www.iaard.net International Association of Advances in Research and Development International Journal of Advanced Agricultural Research International Journal of Advanced Agricultural Research, 2015, 1(1),16-22 Effectiveness of fungicides to control garlic rust ( puccinia allii (rudolphi.)) at haramaya, eastern Ethiopia Worku Mengesha 1* Mashilla Djene 2, Azene Tesfaye 3 1Department of Plant Sciences, Aksum University, Shire Campus P.O. Box 314, Shire,Ethiopia, 2Shool of Plant Sciences, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia 3 Biodiversity research Center, Arba Minch University, Ethiopia *Corresponding author e-mail: [email protected] , ……………………………………………………………………………………………………………… Abstract: Garlic rust is caused by an air-borne obligate pathogen called Puccinia allii (Rudolphi) and seriously reduces the productivity of Alliaceae, especially garlic (Allium sativum) and onion (Allium cepa) crops. A field experiment was carried out at Haramaya University experimental field in 2012/13 cropping season to compare the efficacies of some fungicides against garlic rust using a local garlic cultivar (Chiro). The experiment was laid out in a randomized complete block design in three replications. Four levels of fungicides (bayleton, mancozeb, propiconazole, ridomil) and control. The four fungicides sprayed varied significantly in disease incidence, disease severity, area under disease progress curve (AUDPC), yield and yield components. Propiconazole was found to be the most effective chemical of all the tested fungicides and showed disease severity of 3.72% only at 128 days after planting (DAP). Keywords: Allium sativum , disease incidence, disease severity, fungicides, Puccinia allii …………………………………………………………………………………………………………………………….. 1. Introduction home consumption and as a source of income to Garlic ( Allium sativum L.) an important many peasant farmers in many parts of the country. spice crop belongs to the family Alliaceae and is the In Ethiopia, the total area under garlic production second most widely used Allium next to onion [1]. It in 2013/2014 reached 16,411.19 ha and the is originated on the northwestern side of the Tien- production was estimated to be over 159,093.575 Shan Mountains of Kirgizia in the arid and semi arid tons; CSA, 2014. areas of central Asia [2] . Garlic plant, the green tops Garlic rust is readily identified by as well as the bulbs are principally used as spice for experienced person under field conditions. Early flavoring and seasoning vegetable and meat dishes, symptoms consisted of small (< 2 mm diameter), it gives the food a delightful fragrance. It usually circular to elongate, white flecks that occurred on dehydrated for industrial and home use. Its folk both sides of the infected leaves. As disease medicinal use includes treatment of whooping progressed, these small spots expand into oblong cough, lung diseases, stomach complaints (as lesions. The leaf tissue covering the lesions rupture healing of ulcer of the intestines) and disorders due to fungal structures that develop internally, and resulting from child birth and as a specific for colds, masses of the characteristic orange uredospores sore eyes and ear-ache. become visible in pustules [5] . The unique flavor and health-promoting Severely infected leaves can be almost functions of garlic attributed to its rich content of entirely covered with pustules, resulting in complete sulfur-containing compounds, i.e., alliin, g- yellowing, wilting, and drying of the foliage. As the glutamylcysteine, and their derivatives (Chia-Wen disease progresses, a second, darker spore type (the Tsai et al., 2012). Garli c yields allicin, a powerful so-called teliospores in the fruiting bodies known as antibiotic and antifungal compound (phytoncide). It telia) may also occur on the same leaves, resulting also contains alliin, ajoene, enzymes, vitamin B, in black pustules (fruiting bodies called telia). minerals, and flavonoids. The composition of the Severe rust on garlic and other Alliums can cause bulbs is approximately 84.09% water, 13.38% organic extensive loss of foliage and form concentric groups matter, and 1.53% inorganic matter, while the leaves on the spot periphery [7] . are 87.14% water, 11.27% organic matter, and 1.59% Despite its importance and increased [3] inorganic matter . production in many parts of the world, garlic In Ethiopia, the Alliums group (garlic, onion productivity is relatively low due to genetic and and shallot) are important bulb crops produced by several environmental factors (both biotic and small and commercial growers for both local use abiotic factors) that affect its yield and yield related [4] and export markets . These crops are produced for traits. Numerous and prominent production

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problems accounted for the low yield of garlic in intervals with the rate of 0.5 kg ha -1 with 100 L of Ethiopia include lack of proper planting material, water. inappropriate agronomic practices, absence of Mancozeb (Manzate ): It is a broad spectrum proper pest and disease management practices and fungicide. Applied in 7-day intervals with the rate marketing facilities [4] . of 3.5 kg ha -1. Even though fungicides are able to control Ridomil Gold EC/Copper (mefenoxam plus the disease, they are different in effectiveness. copper): Broad spectrum fungicide containing Hence, this research experiment was initiated with 4.8% metalaxyl and 60% copper hydroxide the objective: to evaluate the efficacies of some effective against both lower and true fungi. Applied selected fungicides against garlic rust. in 7-day intervals with the rate of 3.5 kg ha -1. 2. Materials and methods Propiconazole (Tilt): A protective fungicide for The study was conducted at Haramaya beets, carrots, celery, onions, and corn. Applied University Research Station (Raaree), Ethiopia, with the rate of 1000 ml ha -1 in 10-day intervals. under rainfed conditions during the year 2012/13 Garlic rust was assessed by scoring disease main cropping season. Haramaya Agricultural incidence and disease severity as well as area Research Station is located in eastern Ethiopia about under disease progress curve (AUDPC). 520 km away from Addis Ababa. The site is Disease incidence percentage (plants showing specifically located at latitude of 9 o26’N, longitude symptoms divided by total observation) was of 42 o30’E and an altitude of 1980 m.a.s.l. The rainy assessed from 10 randomly selected plants on the season of the area is bimodal type with an average onset of the first symptom appearance and the annual rainfall of 780 mm. The short rainy period assessment was carried out on weekly basis. (Belg ) extends from March to May and the long Disease severity was also recorded and estimated in rainy season ( kiremt) extends from June to percentage of the leaf surface covered with lesions. September or early October. The mean annual It was assessed from all leaves of a plant and the minimum and maximum temperatures are 8.3 and average was recorded for the respective plant. 23.4 oC, respectively [8] . The soil is generally alluvial Average severity of the 10 plants per plot was used type (heavy clay). for statistical analysis. A uniform sized local garlic (chiro) variety The area under disease progress curve (AUDPC) and four fungicides (bayleton, mancozeb, ridomil was calculated for each treatment from the and propiconazole) and a control. There were a total assessment of disease severity using: of 5 treatments replicated three times. Each plot n-1 consists of five rows of 2 m length with a distance AUDPC = Σ 0.5[(x i + 1 + x i)(t i + 1 - ti)] ------(Shaner of 0.30 m between rows. The treatments were and Finney, 1977) [9] arranged in a randomized complete block design i=1 (RCBD). The gangway between plots and Where, x = is disease severity at i th observation, n = replications was 1 and 1.5 m wide, respectively. The is the total number of days disease assessed and t = plots were fertilized with diammonium phosphate is the time at the i th observation (in days numbered (DAP) and urea at the rate of 200 (92 kg P 2O5 + 36 sequentially beginning with the initial assessment). kg N) and 150 (69 kg N) kilograms per hectare, Data of yield and yield components and other respectively, i.e. a total of 105 kg N ha -1. The urea agronomic parameters were collected as follows. was applied in split, half at the time of planting and 1. Days to maturity: This refers to the number of the remaining half three weeks after planting and days taken from emergence to 75% leaf fall. DAP fertilizer was applied once at the time of 2. Plant height (cm): It refers to the average height planting. Planting was done on 25 July 2012. of 10 plants of each plot measured from ground Fungicide application was started at the level to the tip of the pseudo-stem at maturity. onset or appearance of rust on the foliage. During 3. Total yield (t/ha): Total yield was recorded from application of each of the fungicides a plastic sheet the middle three rows of each plot after curing and was used to prevent drift problems. The four converted to tons per hectare. fungicides were applied in the following manner per 4. Bulb weight (g): The average weight of 10 bulbs factory recommendation. taken from each plot after curing. Triadimefon 125 EC (Baylton): Bayleton 125 5. Bulb diameter (mm): The average diameter of EC Fungicide is a systemic fungicide with 10 randomly sampled bulbs from each plot was protective and curative action. Applied in 10-day measured by using digital caliper after curing.

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6. Number of cloves per bulb: This refers to the 3.Results and discussion average number of cloves of 10 bulbs taken from Garlic rust onset and intensity each plot. Garlic rust was first observed on 21 October 7. Clove weight (g): Clove weight was determined 2012, i.e. 91 days after planting (DAP) and garlic by dividing the bulb weight (10 bulbs) by the rust assessment was started on 23 October 2012 (93 number of cloves per bulb. DAP). The disease first appeared on all plots Statistical data analysis simultaneously. Data on garlic rust severity from each Disease incidence assessment date, yield and yield components, and Propiconazole fungicide significantly agronomic data were subjected to analysis of reduced the rust incidence at 107 DAP in all spacing variance (ANOVA) by using SAS (SAS, 9.0 as compared to the other fungicides and the Version) computer software. Least significant unsprayed checks (Table 1). The garlic rust difference (LSD) values were used to separate incidence was recorded until 107 DAP because the differences among treatment means (Gomez and disease attained nearly 100% incidence in all plots Gomez, 1984). Correlation analysis was carried out except the propiconazole sprayed ones. to know the relationships among disease severity Disease severity and yield and yield related parameters. The applied fungicides were significantly (p Economic analysis ≤ 0.05) different in their effects on disease severity To estimate the profitability of the (Figure 1 and Table 1). However, none of these fungicides, the fungicide costs, fungicide fungicides completely prevented the development application cost (man power used for spraying of of the disease. The maximum disease severity fungicides, equipment like knapsack sprayer), and recorded was 83.45% on the unsprayed plots, while garlic prices were considered. The price of the garlic the lowest (3.72%) garlic average rust severity was crop was estimated based on the current market observed on the plots sprayed with propiconazole. price. The result of this study for propiconazole fungicide Net return from fungicide application was is in agreement with the findings of Yonas calculated using Wegulo, 2010 formula. (2010) [10] , where spraying with propiconazole every Rn = YiP – (Fc + Ac), Where, Rn = the net return seven days significantly reduced garlic rust severity. from fungicide application (birr ha −1); Similarly, in Europe and Brazil, mancozeb and Yi = is yield increase from fungicide application (kg propiconazole have been used for garlic rust control ha −1), obtained by subtracting the yield in the [1, 11-13] . In contrast Steven et al. (2001 ) reported that control treatment from the yield in the fungicide non of ridomil, chlorothalonil, sulfur, copper treatment, P = is the garlic prices (birr kg -1); Fc = is hydroxide or maneb gave adequate control of the the fungicide cost (birr ha -1); and Ac = the fungicide garlic rust. application cost (birr ha -1).

Figure 1 . Garlic rust disease severity progress under different fungicide management Area under disease progress curve (AUDPC) compared to all other fungicides and the unsprayed The area under disease progress curve control (Figure 2). The other fungicides (ridomil, (AUDPC) is used to combine multiple observations mancozeb and bayleton) also significantly reduced of disease progress into a single value. The area the area under rust disease progress curve on the under disease progress curve (AUDPC) as a garlic crop. Hence, all fungicides reduced AUDPC measure of quantitative disease resistance entails compared to the unsprayed plots, but the difference repeated disease assessments and is a quantitative between mancozeb and ridomil in AUDPC values measure of disease intensity with time. was not statistically significant (Figure. 2). Spraying propiconazole every 10 days significantly (p ≤ 0.05) reduced the AUDPC values

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Table 1. Garlic rust incidence and severity on garlic treated with four different fungicides in 2012/13 main cropping season Garlic rust incidences at different Garlic rust severities at different days after planting (DAP) after planting (DAP) Fungicide 93 100 93 100 107 121 128 107 DAP 114 DAP DAP DAP DAP DAP DAP DAP DAP Propiconazol 30.39 36.00 44.44 3.23 1.27 1.60 2.23 1.80 3.72 Ridomil 30.44 68.06 100.00 3.86 19.40 29.86 37.167 39.51 44.45 Mancozeb 33.28 73.61 100.00 4.47 20.23 25.99 36.32 40.88 49.18 Bayleton 31.94 72.22 100.00 4.69 16.36 27.96 38.37 48.50 73.47 Control 31.83 82.50 100.00 4.90 21.09 39.13 46.50 63.70 83.45 CV (%) 19.80 13.88 2.10 15.63 21.20 17.86 8.13 6.68 5.72 SE (±) 1.35 3.39 0.38 0.21 1.24 2.03 1.35 1.10 2.12 LSD (5%) 4.68 6.67 1.39 0.49 2.48 3.33 1.96 1.94 2.18

Figure 2. Graph showing the AUDPC managed with different fungicides against garlic rust at Haramaya University Research Station in 2012/2013 main cropping season. Relative losses in yield and yield components and greater in two locations in the United States, and variation in agronomic parameters 31% greater in Zimbabwe. Losses in total bulb yield Losses in bulb weight The different types of fungicides applied on The research result showed that bulb weight was the experimental garlic plots and the consequent significantly (p ≤ 0.05) different among the difference in disease severity resulted in significant different fungicide treatments. The different disease difference in total bulb yield among the severity levels created by different fungicide sprays experimental plots. The highest (8.28 t ha -1) total caused different bulb weight losses. Bulbs obtained bulb yield was obtained from plots that were from plots treated with the fungicides ridomil and sprayed with propiconazole fungicide and the mancozeb were not significantly (p ≤ 0.05) different lowest (4.18 t ha -1) total bulb yield was obtained from each other but they were significantly (p ≤ from the unsprayed garlic plots. An average yield 0.05) different from other plots treated with loss of 49.33% occurred in the unsprayed plots. bayleton and propiconazole as well as the control. There were also bulb yield losses of 25.22, 34.99 The highest (42.77 g) bulb weight was obtained and 43.13% from plots that were treated with the from plots treated with propiconazole fungicide and fungicides ridomil, mancozeb and bayleton, the lowest (19.55 g) from the unsprayed plots. The respectively (Table 2), by considering and bulb weight (22.43 g) obtained from bayleton comparing with propiconazole-treated plots as fungicide-treated plots and the control did not show completely protected plots. The maximum statistically different values (p > 0.05), but the bulb (49.33%) bulb yield loss that occurred in the weight gained from bayleton-treated plots was experiment is less than the bulb yield loss (83%) greater than the value gained from the control plots which is caused by the same disease (Puccinia allii) (Table 2). on garlic in Nepal [14] and bulb yield loss (58.75%) The highest (54.29%) loss in bulb weight reported for Sinana, Ethiopia (Yonas, 2010) [10] but was recorded on the unsprayed plots. Bulb weight is almost equal to the bulb yield loss (50%) reported losses of 36.75, 34.00 and 12.93% were recorded in the USA [5] . Mueller et al., 2009 reported soybean from plots sprayed with bayleton, mancozeb and yields from plots treated with fungicides were 16 to ridomil, respectively (Table 2). The bulb weight 114% greater than yields from no fungicide control loss calculated due to Puccinia alli infection in this plots in four locations in Paraguay, 12 to 55% finding is similar to the loss (55.12%) estimated by

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Yonas (2010) [10] and that of Koike et al. (2000) [6] ridomil, mancozeb, bayleton-treated plots, and - the who reported 25 - 60% bulb weight loss. unsprayed, respectively (Table 2). Reduction in bulb diameter Losses in number of cloves per bulb Bulb diameter was significantly (p ≤ 0.05) There was no significant (p ≤ 0.05) difference in the different among the different fungicides. All the number of cloves per bulb among the different spray fungicide-treated plots gave higher bulb diameters fungicides. The fungicides sprayed as well as the than the unsprayed plots (Table 2). The highest different spacings used did not show any significant (41.37 mm) bulb diameter was recorded on bulbs difference on the number cloves in the bulbs. harvested from propiconazole-sprayed plots, while Difference in days to maturity the smallest (21.71 mm) was obtained from There was significant (p ≤ 0.05) difference unsprayed plots. Even though the average bulb size in days to maturity (DM) of garlic plots sprayed (38.97 mm) harvested from ridomil-sprayed plots with different fungicides. Days to maturity due to was smaller than that harvested from propiconazole propiconazole (149.44 days) and ridomil (146.56 treated plots, the bulb sizes were not statistically days ) application were statistically (p ≤ 0.05) different. The bulb sizes harvested from plots longer than the DM of plots treated with mancozeb treated with mancozeb (32.39 mm) and bayleton (144.67days), bayleton (143.33 days) and the (27.27 mm) were also significantly different from control (143.11 days) plots (Table 2). This might be each other (Table 2). The highest (47.52%) relative ascribed to the fact that the maximum protected reduction in bulb diameter was obtained from the plots used the maximum photosynthesizing unsprayed plots (Table 2). potential of the crop to mature, whereas plants in Losses in clove weight other plots treated with ridomil, mancozeb and The garlic clove weight was significantly (p bayleton matured earlier because the disease ≤ 0.05) different among the different fungicides facilitated the crop duration in the field, especially (Table 2). The different disease severity levels those plots which were unsprayed where the created by spraying different fungicides caused maximum disease was recorded matured earlier varying levels of clove weight losses. Clove weight than the sprayed plots. Similarly (Koike et al., obtained from plots treated with the fungicides 2001)[5] and [15] reported that garlic leaves that are mancozeb (1.73 g) and ridomil (1.77 g) were not heavily infected by rust dry prematurely. significantly (p > 0.05) different from each other. Difference in plant height The clove weight obtained from plots treated with Even though there was some variation in bayleton (1.19 g) and the control (1.06) were not plant height, the analysis of variance for plant height also significantly different (p > 0.05) from each did not show significant difference. The mean other. The highest (2.39 g) and the lowest (1.06 g) height of garlic was not also significantly affected clove weight were obtained from plots treated with by either fungicide spray or plant spacing propiconazole treated and the control plots, management. Therefore, plant height was not respectively (Table 2). Clove weight losses of affected by garlic rust severity. 10.92, 38.73 40.11 and 55.65% were obtained from Table 2. Yield and yield components of garlic and the corresponding relative losses due to garlic rust under different fungicide spray at Haramaya in 2012/13 main cropping season TY RTYL BW RBWL BD RBDL NC/B RNC/BL CW RCWL DM Fungicide (t/ha) (%) (g) (%) (mm) (%) (%) (g) (%) (Days) Propiconazol 8.28 0.00 42.77 0.00 41.37 0.00 18.08 0.00 2.39 0,00 149.44 Ridomil 7.35 25.22 30.91 12.93 38.97 20.39 17.49 -3.37 1.77 10.92 146.56 Mancozeb 6.43 34.99 29.62 34.00 32.39 32.97 17.39 -6.78 1.73 38.73 144.67 Bayleton 5.59 43.13 22.43 36.75 27.27 44.20 18.91 1.80 1.19 40.11 143.33 Control 4.18 49.33 19.55 54.29 21.71 47.52 18.57 47.52 1.06 55.65 143.11 CV 12.16 - 13.35 - 10.70 - 7.75 - 12.38 - 3.163 SE (±) 0.30 - 1.37 - 1.26 - 0.21 - 0.08 - 0.68 LSD (0.05) 0.73 - 3.75 - 3.34 - 1.35 - 0.19 - 3.44 TY = total yield, RTYL = relative total yield loss, BW = bulb weight, RBWL = relative bulb weight loss, BD = bulb diameter, RBDL = relative bulb diameter loss, NC/B = number of cloves per bulb, RNC/BL = relative number of cloves per bulb loss, CW = clove weight, RCWL, = relative clove weight loss, DM = days to maturity Cost/Benefit Analysis Net return from fungicide application was calculated using the following formula (Wegulo et al., 2011).

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Rn = YiP – (Fc + Ac), Where, Rn = the net return profitable. The net returns obtained from the from fungicide application (birr ha −1); application of those fungicides were Birr 136250, Yi = is yield increase from fungicide application (kg 105250, 73925 and 47700 from propiconazole, ha −1), obtained by subtracting the yield in the ridomil, mancozeb and bayleton, respectively control treatment from the yield in the fungicide (Table 3). In a similar study, an economic treatment, P = is the garlic prices (birr kg -1); Fc = is evaluation of fungicide use in winter wheat in the fungicide cost (birr ha -1); and Ac = the fungicide Sweden during the period from 1983 to 2007, based application cost (birr ha -1). on results from fungicide trials in farmers’ fields, Results from assessment of economic returns in this showed variability in net returns from year to year study indicated that fungicide application for garlic [16] . rust (Pucinia allii) management in garlic could be Table 3. Fungicide and fungicide application costs used to calculate net returns from applying fungicides to garlic in garlic rust ( Puccinia allii ) control in eastern Ethiopia in 2012/13 main cropping season Fungicide Yield Net Return Fungicide Fungicide Treatment Increased (birr/ha) Cost (Birr) Application (kg ha -1) Cost (Birr) Propiconazole 4100 139050 3300 1150 Ridomil 3170 105350 4550 1150 Mancozeb 2250 74925 2625 1150 Bayleton 1410 47700 500 1150

4. Summary and conclusions 4. Yohannes, A. (1987). Current Activities From this research result, it can be Research Recomendation and Future concluded that garlic rust can be controlled with the Strategies of Improvement Conference, selected fungicides, but propiconazol fungicide is Addis Ababa, Ethiopia, pp22-26). very effective than the other ungicides (ridomil, 5. Koike, S.T., R.F. Smith, R.M. Davis, J.J. mancozeb and bayleton). The higher net return Nunz and R.E. Voss. Plant Disease, 585- obtained from plots treated with propiconazol 591, 2001 fungicide than mancozeb, ridomil and bayleton and 6. Koike, S.T., R. Smith, M. Davis and J.J. the less disease incidence and disease severity on Nunez. Crop Protection, 241-243, 2000 propiconazole-protected plots might be due to 7. Davis, R.M., S. Koike, J. Nunz and R. Smith. effectiveness of the fungicide. Since this research is (1998). Garlic rust outbreak in California. done in one location in a single cropping season, University of California Vegetable Research research works should be carried out for and Information Center. confirmation in similar environmental conditions in 8. Tamire Hawando, 1973. Characterization of different seasons in the future. Alemaya Soils. Soil Science Paper, Series No, 5. Acknowledgement 1. Pp. 45 Authors would like to thank Ethiopian 9. Shaner, E and R.E. Finnely. Phytopathology, ministry of education for budget source. Authors 1051-1056, 1977 also wish to express their sincere thanks to Tigst H., 10. Yonas, W. (2010). Status of garlic rust Assegedech M. and Shimelis M. their continual (Puccinia allii L.) and its effect on yield and encouragement and support. yield components of garlic in Bale highlinds 6. References southeastern Ethiopia. Msc Thesis submited 1. Rochecouste, J. Chemical control of garlic to School of Plant Science , Haramaya rust. Journal of Plant Pathology, 47-48, 1984 University, Ethiopia. 2. Etoh, T. and P.W. Simon, 2002. Diversity, 11. Aguilar, J. and B. Reifscheinder. (1986). Fertility and Seed Production in Efficiency of fungicides on the control of Garlic.pp.101- 118 In: Rabinowitch, H.D. garlic rust. www.ajol.info/journals/jorid . and L.Currah (eds) Allium Crop Science: 12. Blum, L. and H. Gabardo. Chemical control Recent Advances. CABI Publishing, of garlic rust in Curitibanos. Brazol, Wallingford, UK. fitopatol, 230-232,1993 3. Sampath K. P. ,Kumar, Debjit Bhowmik, 13. Garcia, D.C., V. Barni,and L.A. Dettman, Chiranjib, Pankaj Tiwari, Rakesh Kharel Fungicides on the control of garlic rust. Santa J.Chem. Pharm. Res ., 135-14, 2(1), 2010. marya, 25-28, 1994

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14. Ahmed, S. and J. Iqbal. Pakistan Journal of and Garlic. american phytological society, Biological Science , 485-486. 2001. pp1-6. 15. Schwartz, H.F.and M.J. Mohan, (1995). The 16. Wiik,L., H. Rosenqvist. The Economics of genius Allium in the Compodium of Onion fungicides use in winter wheat in southern Sweden. Crop Protection, 11-19,2010.

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