Owing to scarceness of new antifungals in the market and environmental jobs, the research workers are now stressing other options such as familial potency of workss to resistance against pathogens and the usage of biotic every bit good as abiotic agents for the development of induce or acquired opposition We investigate the function of opposition inducement substances ( chemicals and works infusions ) in three chickpea cultivars C-44, Pb-91, Bitter-98 in a field experiments against Ascochyta blight disease. These cultivars were selected on the footing of better output possible shown in the experiments. Aqueous solution of Salicylic acid @ 0.5, 1.0 and 1.5mM, Bion® @ 0.4, 0.8 and 1.2 millimeters while KOH @ 25, 50 and 75mM were applied whereas the works infusions of Azadirachta indica, Datura metel and Allium sativum were applied @ 5, 10 and 15 % were used. The information sing the decrease in disease was recorded with different intervals from 4 twenty-four hours to 14 yearss after the initiation and vaccination with the pathogen. The overall consequences revealed that important disease decrease ( 79 % ) was provided by Bion® in the cultivar C-44 at 1.2mM dose rate as compared to salicylic acid nevertheless the least was showed by KOH. Among the works extracts the maximal disease decrease ( 26 % ) against the disease was observed by the application of Azadirachta indica foliage infusion and the infusions of Datura metel and Allium sativum did non proved effectual in cut downing the disease. The present findings suggest that sweetening of opposition before infection of garbanzo workss could be an advanced control method for ascochyta blight of garbanzo.
Cardinal words: Induce opposition, Chemicals, Plant extracts, Reduction.
Chickpea blight caused by Ascochyta rabiei ( Pass. ) Labrousse, is the most annihilating foliar disease of garbanzo ( Cicer arietinum L. ) in many states of the universe ( Pande et al. 2005 ) . This disease caused considerable losingss that may run from 5 to 100 % around the universe ( Haware 1998 ) . In Pakistan, figure of epiphytotics has been reported with complete failure of the harvest ( Aslam, 1984 ) . Chickpea breeders in Pakistan are concentrating their attending to develop blight immune cultivars ( Ilyas et al, 2007: Iqbal et Al, 1993 ) . Different facet of this disease like badness, lifecycle, pathogenicity, epidemiology, engendering for opposition and control measures cultural, chemical have been explored in different portion of the universe with great success but still this disease posses a great menace to chickpea harvest ( Mohamed et al, 2009: Trapero-Cases and Kaiser, 2009 ) . This disease can be managed by the usage of different antifungals through out the universe ( Gan et al. 2006 ) , but the most economical direction scheme is the usage of opposition cultivars ( Turkkan and Dolar, 2009 ) . However, engendering of opposition garbanzo cultivars is more hard undertaking due to the fact that great fluctuation exists in the pathogenicity of A. rabiei isolates ( Ali et al, 2009 ) .
Since the pathogen is invariably altering in nature ( Chaudhry et al, 2001 ) , the already immune cultivars become susceptible. Therefore it is need to keep or relieve infection by utilizing recent direction methods such as induce opposition a new engineering for works disease control is based on the activation of the works ‘s ain defence system with the assistance of low molecular weight man-made molecules ( Cohen et al, 1999 ) . Induced opposition is defined as an addition in the degree of opposition without any alterations in the basic familial fundamental law ( Baysal, 2001 ) which is associated with an enhanced ability of the works to defy infection by an intense activation of defense mechanism responses. This method is alternate to antifungals in works protection as there is more consciousness of hurtful consequence of antifungals on the natural ecosystem ( Vimala and Suriachandraselvan, 2009 ) . At the same clip development of opposition in pathogen to pesticides, wellness and environmental concern, existent and perceived and increasing popularity of organic harvest and sustainable agribusiness ( KuA‡ , 2001 ) . Induce opposition can look locally ( i.e in the organ where the opposition is applied ) or it may be systemically in the works portion which are spatially separated from the site of bring oning agents ( Walter, 2009 ) and there are at least three types of induce opposition, systemic acquired opposition ( SAR ) developed by localized mortification which resulted in allergic reaction ( HR ) , infection by deadly pathogen or by intervention with certain chemicals Induce systemic opposition ( ISR ) that developed due to colonisation of works growing advancing rhizobacteria ( PGPR ) and wound bring on opposition is normally elicited by hurt caused by eating of insects. In systemic acquired opposition an invading pathogen is non needed and assorted defense mechanism tract are stimulated in the induced works which resulted in the production of diverse defense mechanism merchandises that are included lignin, pathogenesis-related proteins some of which show chitinase or ?-1,3-glucanase activity ( new wave Loon 1997 ; Neuhaus, 1999 ) , phytoalexins, thionins and defensins ( Kessmann et al. , 1994 ; Sticher et al. , 1997 ; Kombrink and Schmelzer, 2001: Ziadi et al. , 2001 ) .
Induce opposition is age old phenomena for the direction of works diseases that was foremost reported by ( Ray, 1901 ) in rust diseases and legion surveies have showed the visual aspect of defence responses against several of import works diseases ( Abo-Elyousr and El-Hendawy, 2008: Jiang et Al, 2008 ) . Up till now assorted chemicals salicylic acid, isonicotinic acid ( INA ) , benzothiadiazole ( BTH ) , Rigel ( salicylic acid parallel ) , ?-aminobutyric acid ( BABA ) , NaClO3, HgCl2, Oryzemate® ( Probenzole ) , paraquat, polyacrylic acid, SiO2, Messenger, ( Harpin protein ) , Phoenix ( potassium phosphate ) etc have been used as inducer of opposition against Fungis, bacteriums and viruses ( Schneider et al. , 1996 ; Kuc, 2001 ; Percival et al. , 2009 ) . The infusions of assorted workss have besides been explored as natural opposition inducers like Azadirachta indica against Alternaria leaf topographic point of benne ( Guleria and Kumar, 2006 ) , Datura metel against Rhizoctonia solani, Xanthomonas oryzae pv oryzae, Alternaria solani ( Kagale et al. , 2004 ; Latha et al. , 2009 ) .
Very less work has been carried out on the initiation of opposition in ascochyta blight of garbanzo except from ( Chaudhry et al, 2001 ) , studied the initiation mechanism in susceptible garbanzo cultivar C-727 by the application of aqueous solution of salicylic acerb dipotassium H phosphate and cupric chloride all the intervention showed important consequences.
The present surveies have been conducted to measure the decrease in ascochyta blight disease due to bring on opposition by the application of simple chemicals and works infusions which are safe, inexpensive and easy to use in the field.
5.2 Material and Methods:
5.2.1 Plant stuff
Chickpea cultivars viz C-44, Pb-91 and Bitter-98 which were susceptible but have shown good output character in the pervious experiment were taken and the seed were cultivated in the little secret plans of 20 sq foot in the experimental country of the Department of Plant Pathology, University of Agriculture, Faisalabad during the twelvemonth 2007-08 ( November-April ) . The experiment was laid out under factorial agreement of randomised complete block design with three reproductions with 18 secret plans per repetition. Each secret plan was consists of seven rows of 10 workss each with three rows were induced and inoculated and other three were induced but with out the vaccination and 7th row act as untreated control.
5.2.2 Preparation of works infusions
The infusions of Neem ( Azadirachta indica Juss. ) , Dautra ( Datura metel ) and Garlic ( Allium sativum L. ) were prepared in the phyto-bacteriology research lab of the Department of Plant Pathology, University of Agriculture, Faisalabad. Leafs of Neem and Datura were collected from research country of Agronomy and square No.32, University of the Agriculture, Faisalabad while the cloves of the Gralic were purchased from local market. Leafs of Neem and Datura after thorough rinsing under tap H2O, the stuffs were surface sterilized with 1 % Na hypochlorite solution followed by thorough rinsing with sterilised H2O. Leafs were homogenized ( ? ? ? homogenizer name ) in sterile distilled H2O at 1:1 ( w/v ) in a stamp and howitzer, and filtered through a muslin fabric to bring forth a 100 % petroleum works infusion. For fixing infusion of Gralic from fresh samples, the outer, dry Peel of cloves was foremost removed, surface-sterilized for 2 min in 70 % ethyl alcohol, and washed in three alterations of sterile distilled H2O. Cloves were crushed into a mush in unfertile porcelain howitzer utilizing a stamp and the mush was suspended 100 ml H2O in 250 milliliters Erlenmeyer flask and filtered through a muslin fabric. The works infusions were heated to 40 & A ; deg ; C for 10 min to avoid taint ( Jaganathan and Narasimhan, 1988 ) and diluted to the required concentration ( 5 % , 10 % and 15 % ) with sterile distilled H2O ( v/v ) .
5.2.3 Induction intervention and chemical
Chemicals like Salicylic acid ( Sigma Aldrich, Germany ) , Bion® ( acibenzolar-S-methyl ) , provided by Syngenta Crop Sciences, Germany, and KOH ( Sigma Aldrich, Germany ) were used for the initiation of opposition. Aqueous solution of Salicylic acid @ 0.5, 1.0 and 1.5mM, Bion® @ 0.4, 0.8 and 1.2 millimeters while KOH @ 25, 50 and 75mM were applied nevertheless all the works infusions were applied @ of 5 % , 10 % and 15 % severally. At early blossoming phase all the opposition bring oning agents ( chemicals and works infusions ) were sprayed on the workss until the overflow while the control workss were sprayed with distilled H2O merely.
5.2.4 Challenge intervention
The mass readying of already isolated and preserved inoculant of A. rabiei was carried by the method of Ilyas and Khan ( 1986 ) . The conidial counts were adjusted with the aid of haemocytometer. Normal agronomic patterns were followed throughout the experiment. Four yearss after the initiation of the opposition the workss were challenged with spore suspension of A. rabiei ( 1×105 spores L-1 ) with the aid of lady manus sprayer until run off in the eventide with an thought that temperature gets lower in the dark and it help better sprouting of conidiospore and continued for three yearss to guarantee maximal infection to workss.
5.2.5 Reduction per centum
Data sing the disease decrease per centum was calculated at 4, 6, 7, 11, and 14 yearss interval by utilizing the undermentioned expression ( Altamiranda et al. , 2008 ) with some alteration
Disease decrease ( % ) =100 ( 1-x/y ) , where x= disease evaluation in the opposition induce workss and y= disease evaluation of the control workss.
5.2.6 Statistical analysis
Datas were statistically analyzed utilizing SAS package by analysis of discrepancy and the significance of the interventions was determined utilizing Duncan ‘s multiple scope trial ( P = 0.05 ) .
5.3 Consequences and Discussion:
5.3.1 Disease decrease % by the application of chemicals
There were extremely important differences ( P & A ; lt ; 0.05 )
5.3.1 Disease decrease % by the application of works infusions
There were extremely important differences ( P & A ; lt ; 0.05 )
The research worker is extremely obliged to Dr. Shakeel Ahmad, Head Research and Development Syngenta, Pakistan for supplying me Bion and all aid for its import from Germany.