INTRODUCTION Garlic (Allium sativum L.) is second only to onion in popularity among bulb crops and used as a spice or condiment throughout India. It is an edible and pungent annual bulbous plant in the Amaryllidaceae family. There is constant demand of garlic in the market as it is required daily in small quantity in almost all houses. It has been cultivated in number of countries, due to its vegetative propagation it is susceptible to number of diseases at all stages of plant development. Around the world, downy mildew, rust, purple blotch, stemphylium blight and basal rot have had a significant impact on yields. These diseases also occur during harvesting, post harvesting stages lowering the quality during processing and marketing stages, ultimately reducing the export potential of the crop that significantly causes the qualitative and quantitative economic loss (Prahlad et al., 2021). Garlic is most often affected by purple blotch caused by Alternaria porri (Ellis) Ciferri (Vijaykumar et al., 2021). Purple blotch initially starts as large number of small, whitish circular or irregular spots, smaller than one millimetre diameter. Over time, these spots become larger, increasingly oval-shaped or irregular and turn from white to violet in colour. Afterward, the central part of the spots begins to turn purple accompanied by a pale yellow orange to salmon band extending beyond pale green zone. The dark purple colour is one of the most distinctive characteristics of the disease. The edges of the spots are usually yellow and extend toward the tips and bases of the leaves (Aveling, 1998). The disease is more severe in high humidity levels of 80-90 per cent and moderate temperature of 25-30 °C. A foliar infection upto 90 per cent has been reported in susceptible cultivars of garlic. Complete damage to the leaf tissues is observed at the time of bulb maturity. Leaves being the only photosynthetic organ directly influence the bulb yield. Significant reduction in bulb yield (25-60 %) due to drying of leaves has been observed in garlic (Bisht and Agarwal 1993). It is possible to manage purple blotch with the use of fungicides; however, there are a number of problems associated with using them like environmental pollution, residual effect and killing non-targeted organisms, its use should be minimized. Eco-friendly management practices such as use of bioagents, botanicals and indigenous technology knowledge (ITK’s) proved to be effective in controlling many diseases and also considerably safe to environment and human health. In India, due to purple blotch disease, garlic production has decreased significantly, resulting in an economic loss for the country and ever increasing demand for safe, healthy food in these days, the present investigation has been undertaken. MATERIAL AND METHODS The present investigation was carried out during 2019 at the Department of Plant Pathology, College of Agriculture, Dharwad, Karnataka. For analysing the experimental data, arcsine angular transformations were made and analyzed the experimental data in our study for their significance of difference by the usual statistical method adopted for completely randomized designs and we interpreted the results in accordance with Walter (1967). Various botanicals, bioagents and indigenous technology knowledge were evaluated under laboratory condition against A. porri through different techniques viz., poison food technique, dual culture technique and spore germination method, respectively. For botanicals and bioagents, mycelial growth inhibition was recorded while spore germination was recorded for indigenous technology knowledge. Based on the per cent mycelial growth inhibition and spore germination inhibition, effective organics were identified and those can be used to manage the disease in an eco-friendly way. Poisoned food technique for the efficacy of botanicals on inhibition of mycelial growth of Alternaria porri. Plant based products can be used easily and successfully by farmers against plant pathogenic fungi because of their safety, cheapness and non-hazardous nature. The present study is designed to evaluate the antifungal activity of commercially available botanicals. The following botanicals were evaluated at different concentrations (0.25, 0.5 and 1.0 %) through poison food technique (Nene and Thapliyal, 1982). The required concentrations were prepared by adding known amount of botanical suspension to the melted potato dextrose agar (PDA) media and about 20 ml of poisoned medium was poured in each sterilized Petri plates. No test botanical in the media was served as suitable check. Nine mm mycelial disc of the pathogen was placed in the centre of Petri plate and incubated at 28 ± 1°C. For each treatment, three replications were maintained. Finally the diameter of the colony was measured after reaching maximum growth in control plates. The mycelial growth inhibition per cent was determined through the formula given by Vincent (1947) as follows I= (C-T)/C ×100 Where, I = Mycelial growth inhibition (%). C = Mycelial growth in control. T = Mycelial growth in treatment. Dual culture technique for the efficacy of bioagents on mycelial growth inhibition of Alternaria porri. Four bioagents viz., Trichoderma harzianum Rifai (MH027645.1), Pseudomonas fluorescens Migula(NAIMCC-B-01981) and Bacillus subtilis (Ehrenberg) Cohn(MT383652.1) were collected from Institute of Organic Farming, UAS, Dharwad and another commercially available Trichoderma viride Persoon (Multiplex - market sample) were used to test their bioefficacy against A. porri by following dual culture technique (Dennis and Webster 1971). Twenty ml of sterilized and cooled PDA was poured into sterile Petri plates. Fungal antagonists were evaluated by inoculating the pathogen at one side of the plate and antagonists on the opposite side of the same plate by leaving 3-4 cm gap between them. Bacterial antagonists were streaked in the corner of the plate after which a fungal disk of pathogen was placed. Each treatment was replicated four times with control (without bioagent) maintaining only pathogen. Finally the diameter of the colony was measured after reaching maximum growth in control plates. Per cent mycelial growth inhibition over control was worked out according to the Vincent (1947) formulae as mentioned earlier. Spore germination method for the efficacy of indigenous technology knowledge on spore germination inhibition of Alternaria porri. Five ITK’s such as desi cow urine, butter milk (curd diluted in water @ 1:4 and fermented for two days), panchagavya, jeevamrutha and vermiwash were tested against inhibition of spore germination at 5, 10 and 20 per cent concentrations by following spore germination method using cavity slides. Ready-made preparations of panchagavya, jeevamrutha and vermiwash were taken from Institute of Organic Farming (IOF), UAS Dharwad. Required concentrations were prepared by mixing known volume of ITK’s in sterile distilled water separately under aseptic conditions. The spore suspension was prepared separately in sterile water to obtain 5 × 106 spores per ml. Then a drop of spore suspension was mixed with one drop of ITK's solution in a cavity slide to achieve the required concentration. A control treatment was maintained with only sterile water. Three replications were maintained for each treatment. Slides were incubated at room temperature (25 ± 1 °C) for 12 hr and observation on spore germination was recorded under compound microscope at 10 X magnification. Spore germination per cent was calculated by following formula Per cent germination (PG)=A/B×100 Where, A - Number of germinated conidia B - Total number of conidia observed RESULTS AND DISCUSSION The management of diseases through chemical fungicides leads to various detrimental effects on soil, air and water leading to residual toxicity. Hence, the botanicals, bioagents and indigenous technology knowledge which are easily accessible, non-phytotoxic, renewable, inexhaustible, indigenously available and readily biodegradable, relatively inexpensive and can be utilized in integrated disease management to protect plants. In the present study, different botanicals, bioagents and indigenous technology knowledge were examined under laboratory condition for their antifungal activity against A. porri. Efficacy of botanicals on inhibition of mycelial growth of Alternaria porri. Seven test botanicals reduced the mycelial growth of A. porri at 0.25, 0.50 and 1.00 per cent concentrations and the data is presented in Table 1 and Plate 1. At 1.00 per cent concentration, nimbecidine inhibited maximum mycelial growth (64.20 %) and found to be the best over other botanicals tested. Next best was multineem which had inhibited mycelial growth upto 42.84, 47.53 and 59.88 per cent at 0.25, 0.50 and 1.00 per cent concentrations, respectively. The least inhibition of mycelial growth was observed in raw neem oil which had recorded 5.43, 18.89 and 20.49 per cent at 0.25, 0.50 and 1.00 per cent concentrations, respectively. Increase in concentration has increased mycelial growth inhibition by all the botanicals tested. There was a great deal of variability in the efficacy of botanicals on mycelial growth of A. porri under in vitro. Significantly higher mycelial growth inhibition was noticed in nimbecidine at 1 per cent concentration (64.20 %). Similar findings were made by Patilkulkarni (2013) while evaluating the bioefficacy of plant extracts against A. porri and Azadirachta indica found to be the most effective at 10 per cent in inhibiting the mycelial growth of the test pathogen (71.85 %). The most active component of neem is azadirachtin, followed by nimbolinin, nimbin, nimbidin, nimbidol, sodium nimbinate, gedunin, salannin and quercetin. Azadirachtin is a terpene limonoid present in seeds that has properties that are both antifeedant and toxic to pathogens. Through antimicrobial activity, it inhibits microbial growth or potential to break the cell wall of pathogen. Priyanka et al. (2017) also studied efficacy of Azadirachtin at 2 and 4 per cent concentrations against A. porri and observed 62.09 and 68.61 per cent mycelial growth inhibition, respectively. The results were similar to that of study conducted by Chethana et al. (2012); Abdel-Hafez et al. (2013) who reported that Azadirachtin compound present in nimbecidine has the capacity to inhibit the mycelial growth of pathogen and it has high potentiality to enter the spore and exhibit the fungi toxicity inturn affecting growth of the pathogen. Jabeen et al. (2013) demonstrated that ethyl acetate fraction of Azadirachta indica canretard the mycelial growth of Alternaria solaniwith minimum inhibitory concentration (MIC) of 0.19 mg compared to that of 0.78 g MIC with fungicide (metalaxyl + mancozeb). The results of a study conducted by Shrivastava and Swarnkar (2014) also revealed that methanol and ethanol extracts of neem could inhibitmycelial growth of Alternaria solani. Efficacy of bioagents on inhibition of mycelial growth of Alternaria porri. Based on laboratory evaluation of bioagents through dual culture technique, significant differences were observed in per centage of mycelial growth inhibition of A. porri. Maximum mycelial growth inhibition of 83.89 per cent was noticed with Trichoderma harzianum followed by Pseudomonas fluorescens (63.40 %) and T. viride (61.20 %). The least mycelial growth inhibition of 38.97 per cent was recorded with Bacillus subtilis (Table 2 and Plate 2). It is possible to reduce inoculum levels of pathogens by using antagonistic microorganisms as a non-chemical means of controlling plant diseases. This would prevent pollution and health hazards associated with fungicides. The competitive ability of antagonists against Alternaria porri was studied by dual culture method. Among four bioagents evaluated maximum mycelial inhibition (83.89 %) was noticed in Trichoderma harzianum by over growing on the test fungus. This may simply be a result of the higher competitiveness of Trichoderma sp. either through mycoparasitism or antibiosis, and/or because of the possibility of microbial interactions, such as stimulation, inhibition, mutual intermingling of growth of antagonistic isolates over pathogens. It has been reported that Trichoderma sp produces secondary metabolites such as 6-phenyl-alpha-pyrone (6pp), derivatives of isocyanide, acids (such as heptelidic acid), peptaibols and enzymes that degrade cell wall proteins (CDWE) which are effective in inhibiting the growth of many phytopathogenic fungi (Vinale et al., 2008). Similar findings were observed by Kumari et al. (2006); Pramodkumar (2007); Kareem (2008); Rahman et al. (2015); Sairam et al. (2020) who reported that T. harzianum is effective against A. porri under in vitro condition in inhibiting the maximum mycelial growth of the fungus. These bioagents likely inhibited pathogen functions by the mechanisms of competition and/or antibiosis. Similar mechanism has been explained by many workers (Mishra and Gupta, 2012; Brahmane et al., 2015; Arunakumara et al., 2016). Dennis and Webster (1971) made detailed study related to the mechanism of Trichoderma sp. and explained that antagonism of this bioagent against many fungi is mainly due to production of acetaldehyde, a carbonyl compound which may be one of the reasons for its antagonistic effect on A. porri during the present study. Efficacy of indigenous technology knowledge on spore germination inhibition of Alternaria porri. Five test ITK’s reduced the spore germination of A. porri at 5, 10 and 20 per cent concentrations and obtained results are presented in the Table 3 and Plate 3. Cow urine, at 5 per cent concentration inhibited the maximum spore germination (40.66 %) and found to be superior among all other ITK's tested. Next best was panchagavya with 37.59 per cent spore germination inhibition and found on par with jeevamrutha (36.17 %). The least spore germination inhibition was noticed in vermiwash (14.89 %) followed butter milk (16.55 %) and found on par with each other. At 10 per cent concentration, maximum spore germination inhibition was noticed in cow urine (72.34 %) which was significantly superior over other ITK's tested. Next best was jeevamrutha (69.27 %) followed by panchagavya (65.48 %) whereas, least spore germination inhibition was noticed in vermiwash (20.33 %). Significant inhibition of spore germination was observed with cow urine at 20 per cent concentration (81.56 %) compared to other ITK's tested. Next best was jeevamrutha (78.49 %) followed by panchagavya (74.94 %) whereas, least spore germination inhibition was noticed in vermiwash with 29.08 per cent. Irrespective of ITK’s concentrations tested, cow urine (64.85 %) found to be the best in inhibiting the spore germination of A. porri and found be the best ITK’s among all others tested. However, the mean least spore germination inhibition was noticed in butter milk (28.68 %). People have developed a number of farming methods during the long journey from primitive agriculture to modern farming through trial and error in their attempts to overcome numerous difficulties they faced during the farming process. Based on generations of experience, this knowledge is derived from close interaction with natural and physical micro-environments. This form of knowledge in today's parlance is popularly known as Indigenous Technology knowledge (ITK) or Indigenous Knowledge System (IKS) and play major role in plant disease management strategy of sustainable agriculture. In present investigation five different ITK's (cow urine, butter milk, panchagavya, vermiwash and jeevamrutha) are evaluated against spore germination of A. porri at different concentrations (5, 10 and 20 %) and their efficacy varied from 29.08 (vermiwash) to 81.56 per cent (cow urine) at 20 per cent concentration. However, the highestspore germination inhibition was noticed in cow urine (81.56 %) followed by jeevamrutha (79.94 %). Cow urine is a product of a cow that has many benefits and is nontoxic. Cow urine (gomutra) is a substance/secretion of animal origin that is claimed to have uncountable therapeutic benefits in Ayurvedic texts.In cow urine, 95 per cent of it is water, 2.5 per cent urea, minerals, 24 salts, hormones, and 2.5 per cent enzymes. Additionally it contains calcium, iron, phosphorus, nitrogen, ammonia, carbonic acid, manganese, sulphur, phosphates, potassium, amino acids, enzymes, cytokine and lactose. Bhadauria (2002) found that cow's urine can be as effective as standard drugs against a wide range of diseases caused by plant pathogens, including ofloxacin, cefpodoxime, gentamycin, and amphotericin B. Several phenolic acids (gallic acid, caffeic acid, ferulic acid, o-coumaric acid, cinnamic acid and salicylic acid) found in cow urine may have inhibited the pathogen’s spore germination. The obtained results are in line with the study conducted by Deshmukh et al. (2012) who evaluated the antifungal activity of cow urine at different concentrations against wide range of plant pathogens and found that cow urine at 10 and 20 per cent concentrations were more effective in inhibiting the spore germination of Alternaria solani. Garg and Kumhar (2020) evaluated cow urine against A. solani at four different concentrations (5, 10, 15 and 20 %) under in vitro condition. Their results revealed that cow urine (20 %) was the most effective in inhibiting the mycelial growth (78.49 %) than other concentrations tested. The results are in confirmation with the works of Sumangala and Patil (2009); Sharma et al. (2010); Pandia et al. (2019) who worked on antifungal activity of cow urine against Alternaria sp. on different crops and recorded spore germination inhibition at different concentrations.