SPRAYING TOMATOES FOR THE CONTROL OF LEAF SPOT, EARLY BLIGHT AND LATE BLIGHT

1957 ◽  
Vol 37 (4) ◽  
pp. 385-391
Author(s):  
K. M. Graham ◽  
A. G. Donaldson

Tomato leaf spot, early blight, and late blight were controlled effectively in the Ottawa district by six applications of the fixed copper COCS 55 or of Manzate (maneb). The split schedule consisting of three sprays with Manzate, followed by three sprays with COCS 55, or the tank mixture of these two fungicides, gave results comparable to those obtained with each of them alone. Some of the fungicides tested showed a degree of specificity in the control of certain diseases.

Author(s):  
B. C. Sutton

Abstract A description is provided for Septoria apiicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Apium spp. DISEASE: Leaf spot (or late blight) of cultivated and wild celery and celeriac. On leaves, seeds and seedling roots, reducing yield and causing wastage through blemishes on the edible petioles. Leaf lesions of variable size, 1-6 mm diam., abundant, amphigenous, circular or sometimes vein-limited, confluent when severe, becoming depressed pale brown, margin diffuse. GEOGRAPHICAL DISTRIBUTION: World-wide on Apium spp. TRANSMISSION: Seed-borne (Noble et al., 1958; Sheridan, 1966). Also disseminated by rain-splash, in irrigation water, by contact as well as by animals and workman's tools (Chupp & Sherf, 1960). The pathogen may remain viable in the soil for 18 months in buried celery crop refuse, but for less than 6 weeks in the absence of intact host tissue (42: 82). Viability in infected seed may drop to 2% within 8 months from harvest and both mycelium and conidia can stay alive in seed stored up to 14 months (42: 508; 44, 1332) but not beyond 2 yr.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2388
Author(s):  
Sk Mahmudul Hassan ◽  
Michal Jasinski ◽  
Zbigniew Leonowicz ◽  
Elzbieta Jasinska ◽  
Arnab Kumar Maji

Various plant diseases are major threats to agriculture. For timely control of different plant diseases in effective manner, automated identification of diseases are highly beneficial. So far, different techniques have been used to identify the diseases in plants. Deep learning is among the most widely used techniques in recent times due to its impressive results. In this work, we have proposed two methods namely shallow VGG with RF and shallow VGG with Xgboost to identify the diseases. The proposed model is compared with other hand-crafted and deep learning-based approaches. The experiments are carried on three different plants namely corn, potato, and tomato. The considered diseases in corns are Blight, Common rust, and Gray leaf spot, diseases in potatoes are early blight and late blight, and tomato diseases are bacterial spot, early blight, and late blight. The result shows that our implemented shallow VGG with Xgboost model outperforms different deep learning models in terms of accuracy, precision, recall, f1-score, and specificity. Shallow Visual Geometric Group (VGG) with Xgboost gives the highest accuracy rate of 94.47% in corn, 98.74% in potato, and 93.91% in the tomato dataset. The models are also tested with field images of potato, corn, and tomato. Even in field image the average accuracy obtained using shallow VGG with Xgboost are 94.22%, 97.36%, and 93.14%, respectively.


2016 ◽  
Vol 38 (3) ◽  
pp. 400-404 ◽  
Author(s):  
Mei-Ling Gao ◽  
Yu-Shi Luan ◽  
Hai-Ning Yu ◽  
Yong-Ming Bao

Author(s):  
Noureddine Benkeblia

Abstract Vegetable production in Jamaica, and throughout the world, faces many diseases that affect the yield and the quality of the fresh harvest produce. However, some diseases are more predominant than others. The most observed diseases of vegetables are anthracnose, leaf spot, club root, downy mildew, gray mold, mosaic and geminiviruses, early blight, septoria leaf spot and leaf rusts. Nevertheless, other diseases can also be found seriously affecting the grown vegetable. Greenhouse cropping systems are also affected by similar and other diseases such as septoria leaf spot, early blight, anthracnose, fusarium wilt, verticillium wilt, late blight, bacterial spot, bacterial speck, bacterial canker, gray mold, leaf mold, powdery mildew and elephant's foot disease. Although not specific to the country, other diseases are also found more frequently than others, and the frequency varies with the region and the cropping system (indoor or outdoor).


Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1327-1336 ◽  
Author(s):  
W. R. Stevenson ◽  
R. V. James ◽  
Debra Ann Inglis ◽  
Dennis A. Johnson ◽  
R. Thomas Schotzko ◽  
...  

Defender (A90586-11) is a new late blight-resistant potato cultivar which was released from the Tri-State Potato Variety Development Program in 2004. Conventional and reduced fungicide spray programs were compared on Defender and Russet Burbank (3 years) and Ranger Russet (1 year) in Wisconsin experimental field trials. Useful levels of field resistance to both late blight and early blight were observed in Defender in the absence of fungicide sprays and reduced fungicide input programs. Disease progressed slowest on Defender regardless of fungicide program, relative to Russet Burbank and Ranger Russet. Organic, conventional, and reduced fungicide spray programs also were compared on Defender and Russet Burbank in experimental greenhouse and field tests in Washington. Fungicide spray programs performed similarly on both Defender and Russet Burbank; however, area under the disease progress curve values for no-fungicide treatments were either three times (greenhouse) or six times (field) lower on Defender compared with Russet Burbank. Regardless of the fungicide program, total yield was higher for Defender than Russet Burbank. Mean economic returns associated with Defender also were higher than for Russet Burbank ($6,196 versus $4,388/ha). Fungicide and nonfungicide treatment programs generated similar returns on Defender whereas conventional and reduced fungicide programs generated comparable but higher returns than the nonfungicide program on Russet Burbank.


2018 ◽  
Vol 2ndInt.Conf.AGR (Special Issue) ◽  
pp. 637-650
Author(s):  
Jalal Hama salih Ismael Ismael ◽  
◽  
Shallaw Adulrahman Omer Omer ◽  

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 654-654
Author(s):  
S. M. Tian ◽  
P. Ma ◽  
D. Q. Liu ◽  
M. Q. Zou

Cercospora leaf blotch disease of potato (Solanum tuberosum L.) caused by Cercospora concors (Casp.) Sacc (synonym Mycovellosiella concors (Casp.) Deighton) occurs worldwide but mainly has been reported in the cool and temperate climates of Europe, Asia, North America, and eastern Africa. Cercospora leaf blotch is usually a minor disease and may go unnoticed since it commonly occurs simultaneously with other potato leaf diseases such as late blight (caused by Phytophthora infestans) and early blight (caused by Alternaria solani) (2). Symptoms of Cercospora leaf blotch first appear on lower leaves as small, yellowish green, irregular blotches and later may appear on middle and upper leaves. As the leaves expand, the blotches enlarge and become purplish brown or black. Conidiophores and conidia form on the underside of the lesions, giving the lesions a mildewed appearance similar to late blight. Necrotic lesions are distinguished from those caused by the early blight pathogen A. solani by the lack of concentric rings (1). In more severe epidemics of Cercospora leaf blotch, potato leaves may be killed, stem lesions become dark and entire plants die, but no resulting yield loss from the disease has been documented. Potato tubers are not infected. From August to September of 2005, yellow-brown lesions appeared on the upper side of potato leaves (cv. Zihuabai, certified virus free) and gray mildew developed on the underside of leaves in potato field trials conducted in Jining County, 41°N, 113°E of Inner Mongolia, North China. The infections were observed mostly on lower and middle leaves of plants; 20 to 30% of plants were infected. In the laboratory, the mildew was scraped with a sterile scalpel and examined microscopically. The conidiophores were irregular in width, grayish, and highly branched. The conidia were numerous, light to dark, straight or slightly bent, cylindrical or obclavate, with conspicuous scars, and zero to six septa. The mature spores were from 16 to 59 μm long and 4 to 6 μm wide. The teleomorph of the fungus was not found. On the basis of the morphological characters, the causal agent was identified as C. concors. C. concors has been previously identified from potato leaves in the Engshi District of Hubei Province, China (3), but to our knowledge, this is the first report of the fungus causing Cercospora leaf blotch of potato in Inner Mongolia, North China. References: (1) G. D. Franc and B. I. Christ. Page 22 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (2) E. R. French. Page 19 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (3) S. M. Tian et al. China Potato J. 1:13, 1997.


2018 ◽  
Vol 3 (1) ◽  
pp. 203
Author(s):  
Mangesh R. Deshmukh ◽  
Ganesh M. Bansode ◽  
Pallavi Mahajan

The present investigation on evaluation of varietal performance of various potato varieties under Pune Conditions was initiated in Oct 2012. Potato tubers of Kufri Lauvkar, Kufri Badshah, Kufri Pushkar, Kufri Surya, Kufri Khyati, Kufri Ashoka, Kufri Jyoti, Kufri Pukharaj were planted on ridges and furrows. The results revealed that Kufri Surya recorded significantly higher total tuber yield (20.67 t/ha) followed by Kufri Pukharaj (18.45 t/ha). However percent plant emergence and foliage senescence were found non-significant. Whereas results in respect of yield depicted that the variety Kufri Lauvkar produced the lowest tuber yield of 16.23 t/ha. Tuber dry matter (19.69%) was recorded to be the highest in Kufri Surya which was significantly superior in comparison to the remaining varieties. The least incidence of late blight (9.69%) was recorded on Kufri Khyati which was at par with K. Surya (9.74%). The least incidence of early blight (10.29%) was recorded on K. Lauvkar which too was at par with K. Surya. Keeping this in view K. Surya may be recommended as promising variety for Pune region


2019 ◽  
Vol 40 (5) ◽  
pp. 1805 ◽  
Author(s):  
Henrique da Silva Silveira Duarte ◽  
Laércio Zambolim ◽  
Franklin Jackson Machado ◽  
Hitor Rafael Pereira Porto ◽  
Fabricio Avila Rodrigues

Three experiments were carried out in an experimental field from Viçosa city, Minas Gerais, Brazil, to compare late blight (LB) (Phytophthora infestans) and early blight (EB) (Alternaria grandis) epidemics under different environmental conditions and fungicide application programs. Each experiment consisted of two side-by-side trials that were arranged in a randomized complete block design with five treatments and five replications. At 30 days after planting the potato (‘Ágata’ cultivar) plants in plots of trials 1 and 2 were inoculated with an isolate of P. infestans (A2 mating type) and four isolates of A. grandis, respectively. Fungicide applications were initiated at seven days after inoculation and repeated at 7- or 15-day intervals. The severity of LB and EB was assessed every two days, and the area under disease progress curve (AUDPC) was calculated for both diseases. The yield was quantified by weighing the tubers of all the plants from each plot after their maturation. Yield data were converted into kg ha-1 and the percentage of loss was calculated for each treatment. Based on the AUDPC, the LB severity was greater than the EB severity under all three environmental conditions, and this was reflected in the yield. LB and EB caused yield losses as high as of 82 and 45%, respectively. The fungicide effects on both LB and EB and the associated yield losses changed according to the environmental conditions, therefore, indicating the importance of using tools such as a forecast system to help farmers to decide the best time for fungicide application.


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