Efficacy of Bio-agents on radial growth of Alternaria tenuissima in dual culture technique
Results (Table 1) revealed that all the bio agents evaluated exhibited fungistatic/antifungal activity against
A. tenuissima and significantly inhibited its mycelial growth over untreated control.
Hypocrea rufa was found most effective and recorded least linear mycelial growth (32.72 mm) with highest mycelial inhibition (63.64%) of the test pathogen over untreated control (90.00 mm and 00.00%). The second best antagonists were found
Trichoderma harzianum recorded mycelial growth of 33.90 mm and 33.95 mm respectively and inhibition of 62.33 and 62.27 per cent, respectively both of which was at par. The antagonistic effect of the fungal bio agents against
A. tenuissima found in present study may be attributed to the mechanisms
viz., competition, lysis, myco-parasitism, antibiosis and production of volatile and non volatile compounds by the bio agents.
Similar results were also observed by
Lal and Upadhyay (2002) and
Khare (2006) against
A. tenuissima of pigeonpea
In vitro, Abdul et al., (2001) in
T. harzianum in
A. solani of tomato,
Ambuse et al., (2012) against of leaf spot (
A. tenuissima) of Sorrel,
Gholve et al., (2012) and
Gholve et al., (2014) in
A. macrospora.
Efficacy of fungicide on radial growth of Alternaria tenuissima in poisoned food technique
Efficacy of each fungicide at five different concentrations was tested
In vitro for radial growth of
A. tenuissima. The data recorded as per cent inhibition of radial growth were presented in Table 2. A perusal of data revels that all the fungicides were superior in inhibiting the radial growth of the pathogen over control.
Irrespective of concentration Mancozeb was proved to be most effective fungicides inhibiting the radial growth of pathogen (75.26%) followed by Chlorothalonil (66.34%) and Iprodione (63.85%). Propineb (23.29%) was least effective followed by Carbendazim (27.24%) and Copper oxychloride (41.96%). Higher concentration (500 ppm) of fungicides significantly inhibit the radial growth over low concentrations (50, 100, 200 and 250 ppm) and the maximum inhibition was observed at 500 ppm and minimum at 50 ppm concentration in all the fungicides. Maximum inhibition of radial growth was recorded by Mancozeb (90.16%) followed by Chlorothalonil (83.60%) both at 500 ppm concentration and minimum was recorded by Propineb (8.19%) followed by Carbendazim (13.11%) at 50 ppm. Data further reveals that significant into interaction was observed between fungicides and their concentration. Application of Mancozeb followed by Chlorothalonil and Iprodione all at 500 ppm concentration significantly inhibited the radial growth
A. tenuissima over control Propineb, Carbendazim and Copper oxychloride as compared to other concentrations least effective.
Present findings are collaborated with
Hegde (1988) Mancozeb against
A. tenuissima, Iprodione, Mancozeb, Copper oxychloride, Chlorothalonil and Carbendazim against
A. tenuissima in pigeonpea other worker agree like
Lal et al., (2000), Amaresh and Nargund (2002) against
A. helianthi of sunflower,
Gholve et al., (2012) and
Gholve et al., (2014),
Khan et al., (2007) against
A. macrospora.
Effect of seed treatment with fungicides, antagonist and their treatment combination on Alternaria blight of pigeonpea in field condition
All the six fungicides and two bio agents and their combination tested in seed treatment field condition found significantly or partially effective, reduced the disease intensity as compared to control (Table 3 and Table 4). Twenty five treatment amongst them combination of Mancozeb with
H. rufa was found most effective in reducing the disease intensity two consecutive years (6.33%) followed Mancozeb with
T. harzianum (6.40%) and alone Mancozeb (6.53%), respectively. While,
T. harzianum alone was least effective and maximum disease intensity (14.87%) two consecutive years were observed as compared to control followed by
T. harzianum double dose (14.65%) and
T. harzianum and H. rufa (15.70%) combination treatment, respectively. The combination of Mancozeb with
H. rufa, Mancozeb with
T. harzianum and Mancozeb single were significantly at par in reducing the disease intensity of
A. tenuissima over control. Data further reveals that no significant interaction was observed between fungicides and bio agents in both the years. Application of fungicide and bio-agents combination treatment Mancozeb with
H. rufa followed by Mancozeb with
T. harzianum and Mancozeb alone at recommended dose significantly reduced disease intensity of
A. tenuissima over control. While,
T. harzianum alone,
H. rufa and
T. harzianum treatment combination and
H. rufa alone as compared to other concentration were least effective.
Our results with chemical confirmed with similar findings
Khare and Kumar (2006) Mancozeb and Carbendazim of pigeonpea against the
Alternaria blight,
Girish et al., (2007) A. alternate and
A. brassicae of pigeonpea against Iprodione and Carbendazim,
Ansari et al., (1990) against
A. brassicae infected rapeseed mustard Mancozeb and Copper oxychloride. Our results with bio-agents confirmed with similar findings of
Kumar et al., (2000) with
H. rufa pathogens (
A. alternata) of pigeonpea. Use of antagonists has been reported quite effective against different pathogens
(Chattopadhyay et al., 2002) particularly as seed treatment material followed by fungicidal spray in managing many fungal diseases
(Rohila et al., 2001).
Effect of foliar spray + seed treatment with fungicides, bio agents and their treatment combination on Alternaria blight of pigeonpea
All the fungicides and bio agents and their treatment combinations were tested in seed treatment + foliar spray of field condition were significantly or partially effective in reduced the disease intensity of Alternaria blight as compared to control (Table 3 and Table 4). Out of twenty five treatments, combination of Mancozeb with
H. rufa treatment was found most effective in reducing the disease intensity two consecutive years (11.59%) followed by Mancozeb with
T. harzianum (11.60%) and Mancozeb (11.77%) single treatment, respectively. While, least effective and maximum disease intensity in two consecutive years were observed
T. harzianum (35.12%) single dose followed by
T. harzianum (34.68%) double dose and combination of
T. harzianum and
H. rufa treatment (33.83%), respectively as compared control. A combination of Mancozeb with
H. rufa, Mancozeb with
T. harzianum and Mancozeb alone were significantly at par with each other in reducing the disease intensity of test pathogen over control. Data further reveals that not significantly difference in various interactions was observed between fungicides and bio agents as both the years. Application of combination of Mancozeb with
H. rufa followed by Mancozeb with
T. harzianum and Mancozeb alone at recommended dose significantly reduced disease intensity of
A. tenuissima over control. While,
T. harzianum alone, combination of
H. rufa and
T. harzianum and
H. rufa alone as compared to other concentrations were least effective.
In our results with chemical fungicides Mancozeb and Copper oxychloride against blight
Ansari et al., (1990) of
A. brassicae, Amaresh and Nargund (2002) of Mancozeb, Chlorothalonil, Copper oxychloride, Iprodione and Carbendazim on sunflower percent disease intensity of leaf blight.
Rathi and Singh (2009) bio agents and fungicides as seed treatment with
T. harzianum seed followed by foliar spray,
Karthikeyan et al., (2008) against onion blight disease (
A. palandui) seed treatment+foliar spray Mancozeb was most effective followed by
H. rufa.
Effect of foliar spray with fungicides, bio-agents and their treatment combination on Alternaria blight of pigeonpea
In the present investigation of all the fungicides and bio agents and their treatment combination tested in foliar spray under field conditions were significantly or partially reduced the disease intensity of Alternaria blight in pigeonpea as compared to control (Table 3 and Table 4). Out of twenty five treatments, combination of Mancozeb with
H. rufa treatment was found most effective in reducing the disease intensity two consecutive years (12.07%) followed Mancozeb with
T. harzianum (12.52%) and Mancozeb (12.77%) alone treatments, respectively. Whereas, least effective and maximum disease intensity two for consecutive years were observed with
T. harzianum (36.10%) at a single dose followed by
T. harzianum (35.28%) at a double dose and combination of
T. harzianum and
H. rufa (34.72%) respectively as a compared control. A combination of Mancozeb with
H. rufa, Mancozeb with
T. harzianum and Mancozeb alone were significantly at par with each other in reducing the disease intensity over control. Data further reveals that no significant difference in various interactions was observed between fungicides and bio agents in both years. Application of fungicide and bio agents’ combination treatment Mancozeb with
H. rufa followed by Mancozeb with
T. harzianum and Mancozeb alone at recommended dose significantly reduced disease intensity of
A. tenuissima over control. While,
T. harzianum alone,
H. rufa and
T. harzianum treatment combination and
H. rufa alone as compared to other concentration were least effective.
Our results with chemicals (Mancozeb and Chlorothalonil) is confirmed with
Kushwaha et al., (2010b) in pigeonpea infected by
A. tenuissima, Lal
et al., (2000);
Kushwaha and Narain (2001) Iprodione, Mancozeb, Copper oxychloride, Chlorothalonil and Carbendazim of
A. tenuissima in pigeonpea,
Khan et al., (2007) Carbendazim and Mancozeb in Alternaria blight (
A. brassicae) of rapeseed mustard, Alternaria blight in Mancozeb
(Gondal et al., 2012), Kumar et al., (2005) findings antagonistic against Alternaria leaf spot of
Vicia faba in
H. rufa and
T. harzianum, Kumar
et al., (2000) of pigeonpea against
H. rufa, Lal and Upadhyay (2002) H. rufa and
T. harzianum against
A. tenuissima (pre-rabi pigeonpea), sprays of
H. rufa.
Varma et al., (2008) against
A. solani of tomato, Foliar spray of
H. rufa, Mishra (2011) of
H. rufa application Alternaria leaf spot in pigeonpea,
Reshu and Khan (2012) against
A. brassicae in Mustard
H. rufa.
Hiremath and Sundaresh (1985) the fungal (
A. tenuissima) growth
in vitro and Mancozeb
In vivo Katiyar et al., (2001) Mancozeb and Chlorothalonil was effective.