Stripe disease of wheat is caused by cochliobolus sativus. Wheat’s false eyespot disease is caused by Hymenula cerealis.

Sheath brown rot disease of rice is caused by Pseudomonas fuscovaginae, symptoms appearing at seedling and later stages include discoloration and rotting of sheath. After transplanting, infected seedlings initially show yellow-brown discolorations on their lower leaf sheaths. Later the discolorations turn gray-brown to dark brown. Ultimately, rot results in death of the infected seedlings.

In maize, Stewart's disease is caused by Erwinia stewartii and Holcus spot disease is caused by Pseudomonas syringae.

Early blight of tomato and potato disease is caused by Alternaria solani. Phytophthora infestans causes the Late blight of potato disease.Stem black rust of wheat is caused by Puccinia graminis fungus.Loose smut of wheat is caused by fungi, Ustilago species like-U. tritici, U. segatum.

Agrobacerium rhizogenes in apple causes Hairy root disease.

In carrot, Cottony rot disease is caused by the fungal species- Sclerotinia sp. (S. minor, S. sclerotiarum).

In citrus, psorosis disease is caused by Citrus Psorosis Virus (CPV), blind pocket disease is caused by Viroids and graft-transmissible pathogens (GTP), cochexia disease is caused by Citrus cachexia viroid (CCVr) and concave gum disease is caused by Viroids and graft-transmissible pathogens (GTP). Hence, psorosis disease is caused by CPV.

Dry rot disease is caused by Ashbya gossypii and Nematospora coryli in citrus.

In coffee, warty berry disease is caused by Botrytis cinerea.

Xanthomonas campestris causes fucous blight disease in beans.

In apple, Kernel blight disease is caused by bacteria- Pseudomonas syringae pv. syringae and Basal glume rot is caused by bacteria- Pseudomonas syringae pv. atrofaciens. Anthracnose, Dwarf bunt and Leaf rust are caused by fungal pathogens- Collectotrichum cereale, Tilletia controversa and Puccinia hordei respectively, in apple.

Yes, it is correct. These methods enable the highly sensitive detection of a number of morphologically different viruses in purified preparations and in unclarified extracts of herbaceous hosts and of infected crop plants are employed for the detection of plant viral diseases.

In apple, Diplocarpon mali and Marsonia coronaria cause ‘Marsonia blotch’ disease, Mucor piriformis causes the Mucor rot disease and Nectria galligena causes Canker disease.

Diamond spot disease of banana is caused by Cercospora hayi.

Nucleic acid based detection systems were greatly improved following the development of the polymerase improved following the development of the polymerase chain reaction (PCR). PCR is able to detect pathogens by targeting their genetic material (RNA/DNA). Real time PCR (RT-PCR) is used to combine amplification, detection and quantification in a single step for RNA as target. Immunocapture PCR (IC-PCR) is used to combine the advantages of serology and is a very sensitive method of detection the diseases by targeting both DNA and RNA as genetic material. Multiplex PCR (IC-RT-PCR) allows for simultaneous and sensitive detection of different DNA and RNA as genetic material in the detection of plant diseases in a single reaction.

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.

P. Bunchy top disease of banana is caused by Banana bunchy top virus (BBTV). Pyricularia grisea fungus causes Pitting disease in banana. Q. Pseudostem heart rot disease of banana is caused by Fusarium moniliforme. Pseudomonas solanacearum causes Bugtok disease in banana. R. Rhizome rot disease of banana is caused by Erwinia sp. like- E. carotovora, E. chrysanthemi. Hence, P and Q both the statements are false.

In apple, Perennia canker disease is caused by Neofabraea perennans, Fruit decay is caused by Phomopsis mali, Pink mold rot disease is caused by Trichothecius roseum and Zonate leaf spot disease is caused by Grovesinia pyramidalis. Hence, the correct sequence of codes A-2, B-5, C-3, D-1 is correct.

Aerolate leaf spot in citrus is caused by Rhizoctonia solani.

In rice, the fungus curvularia lunata causes black kernel. Leaf smut disease is caused by Entyloma oryzae, Stackburn disease is caused by Alternaria padwickii and Downy mildew disease is caused by Sclerophthora macrospora. Hence, the correct answer using the codes is P-2, Q-4, R-1, S-3.

In citrus, bacterial spot and canker disease are both caused by the bacteria Xanthomonas campestris. Both the black pit and blast diseases in citrus are caused by the bacteria Pseudomonas syringae. Hence, 1 and 4 both are caused by Xanthomonas campestris in citrus.