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Researcher 2017;9(12)

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Screening of different carrot varieties against Alternaria leaf blight and its chemical management. Muhammad Mubashar Zafar1*, Muhammad Abrar1, Muhammad Umar2, Muhammad Anas Bahoo1, Noman Ahmad Khan2, Muhammad Salahuddin2, Ahmad Bilal3, Abdullah4. 1

Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan. 2 Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan. 3 Institute of Business Management sciences, University of Agriculture, Faisalabad, Pakistan. 4 Wheat Research Institute, Faisalabad, Pakistan. *Corresponding author’s email: [email protected]

Abstract: The experiment was performed for the proper management of ALB of carrot. Five carrot varieties (Gold Mines, Mah Rani, Long Red, Deep Red, and Red Core) under RCBD with three replications were sown. From infected fields diseased samples were collected and fungus Alternaria dauci was isolated in lab of plant pathology by using PDA media. By inoculation in healthy crop disease was established. Field screening experiment was performed to evaluate their resistance against A. dauci. The results of screening trials concluded that Long Red showed resistant response while Red core showed moderately resistant response. Deep Red showed moderately susceptible response. Mah Rani and Gold Mine showed susceptible response. For the chemical management of Alternaria blight of carrot, five chemicals viz. Bravo (Chlorothalonil), Equus (Chlorothalonil + Carbendazim), Cuprofix Dispress (Basic Copper Sulfate), Kocide (Copper Hydroxide) and Champ (Copper Hydroxide) were applied at their standard doses in the field on the standing carrot crop. Among five chemicals, Equus (Chlorothalonil) showed effective response in reducing the pathogenic activity of Alternaria dauci while Champ (Copper Hydroxide) was least effective amongst all chemicals as compared to untreated one after three sprays. [Muhammad Mubashar Zafar, Muhammad Abrar, Muhammad Umar, Muhammad Anas Bahoo, Noman Ahmad Khan, Muhammad Salahuddin, Ahmad Bilal, Abdullah. Screening of different carrot varieties against Alternaria leaf blight and its chemical management.. Researcher 2017;9(12):8-14]. ISSN 1553-9865 (print); ISSN 21638950 (online). http://www.sciencepub.net/researcher. 2. doi:10.7537/marsrsj091217.02. Key words: Alternaria leaf blight (ALB), carrot, Potato dextrose agar (PDA). destructive foliar disorder of carrot (Souza et al., 2001). This disease is both seed and air borne (Rogers et al., 2011). ALB is caused by a growth Alternaria dauci. It has a place with pleosporaceae group of ascomycetes (Kuhn, 1944). The seriousness of this illness come to 80% contingent on ecological conditions and treatment rate (Ben et al., 2001). ALB is the devastating disease of carrot in which leaves are rapidly killed upon infection. Due to ALB necrotic spots becomes on petioles and leaves (Champion, 1997). In severe situation, destruction of entire leaves occurs that make the harvesting difficult. Due to ALB 40–60% yield losses may occur (Vintal et al., 1999). The injuries created by Alternaria dauci are unpredictable fit as a fiddle having dark colored to dark shading and generally shows up on the edges and tips of the develop leaves of the carrot plant (Farrar et al., 2004; Strandberg, 1992). There are a few approaches to deal with this disease. As pathogen is basically presented in the plantings through seeds so one of the best preventive measure is the utilization of treated or ailment free seeds (Farrar et al., 2004). With a specific end goal to lessen the inoculum level, seed ought to be dealt with

1. Introduction Carrot (Daucus carota L) is an essential root vegetable, native to Mediterranean (Shinohara, 1984), and its family is Apiaceae (Peirce, 1987). It is grown worldwide and contains dietary carotenoids (Block 1994; Torronen et al. 1996). Lingappa and Naik (1997) reported that It is used to make many products like candy, halwa, kheer, juice, beverages. It is also used as a blending agent in soups, wine, beverages, stews, jams and pies. It is a major source of polyacetylenes (Kidmose et al. 2004), phenolics (Babic et al. 1993), and carotenoids (Block 1994). It contains β-carotene, tocopherol and ascorbic acid abundantly (Hashimoto and Nagayama 2004). Because of its health benefits it is considered as a functional food (Hager and Howard 2006). Carotenoids are beneficial to human health (Castermiller and West 1998). carrot lowers the chances of different cancers (Giovannucci, 1999), blood and eyes diseases (Pant and Manandhar, 2007). In Pakistan carrots and turnips are grown on area of 30,225 hectares and their annual production is 524,462 tones (FAO, 2014). Carrot crop is prone to parasitic, bacterial, and viral illness. Alternaria leaf blight (Alternaria dauci) is major disease of carrot (Koike et al., 2009). ALB is a

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by heated water treatment or fungicides, for example, azoxystrobin, iprodione, fludioxonil and thiram (Strandberg, 1988). Seed treatment is not the full destruction of applicable pathogen (Farrar et al., 2004). Crop rotation is basic for constraining the contamination in carrot against Alternaria dauci (Pryor et al., 2002). Same pattern of cropping is bad for soil health that outcomes in the inadequacy of fundamental minerals and supplements when contrasted with those soils having crop rotation (Zhou and Zhao, 2011). By using cultivars having resistant to ALB, control of ALB is desirable (Rotem, 1998). Cultivars having partially resistant against ALB have been developed but no one have completely resistant against ALB (Simon & Strandberg, 1998). The breeders are trying to search out cultivars exhibit higher resistance against ALB. To identify genotypes having resistant is a major constraint for such breeding. For this purpose field screening is a procedure used routinely (Santos et al., 2000; BenNoon et al., 2001; Pryor et al., 2002), Resistance germplasm is additionally an essential source that confines its spread (Boedo et al., 2010). Without safe carrot cultivar, other technique to control this infection is the utilization of appropriate fungicide. Variety of fungicides are utilized to control this disease (Langston and Hudgins, 2002). This experiment was conducted for the following purposes. 1. To find out the source of resistance against Alternaria leaf blight disease in carrot under field condition.

2. To evaluate the effect of different fungicides against Alternaria leaf blight of carrot. 2. Material and method Five carrots varieties namely Gold Mines, Deep Red, Red Core, Long Red and Mah Rani were taken from Vegetable Research Institute of AARI, Faisalabad. The experiment was conducted in research zone of Department of Plant Pathology, University of Agriculture, Faisalabad under RCBD with three replications. To keep the crop in sound, condition every social practice were performed timely. From infected fields diseased samples were collected and fungus Alternaria dauci was isolated in lab of plant pathology by using lab PDA media. After this, culture was purified and multiplied for the preparation of inoculum. Pathogenicity test of diseased plants was performed to check whether relevant pathogen is present or not. By inoculation in healthy crop disease was established. For chemical management, five chemicals viz. Bravo (Chlorothalonil), Equus (Chlorothalonil), Cuprofix Dispress (Basic Copper Sulfate), Kocide (Copper Hydroxide) and Champ (Copper Hydroxide) were tested in liquid formulations to control the disease of the carrot on susceptible variety of carrot. Sickness Incidence was ascertained by the accompanying recipe Disease Incidence (%)= (Number of observed contaminated plants)/(Total number of plants observed) ×100 The appraisal of illness was done by ailment rating scale created by Gugino et al. (2007).

Table 1. Disease Rating Scale for the Assessment of Alernaria dauci developed by Gugino et al. (2007). SCALE SYMPTOMS RESPONSE 1 0% plants symptomatic Immune 2 Up to 1% plants symptomatic Highly Resistant 3 2-5% plants symptomatic 4 6-10% plants symptomatic Resistant 5 11-20% plants symptomatic Moderately Resistant 6 21-30% plants symptomatic Moderately Susceptible 7 31-40% plants symptomatic Susceptible 8 41-50% plants symptomatic 9 Over 50% plants symptomatic Highly Susceptible

screening trials concluded that Long Red showed resistant response while Red core showed moderately resistant response. Deep Red showed moderately susceptible response. Mah Rani and Gold Mine showed susceptible response. These results are depicted in Table 1.1 and Fig. 1.

3. Result and discussion: 3.1. Screening of carrot varieties against Alternaria dauci Five carrot varieties viz. Gold Mines, Red Core, Deep Red, Mah Rani and Long Red were evaluated for resistance against A. dauci. These varieties were checked based on disease incidence. The results of

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SCALE 1 2 3 4 5 6 7 8 9


Table 1.1. Screening of carrot varieties against Alternaria blight under field conditions. SYMPTOMS RESPONSE VARIETIES 0% plants symptomatic Immune Up to 1% plants symptomatic Highly Resistant 2-5% plants symptomatic 6-10% plants symptomatic Resistant Long Red 11-20% plants symptomatic Moderately Resistant Red Core 21-30% plants symptomatic Moderately Susceptible Deep Red 31-40% plants symptomatic Mah Rani Susceptible 41-50% plants symptomatic Gold Mine Over 50% plants symptomatic Highly Susceptible

DISEASE INCIDENCE (%)

Table 1.2. Analysis of variance of evaluation of carrot lines against Alternaria blight under field conditions. Source of Variation Degree of Freedom Sum of Squares Mean Sum of Squares F-value P-value 2 45.99 22.995 Replication 4 2748.97 687.243 417.23* 0.0000 Variety 8 13.18 1.647 Error 14 2808.14 Total *: Significant Grand Mean: 25.753 CV: 4.98%

50.00 40.00 30.00 20.00 10.00 0.00 Gold Mine

Red Core

Deep Red VARIETIES

Mah Rani

Long Red Fig. 1.

Screening of carrot varieties against Alternaria dauci. Dispress (Basic Copper Sulfate), Kocide (Copper Hydroxide) and Champ (Copper Hydroxide) were applied at their standard doses in the field on the standing carrot crop.

Evaluation of chemicals against Alternaria dauci under field conditions Five chemicals viz. Bravo (Chlorothalonil), Equus (Chlorothalonil + Carbendazim), Cuprofix Table 1.3. Analysis of after 1st spray. Source of Variation Replication Treatments Error Total *: Significant Grand Mean: 12.567 CV: 10.45%

variance for evaluation of chemicals against Alternaria dauci under field conditions Degree of Freedom 2 5 10 17

Sum of Squares 26.11 978.77 17.24 1022.12

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Mean Sum of Squares 13.055 195.755 1.724

F-value

P-value

113.57* 0.0000



Table 1.4. Evaluation of chemicals against Alternaria dauci under field conditions after 1st spray Chemicals Active Ingredient Disease Incidence (%) Chlorothalonil 7.27de Bravo Chlorothalonil + Carbendazim 4.93e Eqqus Basic Copper Sulphate 9.63cd Cuprofix Dispress Copper Hydroxide 10.77c Kocide Copper Hydroxide 15.40b Champ 27.40a Control Alpha: 0.05 Standard Error: 1.0720 LSD: 2.3885


35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 Bravo

Equus

Cuprofix Dispress

Kocide

Champ

Control

CHEMICALS Fig. 2. Evaluation of chemicals against Alternaria dauci under field conditions after 1st spray After 1st spray, Equus showed 4.93% incidence, Bravo treated plants showed 7.27% incidence, Cuprofix dispress treated plants showed 9.63% incidence, Kocide treated plants showed 10.77% incidence and Champ treated plants showed 15.4% incidence as compared to control (27.4%). Table 1.5. Analysis of variance for evaluation of chemicals against Alternaria dauci under field conditions after 2nd spray Source of Variation Degree of Freedom Sum of Squares Mean Sum of Squares F-value P-value 2 24.41 12.207 Replication 5 2639.17 527.834 92.05* 0.0000 Treatments 10 57.34 5.734 Error 17 2720.93 Total *: Significant Grand Mean: 15.85 CV: 15.11%. Table 1.6. Evaluation of chemicals against Alternaria dauci under field conditions after 2nd spray. Chemicals Active Ingredient Disease Incidence (%) Chlorothalonil 7.73de Bravo Chlorothalonil + Carbendazim 5.33e Eqqus Basic Copper Sulphate 10.87cd Cuprofix Dispress Copper Hydroxide 13bc Kocide Copper Hydroxide 16.43b Champ 41.73a Control Alpha: 0.05 Standard Error: 1.9552 LSD: 4.3564

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50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 Bravo

Equus

Cuprofix Dispress

Kocide

Champ

Control

CHEMICALS Fig. 3. Evaluation of chemicals against Alternaria dauci under field conditions after 2nd spray. After 2nd spray, Equus reduced the incidence of the disease up to 5.53%, Bravo showed 7.73% incidence level, Cuprofix dispress showed 10.87% incidence level, Kocide showed 13% incidence and Champ showed 16.43% incidence of A. dauci Table 1.7. Analysis of after 3rd spray. Source of Variation Replication Treatment Error Total *: Significant Grand Mean: 18.628 CV: 25.58%

variance for evaluation of chemicals against Alternaria dauci under field conditions Degree of Freedom 2 5 10 17

Sum of Squares 88.46 5462.62 226.98 5778.06

Mean Sum of Squares 44.23 1092.52 22.7

F-value

P-value

48.13*

0.0000

Table 1.8. Evaluation of chemicals against Alternaria dauci under field conditions after 3rd spray Chemicals Active Ingredient Disease Incidence (%) Chlorothalonil 7.97c Bravo Chlorothalonil + Carbendazim 5.57c Eqqus Basic Copper Sulphate 11.2bc Cuprofix Dispress Copper Hydroxide 13.53bc Kocide Copper Hydroxide 16.77b Champ 56.73a Control Alpha: 0.05 Standard Error: 3.8899 LSD: 8.6673 After 3rd spray of chemicals, Equus again was the best chemical against A. dauci reducing the incidence up to 5.57%. Bravo treated plants showed 7.97% incidence. Carrot plants treated with Cuprofix dispress showed 11.2% incidence. Kocide treatment showed 13.53% disease incidence and treatment of champ reduces the incidence up to 16.77%. The results concluded that Equus (Chlorothalonil) showed effective response in

reducing the pathogenic activity of Alternaria dauci while Champ (Copper Hydroxide) was least effective amongst all chemicals as compared to untreated one after three sprays. Statistical analysis of variance showed significant response of chemical treatment against the disease incidence as three sprays of chemicals reduces the disease incidence up to an appreciable level at 5% level of significance (P