DISEASES OF MAIZE CROP 

Bacterial stalk rot  of maize  -

> casual organism - Ervinia Carotovora 

. Soil borne pathogen 

> Symptoms - The basal internodes develop soft rot and give a water soaked appearance. 

. A mild sweet fermenting odour accompanies such rotting. 

. Leaves some time show signs of wilting amd affected plants topple down in few days.

SYMPTOMS >

CONTROL > 

. Grow res. var. - Ganga safed -2 

. Copper oxychloride tetracycline or streptocycline 

. Use healthy seed

. Field sanitation 




CHARCOAL ROT OF MAIZE 

> Casual organism - Rhizoctonia bataticola 

. Soil borne pathogen 

> Symptoms - The affected plants exhibit wilting symptoms .

> The stalk of the infected plants can be recognized by grayish streak.

> Shredding of root bark and disintegration of root system are the common feature.


SYMPTOMS - 

> control - 

. Long crop rotation.

. irrigate the crop at the time of ear head emergence to maturity.

, Seed treatment with Carbendazim or Captan at 2 g/kg 

. Grow tolerant varities - SN-65, SWS- 8029, Diva and Zeni.



DOWNY MILDEW OF MAIZE 

> Four type of downy mildew - 

> Sorghum Downy Mildew - ( c.o.- Perenosclerospra sorghi) 

>Sugarcane Downy mildew - ( c. o. - Perenosclerospra sacchari)

> Brown Stripe Downy mildew - ( c.o. - sclerophthora rayssiae)

> Crazy Top Downy Mildew - ( c.o. - Sclerophthora macrospora )


> SYMPTOMS - Crazy top ( The tassels are converted into green leaf like structure which leads to tassels malformation )

. White downy growth is seen on the lower surface of leaves. 


>SYMPTOMS - 


> CONTROL - 

. Grow tolerant var. CO1, COH1 and COH2. 

. seed treatment with Metalaxyl ( 6g/kg).

. Spray Metalaxyl + Mancozeb (1kg) on 20 days after sowing. 

. Deep ploughing.

. Crop rotation with pulses. 

. Rogue out infected plants. 




 RUST OF MAIZE 

> Casual organism - puccinia sorghi 

> Symptoms - 

. Brown powdery pustules are scattered over both surface of the leaves. 

> Control - 

. Remove the alternate host.

. spray Mancozeb at 2 Kg /ha 


SYMPTOMS > 




MOSAIC OF MAIZE 

>Casual organism - Maize Mosaic potyvirus

>Vector - Leaf Hopper ( Perigrimus maidis ) 

> Symptoms -

. Chlorotic spot turn into stripes covering entire leaf blade.

. leaf sheath and stalk. 

. Rosetting of  new growth is observed.


SYMPTOMS > 




LEAF BLIGHT OF MAIZE 

Casual organism - Helminthosporium maydis 

. seed borne pathogen 

> Control- 

. Seed treatment with captan or Thirum at 4 g/kg.

. Spray Mancozeb 2 kg or Captan 1 kg/ha.



SYMPTOMS - 




COMMON SMUT OF MAIZE 

> Casual organism - Ustilago maydis 

. Also known as boil Smut. Blister Smut.

. Local infection 

>Symptoms - 

. Tumor like galss that that form on Actively growing host tissues.

. Sometimes is refferred to as '' maize mushrooms " or "Mexican truffles".


SYMPTOMS 

White bud of maize 

> Physiological disorder 

> Due to Zn deficiency 

>Symptoms -

. Apical portion of leaves become white. 

> Control - Apply ZnSo4 ( 20-25 kg/ha. ) at sowing time. 



SYMPTOMS