Gummy stem blight is a highly destructive fungal disease affecting cucurbit crops like watermelon, muskmelon, cucumber, and pumpkin. If not controlled early, it can lead to severe yield loss, fruit rot, and poor crop quality.

If you notice leaf yellowing, stem cracking, or gum oozing, immediate action is necessary to protect your crop.

Symptoms of Gummy Stem Blight in Cucurbits

Gummy stem blight symptoms can be observed on all parts of the plant except the roots.

Leaf Symptoms

• Water-soaked spots near leaf margins
• Yellowing (chlorosis) around infected areas
• Spots enlarge and merge, causing leaf blight and wilting
• Brown spots on cotyledons in seedlings

Stem Symptoms

• Brown, water-soaked lesions
• Development of cankers with gummy exudation
• Stem splitting and wilting
• Seedling death in severe cases

Fruit Symptoms

• Fruit cracking and rotting
• Characteristic black rot

What causes Gummy Stem Blight in Cucurbits

Following are the conditions which create favourable conditions for the disease to develop and spread:

• High humidity levels of around 85% and moist conditions, especially with frequent rains or overhead irrigation and poor drainage.
• Infected seeds used for planting.
• Wind and rain splashes facilitating the disease’s dissemination within and between fields.
• Undecomposed plant material provides reservoir for fungus survival.
• Alternate host plants and weeds.
• Contaminated tools, equipment or even through clothing of farm workers.

Gummy Stem Blight Preventive Measures

• Use certified disease-free seeds & treat seeds before sowing
• Maintain clean nursery and remove infected seedlings
• Rotate crops every 2 years with non-host crops (Brassicas, onion, legumes)
• Deep plough the soil during summer to expose and kill the fungal spores.
• Keep the field free from weeds.
• Avoid overcrowding of plants for allowing proper penetration of air and sunlight.
• Avoid any damage to the plants as well as fruits to avoid entry of fungus through wounds.
• Collect and burn all the plant debris after harvest.

Management of Gummy Stem Blight in Cucurbits

1. Biological Management

Spray or drench with Trichoderma viride or Pseudomonas or Bacillus spp, 15 days after sowing at every 15 days interval to prevent and manage gummy stem blight disease in melons and other cucurbits.

Product name	Technical content	Dosage
Anand Dr Bacto’s Fluro	Pseudomonas fluorescens	Foliar: 2.5 ml/lit of water Drenching: 10 ml/lit of water
Multiplex Nisarga	Trichoderma viride	Foliar: 3 gm/lit of water Soil Application: 1 – 2 kg of the product + 100 kg of FYM
Mildown Bio Fungicide	Bacillus subtilis	Seed treatment: 0.15 – 0.2 ml/kg seed Seedling treatment/nursery bed: 5 ml/lit Drip: 2.5 ml/lit of water
Multiplex Bio-Jodi	Bacillus spp. & Pseudomonas spp	Foliar: 5 gm/lit of water Soil Application: 2 – 5 kg of product + 120 – 150 kg of FYM

2. Chemical Management

It is recommended to apply fungicides preventively in combination, about 1 week after germination or when the plants have 3-4 leaves to minimize crop damage and losses to a greater extent. As a curative measure, spray fungicides after disease occurrence and at appropriate developmental stages of the crop.

Product name	Technical content	Dosage
Amistar Top Fungicide	Azoxystrobin 18.2% + Difenoconazole 11.4% SC	1 ml/lit of water
Cabrio Top Fungicide	Metiram 55% + Pyraclostrobin 5% WG	3 – 3.5 gm/lit of water
Roko Fungicide	Thiophanate Methyl 70% WP	Foliar: 0.5 gm/lit of water or Drench: 2 – 4 gm/lit of water
Kocide Fungicide 2000	Copper Hydroxide 53.8% DF	2 gm/lit of water
Tata Master Fungicide	Metalaxyl 8% + Mancozeb 64% WP	1.5 – 2.5 gm/lit of water
Custodia Fungicide	Azoxystrobin 11% + Tebuconazole 18.3% w/w SC	1.5 ml/lit of water
Curzate Fungicide	Cymoxanil 8% + Mancozeb 64% WP	2 – 2.5 gm/lit of water

Learn more about Gummy Stem Blight in Watermelon. CLICK HERE