Unraveling Tomato Troubles: A Journey into Tomato Diseases

Damping off : Pythium aphanidermatum

The diagnostic symptoms of this fungal disease that affects seedlings in the early stages of growth. 

It causes the seedlings to rot at the soil level, leading to toppling over or collapsing.The symptoms indicate two phases of the disease: pre-emergence and post-emergence. The pre-emergence phase is characterized by complete rotting of seedlings, which means the disease is affecting the plants before they emerge from the soil or while they are still in the early stages of growth. The post-emergence phase shows that the disease continues to develop even after the plants have emerged from the soil.

Management Practices : 

  • Soil Application/Drenching of Thiophanate Methyl 70% WP @ 2-3 gram/ltr  or Fluopicolide 4.44% + Fosetyl-Al 66.67% WG @ 2 gram/ltr or Copper Oxy-Chloride @ 2-2.5 gram/ltr Water .
  • Avoid stagnation of water in the field.
  • At early stages, if the infection is severe then remove the seedling and replace the healthier ones.
  • Seed treatment with biocontrol agents like Trichoderma sp./ Pseudomonas sp./Bacillus sp. @ 10 gram/kg of seeds.

Early Blight: Alternaria solani

Early blight symptoms can appear on leaves, fruits and stems at any stage of growth. The diagnostic symptoms are brown spots with concentric rings in a bull’s eye pattern and a yellow margin. The fruit gets infected through the calyx around the stem attachment and the infected fruits show brown concentric rings.

Management practices : 

  • Foliar Application of  Iprovalicarb  5.5% + Propineb 61.25% WP @ 2 gram/ltr or Azoxystrobin 23% SC @ 1 ml/ltr or  Cymoxanil 8% + Mancozeb 64% @ 2 gram/ltr water.
  • Remove the infected leaves and stem and fruits to reduce further wide spread.
  • Seed treatment with biocontrol agents like Trichoderma sp./ Pseudomonas sp./Bacillus sp. @ 10 gram/kg of seeds.

Late blight:  Phytophthora infestans

Late blight starts with water-soaked gray-green spots on lower older leaves, which darken and develop white fungal growth underneath. Lesions can expand rapidly and the entire leaf dies (becomes necrotic) spread to the whole plant, causing severe damage to the crop.

Management Practices : 

  • Foliar Application of Famoxadone 16.6% + Cymoxanil 22.1% SC @ 1-1.25 ml/ltr or Fluopicolide 5.56% + Propamocarb Hydrochloride 55.6% SC @ 1.5-2 ml/ltr or Dimethomorph 50% WP @ 2 gram/ltr water.
  • Remove the infected plants to avoid mass spread of the diseases immediately, in severe cases. 
  • Proper drainage & Crop rotation with non-host crops.

Fusarium Wilt : Fusarium oxysporum f. sp. Lycopersici

The plant shows yellowing of lower leaves and clearing of veinlets, followed by the death of younger leaves in succession. The petioles and leaves droop and wilt, and the vascular system turns brown. Eventually, the entire plant wilts and dies.

Management practices : 

  • Removal of infected plants from the main field and burn it.
  • Soil solarization & Crop rotation can reduce the influence of Fusarium wilt.  
  • Seed treatment with Trichoderma viridis, Pseudomonas fluorescens @ 10 gram/kg seeds.

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