Downy mildew disease of African daisy plant is caused by fungus- Plasmopara majewskii.
Cercospora gerberae causes Cercospora leaf spot disease in African daisy plant. Nectria canker disease is caused by Haematonectria haematococca fungus in African daisy plant. Powdery mildew is caused by the fungal pathogen Erysiphe cichoracearum in African daisy plant. Southern blight disease is caused by Sclerotium rolfsii in African daisy plant. Hence, P and Q both are false statements.

Zonate leaf spot is caused by the fungus Stemphylium botryosum.

Scald is one of the most widespread leaf diseases of barley in Western Australia and is caused by the fungus Rhynchosporium secalis.

Red blister disease of coffee is caused by Cercospora coffeicola. Dry root rot disease of coffee is caused by Fusarium solani. Thread blight disease is caused by Corticium koleroga in coffee. Phoma costaricensis causes tip blast disease in coffee. Tracheomycosis is caused by the fungus Gibberella xylarioides in coffee.

Helminthosporium papulosum, fungus causes Black pox disease in apple. Marssonina coronaria causes marssonia blotch in apple.

Infected heads emerge as a mass of dark brown powdery spores is called loose smut. A fungus, Ustilago tritici, causes loose smut disease in barley. Covered smut is caused by the fungus Ustilago segetum var. hordei in which the heads that emerge are dark in colour and smut balls take the place of the grain. Wirrega blotch of leaf is caused by the fungus Pyrenophora wirreganensis.

Pseudopezicula tetraspora is a fungus and causes Angular leaf scorch in grapes.

Black root rot of cotton is caused by Thielaviopsis basicola and Chalara elegans. Ramularia gossypii causes aereolate mildew disease of cotton.

Collectotrichum gloeosporiodes causes anthracnose disease in mango.

Sudden death syndrome of soybean is caused by the fungal pathogen. 

Cottony snow mold disease of wheat is caused by the fungus Coprinus psychromorbidus. Black shoulder disease of tomato is caused by Alternaria alternate. Chalara elegans causes Black root rot of tomato.Tropical cotton rust of cotton is caused by Phakopsora gossypii. Puccinia cacabata causes Southwestern cotton rust in cotton.

Brown leaf spot of sugarcane is caused by Cercosporidium longipes.

In apple, Diplocarpon mali and Marsonia coronaria cause ‘Marsonia blotch’ disease. Bird's-eye rot disease in grapes is caused by Elsinoe ampelina and Sphaceloma ampelinum. Cercospora brachypus causes Angular leaf spot disease in grapes. Chocolate spot disease is caused by Colletotrichum gloeosporioides in papaya. Cylindrocladium crotalariae and Calonectria crotalariae cause Collar rot disease in papaya. Internal blight of papaya is caused by Cladosporium sp., Fusarium sp. and Penicillium sp.

Leaf spot of cherries and palms is caused by Blueriella sp. Brown leaf spot of grapes is caused by Cerecosoridium viticola. Citrus greasy leaf spot is caused by the fungus Mycosphaerella citri. Banana leaf spot is caused by Mycosphaerella musicosa. Taphrina deformans causes leaf curl of peach and apricot. Hence, the correct sequence of codes is P-3, Q-1, R-5, S-2.

Gymnosporangium clavipes causes Quince rust in apple.

Sooty blotch colonies appear dusty to olive green or black on mature fruit depending on the particular fungus species involved. Sooty blotch causing fungal pathogens are- Peltaster fructicola, Geastrumia polystigmatis, Leptodontidium elatius, Gloeodes pomigena. Silver leaf disease is caused by Chondrostereum purpureum in apple. Violet root rot is caused by Helicobasidium mompa.

Gliocladium roseum causes pink mold in citrus.

A general purpose tree fruit spray, available under a variety of trade names, is effective for control of many of the common diseases and insect pests of apple. This mixture usually contains captan as the fungicide component and methoxychlor and malathion or carbaryl as the insecticide component. Other alternative to control of fungal diseases are-coppers (fixed)- early season control of scab and fire blight; 2. fenarimol- control of scab, mildew, and rust; 3. ferbam- some control of scab, rust, black rot, and the summer diseases; causes undesirable black residue when used late in season; 4. maneb, mancozeb- control of rust, scab, fruit rots, and summer diseases; 5. myclobutanil- control of scab, powdery mildew and cedar-apple rust; 6. sulfur- for control of mildew; some control of scab, summer diseases, and fruit rots; can be phytotoxic to some cultivars and may cause fruit russetting and/or yield reduction when sprayed after bloom; 7. thiram- some control of scab, rust, and summer diseases; 8. thiophanate-methyl- control of scab, fruit rots, and summer diseases; 9. triadimefon- very good control of powdery mildew and rust.

Armillaria root rot is caused by the fungi- Armillaria mellea and Rhizomorpha subcorticalis in Almond. Green fruit rot disease of Almond is caused by Botrytis cinerea, Botryotinia fuckeliana and Monilinia fructicola. Hull rot disease of Almond is mainly caused by Rhizopus sp.Venturia carpophila and Cladosporium carpophilum cause Scab disease of Almond. Hence, the sequence of codes A-2, B-4, C-3, D-1 is correct.

Aspergillus niger causes Black mold rot disease in citrus.