White Rust Disease in Mustard and How to Manage It

Rabi crops are sown from October to December and harvested from April to June. Some of the important rabi crops include wheat, barley, peas, and mustard.

Mustard is an important cash crop for farmers in Haryana, Madhya Pradesh, Rajasthan, Uttar Pradesh, etc and although its production is good in India mustard farmers face a lot of problems due to diseases that reduce their yield.

One of the most common diseases in mustard is the White which is caused by Albugo candida that causes significant yield losses. Another name for it is "White Blisters of Crucifers."

White creamy pustules & sporangia give a white rusty appearance by exposing a powdery mass of spores on the infected host surfaces, that's why it is called "white rust." Locally it is known as "Marodia Rog" or "Toontia Rog"

Symptoms: Symptoms appeared on all parts of the plant except the roots. Symptoms appear as a result of two types of infection:

• In local infection: In case of local infection, white creamy yellow raised pustules appear on the leaves which later merge to form patches.

• In systemic infection: In systemic infection and during humid weather, mixed infection of white rust and downy mildew cause swelling and distortion of the stem and floral parts due to hypertrophy and hyperplasia and develop a “stag head” structure.

Favorable environmental conditions:

Temperature below 15 degrees Celsius (12–14-degree Celsius)

High moisture conditions (Relative humidity 60-80%) favor the disease incidence & intensity.

Other factors that support the disease include late sowing (i.e., after October 21st) and irrigation application during the formation stage.

Management of White rust disease:

Cultural Practices:

The pathogen is either soil-borne or can thrive on weeds,

• Use seeds that are clean and healthy or certified seeds.

• Get rid of the weeds in and around the field.

• Collect & destroy infected plant parts.

• Do field sanitation.

• Follow long crop rotation with non-host crops.

• Make early plantings (Grow the crop earlier than 20 Oct.)

Chemical Control:

Use "Apron SD-35" (metalaxyl) at 6 g/kg seed (protect for 60 days) or "mancozeb" at 92.5 g/kg seed to treat the seeds.

At intervals of ten days, apply Ridomil MZ-72 (0.1%), mancozeb (0.25%), or Bordeaux mixture (0.8% = 4:4:50) to the crop.

Use recent fungicides, such as fosetyl-Al (Aliette). It has both apoplastically (via the xylem) and simplistically (through the phloem) movement.

Use Resistant Varieties:

Grow resistant genotypes like- Kranti (PR 15), RN 510, DIR-1522, Varuna, Pusa bold WRR2, and Rohini WRR.