Soft Rot Threat: Protecting Ginger From Destruction

Did you know that ginger is a highly demanded spice crop, with India alone producing around 2.12 million metric tons in 2022? 

However, diseases like soft rot or rhizome rot can threaten your yield, quality, and marketability. But fear not! You have the power to protect your rhizomes and achieve a thriving ginger field. Say goodbye to worries about market value as buyers will no longer reject your produce due to disease concerns. Get ready to enjoy better prices and greater profitability.  

All you want to know about the pathogen’s survival conditions 

Soft rot in ginger is caused by soil-borne fungi, namely Pythium aphanidermatum, Pythium vexans and Pythium myriotylum. These fungi thrive in warm and moist conditions, typically during the onset of the southwest monsoon.  

They have two ways of survival:  

1. They can persist in diseased rhizomes that are kept for seed purposes and 
2. They produce resting spores that can contaminate the soil from infected rhizomes.   

Younger ginger sprouts are particularly vulnerable to these pathogens and the disease becomes more severe when accompanied by nematode infestations. Inadequate soil drainage, leading to waterlogged conditions in the field, further increases the intensity of the disease. 

Identify the signs of soft rot in your ginger field 

• Symptoms of soft rot or rhizome rot in ginger begin at the collar region of the pseudo stem and progresses both upwards and downwards.  
• The affected collar region becomes brown and water-soaked (soft and mushy to touch). 
• The rotting spreads to the rhizomes resulting in soft rot with a distinct foul smell. 
• As the disease progresses, the roots may also become infected. Affected stems can be easily pulled off.  
• Light yellowing of the leaf margins on the lower leaves, which gradually extends to the entire leaf surface. 
• During the early stages of the disease infection, the middle portion of the leaves may remain green while the margins turn yellow.  
• The yellowing then spreads to all leaves of the plant, starting from the lower region and moving upwards. 
• Affected pseudo stems droop, wither and dry.  

Rhizome Rot or Soft Rot in Ginger Management

Cultural Management soft rot in ginger

• Select disease free seed rhizomes for planting. 
• Select well-drained soils for planting ginger. 
• Before planting, cover the moist soil with transparent polythene sheet for about 45 – 50 days (Soil solarization).  
• Follow crop rotation with non-host crops like maize, soybean or cotton for at least 2 – 3 years. 

Mechanical Management soft rot in ginger

• Remove and destroy the infected plants if you notice them in the field. 

Biological Management soft rot in ginger

• Treat the seed rhizomes with Trichoderma viride or Trichoderma harzianum or Pseudomonas fluroscens at 10 – 20 gm/lit of water before sowing.  
• Apply Trichoderma viride or Trichoderma harzianum or Pseudomonas fluroscens as mentioned below 10 – 15 days before sowing. In addition, apply neem cake at the rate of 1 kg per acre along with the bio-control agents.  

Chemical Management soft rot in ginger

• Treat the seed rhizomes with Mancozeb 75% WP (3 gm/kg of seeds) or Metalaxyl 4% + Mancozeb 64% WP (1.5 gm/kg seed) for 30 minutes before storage as well as before planting to reduce the disease incidence. 
• Apply Neel Cu-Copper EDTA 12% at 0.5 gm/lit of water (dry conditions) or at 1.5 – 2 gm/lit of water (wet or rainy conditions).  
• Drench the soil with any of these mentioned fungicides or 1% Bordeaux mixture.  

Read more: Ginger Planting & Best Practices.