PHYSIOLOGICAL DISORDER,PEST AND DISEASE IN TOMATO 

Physiological disorder:

Blossom end rot:

  • Brown water soaked discoloration appears at the blossom end of the fruit.
  • The spots enlarge and darken rapidly and the affected portion of the fruit becomes sunken, leathery and dark coloured

Control 

  • This disorder is decreased by increasing irrigation.
  • Judicial fertilizer application
  • Liming decreases the incidence of blossom end rot.

Fruit cracking 

  • Radial cracking, where surface of the mostly full ripe fruits cracks radially from the stem end to the fruit.

Control

  • Irrigation with regular intervals
  • Pruning and staking during summer season should be avoided
  • Spraying seedlings before transplanting with 0.3-0.4% borax solution.

Sun scald:

Exposed portion of either green or nearly ripe fruits get blistered and water soaked due to extreme heat of scorching sunshine

Control:

  • Protection of plants from defoliation by diseases and insect pests
  • Training and pruning in summer months should be avoided.

Puffiness:

Outer wall of the grown up fruits (two-third normal size) continues to develop normally but growth of the remaining internal tissues

Control

  • Over irrigation should be avoided.
  • Less nitrogen should be applied
  • Boron should be applied by spraying 0.3-0.4% borax solution.

Pests:

Thrips: Thrips tabaci

Management - 

  • Use yellow sticky traps @ 15/ha
  • Spray methyl demeton 25 EC @llit/ha or dimethoate 30 EC @llit/ha

Serpentine leaf miner: Liriomyza trifolii

Symptoms:

  • Leaf miner damage
  • Mining in the leaf
  • Dried leaves

Mgt -

  • Collect and destroy mined leaves 
  • Spray NSKE 5%

Whitefly: Bemisia tabaci

Whitefly in tomato

 Sym :

  • Tomato leaf curling
  • Silvery damage
  • Fruit damage

Mgt : 

  • Apply carbofuran 3% G @ 40 kg/ha
  • Spray of dimethoate 30% EC @1ml It or malathion 1.5ml/lt.

Fruit Borer: Helicoverpa armigera

Fruit borer in tomato

Sym : Bore holes in fruit

Mgt : 

  • Set up pheromone trap with Hentar 2/ha Collection and destruction of damaged fruits and grown up caterpillars
  • Spray Bacillus thuringiensis 2g/lit
  • Set up pheromone trap with Hentar 2/ha

Damping off: Pythium aphanidermatum

Mgt:

  • Use raised seed bed Drench with Copper oxychloride 0.2% or Bordeaux mixture 1%.
  • Seed treatment with fungal culture Trichoderma viride (4 g/kg of seed) to control pre emergence damping off.

DISEASE:

Early Blight: Alternaria solani

Early blight in tomato

Sym : Concentric ring on infected parts.

Mgt : 

  • Removal and destruction of crop debris.
  • Practicing crop rotation helps to minimize the disease incidence.
  • Spray the crop with Mancozeb 0.2% for effective disease control.

Late blight : phytophthora infestans

Late blight in tomato

Concentric rings in tomato






Sym :

  • Concentric ring on infected parts
  • plant become dead

Mgt:

  • The affected plants should be removed and destroyed.
  • Practicing crop rotation helps to minimize the disease incidence.
  • Drench with Copper oxychloride 0.2% or Bordeaux mixture 1%.

Fusarium Wilt: Fusarium oxysporum fsp.lycopersici

Sym : whole plant become dead 

Mgt:

  • The affected plants should be removed and destroyed. 
  • Spot drench with Carbendazim (0.1%)
  • Crop rotation with a non-host crop such as cereals.

Bacterial Wilt: Ralstonia solanacearum

Sym: plant become dead 

Mgt:

  • Crop rotations, viz., cowpea-maize-cabbage, okra-cowpea-maize, maize-cowpea-maize and finger millet-egg plant are reported effective in reducing bacterial wilt of tomato.
  • Use of disease resistane varieties like Arka Abha, Arka Alok.

Mosaic: Tomato mosaic virus (TMV)


Sym : Yellow patches in leaves

Mgt : 

  • Use of disease-free seed and seedling Crop rotation with non-host crops
  • Soaking of the seeds in a solution of Trisodium Phosphate (90 g/litre water) a day before sowing
  • Spray Imidachloprid 0.05 % or Dimethoate 0.05% to control vector

Leaf curl: Tomato leaf curl virus (ToLCV)

Sym :

Yellowing between veins and an upward curing of their margins

Mgt :

  • Keep yellow sticky traps @ 12/ha to control white fly. 
  • Raise barrier crops cereals around the field.
  • Spray Imidachloprid 0.5 % or Dimethoate 0.5% @ 15, 25, 45 DAT to control vector




Reference:

Textbook of vegetable crops by Prem nath k.R.M.swamy

Vegetable science by D.singh