Which of the following statement(s) is/are true? P. Spot anthracnose disease of rose is caused by Sphaceloma rosarum. Q. Bordeaux mixture was introduced by Pierre-Marie-Alexis Millardet in 1885. R. Plant pathogenic disorders can be controlled by crop rotation.

In rose, Spot anthracnose disease is caused by the fungus- Sphaceloma rosarum. In the 19th century, several outbreaks of vine diseases occurred among the Vitis vinifera vines of the classicial European wine regions. After the downy mildew had struck, botany professor Pierre-Marie-Alexis Millardet of the University of Bordeaux studied the disease in vineyards of the Bordeaux region. In1885, Millardet published your findings on mildew of grapes and introduced Bordeaux mixture to control downy mildew of grapes. Crop rotation may be an effective means to prevent a parasitic population from becoming well-established, as an organism affecting leaves would be starved when the leafy crop is replaced by a tuberous type, etc. Other means to undermine parasites without attacking them directly may exist.