visit is arecanut farm
Inflorescence caterpillar: Tirathaba mundella
Symptom of damage:
- Caterpillars feed on the inflorescences (tender female flowers) and rachillae
- Webbing and feeding the inflorescence
- Spathe opening is delayed.
- Yellowing of spadices,
- Presence of small holes with frass and drying on the spathe
Management:
- Infected spadices may be forced open and sprayed with malathion 0.05%
| Paddy stemborer: Scirpophaga incertulasSymptom of damage:Presence of brown coloured egg mass near leaf tipCaterpillar bore into central shoot of paddy seedling and tiller, causes drying of the central shoot known as “dead heart”Grown up plant whole panicle becomes dried “white ear”Plants could be easily pulled by hand Management: ETL: 25% Dead heart symptoms ATL (Action Threshold Level): 2 egg masses/m2 At ATL release egg parasitoid, Trichogramma japonicum for the management of the rice yellow stem borer Spraying Neem seed kernel extract controls stem borer Clip the seedling tips before transplanting to eliminate egg masses and collect and destroy the egg masses in main field |
| Blast: Pyricularia grisea |
| Symptom:Infects at any stage of the growth from the seedling to the grain formation stageThe infection appears in the nursery from second week of germination and spread quickly to entire nursery as well as to main field.Small brown circular to elongated spots appear on leaves which eventually develop into large elongated spindle shaped areas in the seedling stage. Young leaves dry completely in the nursery itselfThe spindle shaped spots appear on leaves in the main field. Several spots coalesce and cause drying of foliageMaximum damage is caused by the neck blast. The neck region turns black and shrinks.Infection occurs at the basal portions of the panicle branches including the fingers and the ear head breaks away from the stalk. The affected portions turn brown and ears become chaffy and only few shriveled grains are formedSome of the fingers are also affected causing finger blast. The fingers become chaffy and only few shriveled grains are formed |
   INFECTED PLANT BLAST ON LEAF FINGER BLAST |
| Identification of pathogen:Mycelium is intra and inter-cellularNumerous conidiophores and conidia are produced in the central portion of the spindle shaped spots under humid conditions. As a result, the spot assumes a smoky appearanceConidiophores emerge through the stomata or through the epidermal cells are simple septate and dark colouredConidia are borne at the tip of the conidiophoresConidia are pyriform, 3 celled, hyaline, 2 septateConidia germinate with germ tubes which infect the leaf wither through epidermal cells or stomata |   Pyricularia grisea Conidia of Pyricularia grisea |
| MANAGEMENT:Life cyle of Pyricularia grisea | |
Cultural methodUse disease free seedsGrow resistant varieties like CO RA (14), Paiyur (RA)-2, GPU-28, GPU-45,GPU-48, L-5Proper plant spacing and transplanting is advisableEarly sowing (July month) reduces the blast severityBiological methodSpray Pseudomonas fluorescens (Pf1) at 2 g/lit of water. First spray immediately after noticing the symptom. Second and Third sprays at flowering stage at 15 days intervalTreat the seed with Pseudomonas fluorescens @ 6g/Kg seed and spray the extracts of Prosopis juliflora leaf extract (10%), Ipomoea carnea leaf extract (10%)Foliar spray with premixture fungicide (Carbendazim+Mancozeb) @ 0.2% concentration at 50% earhead emergence followed by a second spray with Pseudomonas fluorescens (Pf1) at 2g/lit of water 10 days laterChemical methodSeed treatment with carbendazim @ 1 gm/Kg of seedSpray Carbendazim 0.1% in nursery 10-12 days after sowing. Repeat the spray 20-25 days after transplanting and 40 to 45 days after transplantingSpray any one of the fungicides Carbendazim 500 g or Iprobenphos (IBP) @ 500 ml/ha or premixture fungicide (Carbendazim+Mancozeb) @ 500g/ha. First spray immediately after noticing the symptoms. Second and third sprays at flowering stage at 15 days interval to control neck and finger infection. |