management of seed borne pathogens of maize Essay Example For Students

management of seed borne pathogens of maize Essay Outline1 Abstraction 2 Introduction3 Material and methods4 Management of seed mycoflora5 Seed intervention6 Physical seed intervention methods7 Hot H2O intervention8 Dry heat intervention9 Solar heat intervention10 Chemical seed intervention11 Biological seed intervention12 RESULTS AND DISCUSSION13 Hot H2O intervention14 Table 1: Consequence of hot H2O intervention for control of corns seed mycoflora15 Sl.16 No17 Hot H2O18 temperature19 ( EsC )20 Time21 ( min )22 Seed23 sprouting24 ( % )25 Per cent seed mycoflora26 Per cent decrease over control27 Aspergillus Niger28 Aspergillus29 flavus30 Penicillium31 sp.32 Fusarium sp.33 Rhizopus sp.34 Curvularia sp.35 Bipolaris sp.36 Cladosporium sp.37 Boryodiplodia theobromae38 Alternaria sp.39 Nigrospora oryzae40 Mean41 1.42 3543 1044 8545 7046 7847 10048 3349 4850 451 252 2053 554 355 656 33.557 2.658 1559 8560 7061 7762 10063 3364 4865 266 267 2068 569 270 571 33.072 4.073 2074 8675 6876 7577 10078 3379 4780 281 282 1983 484 285 486 32.387 6.188 2589 8790 6691 74 92 10093 3294 4695 196 197 1898 499 2100 3101 31.5102 8.4103 30104 88105 63106 72107 100108 32109 43110 1111 15112 4113 2114 2115 30.3116 11.9117 2.118 40119 10120 86121 66122 72123 100124 32125 45126 4127 2128 18129 4130 3131 4132 31.8133 7.5134 15135 87136 61137 71138 100139 32140 43141 3142 2143 17144 4145 2146 3147 30.7148 10.7149 20150 88151 58152 70153 100154 31155 41156 2157 2158 15159 3160 1161 2162 29.5163 14.2164 25165 89166 52167 68168 99169 30170 39171 1172 1173 13174 3175 1176 2177 28.0178 18.6179 30180 89181 49182 67183 98184 29185 35186 11187 3188 2189 26.7190 22.3191 3.192 45193 10194 87195 60196 70197 100198 30199 41200 3201 2202 14203 4204 2205 2206 29.8207 13.4208 15209 88210 58211 69212 99213 29214 39215 2216 2217 12218 3219 1220 2221 28.7222 16.5223 20224 89225 55226 68227 98228 27229 38230 1231 10232 2233 27.7234 19.5235 25236 88237 52238 66239 98240 26241 36242 9243 2244 26.2245 23.8246 30247 86248 46249 65250 97251 24252 34253 7254 2255 25.0256 27.3257 4.258 50259 10260 86261 56262 68263 98264 27265 38266 3267 8268 2269 1270 2271 27.5272 20.0273 15274 84275 49276 67277 97278 26279 35280 2281 5282 2283 25.7284 25.3285 20286 83287 46288 65289 95290 24291 32292 3293 1294 24.1295 29.9296 25297 79298 42299 62300 93301 19302 30303 22.3304 35.1305 30306 77307 38308 60309 90310 17311 28312 21.1313 38.6314 Control315 85316 74317 79318 100319 33320 49321 5322 2323 22324 5325 3326 6327 34.4328 329 Dry heat intervention330 Table 2: Consequence of dry heat intervention for control of corns seed mycoflora331 ( % )332 333 Solar intervention334 Table 3: Consequence of solar heat intervention for control of corns seed mycoflora335 ( % )336 337 Chemical seed intervention338 Table 4: Consequence of chemical seed intervention for control of corns seed mycoflora339 ( % )340 341 Biological seed intervention342 Table 5: Consequence of bio agents on corns seed mycoflora343 Sl.344 No.345 Bioagent346 Concentration347 g/kg348 Seed349 sprouting350 ( % )351 Per cen t seed mycoflora352 Per cent decrease over control353 Aspergillus Niger354 Aspergillus355 flavus356 Penicillium357 sp.358 Fusarium sp.359 Rhizopus sp.360 Cladosporiumsp.361 Botryodiplodia theobromae362 Curvularia sp.363 Alternaria sp.364 Bipolaris sp.365 Nigrospora oryzae366 Mean367 1.368 Trichoderma viride369 2370 88371 18372 17373 32374 8375 18376 12377 2378 9.7379 71.47380 4381 90382 7383 13384 26385 4386 15387 8388 6.6389 80.58390 6391 92392 6393 20394 13395 3.5396 89.70397 8398 92399 2400 19401 11402 2.9403 91.47404 2.405 Trichoderma406 harzianum407 2408 87409 15410 15411 18412 10413 12414 13415 7.5416 77.94417 4418 89419 10420 8421 12422 7423 10424 7425 4.9426 85.58427 6428 91429 7430 5431 6432 3433 1.9434 94.41435 8436 91437 5438 4439 5440 1.3441 96.17442 3.443 Bacillus subtilis444 2445 86446 69447 56448 45449 25450 36451 18452 3453 22.9454 32.64455 4456 88457 63458 50459 41460 21461 29462 15463 1464 20.0465 41.17466 6467 89468 57469 45470 35471 18472 26473 13474 17.6475 48.2 3476 8477 89478 52479 43480 28481 15482 20483 10484 15.2485 55.29486 4.487 Pseudomonas fluorescens488 2489 87490 66491 55492 63493 17494 45495 15496 3497 24.0498 29.41499 4500 89501 61502 49503 50504 13505 40506 11507 20.3508 40.29509 6510 92511 52512 38513 46514 11515 39516 8517 17.6518 48.23519 8520 92521 47522 32523 41524 8525 38526 5527 15.5528 54.41529 Control530 85531 75532 80533 100534 33535 48536 22537 5538 2539 3540 3541 3542 34.0543 Abstraction Management of seed mycoflora was studied by different seed intervention methods viz. , physical, chemical and biological methods. By physical methods, seeds treated with hot H2O at 45EsC for 25 and 30 proceedingss and at 50EsC for 10, 15, 20, 25 and 30 proceedingss reduced seed mycoflora, but adversely affected seed sprouting. However, maximal seed sprouting was recorded when seeds were treated at 40EsC for 30 proceedingss and this intervention besides reduced seed mycoflora efficaciously. In dry heat intervention, seed intervention at 50EsC for one hr efficaciously reduced the seed mycoflora, but adversely affected seed sprouting. However, dry heat intervention at 40EsC for one hr reduced the seed mycoflora without impacting seed sprouting. In solar heat intervention, seeds exposed to solar heat intervention at 12-14 H on patio efficaciously reduced the seed mycoflora followed by 13-15 H, 14-16 H, 12-13 H, 13-14 H, 14-15 H and 15-16 h. Seed intervention with antifungals viz. , carbe ndazim, thiophanate methyl, captan, mancozeb and chlorothalonil at the rate of 2 g and 3 g per kilogram of seed efficaciously eliminated seed mycoflora. The maximal seed sprouting of 90 per cent was recorded when seeds were treated with carbendazim @ 2 and 3 g per kilogram of seed. In seed intervention with bioagents viz. , Trichoderma viride, T. harzianum, P. fluorescens and Bacillus subtilis, seed mycoflora was significantly reduced when corn seeds were treated with T. harzianum and T. viride at 6 g per kilogram of seed, where as maximal seed sprouting of 92 per cent was recorded when seed were treated with T. viride and P. fluorescens at 6 g per kilogram of seed. Introduction Maize ( Zea mays L. ) is one of the of import cereal harvests next merely to wheat and rice in the universe and utilised as nutrient, as provender for farm animal and as natural stuff for industry. World country under corn harvest is 147.56 million hectares with a production of 701.27 million metric tons ( Muhammad Akber et al. , 2008 ) whereas, in India corn is cultivated on an country of 8.11 million/ha. Entire maize production is 19.77 Mt, with an mean output of 2,435 kg/ha in 2007-08 ( Anon, 2008 ) . In Karnataka, maize occupies an country of 1.11 million hectares bring forthing of 3.20 million metric tons with a productiveness of 2894 kg/ha ( Anon. , 2008 ) . A sum of 112 diseases are known to happen on corn doing economic harm to the harvests ( Anon, 1960 ) and among them more than 70 diseases are reported as seed-borne. Important seed-borne diseases of corn are leaf topographic point, foliage blight, Collar putrefaction, meat putrefaction, scutellum putrefaction, seedling blight, anthracnose and head carbon black ( Richardson, 1990 ) . Seeds are known to transport a considerable sum of micro-organism. Some of these cause assorted diseases. Pathogens are associated with seeds in the signifier of contaminations, externally and internally as seed borne. These organisms become active under favorable status and impact the seed sprouting ( Christensen and Lopez, 1963 ) which consequences in lower works population and unnatural seedlings in field, thereby doing considerable decrease in output. Invasion by Fungis in storage might ensue in the stain of the seeds, rise in temperature, moldiness, loss in weight and assorted alterations in the seed components. Some of the seeds infecting fungi green goods mycotoxins such as aflotoxin, patulin, citrinine and ochratoxin ( Bilgrami et al. , 1979 ) . Seed intervention occupies one of the of import places in the incorporate direction of any disease and has provided first-class consequences in cut downing losingss caused by diseases with addition in quality and measure of seeds. Material and methods Management of seed mycoflora Seed intervention To command seed mycoflora extremely septic seeds of the intercrossed assortment Nithyashree were selected and subjected to different seed intervention methods viz. , 1 ) Physical 2 ) Chemical and 3 ) Biological methods. 400 seeds were incubated at room temperature on moist blotting papers as per criterion blotting paper method. Seeds without intervention served as control. Effect of seed intervention on seed sprouting and per cent seed mycoflora were recorded by utilizing steriobinocular microscope in all seed intervention methods. Physical seed intervention methods Hot H2O intervention Maize seeds were subjected to hot H2O intervention at 35 A ; deg ; C, 40 A ; deg ; C, 45 A ; deg ; C and 50 A ; deg ; C with clip interval of 10, 15, 20, 25 and 30 min. at each temperature degree, and experiment was replicated four times. Seeds without intervention served as control. Seeds were shade dried for half an hr and incubated for seven yearss on moist blotting papers. Observations were recorded on 8th twenty-four hours. Dry heat intervention Maize seeds were subjected to different temperature degrees viz. , 35, 40, 45 and 50 A ; deg ; C for an hr by maintaining them in hot air oven. 400 seeds were placed on moist blotting papers as per the criterion blotting paper method and incubated for seven yearss. Observations were recorded on 8th twenty-four hours. Solar heat intervention Maize seeds were subjected to solar heat intervention by maintaining them on patio in afternoon at clip continuance of 12-13 H, 13-14 H, 14-15 H, 15-16 H, 12-14 H, 13-15 H, and 14-16 H in April month. 400 seeds were placed on moist blotting papers as per criterion blotting paper method and incubated for seven yearss. Observations were recorded on 8th twenty-four hours. Chemical seed intervention The corn seeds were treated with six antifungals namely, carbendazim, captan, chlorothalonil, mancozeb, thiophanate methyl and ridomil at the rate of 2 g, 3 g and 4 g per kilogram of seed at each intervention degree. In each intervention were 400 seeds plated on moist blotting papers with four reproductions. Seeds without intervention served as control and incubated for seven yearss. Observations were recorded on 8th twenty-four hours. Biological seed intervention In this experiment corn seeds were treated with commercial preparations of Trichoderma viride, T. harzianum, Pseudomonas fluorescens and Bacillus subtilis at the rate of 2, 4, 6, and 8 g per kilogram of seed. After each intervention seeds were plated on moist blotting paper by utilizing standard blotting paper method. Seeds were incubated for seven yearss and observations were recorded on 8th twenty-four hours. RESULTS AND DISCUSSION Hot H2O intervention In the direction of corn seed borne Fungi, seed intervention with hot H2O at 50EsC for 15, 20, 25 and 30 proceedingss inhibited seed sprouting compared to command. However, seed intervention with hot H2O at 40EsC for 30 proceedingss significantly increased seed sprouting and reduced seed mycoflora efficaciously. Hence this appears the optimal temperature and continuance combination that reduces seed mycoflora and enhances seed sprouting ( Table 1 ) . This is inconformity with the consequences of Rahman et Al. ( 2008 ) who reported that seed intervention with different degrees of hot H2O intervention viz. , 48EsC, 50EsC and 52EsC significantly reduced the seed borne infective Fungis of corn viz. , Bipolaris maydis, Curvularia lunata and Fusarium spp. from 60.47, 71.07 and 76.99 % to 19.31, 29.37 and 4.01 % severally. Seed sprouting was besides increased after the seed intervention with hot H2O. Table 1: Consequence of hot H2O intervention for control of corns seed mycoflora Sl. No Hot H2O temperature ( EsC ) Time ( min ) Seed sprouting ( % ) Per cent seed mycoflora Per cent decrease over control Aspergillus Niger Aspergillus flavus Penicillium sp. Fusarium sp. Rhizopus sp. Curvularia sp. Bipolaris sp. Cladosporium sp. Boryodiplodia theobromae Alternaria sp. Nigrospora oryzae Mean 1. 35 10 85 70 78 100 33 48 4 2 20 5 3 6 33.5 2.6 15 85 70 77 100 33 48 2 2 20 5 2 5 33.0 4.0 20 86 68 75 100 33 47 2 2 19 4 2 4 32.3 6.1 25 87 66 74 100 32 46 1 1 18 4 2 3 31.5 8.4 30 88 63 72 100 32 43 1 15 4 2 2 30.3 11.9 2. 40 10 86 66 72 100 32 45 4 2 18 4 3 4 31.8 7.5 15 87 61 71 100 32 43 3 2 17 4 2 3 30.7 10.7 20 88 58 70 100 31 41 2 2 15 3 1 2 29.5 14.2 25 89 52 68 99 30 39 1 1 13 3 1 2 28.0 18.6 30 89 49 67 98 29 35 11 3 2 26.7 22.3 3. 45 10 87 60 70 100 30 41 3 2 14 4 2 2 29.8 13.4 15 88 58 69 99 29 39 2 2 12 3 1 2 28.7 16.5 20 89 55 68 98 27 38 1 10 2 27.7 19.5 25 88 52 66 98 26 36 9 2 26.2 23.8 30 86 46 65 97 24 34 7 2 25.0 27.3 4. 50 10 86 56 68 98 27 38 3 8 2 1 2 27.5 20.0 15 84 49 67 97 26 35 2 5 2 25.7 25.3 20 83 46 65 95 24 32 3 1 24.1 29.9 25 79 42 62 93 19 30 22.3 35.1 30 77 38 60 90 17 28 21.1 38.6 Control 85 74 79 100 33 49 5 2 22 5 3 6 34.4 Dry heat intervention In dry heat intervention as the temperature increased from 35EsC to 50EsC for continuance of one hr, seed mycoflora was decreased but adversely affected seed sprouting. Seed intervention at 50EsC recorded minimal association of 17 per cent by Rhizopus sp. followed by Fusarium sp. ( 17 per cent ) , A. niger ( 28 per cent ) , A. flavus ( 45 per cent ) , and Penicillium sp. ( 93 per cent ) and inhibited seed sprouting. However seed intervention at 40EsC recorded 98 per cent association by Penicillium sp. followed by, A. flavus ( 62 per cent ) , Rhizopus sp. ( 35 per cent ) , Fusarium sp. ( 25 per cent ) , A. niger ( 57 per cent ) , N. oryzae ( 2 per cent ) , Cladosporiuym sp. ( 11 per cent ) , Botryodiplodia theobromae ( 2 per cent ) and Curvularia sp. ( 1 per cent ) . Seed mycoflora was inhibited upto 22.7 per cent when seeds were treated at 40EsC dry heat and maximal seed sprouting of 87 per cent was besides recorded. Hence this appears the optimal temperature and continuance combinat ion that reduces seed mycoflora and enhances sprouting of seeds ( Table 2 ) . The present probe besides agrees with the studies of Prasanna Kumara ( 2004 ) . He reported that in dry heat intervention when seeds treated at 50 A ; deg ; C for one hr significantly decreased seed mycoflora of pigeonpea but inhibited seed sprouting, where as maximal seed sprouting was recorded when the seeds were treated at 40 A ; deg ; C. Table 2: Consequence of dry heat intervention for control of corns seed mycoflora Sl. No Dry heat temperature ( EsC ) for 60 min. Seed sprouting ( % ) Per cent seed mycoflora Per cent decrease over control Aspergillus Niger Aspergillus flavus Penicillium sp. Fusarium sp. Rhizopus sp. Curvularia sp. Alternaria sp. Cladosporium sp. Nigrospora oryzae Bortyodiplodia theobromae Bipolaris sp. Mean 1. 35 86 70 73 100 29 49 2 2 19 3 4 2 32 6.9 2. 40 87 57 62 98 25 35 1 11 2 2 26.6 22.7 3. 45 86 43 51 95 21 23 5 1 21.7 36.9 4. 50 84 28 45 93 17 17 18.1 47.4 Control 85 75 80 100 32 50 5 3 22 5 5 2 34.4 Solar intervention Surveies on solar heat intervention for the direction of corn seed mycoflora revealed that minimal association of 92 per cent by Penicillium sp. followed by Fusarium sp. ( 61 per cent ) , A. flavus ( 45 per cent ) , A. niger ( 30 per cent ) , and Rhizopus sp. ( 3 per cent ) . The maximal decrease of 19.4 per cent by seed mycoflora was recorded when seeds were exposed to 12-14 hour solar heat and maximal seed sprouting of 89 per cent was besides observed ( Table 3 ) . Similarly Rai et Al. ( 2001 ) treated maize seeds with UV radiation and ascertained decrease of fungous species with increased continuance of exposure. Table 3: Consequence of solar heat intervention for control of corns seed mycoflora Sl. No Time ( H ) Seed sprouting ( % ) Per cent seed mycoflora Per cent decrease over control Aspergillus Niger Aspergillus flavus Penicillium sp. Fusarium sp. Rhizopus sp. Alternaria sp. Nigrospora oryzae Bipolaris sp. Curvularia sp. Cladosporium sp. Botryodiplodia theobromae Mean 1. 12-13 87 68 72 98 30 45 1 3 1 4 16 4 31.0 10.1 2. 13-14 86 68 73 100 31 46 2 3 2 5 16 5 31.9 7.53 3. 14-15 86 69 74 100 31 47 2 4 2 5 18 5 32.4 6.00 4. 15-16 86 70 74 100 32 47 2 4 2 5 19 5 32.7 5.21 5. 12-14 89 58 67 92 28 42 1 2 14 2 27.8 19.4 6. 13-15 88 60 68 95 29 43 2 1 3 15 3 29.0 15.9 7. 14-16 87 67 70 97 30 45 1 3 1 4 16 4 30.7 11.0 Control 85 75 80 100 33 50 3 5 2 6 21 5 34.5 Chemical seed intervention The consequences of the chemical seed intervention revealed that seed intervention with carbendazim, thiophanate methyl and captan at rate of 3 g per kilogram of seed wholly eliminated A. Niger, A. flavus, Curvularia sp. , Trichoderma sp. , N. oryzae, B. theobromae, Alternaria sp. , Cladosporium sp. and Bipolaris sp. without impacting seed sprouting, where as chlorothalonil decreased entire seed mycoflora upto 94.11 per cent. Minimum decrease of 37.05 per cent seed mycoflora was recorded when corn seeds were treated with metalaxyl 8 % + mancozeb 64 wp @ 2 g per kilogram of seed. The maximal seed sprouting of 90 per cent was recorded when seeds were treated with carbendazim ( Table 4 ) . Similarly Manoj Kumar and Agarwal ( 1998 ) besides reported that seed intervention with antifungals viz. , thiram, rovral, dithane M-45, dithane Z-78, and bavistin + thiram ( 1:1 ) , well reduced seed borne pathogen particularly B. maydis, B. theobromae and F. moniliforme. Thiram and bavistin were sig nificantly superior to other antifungals in bettering seedling energy of discolored corns seed. Table 4: Consequence of chemical seed intervention for control of corns seed mycoflora Sl. No Antifungals Chemical concentration @ g/kg Seed sprouting ( % ) Per cent seed mycoflora Per cent decrease over control Aspergillus Niger Aspergillus flavus Penicillium sp. Fusarium sp. Rhizopus sp. Curvularia sp. Alternaria sp. Nigrospora oryzae Bipolaris sp. Cladosporium sp. Botryodiplodia theobromae Mean 1. Carbendazim 2 90 20 46 1 1 6.1 82.02 3 90 12 44 5.0 85.29 4 88 8 41 4.4 86.91 2. Thiophanate methyl 2 89 48 4.3 87.35 3 87 46 4.1 87.94 4 85 40 3.6 89.41 3. Captan 2 89 14 11 45 6.3 81.47 3 89 43 3.9 88.52 4 88 38 3.4 90.00 4. Mancozeb 2 87 15 22 9 46 8.3 75.58 3 88 7 14 7 42 6.3 81.47 4 88 8 5 31 4.0 88.23 5. Metalaxyl 8 % +mancozeb 64 % wp 2 86 35 57 67 28 38 8 3 21.4 37.05 3 87 19 55 58 24 35 3 1 17.7 47.94 4 87 10 51 45 21 26 13.0 61.76 6. Chlorothalonil 2 88 11 18 7 22 12 2 6.5 80.88 3 88 12 5 17 5 3.5 89.70 4 87 8 15 2.0 94.11 Control 84 75 78 100 31 48 5 3 3 3 23 5 34.0 Biological seed intervention In seed intervention with bioagents viz. , T. viride, T. harzianum P. fluorescens and B. subtilis, seed mycoflora was significantly reduced when corn seeds were treated with T. harzianum and T. viride at 6 g per kilogram of seed, where as maximal seed sprouting of 92 per cent was recorded when seed were treated with T. viride and P. fluorescens at 6 g per kilogram of seed ( Table 5 ) . Manjunatha and Rao ( 2002 ) besides reported that seed intervention with P. fluorescens, T. viride and T. harzianum efficaciously reduced A. alternata, F. moniliforme, A. flavus, A. Niger, R. stolonifer, C. lunata and C. globosum infection from wheat seeds. Table 5: Consequence of bio agents on corns seed mycoflora Sl. No. Bioagent Concentration g/kg Seed sprouting ( % ) Per cent seed mycoflora Per cent decrease over control Aspergillus Niger Aspergillus flavus Penicillium sp. Fusarium sp. Rhizopus sp. Cladosporiumsp. Botryodiplodia theobromae Curvularia sp. Alternaria sp. Bipolaris sp. Nigrospora oryzae Mean 1. Trichoderma viride 2 88 18 17 32 8 18 12 2 9.7 71.47 4 90 7 13 26 4 15 8 6.6 80.58 6 92 6 20 13 3.5 89.70 8 92 2 19 11 2.9 91.47 2. Trichoderma harzianum 2 87 15 15 18 10 12 13 7.5 77.94 4 89 10 8 12 7 10 7 4.9 85.58 6 91 7 5 6 3 1.9 94.41 8 91 5 4 5 1.3 96.17 3. Bacillus subtilis 2 86 69 56 45 25 36 18 3 22.9 32.64 4 88 63 50 41 21 29 15 1 20.0 41.17 6 89 57 45 35 18 26 13 17.6 48.23 8 89 52 43 28 15 20 10 15.2 55.29 4. Pseudomonas fluorescens 2 87 66 55 63 17 45 15 3 24.0 29.41 4 89 61 49 50 13 40 11 20.3 40.29 6 92 52 38 46 11 39 8 17.6 48.23 8 92 47 32 41 8 38 5 15.5 54.41 Control 85 75 80 100 33 48 22 5 2 3 3 3 34.0