Response of groundnut (Arachis hypogaea L.) cultivars to late leaf spot disease (Passalora personata) under different sowing dates

2016 ◽  
Vol 39 (6) ◽  
Author(s):  
Utpal Dey ◽  
D. N. Dhutraj ◽  
A. P. Suryawanshi ◽  
Ritika Bhattacharjee ◽  
Diganggana Talukdar
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Size Range ◽  
Test Weight ◽  
Leaf Spot Disease ◽  
Frequency Range ◽  
Late Leaf Spot ◽  
Spot Disease ◽  
Pod Yield ◽  
Defoliation Frequency

Experiments were conducted to investigate the effect of date of sowing on groundnut cultivars against late leaf spot disease severity, defoliation, frequency and size of the leaf spot which revealed that all these aspects were significantly influenced by the date of sowing and crop varieties which directly affect the pod yield and test weight. The crop sown early on 25th June exhibited maximum mean late leaf spot disease severity (range 43.63 to 54.05%), defoliation (range, 17.22 to 22.30%), frequency (range, 1.32 to 1.78 / mm2) and size (range, 1.49 to 1.56 / mm2) and thereby gave reduced pod yield (range, 1225 to 1720 kg/ha) and test weight (28.66 to 32.97 g) followed by 10th July and 25th July. Among the groundnut cultivars, susceptible cv. JL 24 exhibited maximum mean disease severity (range, 35.94 to 54.05 %), defoliation (range, 11.61 to 22.30 %), frequency (range, 1.23 to 1.78 / mm2) and size (range, 1.26 to 1.56 / mm2), followed by TAG 24 and TG 26. However, LGN 1 exhibited least mean disease severity, defoliation, frequency and size with the highest pod yield (ranges, 1720 to 2332 kg/ha) and test weight (ranges, 32.97 to 38.59 g).

scholarly journals Registration of three peanut allotetraploid interspecific hybrids resistant to late leaf spot disease and tomato spotted wilt

2021 ◽  
Author(s):  
Ye Chu ◽  
H. Thomas Stalker ◽  
Kathleen Marasigan ◽  
Chandler M. Levinson ◽  
Dongying Gao ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Interspecific Hybrids ◽  
Leaf Spot Disease ◽  
Late Leaf Spot ◽  
Spot Disease ◽  
Tomato Spotted Wilt

scholarly journals Lack of Induced Systemic Resistance in Peanut to Late Leaf Spot Disease by Plant Growth-Promoting Rhizobacteria and Chemical Elicitors

Plant Disease ◽  
2001 ◽  
Vol 85 (8) ◽  
pp. 879-884 ◽  
Author(s):  
Shouan Zhang ◽  
M. S. Reddy ◽  
Nancy Kokalis-Burelle ◽  
Larry W. Wells ◽  
Stevan P. Nightengale ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Acquired Resistance ◽  
Plant Growth Promoting Rhizobacteria ◽  
Systemic Resistance ◽  
Leaf Spot Disease ◽  
Late Leaf Spot ◽  
Spot Disease ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Significant Disease

A disease assay was optimized for late leaf spot disease of peanut using Cercosporidium per-sonatum in the greenhouse, and this assay was used in attempts to elicit induced systemic resistance using strains of plant growth-promoting rhizobacteria (PGPR) and chemical elicitors. Nineteen strains of spore-forming bacilli PGPR, including strains of Paenibacillus macerans, Brevibacillus brevis, Bacillus laterosporus, B. subtilis, B. pumilus, B. amyloliquefaciens, B. sphaericus, B. cereus, and B. pasteurii, which previously elicited systemic disease control activity on other crops, were evaluated in greenhouse assays. Seven PGPR strains elicited significant disease reduction in a single experiment; however, none repeated significant protection achieved in the greenhouse assay, while significant protection consistently occurred with the fungicide chlorothalonil (Bravo). In other greenhouse trials, neither stem injections of C. personatum nor foliar sprays of chemicals, including salicylic acid, sodium salicylate, isonicotinic acid, or benzo[1,2,3]thiadiazole-7-carbothioc acid S-methyl ester (Actigard), which elicit systemic acquired resistance on other crops, elicited significant disease protection. In contrast, foliar sprays with DL-β-amino-n-butyric acid (BABA), which is an elicitor of localized acquired resistance, resulted in significantly less late leaf spot disease in one of two tests. Combination treatments of four PGPR strains with BABA in the greenhouse did not significantly protect peanut from late leaf spot. Field trials conducted over two growing seasons indicated that none of the 19 PGPR strains, applied as seed treatments at two concentrations, significantly reduced late leaf spot disease. The same chemical elicitors tested in the greenhouse, including BABA, did not elicit significant disease protection. Some combinations of four PGPR and BABA significantly reduced the disease at one but not at two sample times. Collectively, these results suggest that late leaf spot resistance in peanut is not systemically inducible in the same manner as is resistance to diseases in other crops by PGPR and chemical inducers.

scholarly journals Leaf and canopy reflectance spectrometry applied to the estimation of angular leaf spot disease severity of common bean crops

PLoS ONE ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. e0196072 ◽  
Author(s):  
Víctor Martínez-Martínez ◽  
Jaime Gomez-Gil ◽  
Marley L. Machado ◽  
Francisco A. C. Pinto
Keyword(s):  
Common Bean ◽  
Disease Severity ◽  
Leaf Spot ◽  
Angular Leaf Spot ◽  
Leaf Spot Disease ◽  
Canopy Reflectance ◽  
Reflectance Spectrometry ◽  
Spot Disease

scholarly journals A study of Eggplant Leaf Spot Disease in Greenhouses at Basrah Province

2019 ◽  
Vol 32 ◽  
pp. 182-193
Author(s):  
Yehya A. Salih ◽  
Rusul J. Abdul Ridha
Keyword(s):  
Disease Severity ◽  
Leaf Spot ◽  
Dry Weight ◽  
Control Treatment ◽  
Leaf Spot Disease ◽  
Curvularia Lunata ◽  
Pathogenicity Test ◽  
Spot Disease ◽  
Tomato Cultivars ◽  
First Time

The present study has been conducted to isolate and identify the leaf fungal spot pathogens of eggplant at different regions of Basrah city and their  chemical  control. The results showed that the disease was spread at all regions cultivated with eggplant at Basrah province with infection percentages of 46.6-88.5%. The highest infection percent was recorded at Garmat Ali region (88.5%), while the lowest percent was recorded at the Agricultural station (46.6%). The highest percent of  disease severity (50 %) was recorded at Tomato Cultivars Breeding Project, while the lowest percent was recorded at Agricultural station (20%). Alternaria alternata, Cladosporium oxysporum and Curvularia lunata were isolated from the leaves infected with spot disease, the pathogenicity test revealed that all isolated fungi were pathogenic. C. oxysporum and C. lunata were recorded for the first time in Iraq as causal agents of eggplant leaf spot. The results showed that the fungicide Ortiva inhibited the growth of the fungi with an average of 95.7%, followed by Difecor ( 94.9%), additionally, it was noticed that all examined fungicides completely inhibited the growth of both C. oxysporum and C. lunata ( %100 for each one). The study revealed that the fungicide Ortiva significantly reduced the disease severity of eggplant leaf spot disease up to 11.6% compared with control treatment which was 25%. Finally the results explained that the fungicide Ortiva gave the best protection to eggplant which infected with leaf spot disease compared to the other fungicides, it achieved a best plant height, higher dry weight of shoot and root systems, higher leaf area and higher leaves number. Therefore it is recommended for controlling the spot disease.

scholarly journals Comparative Performance of Chemical and Biological-based Products in Management of Algal Leaf Spot on Magnolia

2020 ◽  
Vol 30 (6) ◽  
pp. 733-740
Author(s):  
Fulya Baysal-Gurel ◽  
Ravi Bika ◽  
Christina Jennings ◽  
Cristi Palmer ◽  
Terri Simmons
Keyword(s):  
Hydrogen Peroxide ◽  
Disease Severity ◽  
Leaf Spot ◽  
Growth Parameters ◽  
Leaf Spot Disease ◽  
Copper Oxychloride ◽  
Spot Disease ◽  
Disease Progress ◽  
Dimethyl Ammonium Chloride ◽  
Dimethyl Ammonium

Magnolia trees (Magnolia sp.) are a popular choice for consumers when choosing flowering woody plants for landscapes. Magnolia species grow in a wide variety of both temperate and tropical locations. Southern magnolia (Magnolia grandiflora) is one of the more popular magnolias due to its pleasing aesthetics: large showy flowers in a range of colors and evergreen foliage. However, magnolias can be affected by algal leaf spot. Algal leaf spot is caused by Cephaleuros virescens, which is a widespread plant parasitic green alga. There has been little research on how to treat algal leaf spot on magnolia plants. This study focuses on identifying effective biological- and chemical-based fungicides for the management of algal leaf spot disease of magnolia plants. Two experiments were conducted in a randomized complete block design with six replications per treatment and a total of 12 treatments, including a nontreated control. The first experiment (Expt. 1) was conducted in a shade house (56% shade) at McMinnville, TN, using southern magnolia plants. The second experiment (Expt. 2) was conducted at a commercial nursery in McMinnvillle, TN, in a field plot planted with ‘Jane’ magnolia (Magnolia liliiflora ‘Nigra’ × Magnolia stellata ‘Rosea’). The algal leaf spot disease severity, disease progression, plant marketability and growth parameters were evaluated. In both experiments, all treatments reduced algal leaf spot disease severity and disease progress in comparison with the nontreated control. In Expt. 1, copper octanoate, copper oxychloride, chlorothalonil water-dispersible granules, chlorothalonil suspension concentrate, didecyl dimethyl ammonium chloride, azoxystrobin + benzovindiflupyr, hydrogen peroxide + peroxyacetic acid, and mono- and di-potassium salts of phosphorus acid + hydrogen peroxide reduced the disease severity and disease progress the most and were not statistically different from one another. In Expt. 2, azoxystrobin + benzovindiflupyr, didecyl dimethyl ammonium chloride, and copper oxychloride significantly reduced disease severity and disease progress (area under disease progress curve). Treatments had no deleterious effect on plant growth parameters such as height and width, and no phytotoxicity of applied treatments or defoliation was observed. Treated magnolia plants had better plant marketability compared with the nontreated control plants. The findings of this study will help growers to achieve better management of algal leaf spot disease on magnolia trees.

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