Grown across 0.7 million hectares of Rajasthan, UP, and Bihar as a rabi cereal; valued for malt, feed, and increasingly for human nutrition.
Barley : 5 Major Threats and Their Control
For guidance only. Does not replace local expert advice. Check region-specific recommendations with your nearest KVK or State Agriculture Department before buying seeds, fertilizers, or pesticides.
1. Powdery Mildew
(Blumeria graminis f.sp. hordei)
The Threat:
- Powdery mildew appears as a white, floury coating on leaves and leaf sheaths during cool, humid weather (15–22°C).
- As colonies expand, they reduce the photosynthetic capacity of the flag leaf, which is critical for grain fill in barley.
- Severe infections can cover the flag leaf, shortening the grain-fill period and producing small, shrunken grains with poor test weight.
- Malt barley is especially sensitive, as low test weight grain is rejected by breweries.
- Yield losses range from 8–15% in epidemic years.
The Solution:
- Grow recommended resistant varieties.
- Avoid dense sowing — keeps the crop less humid and reduces disease.
- Start watching from the first symptoms on lower leaves.
- When to spray:
• Spray only when disease reaches upper leaves or flag leaf.
• Do not spray early for lower-leaf infection — it is not economical. Use only ONE fungicide at a time:
• Wettable Sulphur 80 WP (Contact Fungicide — Inorganic Sulphur) @ 3 g/litre
– Use for mild to moderate infection and before it reaches the flag leaf
– Works on leaf surface; stops spore growth; safe for organic use• OR Propiconazole 25 EC (Systemic Fungicide — Triazole) @ 1 ml/litre
– Use when infection is fast-spreading or flag leaf is affected
– Enters the plant; gives stronger and faster control- Do not mix both fungicides — no extra benefit, only higher cost.
- If second spray is needed:
• Change the fungicide type (contact ↔ systemic) to prevent resistance - Spray again after 10–14 days if cool and humid weather continues.
2. Loose Smut
(Ustilago nuda var. hordei)
The Threat:
- Loose smut is a seed-borne disease where the entire spike is replaced by olive-brown to black spores at heading.
- The spore mass is exposed and disperses immediately, infecting neighbouring healthy plants and continuing the cycle.
- Infected plants appear normal until heading, making the disease invisible without seed testing.
- Causes 5–10% yield loss and increases over seasons if infected seed is reused.
The Solution:
- Treat seed before sowing with Carboxin 37.5% + Thiram 37.5% DS (a broad-spectrum, dual-action (systemic and contact) fungicide designed for seed treatment) @ 3 g/kg.
- This treatment controls both internally seed-borne and surface pathogens.
- Use certified, disease-free seed from reliable sources.
- This low-cost treatment provides full-season protection.
- Never use seed from smut-affected fields.
3. Yellow Rust
(Puccinia striiformis f.sp. hordei)
The Threat:
- Stripe rust in barley behaves similarly to wheat, spreading rapidly in cool, humid January–February conditions through wind-dispersed spores.
- Produces yellow stripe-like pustules along leaf veins, reducing photosynthetic area during grain filling.
- New virulent races can overcome resistant varieties quickly, making resistance unreliable without annual updates.
- Causes 8–20% yield loss in susceptible varieties during epidemic years.
The Solution:
- Follow ICAR-IIWBR advisories each year before selecting varieties.
- At the flag-leaf stage, spray Propiconazole 25 EC (systemic fungicide) @ 1 ml/litre on susceptible crops.
- Protecting the flag leaf during grain fill is critical for yield.
- Apply a second spray after 10–14 days if disease pressure remains high.
4. Scald Disease
(Rhynchosporium commune)
The Threat:
- Scald produces pale, water-soaked lesions with dark margins, giving a “scalded” appearance.
- Primarily seed-borne and spreads through infected seed and rain splash in cool, wet conditions.
- Progresses up the canopy in humid seasons, reducing photosynthesis in upper leaves.
- Dense, lodging-prone crops are more severely affected due to prolonged leaf wetness.
- Often misdiagnosed as early-stage leaf rust.
The Solution:
- Treat seed with Iprodione 25 WP (a broad-spectrum dicarboximide contact fungicide and nematicide )@ 2 g/kg before sowing.
- Use recommended scald-resistant varieties.
- Maintain proper spacing (22.5 cm row spacing) to improve air circulation.
- In high-rainfall areas, apply Iprodione 25 WP @ 1.5 g/litre at first lesion appearance.
5. Drought at Grain Filling
The Threat:
- Moisture deficit during grain fill is the main yield-limiting factor in rain-shadow barley zones of western Rajasthan and dryland Bihar.
- When soil moisture is exhausted early, the grain-fill period shortens, producing small, lightweight grains.
- This reduces both yield and grain quality (test weight).
- Malt barley with low test weight is downgraded or rejected at procurement.
- Yield losses from grain shrinkage can reach 10–15% in severe years.
The Solution:
- Grow recommended early-maturing, drought-escape varieties.
- Provide one protective irrigation at the booting stage (10–12 days before heading).
- Practice conservation tillage (zero/minimum tillage with residue retention) to conserve soil moisture.
- Use mulching with organic material to reduce evaporation during grain filling.
Additional Reads
Ph.D. in Agricultural Engineering.