Cereal Cyst Nematode Overview

Cereal Cyst Nematode (Heterodera avenae) Overview

• Discovered as a cereal parasite in Germany (Kuhn, 1874), first recorded in India (Vasudeva, 1958) from Rajasthan.
• Major hosts include wheat and barley; oats are significant in Europe.
• Known as 'Molya' disease in Rajasthan and Haryana, causing losses between 8.2% - 28.8%.

Infection Symptoms

• Stunted plant growth and chlorosis observed when crops are 1-2 months old.
• Reduced tillering leads to thinner, weaker culms.
• Premature flowering and decreased grain yield; severe cases may result in no grain formation.
• Roots exhibit bushy, swollen appearances; white female nematodes are visible on roots by January-February.

Nematode Biology

• Lemon-shaped brown cysts containing approximately 400 eggs form at crop maturity (March-April).
• Cysts detach from roots and remain dormant in soil until November.
• J2 larvae hatch and emerge from cysts between November and January; only about 50% eggs hatch per season.
• J2 penetrate roots behind the tip, become sedentary in vascular bundles, and form syncytia.
• After feeding, develop into adults through three molts, while retaining a stylet and flask shape.

Control and Management Strategies (INM)

• Effective crop rotation for 1-2 years with non-host crops such as mustard, chickpea, and carrots.
• Deep summer ploughing (2-3 times in May-June) reduces nematode populations through desiccation.
• Early sowing of wheat by two weeks can minimize crop loss.
• Resistant barley varieties like Rajkiran, C-164, and BH 393 limit nematode reproduction.
• Resistant wheat variety Raj MR-1 available for molya-infested fields.
• Application of carbofuran (2 kg a.i./ha) in heavily infected fields can increase wheat yield by 150-200%.

Lifecycle Key Points

• Cysts remain viable in soil for multiple years; one generation completed annually.
• Root exudates typically do not stimulate hatching.
• The lifecycle includes three juvenile stages (J2, J3, J4), with adults visible as pearly white dots on roots by late January.

Explore the characteristics, symptoms, and biology of the Cereal Cyst Nematode (Heterodera avenae), a significant parasite affecting wheat and barley. Learn about its discovery, impact on crop growth, and life cycle stages. This quiz provides key insights into this crop-threatening nematode.