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Q99 (IAS/2018) Economy › Agriculture & Rural Economy › Agricultural pests diseases Official Key

Consider the following : 1. Birds 2. Dust blowing 3. Rain 4. Wind blowing Which of the above spread plant diseases ?

Result
Your answer: —  ·  Correct: D
Explanation

The correct answer is option D because all four agents—birds, dust blowing, rain, and wind blowing—can spread plant diseases.

Birds can carry fungal spores to other branches and trees[1], acting as vectors for plant pathogens. Wind-blown dust can completely cover small plants[2], and dust particles can carry fungal pathogens and spores across distances. Heavy rainfall may directly damage plants or interfere with flowering and pollination, and can promote spoilage and diseases[3], as rain splash disperses pathogens from infected to healthy plants. Wind-blown rain carries fungal spores[1], and wind blows spores and seeds further inland, with this effect visible even a thousand miles from the shoreline[4].

Therefore, all four agents (birds, dust, rain, and wind) are confirmed vectors or dispersal mechanisms for plant diseases, making option D the comprehensive and correct answer.

Sources
  1. [1] https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/plant-disease
  2. [2] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 19
  3. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 18
  4. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > Speed Dispersal To Faraway Locations > p. 376
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Don’t just practise – reverse-engineer the question. This panel shows where this PYQ came from (books / web), how the examiner broke it into hidden statements, and which nearby micro-concepts you were supposed to learn from it. Treat it like an autopsy of the question: what might have triggered it, which exact lines in the book matter, and what linked ideas you should carry forward to future questions.
Q. Consider the following : 1. Birds 2. Dust blowing 3. Rain 4. Wind blowing Which of the above spread plant diseases ? [A] 1 and 3 on…
At a glance
Origin: Books + Current Affairs Fairness: Moderate fairness Books / CA: 5/10 · 2.5/10

This is a classic 'Applied Common Sense' question disguised as technical biology. While books explicitly mention Rain and Wind, 'Dust' and 'Birds' require derivative logic: if an agent transports matter (soil, seeds, pollen), it inevitably transports the microbes attached to that matter. The strategy here is inclusive logic, not exclusive textbook hunting.

How this question is built

This question can be broken into the following sub-statements. Tap a statement sentence to jump into its detailed analysis.

Statement 1
Can birds act as vectors for plant pathogens and thereby spread plant diseases?
Origin: Weak / unclear Fairness: Borderline / guessy
Indirect textbook clues
Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of plants in Migration > p. 6
Strength: 5/5
“Hooked or sticky seeds may adhere extremely to fur, and others may be carried in mud clinging to feet. In addition, seeds may be dispersed by being eaten, particularly by birds, and then passed out with the faeces of animals. Humans have also contributed to seed dispersal. Many agricultural pests are the results of unwitting transport of seeds by humans travelling from one area to another.”
Why relevant

States that seeds may be dispersed by being eaten by birds and then passed out with faeces, showing birds transport viable plant material and biological matter between locations.

How to extend

A student could infer that if birds move seeds and faeces, they might also move pathogen-bearing material (spores, infected tissue, bacteria) on or in their droppings to new plants or soils.

Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 13: Our Home: Earth, a Unique Life Sustaining Planet > Sexual reproduction in plants > p. 222
Strength: 4/5
“Plants use different parts of their flowers to produce male and female gametes. Pollen grains found inside the anther of a flower are the male gametes, while ovules, found deep inside the flower, are the female gametes. Pollen is carried to another flower by wind, insects, or animals—this process is called pollination. When the male and female gametes combine, it is called fertilisation, forming a zygote that becomes the seed. The fleshy part of the flower around the ovule develops into a fruit (Fig. 13.13). When birds or animals eat the fruit, the seeds often get dropped far from the original plant—a helpful way for plants to spread.”
Why relevant

Explains that pollen and seeds are carried by animals such as birds, demonstrating birds regularly contact flowers/fruits and move reproductive plant material among plants.

How to extend

Combine this with the fact that contact with infected flowers/fruits can transfer pathogens (e.g., spores or contaminated pollen) to other plants visited by the same bird.

Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 3: Health: The Ultimate Treasure > 3.4.1 How are communicable diseases caused and spread? > p. 33
Strength: 4/5
“personal items of an infected person. Some of the communicable diseases spread through contaminated drinking water or food. Some pathogens are also spread by insects like mosquitoes and houseflies—these insects are called vectors (Fig. 3.4). By understanding how diseases spread, we can take simple steps to protect ourselves and others. Let us find out how these communicable diseases spread and how we can prevent them.”
Why relevant

Defines vectors as animals (insects) that spread pathogens, giving the general rule that animals can act as carriers to transmit disease-causing agents.

How to extend

By analogy, a student can reason that other animals (birds) that contact plants could similarly act as vectors for plant pathogens under the right circumstances.

Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > 3. Plant Protection Chemicals > p. 48
Strength: 3/5
“substantially. The danger of pests and insects may be reduced by using plant protection chemicals. The problem may be tackled either by developing the disease resistant seeds or by spraying insecticides and pesticides at the appropriate time prescribed or advised for different crops. The problems of crop disease and pests may also be tackled by timely application of insecticides and pesticides. Thus, the farmer must have adequate knowledge of plant disease and their controlling chemicals. At the outbreak of a disease in the crop, the entire area should be sprayed. If the timely spray of the insecticides and pesticides is not done, the crop of the entire village/region may vanish.”
Why relevant

Notes that crop diseases can spread widely across areas and require region-wide chemical control, implying the existence of mechanisms (including mobile carriers) that move pathogens over distances.

How to extend

A student could link this pattern of regional spread to mobile animals (like birds) as one possible dispersal mechanism to investigate further.

Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 5: Natural Vegetation and National Parks > Natural Vegetation and National Parks > p. 1
Strength: 3/5
“Some of the exotic varieties are troublesome weeds. They thrive under conditions of tropical sun with abundant moisture, multiply rapidly and spread out as there are no 'natural' enemies to curb them in the new habitat. In course of time, their eradication becomes difficult; they invade the land and reduce the area for other uses, prevent the growth of plants which are economically important and become a hazard to public health by indirectly helping the spread of several diseases. We can cite two striking examples: lantana (Lantana camara varauyleata Mold) and water hyacinth (Eichhornia crassipes Solms).”
Why relevant

Describes how exotic plants spread rapidly in new habitats when 'natural' enemies are absent, illustrating that movement of organisms into new areas can enable spread and establishment of biological agents.

How to extend

Using that pattern, a student might consider birds as agents that move plant-associated organisms (including pathogens) into new habitats where they could establish.

Statement 2
Can dust blowing (wind‑blown dust) carry plant pathogens and spread plant diseases?
Origin: Web / Current Affairs Fairness: CA heavy Web-answerable

Web source
Presence: 5/5
"we identified a total of 386 different species of putative fungal plant pathogens across all 1,289 dust samples. The average number of different putative fungal plant pathogens (i.e., richness) per outdoor dust sample was 45, and the average relative abundance of total fungal pathogens per sample was 21.5%"
Why this source?
  • Direct measurement: the study identified many putative fungal plant pathogens in dust samples, showing pathogens are present in airborne dust.
  • Quantitative support: reports averages (45 species per outdoor dust sample; 21.5% relative abundance), indicating substantial pathogen load in dust.
Web source
Presence: 3/5
"the fungus produces spores that are carried to other branches and trees by wind-blown rain, by insects, and by birds."
Why this source?
  • Describes airborne dispersal of fungal spores by wind-related processes, supporting that windborne particles can move infectious propagules between plants.
  • Although it mentions wind-blown rain and other vectors, it demonstrates the principle that spores carried by wind-related mechanisms reach new host plants.

Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 7: Arid or Desert Landforms > Landforms of Wind Deposition in Deserts > p. 72
Strength: 5/5
“Materials eroded and transported by winds must come to rest somewhere. The finest dust travels enormous distances in the air, and may be moved completely out of the desert. It has been estimated that some dust grains travel as far as 3, 700 km (2, 300 miles) before they are finally deposited on land or sea. The dust from the Sahara Desert is sometimes blown across the Mediterranean to fall as 'blood rains' in Italy or on the glaciers of Switzerland. The following are some of the major features of wind deposition: 1. Dunes. Dunes are, in fact, hills of sand formed by the accumulation of sand and shaped by the movement of winds.”
Why relevant

Shows that the finest dust can travel very long distances (thousands of km) and be deposited far from its source.

How to extend

A student could infer that if dust can travel far, any biological material (spores, bacteria) attached to that dust might also be transported long distances and then tested at downwind sites.

FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > Dust Particles > p. 65
Strength: 5/5
“Atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors. Dust particles are generally concentrated in the lower layers of the atmosphere; yet, convectional air currents may transport them to great heights. The higher concentration of dust particles is found in subtropical and temperate regions due to dry winds in comparison to equatorial and polar regions. Dust and salt particles act as hygroscopic nuclei around which water vapour condenses to produce clouds.”
Why relevant

States that atmosphere carries small solid particles including pollen and dust and that convectional currents can lift them to great heights.

How to extend

Combine with knowledge that some plant pathogens are pollen‑borne or attach to particulates to justify sampling airborne dust for pathogens at different altitudes/locations.

Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 19
Strength: 4/5
“Direct winds result in the breaking of plant structure, dislodging of cereals, fodder and cash crops and shattering of seed-heads. Fruit and nut crops may be stripped from the trees in high winds. Small plants are sometimes completely covered by wind-blown dust or sand. The indirect effect of winds are in the form of transport of moisture and heat in the air. In fact, the movement of winds increases evaporation and transpiration.”
Why relevant

Describes wind‑blown dust/sand covering small plants and directly impacting plant surfaces.

How to extend

If dust lands on plants, a student could test whether deposited dust contains viable pathogen cells/spores capable of infecting those plants.

Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of plants in Migration > p. 6
Strength: 4/5
“are a few which have exploding or twisting seed cases that expel the seeds. In other species the seeds may not have any structural modifcation, but may be light enough to be blown about by wind; a good example of this can be seen in the dust seeds of the orchids, which are minute but are produced in vast numbers. Many seeds have special adaptations such as wings or plumes of hairs to help them to become dispersed by wind, whereas others may rely on water or even ice, for transport. Tere are also many examples of seed dispersal by animals.”
Why relevant

Explains that very small biological propagules (e.g., orchid 'dust seeds') are light enough to be wind‑dispersed.

How to extend

By analogy, a student could consider that similarly small fungal spores or bacterial cells might hitch a ride on dust and be dispersed by wind.

Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 3: Health: The Ultimate Treasure > 3.4.1 How are communicable diseases caused and spread? > p. 32
Strength: 3/5
“All communicable diseases are caused by pathogens. These pathogens can enter our body through the air we breathe or by consuming contaminated food or water and more. But how do these pathogens spread from one person to another? One common way is through air, when an infected person coughs or sneezes, or through direct contact like shaking hands, or indirectly by sharing”
Why relevant

Establishes that many communicable diseases spread through air, showing a general mechanism for airborne pathogen transmission.

How to extend

Use the general principle of airborne spread to motivate testing whether plant pathogens can similarly travel attached to wind‑blown dust.

Statement 3
Can rain (including rain splash) disperse plant pathogens and spread plant diseases?
Origin: Direct from books Fairness: Straightforward Book-answerable
From standard books
Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 18
Presence: 4/5
“Heavy rainfall may directly damage plants or interfere with flowering and pollination. Cereal crops are often lodged by rain and this makes harvest difficult and promotes spoilage and diseases. Heavy rainfall at the maturity stage of wheat, gram, millets, oilseeds, and mustards causes loss of grains and fodder. Indian farmers all over the country have often suffered on account of failure of rains or fury of floods. (iii) Drought: Drought has devastating consequences on the crops, their yields and production. Soil drought has been described as a”
Why this source?
  • Explicitly links heavy rainfall to increased spoilage and diseases in crops.
  • Mentions rain-caused lodging that promotes spoilage and disease incidence.
Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 12: Major Crops and Cropping Patterns in India > Banana > p. 60
Presence: 3/5
“the plant stops growth and in the cold weather it is damaged by frost. In fact, a great deal of banana cultivation in India is located close to the coastal areas. About 150 to 250 cm of rain, well distributed through out the year is desirable for banana. It however, can stand rain up to 400 cm. Stagnation of water is injurious and may cause diseases like Panama-wilt. In India, banana ranks third in area with about 5 lakh hectare, covering about 12.5% of the total area under fruits. Most of the banana is produced on small scale basis. A unique feature of banana cultivation in the country is that Dwarf Cavendish banana is grown in dry climate where leaf-spot is not a serious problem, unlike in other banana growing countries.”
Why this source?
  • Identifies water stagnation as injurious and as a cause of specific plant diseases (Panama-wilt).
  • Shows a direct connection between excess water conditions and disease occurrence in plants.
Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 17: Contemporary Issues > Cloudburst > p. 28
Presence: 3/5
“Cloudburst is a sudden rainfall which can be quite unexpected, very abrupt, characterised with flash floods. In other words, cloudburst is an extreme amount of precipitation, sometimes with hail and thunder which normally lasts no longer than a few minutes but is capable of creating havoc condition of flood, landslides, avalanches, mudflow, earth-flow, rock-fall, subsidence, slumps, soil-creep and mass wasting. In some cloudbursts up to 13 cm (5 inche) of rain can fall in one hour, often in the form of extremely large droplets. The rain characteristic of a cloudburst is caused by a phenomenon known as Langmuir Precipitation, in which drops of rain fuse together to create large drops as they fall, falling quickly as they grow.”
Why this source?
  • Describes very large raindrop formation (Langmuir precipitation) and extreme droplets during cloudbursts.
  • Provides a physical basis for strong rain splash that can move material (supporting a mechanical dispersal mechanism).
Statement 4
Can wind blowing disperse plant pathogens and thereby spread plant diseases?
Origin: Direct from books Fairness: Straightforward Book-answerable
From standard books
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > Speed Dispersal To Faraway Locations > p. 376
Presence: 5/5
“• Tropical cyclone wind blows spores and seeds further inland from where they would normally fall; this effect can be seen a thousand miles inland as storms move away from the shoreline. These seeds can replenish lost growth after fires and urbanisation.”
Why this source?
  • Explicitly states tropical cyclone winds blow spores (biological propagules) far inland — spores are common agents of plant disease.
  • Demonstrates wind can carry infective propagules over long distances, enabling spread of plant organisms (and by extension pathogens).
Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 19
Presence: 3/5
“Direct winds result in the breaking of plant structure, dislodging of cereals, fodder and cash crops and shattering of seed-heads. Fruit and nut crops may be stripped from the trees in high winds. Small plants are sometimes completely covered by wind-blown dust or sand. The indirect effect of winds are in the form of transport of moisture and heat in the air. In fact, the movement of winds increases evaporation and transpiration.”
Why this source?
  • Describes wind dislodging plant material and depositing wind-blown dust/sand onto plants — mechanisms that can transport contaminants/pathogens.
  • Notes indirect effects of wind (transport of moisture and heat) that alter microenvironment and could influence pathogen survival and spread.
Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of animals > p. 9
Presence: 3/5
“As stated above, animals generally have far more capacity for dispersal than plants because most of them are mobile, and they can also be aided in their movement by external agents. Te animals difer from plants in respect of dispersal, food, mobility, life cycle, reaction and response. Te dispersal of animals may be gradual, rapid, seasonal, anthropogenic and sudden due to volcanic eruption, drought, foods and sea surges. Te agent of dispersal of animals can be biotic or abiotic, but in either case the resulting change in location is said to be due to passive dispersal. Parasites are carried with their hosts, whereas many other animals are blown about by the wind – particularly the insects – or foat with water currents.”
Why this source?
  • States insects and parasites can be blown about by wind, indicating wind can move biological vectors that may carry pathogens.
  • Illustrates passive dispersal by abiotic agents (wind) of organisms that can transport disease agents between plants.
Pattern takeaway: In Science & Environment questions asking 'Which of these can cause/spread X?', the answer is almost always 'All of the above' unless one option is scientifically absurd. Nature is permissive; if a physical pathway exists, biology will use it.
How you should have studied
  1. [THE VERDICT]: Logical Sitter. While 'Dust' isn't a chapter title, the mechanism is derived from basic NCERT Geography (wind transport) + Biology (microbes exist everywhere).
  2. [THE CONCEPTUAL TRIGGER]: Epidemiology of Plants (Modes of Transmission: Biotic vs. Abiotic).
  3. [THE HORIZONTAL EXPANSION]: Memorize specific vectors: Aphids (Viral vectors), Whiteflies (Leaf curl), Nematodes (Soil vectors), Farm tools (Fomites), Irrigation water (Bacterial wilt), and Infected Seeds (Loose Smut).
  4. [THE STRATEGIC METACOGNITION]: Stop looking for the exact sentence. Ask: 'Is this physically possible?' If wind moves dust (Geography) and dust holds bacteria (Biology), then wind-blown dust spreads disease. Connect the dots between subjects.
Concept hooks from this question
📌 Adjacent topic to master
S1
👉 Biotic vectors (organisms that transfer pathogens)
💡 The insight

Reference [1] defines vectors as organisms that spread pathogens, giving the core idea needed to assess whether an animal (e.g., a bird) could serve that role.

High-yield for UPSC biology/ecology questions: understanding 'vector' clarifies mechanisms of disease spread across human, animal and plant health topics. Connects to epidemiology, agricultural protection and biodiversity topics; useful for questions comparing biotic vs abiotic transmission. Master by mapping examples (insects, animals) to transmission pathways.

📚 Reading List :
  • Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 3: Health: The Ultimate Treasure > 3.4.1 How are communicable diseases caused and spread? > p. 33
🔗 Anchor: "Can birds act as vectors for plant pathogens and thereby spread plant diseases?"
📌 Adjacent topic to master
S1
👉 Animal-mediated pollination and transfer of plant material
💡 The insight

References [8] and [6] show animals (including birds) carry pollen and disperse seeds, demonstrating animals routinely move plant biological material between sites.

Important for questions on plant reproduction, ecosystem services and plant–animal interactions. Helps link pollination/seed dispersal to agricultural outcomes and disease/weed spread. Learn by categorising agents (wind, insects, birds) and their ecological/agricultural implications.

📚 Reading List :
  • Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 13: Our Home: Earth, a Unique Life Sustaining Planet > Sexual reproduction in plants > p. 222
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of plants in Migration > p. 6
🔗 Anchor: "Can birds act as vectors for plant pathogens and thereby spread plant diseases?"
📌 Adjacent topic to master
S1
👉 Seed dispersal mechanisms by animals (external and internal transport)
💡 The insight

Reference [6] describes seeds adhering to fur/feet or being eaten and excreted — two distinct ways animals (including birds) move plant propagules.

High-yield for questions on species spread, invasive plants and agricultural biosecurity. Understanding endozoochory vs epizoochory enables analysis of how organisms or attached microbes might spread geographically. Study by comparing mechanisms, vectors, and management implications.

📚 Reading List :
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of plants in Migration > p. 6
🔗 Anchor: "Can birds act as vectors for plant pathogens and thereby spread plant diseases?"
📌 Adjacent topic to master
S2
👉 Aeolian transport of fine particles
💡 The insight

Several references describe wind lifting and carrying fine dust long distances and depositing it elsewhere.

High-yield for geography and environment questions: explains soil erosion, long-range transport of particulates, and impacts on human and natural systems. Connects to topics on desertification, transboundary dust, and deposition effects; useful for questions on environmental hazards and climate interactions.

📚 Reading List :
  • Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 7: Arid or Desert Landforms > Landforms of Wind Deposition in Deserts > p. 72
  • Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 7: Arid or Desert Landforms > The Mechanics of Arid Erosion > p. 69
  • Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 17: Major Landforms and Cycle of Erosion > Wind Eroded Arid Landforms > p. 235
🔗 Anchor: "Can dust blowing (wind‑blown dust) carry plant pathogens and spread plant diseas..."
📌 Adjacent topic to master
S2
👉 Wind as a biological dispersal agent
💡 The insight

References show wind disperses light seeds and can carry insects/organisms, highlighting wind‑mediated movement of biological material.

Important for ecology/agriculture: links plant migration, pest dispersal, and vector movement under abiotic agents. Helps answer questions on species distribution, pest outbreaks, and how abiotic factors influence biotic spread — a recurrent UPSC theme combining geography and biology.

📚 Reading List :
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of plants in Migration > p. 6
  • Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 2: PLANT AND ANIMAL KINGDOMS > Dispersal of animals > p. 9
  • FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > Dust Particles > p. 65
🔗 Anchor: "Can dust blowing (wind‑blown dust) carry plant pathogens and spread plant diseas..."
📌 Adjacent topic to master
S2
👉 Dust particle effects on plants and atmosphere
💡 The insight

Evidence notes plants being covered by dust and dust acting as atmospheric nuclei, indicating both direct surface impacts and climatic interactions.

Useful for questions on crop vulnerability and microclimate: shows how particulate deposition can physically affect plants and alter atmospheric processes (cloud formation, evaporation). Connects to agriculture, climate, and environmental health topics in the exam.

📚 Reading List :
  • Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 19
  • FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > Dust Particles > p. 65
🔗 Anchor: "Can dust blowing (wind‑blown dust) carry plant pathogens and spread plant diseas..."
📌 Adjacent topic to master
S3
👉 Rain-mediated dispersal of plant pathogens
💡 The insight

References link heavy rainfall and large raindrops to increased disease/spoilage and to strong splash potential, which together indicate rain can disperse pathogens.

High-yield for UPSC topics on agriculture and environmental hazards; connects plant pathology with meteorology and disaster impacts. Mastering this helps answer questions on disease epidemiology in crops, impacts of extreme weather on agriculture, and mitigation strategies.

📚 Reading List :
  • Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 9: Agriculture > b) Climate > p. 18
  • Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 17: Contemporary Issues > Cloudburst > p. 28
🔗 Anchor: "Can rain (including rain splash) disperse plant pathogens and spread plant disea..."
🌑 The Hidden Trap

Fomites (inanimate objects). UPSC will likely ask about 'Anthropogenic vectors' next: Farm machinery, pruning shears, and packaging material are major vectors for invasive pests (e.g., Nematodes in soil on imported tractors).

⚡ Elimination Cheat Code

The 'Zero Probability Test'. For an option to be false, the probability of it happening must be effectively zero. Can you guarantee a bird *never* carries a fungal spore on its feet? No. Therefore, it must be true. When in doubt about natural phenomena, choose the broadest scope.

🔗 Mains Connection

Connect to GS-3 Agriculture & Biosecurity. The spread of transboundary diseases (like Wheat Blast entering Bengal via wind or trade) is a national security issue requiring Sanitary and Phytosanitary (SPS) Measures under WTO norms.

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