forewarn Alternaria blight of rapeseed-mustard

Alternaria blight [Alternaria brassicae (Berk.) Sacc.] is one of the most widespread and harmful maladies of rapeseed-mustard, causing yield loss up to 47 per cent. Meteorological parameters especially temperature, relative humidity and bright sunshine hours play major role in the development of Alternaria blight disease. Infection by the pathogen is highly influenced by meteorological conditions. A well-tested model based on meteorological variables is an efficient tool for forewarning this disease. Epidemiology of Alternaria blight of brassicas was investigated based on long term data during 2003-2018 crop seasons on the disease severity and meteorological variables, which was validated with data for two subsequent years. During this study, meteorological variable-based regression model of forewarning was developed for maximum severity (%) of Alternaria blight on leaves and pods for three locations viz., New Delhi, Hisar (Haryana) and Mohanpur (West Bengal)] in India. Validation of the forewarning models for maximum severity (%) of Alternaria blight proved the efficiency of the targeted forecasts.

Effect of Selected Essential Oils and Botanicals on Alternaria Blight (Alternaria brassicae (Berk) Sacc) of Mustard (Brassica juncea (Linn) Czern and Coss

Indian mustard (Brassica juncea (L.) Czern.coss) is also known as sarson, rai or raya, toria or Lahi.it is a herbaceous annual plant. Mustard is the second important oilseed crop in the world after sunflower, soybean and palm oil. Alternaria blight disease caused by Alternaria brassicae (Berk.) Sacc. It has been reported from all the continents of the world. Average yield losses occur due to various pest and diseases among which Alternaria blight is an important disease. Field experiment was conducted at the research plot of the Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh during the rabi season of 2020-2021 to test, Effect of selected essential oils and botanicals against Alternaria blight (Alternaria brassicae (Berk.) Sacc) of mustard (Brassica juncea (Linn.) Czern and Coss), by foliar spray of certain essential oil, plant extracts and fungicide. The treatments were Neem oil @2%, Eucalyptus oil @2%, Pongamia oil @2%, Lawsonia inermis extract @15%, Chenopodium album extract @15% Mancozeb (treated check) @ 0.2% and control (untreated check). The percent disease intensity on leaves at 45, 60 and 75 DAS, number of siliquae per plant, number of seeds per siliquae, length of siliquae (cm), test weight of seed (1000 number), biological yield (gm) and seed yield were recorded. Among the treatments, maximum number of number of siliquaes (243.13), maximum number of seeds per siliquae (12.27), length of siliquae (5.16 cm), minimum disease intensity (%) (29.01 %), maximum test weight (3.57 gm), maximum yield (9.43 qt) and biological yield (24.70 gm) were recorded in the treatment T2 Eucalyptus oil @2% followed by T1 Neem oil @2%, T4 Lawsonia inermis extract @15%, T3 Pongamia oil @2%, T5 Chenopodium extract @15%, when compared to treated check T6 Mancozeb @ 0.2% and untreated check T0. Higher gross return value (Rs. 66295), net return value (Rs. 29295), and B: C ratio (1.7:1) was found in the treatment T2 – Eucalyptus oil @2% as compared to T5–mancozeb and T0–control.

Genome wide association mapping for identification of QTL(S) underlying resistance to Alternaria blight (Alternaria brassicae (Berk) Sacc.) in Indian mustard (Brassica juncea L. Czern. & Coss.)”

Disease screening against Alternaria blight under field condition showed that, none was free from disease only 13 genotypes were found MR and 152 genotypes were found MS, 252 S and 3HS. The high estimate of phenotypic and genotypic coefficient of variation was recorded for YPP and SB., high estimate of broad sense heritability was recorded all characters except YPP. The genetics advance in per cent of mean was found high for PB, high heritability along with high genetic advance was observed for HPF. At phenotypic and genotypic level both YPP shoes highly significant and positive correlation. At phenotypic and genotypic level path coefficient reveled that in HPF, PL. The genotypes were grouped into eight different non overlapping cluster (five 115, three 100, six 84, one 78, seven 37 and three, two and four 1, eight 36 genotypes). The maximum and minimum inter cluster distance was between six, eight and one, three. One highest cluster mean for PH, MAT, and HPF and two (MAT, PH, HPF). Three (MAT, PH, HPF) four (MAT, PH, HPF) five (PH, MAT, HPF) six (MAT, PH, HPF) seven (MAT, HPF. PH), eight had no values due to reason no geminated or un survived plant and GWAS analysis of identified six significant association for Alternaria blight resistance on chromosome (A07, A09, A03, B07, B04, B03) respectively, This study showed that the diversity panel of Indian mustard identified QTLs for controlling of disease resistance against Alternaria blight in Indian mustard.

Investigation on the Severity of Alternaria Blight of Pigeonpea and its Characterisation in Northern Karnataka

Background: The Alternaria blight of pigeonpea is considered as an important foliar disease and poses threat to the pigeonpea cultivation due to change in the climatic condition, cultivation practices and variation in pathogenic character. Though the disease is noticed in an alarming proportion after the post rainy season and causing economic yield, little is known about the severity of disease and its impact on crop production. The current study is aimed to study the disease severity and variability of the pathogen and which would helps us to understand the biology of the pathogen to develop suitable management strategies. Methods: In the field and laboratory investigations during 2015 and 2017, different localities of Northern Karnataka were surveyed. Twenty sampling localities were selected based on geographical situation. In the laboratory, collected diseased samples were isolated and determined morphologically and culturally based on taxonomic and molecular characters. Result: Our investigations revealed the varied disease severity in surveyed districts, Vijayapura district recorded the maximum disease severity with a range of 38.67 to 49.33 and this might be due to variation in pathogenic character, rainfall pattern and climatic conditions and also disease severity varied with varieties indicating the source of resistance. The present study contributed for identification of geographical distribution of the disease and its severity in different varieties and places of Northern Karnataka and their genetic and morphological variations.

Исследование эффективности иммунопротекторного действия препарата Стимпо против альтернариоза картофеля в условиях западноукраинской лесостепной провинции

The proposed researches results touches the determining preparation Stympo immunoprotective action against potato alternaria blight. It was determined that the biopreparation usage plays important role for receiving high yield indexes through the disease development decrease favoring.