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WBCHSE HS Vocational Agriculture study materials
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WBCHSE HS Vocational Agriculture practice questions

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Question 1Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

In soil science, the term 'soil texture' refers to which property of the fine earth fraction?

  1. The relative proportion of sand, silt and clay particles Correct answer.
  2. The arrangement of soil particles into aggregates
  3. The total volume of pore space present in the soil
  4. The concentration of soluble salts in the soil solution

Explanation

Soil texture is defined by the relative proportions of the three primary mineral particle separates: sand, silt and clay. It is a fixed, largely permanent property of a soil because it depends on particle size distribution rather than on how those particles are packed together. Structure, porosity and salinity are separate, more changeable properties.

Question 2Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which soil particle size class generally has the greatest capacity to hold plant-available water and adsorbed cations?

  1. Coarse sand
  2. Silt
  3. Clay Correct answer.
  4. Fine gravel

Explanation

Clay particles are the smallest mineral separates and carry a large specific surface area with net negative charge, giving high water retention and high cation exchange capacity. Silt holds water well but has far less surface charge, and sand drains freely with very low retention. Gravel is not part of the fine earth fraction at all.

Question 3Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A soil sample has a bulk density of 1.3 g/cm3 and a particle density of 2.6 g/cm3. What is its approximate porosity?

  1. 65 per cent
  2. 25 per cent
  3. 75 per cent
  4. 50 per cent Correct answer.

Explanation

Porosity is calculated as 1 minus the ratio of bulk density to particle density, so 1 − (1.3/2.6) = 0.50, which is 50 per cent pore space. The calculation assumes the standard particle density of about 2.6 to 2.65 g/cm3 for mineral soil. A bulk density exactly half the particle density always gives 50 per cent porosity.

Question 4Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which soil horizon is the zone of maximum accumulation of illuvial clay, iron or aluminium in a well-developed soil profile?

  1. C horizon
  2. B horizon Correct answer.
  3. A horizon
  4. O horizon

Explanation

The B horizon is the subsoil zone of illuviation, where materials leached from overlying layers accumulate. Clay, iron oxides and aluminium oxides commonly precipitate there, forming a textural or sesquioxide B horizon. The A horizon is a zone of eluviation and organic accumulation, while the C horizon is weathered parent material.

Question 5Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Cation exchange capacity of a soil is best described as which of the following?

  1. The rate at which water moves through the soil profile
  2. The amount of organic matter decomposed each season
  3. The number of exchangeable cations a soil can retain per unit mass Correct answer.
  4. The total quantity of anions held on clay surfaces

Explanation

Cation exchange capacity measures the total negative charge available on clay and humus surfaces, expressed as the quantity of exchangeable cations retained per unit mass, commonly in centimoles of charge per kilogram. It reflects the soil's ability to hold nutrient cations such as calcium, magnesium and potassium against leaching. It does not describe anion retention, water flow or decomposition.

Question 6Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Applying gypsum to a sodic soil mainly improves the soil by which mechanism?

  1. Reducing bulk density by increasing pore space directly
  2. Supplying calcium that replaces exchangeable sodium on the clay complex Correct answer.
  3. Raising the soil pH by neutralizing acidity
  4. Increasing soil organic carbon through microbial decomposition

Explanation

Gypsum supplies soluble calcium, which displaces exchangeable sodium from clay surfaces, and the displaced sodium is leached away with drainage water. This lowers the exchangeable sodium percentage and improves aggregation and infiltration. Gypsum does not neutralize acidity, add organic carbon or directly create pore space.

Question 7Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which process converts atmospheric nitrogen gas into ammonia within the root nodules of legumes?

  1. Biological nitrogen fixation Correct answer.
  2. Ammonification
  3. Denitrification
  4. Nitrification

Explanation

Biological nitrogen fixation is carried out by symbiotic bacteria such as Rhizobium inside legume root nodules, using the nitrogenase enzyme to reduce atmospheric dinitrogen to ammonia. Nitrification converts ammonium to nitrate in the soil, while ammonification releases ammonium from organic matter and denitrification returns nitrogen to the atmosphere.

Question 8Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

In crop physiology, the light-dependent reactions of photosynthesis take place in which part of the chloroplast?

  1. Thylakoid membrane Correct answer.
  2. Intermembrane space
  3. Outer envelope membrane
  4. Stroma

Explanation

The light-dependent reactions occur on the thylakoid membranes, where photosystems, electron transport carriers and ATP synthase are embedded. These reactions generate ATP and NADPH using light energy. The stroma hosts the light-independent Calvin cycle, which uses those products to fix carbon dioxide.

Question 9Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which enzyme catalyses the first committed step of carbon fixation in the Calvin cycle?

  1. Nitrate reductase
  2. Catalase
  3. Amylase
  4. Rubisco Correct answer.

Explanation

Ribulose-1,5-bisphosphate carboxylase/oxygenase, or rubisco, attaches carbon dioxide to ribulose-1,5-bisphosphate to begin the Calvin cycle. It is the primary carboxylating enzyme of C3 plants and also the enzyme responsible for photorespiration. The other enzymes listed act in nitrogen assimilation, starch breakdown and hydrogen peroxide detoxification respectively.

Question 10Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A C4 plant such as maize fixes carbon dioxide initially into which compound?

  1. Ribulose-1,5-bisphosphate
  2. Oxaloacetate Correct answer.
  3. Glycolate
  4. 3-phosphoglycerate

Explanation

In C4 plants, phosphoenolpyruvate carboxylase in mesophyll cells fixes carbon dioxide onto phosphoenolpyruvate to form the four-carbon acid oxaloacetate. This acid is converted to malate or aspartate, shuttled to bundle-sheath cells and decarboxylated there to feed the Calvin cycle. 3-phosphoglycerate is the first product of C3 fixation, not C4.

Question 11Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which condition most directly causes stomata to close in a well-watered crop during midday?

  1. Increased sucrose loading into the phloem
  2. A decrease in leaf temperature below the dew point
  3. A rise in leaf water potential above zero
  4. Rapid accumulation of abscisic acid and loss of guard-cell turgor Correct answer.

Explanation

Stomatal closure is driven by loss of turgor in the guard cells, commonly triggered by abscisic acid produced under water stress or high evaporative demand. Abscisic acid promotes ion efflux from guard cells, water follows osmotically and the pore closes. A rise in leaf water potential above zero would indicate a turgid, not stressed, leaf.

Question 12Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which plant hormone is chiefly responsible for promoting cell elongation and apical dominance?

  1. Abscisic acid
  2. Auxin Correct answer.
  3. Ethylene
  4. Cytokinin

Explanation

Auxin, principally indole-3-acetic acid, promotes cell wall loosening and elongation and, when produced at the shoot apex, suppresses lateral bud outgrowth to produce apical dominance. Abscisic acid and ethylene are generally growth inhibitors, while cytokinins promote lateral bud growth and counteract apical dominance.

Question 13Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A farmer observes that a crop shows interveinal chlorosis on older leaves first. Which nutrient deficiency is most consistent with this symptom?

  1. Iron
  2. Magnesium Correct answer.
  3. Boron
  4. Calcium

Explanation

Magnesium is a mobile nutrient and a central component of the chlorophyll molecule, so deficiency appears as interveinal chlorosis that begins on older leaves as magnesium is redistributed to new growth. Iron, calcium and boron are relatively immobile, so their deficiency symptoms appear first on young leaves.

Question 14Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which nutrient is described as a micronutrient essential for the activation of several enzymes and for chlorophyll formation, and is commonly supplied as a foliar spray of its sulphate?

  1. Nitrogen
  2. Zinc Correct answer.
  3. Potassium
  4. Phosphorus

Explanation

Zinc is a micronutrient required in small amounts, acting as a cofactor for many enzymes and supporting chlorophyll formation and auxin synthesis. It is often applied as zinc sulphate, including foliar sprays for quick correction. Nitrogen, phosphorus and potassium are macronutrients required in much larger quantities.

Question 15Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A soil test reports a pH of 4.8 for a field intended for a sensitive legume crop. Which amendment is most appropriate to raise pH to about 6.5?

  1. Elemental sulphur
  2. Agricultural lime Correct answer.
  3. Ammonium sulphate
  4. Muriate of potash

Explanation

Agricultural lime, mainly calcium carbonate, neutralises soil acidity and raises pH toward the target range for most crops. Elemental sulphur and ammonium sulphate both acidify soil, and muriate of potash supplies potassium without a liming effect. The quantity of lime required should be based on the soil's lime requirement test.

Question 16Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which of the following best explains why heavy irrigation with low-salinity water can increase nitrate leaching from sandy soil?

  1. Nitrate is immobilised by calcium carbonate
  2. Nitrate is strongly adsorbed on clay surfaces
  3. Denitrification is stimulated by oxygen-rich conditions
  4. Nitrate is an anion and moves freely with drainage water Correct answer.

Explanation

Nitrate carries a negative charge and is not retained on the negatively charged soil exchange complex, so it remains in the soil solution. Excess water moving below the root zone therefore carries nitrate with it, and sandy soils with high hydraulic conductivity lose it quickly. This is why split nitrogen applications are recommended.

Question 17Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which of the following describes the role of soil organic matter in improving soil physical conditions?

  1. It raises soil pH to neutral in all acid soils
  2. It eliminates the need for mineral fertilisers in all crops
  3. It promotes stable aggregates and increases water-holding capacity Correct answer.
  4. It increases bulk density and reduces pore space

Explanation

Organic matter binds mineral particles into stable aggregates, improving aeration and infiltration, and its high surface area and water-holding pores raise the soil's water retention. It also supplies nutrients slowly through mineralisation. It does not make mineral fertiliser unnecessary, nor does it reliably neutralise acidity.

Question 18Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

In a crop rotation, including a cereal after a legume mainly benefits the cereal because of which effect?

  1. The legume lowers soil pH to a range preferred by cereals
  2. The legume leaves a herbicide residue that suppresses cereal weeds
  3. The legume increases soil bulk density for better anchorage
  4. Residual nitrogen fixed by the legume becomes available to the following crop Correct answer.

Explanation

Legumes fix atmospheric nitrogen symbiotically and leave nitrogen-rich residues, so part of that nitrogen becomes available to the subsequent cereal through mineralisation. This is a key reason for cereal-legume rotations. The other stated effects are not recognised benefits of legume inclusion.

Question 19Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which of the following is the principal function of potassium in crop plants?

  1. Osmoregulation, enzyme activation and stomatal movement Correct answer.
  2. Formation of the peptide bonds in proteins
  3. Storage of genetic information in the nucleus
  4. Formation of the chlorophyll porphyrin ring

Explanation

Potassium is not incorporated into organic molecules but acts as a mobile ion regulating cell turgor, stomatal opening and many enzyme activities. It also contributes to translocation and stress tolerance. Chlorophyll contains magnesium, proteins contain nitrogen and genetic information is stored in nucleic acids.

Question 20Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which process describes the movement of water from soil into root hairs driven by the water potential gradient?

  1. Translocation
  2. Osmosis Correct answer.
  3. Guttation
  4. Active transport

Explanation

Water moves from the soil, where water potential is higher, into root hair cells along a water potential gradient by osmosis across semi-permeable membranes. Active transport moves ions against a gradient and requires energy. Translocation refers to movement of solutes in the phloem, and guttation is the exudation of water droplets from leaf margins.

Question 21Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A crop growing in a field shows wilting at midday even though the soil contains adequate moisture. Which explanation is most plausible?

  1. The plant is deficient in potassium
  2. Transpiration exceeds the rate at which roots can supply water Correct answer.
  3. The soil has reached its permanent wilting point
  4. Roots have stopped functioning because of waterlogging

Explanation

Midday wilting with adequate soil moisture is commonly temporary wilting, where atmospheric demand drives transpiration faster than root uptake and stem conduction can replace the water. The plant recovers in the evening as transpiration declines. Permanent wilting point and waterlogging would produce persistent symptoms, and potassium deficiency does not cause midday wilting of this kind.

Question 22Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which practice is most effective for conserving soil moisture in a rainfed crop field?

  1. Increasing the slope of the field
  2. Removing all crop residues after harvest
  3. Mulching the soil surface with crop residues Correct answer.
  4. Frequent deep ploughing to expose fresh soil

Explanation

Mulching with crop residues reduces evaporation from the soil surface, lowers surface temperature and protects the soil from raindrop impact. Retaining residues also adds organic matter over time. Deep ploughing and residue removal increase evaporation, and increasing slope accelerates runoff and erosion.

Question 23Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which soil structure type is generally most favourable for crop root growth and water movement?

  1. Platy structure
  2. Massive structure
  3. Single-grained structure
  4. Granular structure Correct answer.

Explanation

Granular structure consists of small, rounded, porous aggregates that provide a good balance of large and small pores, supporting aeration, infiltration and root penetration. Massive and platy structures restrict water and air movement, and single-grained sandy soil has little aggregation and low water retention.

Question 24Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A fertiliser is labelled 20-10-10. What does this indicate about its composition?

  1. 20 per cent nitrogen, 10 per cent phosphorus pentoxide and 10 per cent potassium oxide Correct answer.
  2. 20 per cent phosphorus, 10 per cent nitrogen and 10 per cent potassium
  3. 20 per cent potassium, 10 per cent nitrogen and 10 per cent phosphorus
  4. 20 per cent organic matter, 10 per cent nitrogen and 10 per cent phosphorus

Explanation

Fertiliser grades are expressed as percentages of nitrogen, available phosphorus expressed as phosphorus pentoxide and soluble potassium expressed as potassium oxide, always in that order. A 20-10-10 grade therefore contains 20 per cent nitrogen, 10 per cent phosphorus pentoxide and 10 per cent potassium oxide. The remaining 60 per cent is carrier material and other elements.

Question 25Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which of the following correctly pairs a macronutrient with its principal role in plants?

  1. Phosphorus with energy transfer in ATP and nucleic acids Correct answer.
  2. Molybdenum with chlorophyll formation
  3. Copper with protein synthesis as a major structural element
  4. Chlorine with cell wall strength as a structural component

Explanation

Phosphorus is a macronutrient and a key component of ATP, nucleic acids and phospholipids, so it is central to energy transfer and genetic function. Molybdenum and copper are micronutrients acting mainly in enzyme systems, and chlorine functions in osmoregulation and photosynthesis rather than as a cell wall structural element.

Question 26Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

In soil science, the cation exchange capacity (CEC) of a soil is best defined as which of the following?

  1. The amount of soluble salt present in the soil solution at field capacity
  2. The rate at which water moves downward through the soil profile under gravity
  3. The total quantity of exchangeable cations a soil can hold per unit mass, usually expressed in cmol(+) per kg Correct answer.
  4. The weight of soil particles smaller than 0.002 mm in a given volume of soil

Explanation

CEC measures the negative charge sites on clay and humus that reversibly hold cations such as Ca2+, Mg2+, K+ and NH4+, and it is reported in cmol(+) per kg (formerly meq/100 g). A high CEC means the soil retains nutrient cations against leaching. The other quantities describe hydraulic conductivity, clay content and salinity, which are distinct soil properties.

Question 27Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A soil sample is dominated by kaolinite clay and has a low organic matter content. Compared with a soil rich in montmorillonite and humus, which property is most likely for the kaolinite-dominated soil?

  1. A lower cation exchange capacity and less swelling on wetting Correct answer.
  2. A higher cation exchange capacity and stronger swelling on wetting
  3. A higher pH buffering capacity arising from its clay fraction
  4. A greater ability to fix potassium ions between its layers

Explanation

Kaolinite has a 1:1 crystal structure with little interlayer space and few permanent charge sites, so its CEC is low and it does not swell appreciably when wetted. Montmorillonite is 2:1 with expandable interlayers, and humus carries high charge, so that combination gives high CEC and strong swelling. The kaolinite soil therefore shows the opposite pattern.

Question 28Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

In the Calvin cycle of a C3 crop, the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) can bind oxygen instead of carbon dioxide. What is the direct consequence of this oxygenase reaction?

  1. Immediate closure of stomata and cessation of transpiration
  2. Formation of phosphoglycolate, which must be metabolised through photorespiration Correct answer.
  3. Conversion of ribulose-1,5-bisphosphate into sucrose without energy cost
  4. Increased net carbon fixation because oxygen is consumed

Explanation

When Rubisco accepts O2 rather than CO2, the products are one molecule of 3-phosphoglycerate and one of phosphoglycolate. Phosphoglycolate is not usable in the Calvin cycle and enters the photorespiratory pathway, which consumes energy and releases previously fixed carbon as CO2. This oxygenase activity increases at high temperature and low internal CO2.

Question 29Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

Which statement correctly distinguishes the apoplastic pathway from the symplastic pathway of water and mineral movement in roots?

  1. The apoplast is the pathway through xylem vessels, while the symplast is the pathway through phloem sieve tubes
  2. The apoplast permits movement only through plasmodesmata, while the symplast allows free flow through cell walls
  3. The apoplast is the continuum of cell walls and intercellular spaces, while the symplast is the interconnected cytoplasm linked by plasmodesmata Correct answer.
  4. The apoplast lies inside the vacuoles, while the symplast is the external cell-wall region of the root cortex

Explanation

The apoplast is the non-living continuum formed by cell walls and intercellular spaces, through which water and solutes can move without crossing a membrane. The symplast is the living continuum of cytoplasm connected by plasmodesmata, and movement here crosses membranes. The Casparian strip in the endodermis blocks the apoplastic route and forces solutes into the symplast for selective uptake.

Question 30Agricultural Science Fundamentals (soil science, crop physiology, plant nutrition)

A farmer applies a large dose of ammonium sulphate to a well-aerated sandy loam. Over several weeks the surface soil pH falls markedly. Which explanation best accounts for this acidification?

  1. The fertiliser supplies free sulphuric acid directly, which acidifies the soil immediately on dissolution
  2. Ammonium ions are adsorbed on clay and displace hydrogen ions into the soil solution without any microbial action
  3. Sulphate ions are leached rapidly, leaving behind hydroxyl ions that raise alkalinity
  4. Nitrification of ammonium releases hydrogen ions, and nitrate is leached with base cations, leaving the soil more acidic Correct answer.

Explanation

In well-aerated soil, ammonium is converted to nitrate by nitrifying bacteria, and this oxidation releases H+ into the soil solution. Because nitrate is mobile, it is readily leached together with base cations such as Ca2+, so the soil loses bases and becomes more acidic. Sandy soils with low buffering capacity show this effect strongly.

Question 31Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which pulse crop is a major rabi (winter) season pulse grown widely in West Bengal for its protein-rich seeds?

  1. Lentil (masur) Correct answer.
  2. Green gram (moong)
  3. Black gram (urad)
  4. Cowpea (lobia)

Explanation

Lentil is a cool-season rabi pulse sown after the kharif harvest and harvested in winter, making it a staple rabi pulse in eastern India. Black gram, green gram and cowpea are predominantly warm-season kharif or summer crops.

Question 32Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

The practice of growing two or more crops simultaneously in the same field in a definite row proportion is called:

  1. Sole cropping
  2. Intercropping Correct answer.
  3. Relay cropping
  4. Sequence cropping

Explanation

Intercropping places two or more crops together in the same field during the same season in a defined row arrangement. Sequence cropping and relay cropping involve crops separated in time rather than grown simultaneously throughout.

Question 33Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which of the following is a kharif oilseed crop commonly grown in West Bengal?

  1. Mustard
  2. Linseed
  3. Safflower
  4. Sesame (til) Correct answer.

Explanation

Sesame is a warm-season kharif oilseed sown with the monsoon rains and harvested in autumn. Mustard, linseed and safflower are predominantly rabi oilseeds grown in cooler, drier winter conditions.

Question 34Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

In paddy cultivation, the nursery bed is kept shallow and well-drained primarily to:

  1. Encourage vigorous, healthy seedlings that transplant without damage Correct answer.
  2. Prevent the seedlings from forming roots
  3. Increase the water requirement of the seedlings
  4. Delay germination so seedlings mature late

Explanation

A shallow, well-drained nursery produces sturdy seedlings with healthy roots that establish quickly after transplanting. Waterlogged, deep nursery beds give weak, elongated seedlings that suffer transplanting shock.

Question 35Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which vegetable is a cool-season crop best suited to the winter months in the Gangetic plains?

  1. Cauliflower Correct answer.
  2. Brinjal
  3. Okra (bhindi)
  4. Bitter gourd

Explanation

Cauliflower is a temperate-origin cole crop that requires cool weather for proper curd formation and is grown as a winter vegetable in the plains. Brinjal, okra and bitter gourd are warm-season vegetables that perform poorly in cold weather.

Question 36Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

The main purpose of puddling in paddy transplanting is to:

  1. Reduce soil permeability and create soft mud for easy transplanting Correct answer.
  2. Loosen the soil to encourage weed growth
  3. Increase soil aeration for deep root respiration
  4. Promote rapid drainage of standing water

Explanation

Puddling breaks soil aggregates under wet conditions, reducing percolation losses and creating soft mud in which seedlings can be planted easily. It also helps suppress many weeds by creating a standing-water environment.

Question 37Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which horticultural practice involves removing the growing tip of a shoot to encourage lateral branching?

  1. Girdling
  2. Pinching Correct answer.
  3. Pruning of roots
  4. Defoliation

Explanation

Pinching removes the apical bud or tender tip, breaking apical dominance and promoting side shoots, which is useful in many ornamental and vegetable crops. Girdling, defoliation and root pruning serve different purposes and can stress the plant.

Question 38Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Seed rate for a crop is commonly expressed in:

  1. Litres per hectare
  2. Grams per plant
  3. Plants per kilogram
  4. Kilograms per hectare Correct answer.

Explanation

Seed rate is the quantity of seed required to sow one hectare and is conventionally expressed in kilograms per hectare. It depends on seed size, germination percentage and the recommended plant population.

Question 39Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

A farmer wants to grow a pulse after the paddy harvest on the same land. Which cropping sequence is most appropriate for a rainfed lowland situation in West Bengal?

  1. Jute – paddy
  2. Paddy – deep-water paddy
  3. Paddy – lentil Correct answer.
  4. Maize – jute

Explanation

Lentil fits well as a residual-moisture rabi pulse after paddy, using stored soil moisture without additional irrigation. The other sequences either repeat a summer crop or replace the pulse with another cereal or fibre crop.

Question 40Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

In oilseed rape-mustard, the recommended practice of sowing on time in October–November mainly helps to:

  1. Increase seed dormancy for better storage
  2. Reduce the oil content of the seed
  3. Force early flowering before vegetative growth is complete
  4. Ensure adequate vegetative growth before flowering and avoid aphid build-up Correct answer.

Explanation

Timely sowing lets the crop build sufficient vegetative growth before low temperatures induce flowering, and it escapes the peak aphid infestation that builds on late-sown crops. Late sowing shortens the vegetative phase and lowers yield.

Question 41Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

A vegetable grower observes that tomato fruits are cracking and the plants show poor fruit set in hot, dry weather. Which management measure is most directly useful?

  1. Stop all irrigation until fruits mature
  2. Remove all flowers to save plant energy
  3. Maintain uniform soil moisture and apply mulch Correct answer.
  4. Increase nitrogen application heavily

Explanation

Fruit cracking is largely caused by irregular water supply, so mulching and uniform irrigation stabilise moisture and reduce cracking, while also improving fruit set. Excess nitrogen, withholding water or removing flowers would worsen the problem.

Question 42Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

In pulse cultivation, inoculation of seed with Rhizobium culture before sowing is done to:

  1. Enhance symbiotic nitrogen fixation in root nodules Correct answer.
  2. Supply phosphorus directly to the seedling
  3. Kill soil-borne fungal pathogens
  4. Increase the seed germination percentage sharply

Explanation

Rhizobium inoculant introduces effective nodulating bacteria so that the pulse forms active root nodules and fixes atmospheric nitrogen. This improves nitrogen nutrition and often leaves residual nitrogen for the following crop.

Question 43Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which irrigation practice is most suitable for a horticultural orchard to deliver water directly to the root zone with minimum loss?

  1. Flood irrigation of the whole field
  2. Basin flooding around the whole orchard
  3. Furrow irrigation along the entire plot
  4. Drip irrigation Correct answer.

Explanation

Drip irrigation applies water slowly and directly near the root zone, minimising evaporation, runoff and deep percolation, and it suits widely spaced orchard trees. Flood, furrow and basin methods wet large areas and waste water.

Question 44Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

A farmer applies a nitrogenous fertilizer in three split doses to a transplanted paddy crop. The main advantage of splitting is to:

  1. Delay crop maturity by several weeks
  2. Prevent the crop from absorbing phosphorus
  3. Match nitrogen supply to crop demand and reduce leaching and volatilization losses Correct answer.
  4. Increase the total quantity of nitrogen applied

Explanation

Split application synchronises nitrogen supply with the crop's growth stages, improving nitrogen use efficiency and reducing losses through leaching and volatilization. It does not increase the total dose but improves its effectiveness.

Question 45Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

In the cultivation of green gram, which practice helps to escape damage from the yellow mosaic disease spread by whitefly?

  1. Sowing very late in the season
  2. Growing a resistant or tolerant variety and sowing at the recommended time Correct answer.
  3. Applying only farmyard manure and no other input
  4. Increasing plant density fourfold

Explanation

Yellow mosaic is a whitefly-transmitted virus disease, and using resistant or tolerant varieties with timely sowing reduces vector pressure and infection. Late sowing, overcrowding and unbalanced nutrition increase susceptibility without controlling the vector.

Question 46Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which of the following is the correct order of operations for raising a transplanted vegetable nursery?

  1. Watering, hardening, sowing, bed preparation
  2. Sowing, bed preparation, hardening, watering
  3. Hardening, sowing, bed preparation, watering
  4. Raised bed preparation, sowing, watering, hardening before transplanting Correct answer.

Explanation

A raised bed is prepared first, seed is sown, regular watering supports germination and growth, and seedlings are hardened off before transplanting to tolerate field conditions. Hardening must come last, just before lifting.

Question 47Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

A grower wants to reduce the seed rate of a bold-seeded pulse without reducing the recommended plant population. Which factor most directly justifies a lower seed rate?

  1. High germination percentage and larger seed size with good field establishment Correct answer.
  2. Very low germination percentage
  3. Small seed size with poor viability
  4. High weed infestation in the field

Explanation

Seed rate is adjusted for seed size and germination; bold seed with high germination and good establishment needs fewer kilograms to achieve the target plant population. Poor germination, small seed and heavy weeds would call for higher rates or different management.

Question 48Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

In mango orchards, the practice of removing a ring of bark from a branch to promote flowering is known as:

  1. Earthing up
  2. Thinning
  3. Staking
  4. Girdling Correct answer.

Explanation

Girdling interrupts phloem transport so carbohydrates accumulate above the cut, which can induce flowering in some fruit trees. Staking supports plants, thinning removes excess fruits or plants, and earthing up raises soil around the base.

Question 49Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

A farmer notices that a mustard crop grown after a heavy paddy harvest shows poor early growth. Which explanation is most plausible?

  1. Excess residual nitrogen from the paddy
  2. Too much soil aeration from deep ploughing
  3. Complete absence of soil-borne pathogens
  4. Poor seedbed preparation and residual moisture deficit after paddy Correct answer.

Explanation

After paddy, the field often has a hard, cloddy surface and limited residual moisture, so poor seedbed preparation and moisture deficit restrict mustard establishment. Residual nitrogen is usually low after paddy, and excessive aeration is not the limiting factor in this situation.

Question 50Crop Production and Management (cereals, pulses, oilseeds, vegetables, horticulture)

Which statement correctly distinguishes hybrid seed from ordinary variety seed in vegetable cultivation?

  1. Hybrid seed must be produced by controlled crossing of parental lines each time and gives uniform, high-vigour plants Correct answer.
  2. Hybrid seed is produced only by vegetative propagation
  3. Hybrid seed can be saved and reused for many generations without loss of vigour
  4. Hybrid seed is always open-pollinated and genetically variable

Explanation

Hybrid seed results from a controlled cross between selected parental lines and must be re-produced each generation; the F1 plants are uniform and vigorous. Saved F2 seed segregates and loses uniformity, so it cannot be reused indefinitely.