Question

White rust of crucifers is
a. Puccinia Graminis
b. Ustilago Tritici
c. Albugo candida
d. Aspergillus Flavus

Answer 1

Hint: White rust is a white/creamy spots on leaves, stem, flower stalk. White rust appears as the powdery growth on plants. It is caused by fungal species. It is considered a very harmful disease as it can cause damage hugely in the cultivation of crops. The favourable condition for the growth of white rust is moist low temperature.

Complete answer:
The oomycete Albugo candida causes the White rust is a disease in plants. It occurs worldwide, wherever the cultivation of the crops are done. Both wild and cultivated varieties are attacked. White rust affects every known cruciferous crop. The disease affects a large number of cruciferous crops like mustard, Cress, Cabbage, Radish, Cauliflower, Broccoli, etc. The disease affects all the aerial parts of the plant, the roots are not attacked. Symptoms may appear as a result of two types of infection: Local and Systemic.

In systemic infections, young stems and inflorescence are infected. Light yellow areas develop on leaves, with chalky white, waxy, and then powdery pustules that finally darken on the underleaf surfaces and the above-ground part. The white blisters contain sporangia, these sporangia are released from these blisters by bursting through the plant tissue. Symptoms manifest as chlorotic and necrotic spots on upper leaf surfaces.

There are no fungicides specific to treat white rust, and once the disease becomes rampant there is little to be done. That being said fungicides used to treat downy mildew are sometimes effective against white rust, particularly the more leafy crops. Treatment must begin at the first sign of infection.

Hence, the correct answer is option (C).

Note: Albugo candida commonly known as white rust is a species of oomycete in the family Albuginaceae. Oomycetes are commonly known as water molds. A.candida is an obligate plant pathogen that infects Brassicaceae species and causes the disease known as white rust or white blister rust.