Little Leaf of Brinjal, Alternaria Blight of Cabbage/Cauliflower, Lady's Finger Yellow mosaic disease

Little Leaf of Brinjal 

Causal organism: Mycoplasma Like Organism (MLO).

Symptoms 

1.  Short, smaller leaves are produced.

2.  Petioles are reduced; Leaves appear stiking to them.

3.  Leaves become narrow, soft, smooth, thin and yellow in colour.

4.  Distance between inter node is small.

5.  Floral part transfer to green foliage.

6.  Fruiting react mostly sterile.

Little Leaf of Brinjal. https://cststudy.blogspot.com/ 

Transmission 

Not sap transmitted. MLO transmitted by Leaf hopper. Alternate host  Tomato, potato etc.

Control Measure  

♦  Destruction of infested plant and hosts. 

♦  Growing on resistant varieties. e.g. Black beauty, Brinjal round etc. 

♦  Chemical treatment with tetracyclins. e.g. Tetramycin @ 500 ppm.

Alternaria Blight of Cabbage/Cauliflower 

Causal Organism: Alternaria brassicae.   Alternaria brassicicola.

Symptoms 

1.  Yellowing of leaves and dwarf plant.

2.  Dropping lower leaves one by one.

3.  Root infection, Collar region rotten.

4.  The edges of affected leaves become purplish and the base become brownish.

Alternaria Blight of Cabbage/Cauliflower. https://cststudy.blogspot.com/ 

Disease Cycle

Control Measure  

♦  Seed treatment with Provax 200 @ 3g/kg of seed. 

♦  Foliar spraying with Rubral (2 ml/1 litre of water). 

♦  Crop rotation should be followed. 

♦ Spraying with Redomil  (0.2%) or Dithane M­45 or Cupper oxichloride @ 3­4 g/L of water  for 2­3 times at 10­15 days interval. 

♦  Using disease resistant varieties. 

♦  Crop residues and alternate host should be destroyed. 

♦  Avoid overhead irrigation during head development. 

♦  Control cruciferous weeds. 

♦  Treat seed with hot water.

Lady's Finger Yellow mosaic disease 

Causal organism: Yellow mosaic virus.

Vector: White fly (Bemisia tebaci), Persistent virus.

Symptoms 

1.  The vein is clearing and veinal chlorosis occur.

2.  The leaves, vein and veinlets are conspicuous yellowing and they become thick.

3.  In severe cases, the leaves become completely yellow.

4.  Distortion of leaf stalks and stems occurs at the advanced stage of infection.

5.  Fruits become dwarfed, malformed and are yellowing green.

Lady's Finger Yellow mosaic disease. https://cststudy.blogspot.com/ 

Alternate host: Cotton.

Transmission 

The virus is not sap transmissible. It is graft transmissible.

Control Measures 

1. Cultivate resistant varieties.

2.  Use seeds collected from disease­free plants.

3.  Remove and destroy disease­affected plants from crop fields to avoid secondary spread.

4.  Destroy host weeds, such as Croton sparsiflora and Ageralium spp.

5.  Follow crop rotation.

6.  Control the insect vector by spraying dimethoate 0.03 % or  monocrotophos 0.05 %.