1. Which of the following statements is/are correct?
Viruses can infect
1. Bacteria
2. Fungi
3. Plants
Select the correct answer using the code given below:
(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
[I.A.S. (Pre) 2016]
Ans. (d) 1, 2 and 3
- A virus is a tiny, infectious thing that can only grow and multiply by living inside the cells of other living things.
- It can affect animals, plants, bacteria, fungi, and other microorganisms.
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2. Which one of the following in not correctly matched ?
(a) Wheat – Phalaris minor
(b) Potato – Late blight
(c) Bajra – Ergot
(d) Sugarcane – Powdery mildew
[U.P.P.C.S. (Mains) 2009]
Ans. (d) Sugarcane – Powdery mildew
- Powdery mildew affects certain plants like wheat, grape, barley, onion, apple, and pea but not sugarcane.
- The other plants and mildew types are correctly matched.
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3. Which one of the following is not correctly matched? Crop Disease
(a) Rice Green hair
(b) Bajra Ergot
(c) Pea Powdery mildew
(d) Gram Wilt
[U.P. Lower Sub. (Pre) 2015]
Ans. (a) Rice Green hair
- Bajra has a disease called Green Hair disease, which causes the hairs of the plant to twist and look like a broom.
- The leaves will also be green, and the plant will be shorter than usual. All other options in the statement are correct.
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4. Which element deficiency causes chlorosis in maize plant?
(a) Nitrogen
(b) Zinc
(c) Copper
(d) Mangnese
[U.P. U.D.A./L.D.A. (Pre) 2006]
Ans. (b) Zinc
- Zinc is a type of nutrient that plants only need a tiny bit of. If they don’t have enough Zinc, maize plants can get a condition called chlorosis.
- This makes the leaves of the plant undeveloped, short, and have white tips with yellow and brown spots.
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5. White tip of maize leaves indicates the deficiency of
(a) Fe
(b) Mn
(c) N
(d) Zn
[U.P.P.C.S. (Mains) 2010]
Ans. (d) Zn
- Zinc is a nutrient that plants only need a very small amount of. If they don’t get enough Zinc, maize plants can get a disease known as chlorosis.
- This disease causes the leaves of the plant to be smaller than normal, with white tips and yellow and brown spots.
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6. White Bud disease in plant is caused by deficiency of
(a) Zinc
(b) Copper
(c) Boron
(d) Manganese
[Jharkhand P.C.S. (Pre) 2016]
Ans. (a) Zinc
- Zinc deficiency has other names such as khaira disease (in rice), white bud (in maize), mottle leaf (in citrus) and frenching (in cotton).
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7. Pyrilla is pest of which crop?
(a) Wheat
(b) Rice
(c) Sugarcane
(d) Soyabean
[M.P. P.C.S. (Pre) 1990]
Ans. (c) Sugarcane
- Pyrilla is a type of leafhopper which feeds on the leaves and sap of sugarcane plants.
- If there is a small infestation, the leaves will turn yellow and eventually dry up.
- This will disrupt the growth of the sugarcane crop and make it very harmful.
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8. White rust is prominent fungal disease of –
(a) Wheat
(b) Mustard
(c) Rice
(d) Millet
[R.A.S./R.T.S. (Pre) 1996]
Ans. (b) Mustard
- White rust is a type of fungus that affects mustard plants. It is caused by a fungus called Albugo candida and can be seen on the stem, leaves and flowers of the plant.
- This can reduce the plant’s capacity, so using fungicide is recommended to treat it.
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9. Two common fungal diseases of wheat are :
(a) Black rust & smut
(b) White rust & smut
(c) Smut & leaf curl
(d) Black rust & white rust
[R.A.S./R.T.S. (Pre) 1996]
Ans. (a) Black rust & smut
- Wheat can get two different types of fungal diseases: black rust and loose smut.
- The fungus that causes black rust is Puccinia graminis tritici and the fungus that causes loose smut is Ustilago nuda tritici.
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10. Karnal Bunt is a disease of :
(a) Barley crop
(b) Wheat crop
(c) Bajra crop
(d) Jowar crop
[U.P. R.O./A.R.O. (Pre) 2016]
Ans. (b) Wheat crop
- Karnal Bunt is an illness caused by a type of fungus called Tilletia indica. It affects wheat and was first seen in 1931 in wheat fields near Karnal, Haryana.
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11. Tungro virus of rice is spread by –
(a) Borer
(b) Inflorescent Bug
(c) Golmiz
(d) Green leafhoppers
[U.P.P.C.S. (Mains) 2009]
Ans. (d) Green leafhoppers
- Tungro is a type of sickness that affects rice crops in South-East Asia. It is caused by two different viruses.
- RTSV : Rice Tungro Spherical Virus
- RTBV : Rice Tungro Bacilliform Virus
Both are transmitted together by green leafhoppers. |
12. Consider the following :
1. Birds
2. Dust blowing
3. Rain
4. Wind blowing
Which of the above spread plant diseases?
(a) 1 and 3 only
(b) 3 and 4 only
(c) 1, 2 and 4 only
(d) 1, 2 , 3 and 4
[I.A.S. (Pre) 2018]
Ans. (d) 1, 2 , 3 and 4
- Plant Pathology is the study of diseases in plants that are caused by different sources such as wind, rain, animals, soil, nursery graft, contaminated equipment, infected seeds, pollen, dust storms, irrigation water, birds, and humans.
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13. What causes ‘Blackheart’ in potato ?
(a) Copper deficiency
(b) Boron deficiency
(c) Oxygen deficiency
(d) Potassium deficiency
[U.P.P.C.S. (Spl) (Pre) 2008]
Ans. (c) Oxygen deficiency
- Blackheart is a disease that is not caused by any organism, but instead is caused by a lack of oxygen in potatoes while they are stored.
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14. Yellow vein mosaic disease in okra, caused by :
(a) Aphids
(b) Whitefly
(c) Leafhopper
(d) Fungi
[U.P.P.C.S. (Mains) 2002]
Ans. (b) Whitefly
- Okra can get a virus called yellow vein mosaic, which is caused by whiteflies.
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15. ‘Yellow Vein Mosaic’ is a serious disease of :
(a) Brinjal
(b) Okra
(c) Pea
(d) Cabbage
[U.P. P.C.S. (Mains) 2016]
Ans. (b) Okra
- Okra can get a virus called yellow vein mosaic, which is caused by whiteflies.
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16. ‘Spongy Tissue’ is a serious disorder hampering the export of mango variety. It is –
(a) Alphonso
(b) Dashehari
(c) Neelum
(d) Langra
[U.P.P.C.S. (Mains) 2002]
Ans. (a) Alphonso
- A ripening problem called “spongy tissue” is seen only in Alphonso mangoes grown in South India. It is recognized by soft white corky tissue or internal breakdown.
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