Seed Health Management for Better Productivity - Govind Ballabh ...

More documents

Recommendations

Info

(Seed Health Management for Better Productivity)loose smut. The smut spores being formed in place of grains get blown away by wind as the thinmembrane ruptures leaving behind the bare rachis in loose smut, while the inflorescence tend toretain its shape in case of covered smut infection due to presence of persistent membrane(epidermis) covering the smut spores. Loose smut and covered smut being internally andexternally seed borne respectively can be best managed by seed treatment with differentchemicals as used for loose smut of wheat.Rice Leaf Smut (Entyloma oryzae)The disease initially reported from India and Burma is now known to occur in Japan,Taiwan; Philippines, Afghanistan Venezuela, USA and China. However, the disease is noteconomically much important. The disease is characterized by distinct lead black colored sporeslinear, rectangular or angular in shape, and covered by epidermis which ruptures only when theleaves are soaked in water. As disease perpetuates through hypophyllous sori lying in the field indiseased leaf trash, it can be controlled by following clean cultivation practices.Paddy Bunt (Neovossia horrida or Tilletia barclayana)Paddy bunt initially being reported from Japan has now spread to almost all rice growingareas in India and abroad in Uttar Pradesh, the loss has been estimated up to 3.2 per cent. Thedisease has become a major bottleneck in hybrid seed production. Because of localized air borneinfection all ears in a stool and all grains in a ear are not affected. Usually the sori are hidden byglumes but sometimes glumes are forced apart giving a appearance of minute black pustules orstreaks as a feature of disease. As the disease is initiated by air borne sporidia produced fromtetiospores lying in the soil at the time of flowering, seed treatment is not so effective, howeverfoliar sprays of the same chemicals as used for karnal bunt of wheat are recommended atflowering stage. Cultural practices like crop rotation, field sanitation etc. help in reducing inoculum.Usually early sowing varieties escape infection of florets by air borne sporidia The tolerance levelsfor kernel smut of rice are fixed at 0.1 and 0.5 % for foundation and certified seed, respectively..Smut of Sugarcane (U. scitaminea)The disease has been reported from all sugarcane growing areas of the world except Australia.In India, it is more serious in tropical regions (Maharashtra, Andhra Pradesh, Karnataka, and Kerala)causing both cane yield and quality losses. The disease is characterized by the formation of whip likestructure having black smut spores arising from the central axis of plant. The affected canes becomeslender and thin. As the disease perpetuates through smut spores present on infected canes/canesets or ratooned canes, the disease can be managed by following cultural practices like removal ofsmutted whips, avoiding preparation of plant sets from smutted canes, discouraging the practice ofratooning, along with disinfection of sets before planting with Agallol (0.25% suspension), mercuric- 124 -
(Seed Health Management for Better Productivity)chloride (0.1%) formalin (1.0%), Bordeaux mixture (4:4:50), vitavax, benlate, bavistin. Hot watertreatment (55-60°C for 10 min) has also being recommended against smut.Common Smut of Maize (U. maydis)Common smut of maize is of minor importance, being confined to Kashmir; less common inPunjab and rarely noticed in North Western parts of UP. The disease is distinct because of itseffect on maize which is not common among smut fungi and results in to formation of galls.Infection of female flowers gives rise to galls while stem galls result in bending of stalk. Themembrane (epidermis) covering the galls later ruptures, exposing the black spore mass. Being soilborne, the disease can be reduced drastically by following crop rotation, field sanitation and seedtreatment.Head Smut of Maize (U. reiliana)Head smut has been found moderately destructive in Sub-temperate Himalayas and hillyareas of Rajasthan, while a minor incidence has also been reported from TN, Andhra Pradesh, UPand Punjab. The whole tassel is converted in to a large sac having smut spores with floral bractsgrowing in to leafy structures. Columella is not formed. Disease is soil borne so crop rotation,sanitation and seed treatment is effective in reducing soil inoculum. The tolerance levels in thefield for head smut of sorghum are fixed at 0.05 and 0.1 % for foundation and certified seed,respectively.Grain Smut of Sorghum (Sphacelotheca sorghi)Grain Smut despite being known to cause huge losses in different countries (US Myanmar,S. Africa, Italy) has been reported to be a destructive disease causing up to 25 % grain losses inIndia. The disease results in to formation of oval dirty gray sori having black smut spores andcentral hard column called Columella composed of host tissues. Infection of plant occurs atseedling stage and hence the disease can be controlled by solar heat treatment, treatment withFormalin (0.5% for 2 hrs), Copper Sulphate Solution (0.5-3.0 % for 15 min). The tolerance levels inthe field for grain smut of sorghum are fixed at 0.05 and 0.1 % for foundation and certified seed,respectively.Loose Smut of Sorghum (S. cruenta)In India it is prevalent in Andhra Pradesh, Bombay, Karnataka and TN causing not onlygrain damage but also affects plant growth and hence fodder yield. The smutr spores produced inplace of grains get exposed duer yto rupturing of membrane. Columella is formed and persistseven after dispersal of spores. The management practices followed against grain smut also takescare of loose smut in sorghum.Head Smut of Sorghum (S. reiliana)- 125 -
Page 13 and 14:
(Seed Health Management for Better
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74: (Seed Health Management for Better
Page 123: (Seed Health Management for Better
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
potential. An improvement in qualit
Page 221 and 222:
9. Session Arrangement CommitteeDr.
Page 223 and 224:
9. Dr. Pradip Kumar BorahSr. Scient
Page 225 and 226:
TRAININGONANNEXURE-IIISEED HEALTH M
Page 227 and 228:
ANNEXURE-IVCENTRE OF ADVANCED STUDI
Page 229 and 230:
SundayApril 6MondayApril 7TuesdayAp
Page 231:
TuesdayApril 15WednesdayApril 16Thu
show all

Seed Health Management for Better Productivity - Govind Ballabh ...

Create successful ePaper yourself

Delete template?

Save as template?