scholarly journals Survey for incidence and severity of grain discolouration of paddy in northern parts of Karnataka

2021 ◽  
Vol 17 (2) ◽  
pp. 209-215
Author(s):  
K.B. Yadahalli ◽  
Jyoti A. Konnur

A roving survey was conducted in major paddy growing areas of northern parts of Karnataka. A total five districts viz., Belagavi, Dharwad, Haveri, Koppal and Uttara Kannada were surveyed during Kharif 2017 to record the severity and incidence of grain discolouration. In all the areas surveyed, rice was grown in black and red soils under both irrigated and rainfed condition. During the survey the disease was observed at early grain filling to maturity stage. The disease severity ranged from 06.66 to 26.23 PDI and per cent disease incidence ranged from 12.21 to 46.66 per cent. The maximum severity (26.23 %) and per cent incidence (46.66 %) was recorded in Medleri village of Ranebennur taluk on Haveri district. The minimum severity (06.66 %) and per cent incidence (15.19 %) was recorded in Gundenhatti village of Khanapur taluk on Belagvi district. The maximum disease severity and incidence was observed in black soil under irrigated conditions during maturity stage.

Author(s):  
Chavan A. A. ◽  
Dhutraj D. N.

Among fungal diseases anthracnose caused by Colleotrichum gloeosporioides is the most important disease. Survey of pomegranate (Punica granatum) orchards was conducted during 2013-14 in all the cropping seasons viz. mrig bahar, Hastabar and ambia bahar to assess the incidence and severity of anthracnose on pomegranate in Aurangabad, Jalna, Beed Osmanabad, Latur, Nanded, Hingoli and Parbhaani district of Marathwada region of Maharashtra state. The per cent disease incidence (PDI) and disease severity were recorded using 0-5 point scale. The maximum PDI on leaf was recorded in Hingoli (24.04%) followed by Nanded (22.62%) and Parbhani (22.22%) while least PDI recorded in Aurangabaad (15.09%). On fruit maximum PDI recorded in Parbhani (28.80%) which least in Beed district (19.02%). The 9.83 per cent disease variety on leaf was observed in Hingoli district and 10.70 per cent on fruit in Parbhani district. The maximum PDI (27.44%) on fruit and disease severity 12.45 per cent on fruit was recorded in Arakata. The maximum mean PDI 21.30 per cent on leaf and 25.85 per cent on fruit was recorded on trees aged above 5 years. The highest per cent disease incidence 25.34 per cent on leaf and 26.78 per cent on fruit was recorded on mrig bahar and the highest disease severity of leaf 10.05 per cent and fruit 11.22 per cent was reocrded in mrig bahar.


2019 ◽  
Vol 38 (4) ◽  
Author(s):  
Meenu Gupta ◽  
Munish Leharwan ◽  
Arti Shukla

Stem gall is one of the most important diseases of coriander. The effects of different temperature (15–35°C) and moisture levels (15-75 per cent) was studied on the development of stem gall of coriander caused by Protomyces macrosporus plants grown under controlled conditions. Results revealed that disease development was maximum (77.50%) at 25°C soil temperature followed by 30°C temperature giving 52.50 per cent disease incidence and 30.00 per cent disease severity, while very low and high temperature were not favourable for development of disease. In other experiment on different moisture regimes, 45 per cent of soil moisture level was favourable for disease development and resulted in 70.25 per cent disease incidence and 35.25 per cent disease severity. Very low and very high soil moisture levels were not favourable for disease development.


2018 ◽  
pp. 17-21
Author(s):  
SANDEEP PANDEY

Field experiments were undertaken during kharif 2012 and 2013 under irrigated ecosystem to evaluate the efficacy of botanicals along with standard fungicides for assessing per cent disease incidence, plant height, number of tiller per plant, number of spikelet per panicle, panicle length, 100-grain weight and grain yield against blast of rice. Pooled data of two years suggest that neem based commercial biopesticides with azadiractin as active ingredients were found effective in reducing disease severity and improving the yield attribute of the crop and proves promising products when compared to standard fungicides. Among the botanicals the spraying of Achook, Neem Azal T/S, Neem gold and Tricure shows significant reduction in disease severity, along with improving yield attributes, increasing the 100-grain weight and grain yield.


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

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.


1970 ◽  
Vol 34 (3) ◽  
pp. 417-424
Author(s):  
SK Biswas ◽  
MA Razzaque Akanda ◽  
M Rafi Uddin ◽  
PK Sarker

A two-year field experiment was conducted at Regional Agricultural Research Station, Jessore during the rabi seasons of 2002-2003 and 2003-2004 to find out the level of disease incidence under different levels of irrigation and fungicide spray on the bulb yield of onion. Four irrigation levels: no irrigation (I1), irrigation at 10 days interval (I2), 20 days interval (I3), and 30 days interval (14) with 4 spray schedules: no spray (F1), one spray at 40 days after transplanting (DAT) (F2), two sprays each at 40 and 55 DAT (F3) and three sprays each at 40, 55, and 70 DAT (F4) were used. Yield and yield attributes varied significantly (p = 0.05) between sprayed and unsprayed, and irrigated and non-irrigated treatments, respectively. Higher yields were obtained with the higher frequencies of irrigation and spray. Application of fungicide reduced the disease severity significantly, while irrigation had no significant effect on disease infection. But there was a decreasing trend of the disease severity with increasing irrigation frequency. The highest bulb yield of onion (12.45 t/ha) was obtained with a total water use of 245 mm in six applications including an effective rainfall of 16 mm and three sprays. The disease severity between sprayed and unsprayed plots ranged from 1.33 to 3.16 for I1, 1.08 to 2.33 for I2 1.16 to 2.83 for I3, and 1.16 to 3.00 for I4, respectively. Key Words: Onion, disease incidence, irrigation, water use efficiency. DOI: 10.3329/bjar.v34i3.3967 Bangladesh J. Agril. Res. 34(3) : 417-424, September 2009


2006 ◽  
Vol 32 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Jefferson Fernandes do Nascimento ◽  
Laércio Zambolim ◽  
Francisco Xavier Ribeiro do Vale ◽  
Paulo Geraldo Berger ◽  
Paulo Roberto Cecon

Four cultivars and 21 lines of cotton were evaluated for resistance to ramulose (Colletotrichum gossypii f. sp. cephalosporioides) in a field where the disease is endemic. The seeds of each genotype were planted in 5 x 5 m plots with three replications. The lines CNPA 94-101 and 'CNPA Precoce 2'were used as standard susceptible and resistant references, respectively. The disease incidence (DI) was calculated from the proportion of diseased plants in the plot. The disease index (DIn) was calculated from the disease severity using a 1 to 9 scale, and was evaluated at weekly intervals starting 107 days after emergence. The data collected was used to calculate the area under disease progress curve (AUDPC). In general, the DIn increased linearly with time and varied from 20.0 to 57.1 and AUDPC from 567 to 1627 among the genotypes which could be clustered in to two distinct groups. The susceptible group contained two cultivars and nine lines and the resistant group contained one cultivar and 12 lines. The relationship between disease index and evaluation times was linear for the 25 genotypes tested. The line CNPA 94-101, used as susceptible standard, was the most susceptible with an average DI = 83.4, DIn = 57.1 and AUDPC = 1627.7. The line CNPA 96-08 with DI = 37.8, DIn = 20.0 and AUDPC = 567.7 was the most resistant one. Among the commercial cultivars 'IAC 22' was the most susceptible and 'CNPA Precoce 2', used as resistant standard was the most resistant. The variability in virulence of the pathogen was studied by spray inoculating nine genotypes with conidial suspensions (10(5)/mL) of either of the 10 isolates. The disease severity was evaluated 30 days later using a scale of 1 to 5. The virulence of the isolate was expressed by DIn. All the isolates were highly virulent but their virulence avaried for several genotypes and could be clustered in two distinct groups of less and more virulent isolates. The isolate MTRM 14 from Mato Grosso was the least virulent while Minas Gerais was the most virulent, with DIn of 6.36 and 46.47, respectively. In this experiment the line HR 102 and the cultivar 'Antares' were the most resistant ones with DIns of 18.32 and 19.14, respectively.


2021 ◽  
Author(s):  
Renata Lebecka ◽  
Jadwiga Śliwka ◽  
Anna Grupa-Urbańska ◽  
Katarzyna Szajko ◽  
Waldemar Marczewski

AbstractSoft rot is a bacterial disease that causes heavy losses in potato production worldwide. The goal of this study was to identify quantitative trait loci (QTLs) for potato tuber resistance to bacteriumDickeya solaniand for tuber starch content to study the relationship between these traits. A highly resistant diploid hybrid of potato was crossed with a susceptible hybrid to generate the F1 mapping population. Tubers that were wound-inoculated with bacteria were evaluated for disease severity expressed as the mean weight of rotted tubers, and disease incidence measured as the proportion of rotten tubers. Diversity array technology (DArTseq™) was used for genetic map construction and QTLs analysis. The most prominent QTLs for disease severity and incidence were identified in overlapping regions on potato chromosome IV and explained 22.4% and 22.9% of the phenotypic variance, respectively. The second QTL for disease severity was mapped to chromosome II and explained 16.5% of the variance. QTLs for starch content were detected on chromosomes III, V, VI, VII, VIII, IX, XI, and XII in regions different than the QTLs for soft rot resistance. Two strong and reproducible QTLs for resistance toDickeya solanion potato chromosomes IV and II might be useful for further study of candidate genes and marker development in potato breeding programs. The relationship between tuber resistance to bacteria and the starch content in potato tubers was not confirmed by QTL mapping, which makes the selection of genotypes highly resistant to soft rot with a desirable starch content feasible.


2017 ◽  
Vol 2 (2) ◽  
pp. 159
Author(s):  
Altaf Hussain ◽  
Muhammad Arif ◽  
Aqleem Abbas

The aim of this study was the management of potato virus Y (PVY) in potato cv. Desiree through chemical and non-chemical methods. The experiment was carried out at the New Developmental Farm (NDF), The University of Agriculture, Peshawar during spring season, 2014 under field conditions. One of the major objectives of the experiment was to assess the effectiveness of the treatments application in their individual state as well as in combinations under field conditions. The treatments were mineral oil, insecticide, biocide and their combinations. Among various treatments, Diver was effective with disease severity level (1) and % disease incidence (40) in individual state and in combination (Diver + Confidor) and (Diver + Confidor + Neem extract) gave good results with % disease incidence (33.33) and with disease severity level (1). Neem extract was found to be less effective when used individually with % disease incidence (56.66) and with disease severity level (3), whereas Confidor when applied individually was more effective than Neem extract with % disease incidence (50) and with disease severity level (2). Moreover Diver in combination with Neem extract was found to be less effective in management of PVY as compared to Diver in combination with Confidor with % disease incidence (40) and disease severity level (1). Three aphid species were found in the field i.e Myzus persicae (Sulzer), Aphid gossypii (Glover) and Macrosiphum euphorbiae (Thomas). In case of aphid’s population, Confidor was more effective in reducing aphid’s population as compared to Diver and Neem extract. Finally, it can be concluded that Diver alone was more effective in the management of PVY. However in combination, Diver with Confidor significantly managed PVY under field conditions


Author(s):  
K. Swathi ◽  
P. Seetharamu ◽  
S. Dhurua ◽  
M. Suresh

A field experiment was conducted to determine the efficacy of different insecticides against sucking pests viz., thrips, Caliothrips indicus Bangall and whitefly Bemisia tabaci Gennadius, infesting blackgram in North coastal Andhrapradesh at Agricultural College, Naira during rabi 2017-2018.The experimental results revealed that all the treatments showed significant differences in reducing the population of sucking pests over untreated check. Among the tested insecticides, thiacloprid 21.7 SC @ 0.0325% was found to be highly effective against thrips by reducing74.80 per cent thrips population followed by acetamiprid 4 % + fipronil 4% @ 2ml l-1 with 70.81 per cent over untreated control, whereas flonicamid 50 WG @ 0.0325% was very effective against the population of whitefly byreducing 72.19 per cent and lowest per cent disease incidence (17.66%) followed by acetamiprid 4% + fipronil 4% @ 2ml l-1 (64.94%) and thiamethoxam 25 WG @ 0.005% (62.21%) which were on par with each other over control.


2021 ◽  
Author(s):  
Guangchao Sun ◽  
Ravi V. Mural ◽  
Jonathan D. Turkus ◽  
James C. Schnable

Southern rust is a severe foliar disease of maize (Zea mays) resulting from infection with the obligate biotrophic fungus Puccinia polysora. This disease reduces photosynthetic productivity, which in turn reduces yields, with the greatest yield losses (up to 50%) associated with earlier onset infections. P. polysora urediniospores overwinter only in tropical and subtropical regions but cause outbreaks when environmental conditions favor initial infection. Increased temperatures and humidity during the growing season combined with an increased frequency of moderate winters are likely to increase the frequency of severe southern rust outbreaks in the US corn belt. In summer 2020, a severe outbreak of southern rust was observed in eastern Nebraska (NE), USA. We scored a replicated maize association panel planted in Lincoln, NE for disease severity and found that disease incidence and severity showed significant variation among maize genotypes. Genome-wide association studies identified four loci associated with significant quantitative variation in disease severity. These loci were associated with candidate genes with plausible links to quantitative disease resistance. A transcriptome-wide association study identified additional genes associated with disease severity. Together, these results indicate that substantial diversity in resistance to southern rust exists among current temperate-adapted maize germplasm, including several candidate loci that may explain the observed variation in resistance to southern rust.


Sign in / Sign up

Export Citation Format

Share Document