500 Most Important MCQ on Agronomy B.Sc. Agriculture, and useful for CUET-UG, ICAR-AIEEA (UG), AAO/AFO/AHO & State Agri Exams

Correct Answer: b) Scholer; crop cultivation laws

Agronomy originates from 'agros' (field) and 'nomos' (to manage/law), formalized by Scholer in 1814; it encompasses scientific management of land for crop production, distinguishing from horticulture by scale and focus on field crops.

Correct Answer: b) Integrating soil, water, nutrient, and crop management for sustainable intensification

Agronomists bridge crop ecology, tillage, nutrient dynamics, and cropping systems to enhance land productivity (e.g., 2-3 fold via Green Revolution practices), addressing 9-10 billion population needs by 2050 without expanding arable land.

Correct Answer: b) Human intervention for energy subsidy and output optimization

Agro-ecosystems receive external inputs (fertilizers, irrigation) to maximize harvestable yield (10-50% of NPP vs. <1% in natural), altering trophic structure and increasing vulnerability to pests if not managed sustainably.

Correct Answer: a) 10°C, 30-35°C, 44°C

Below 10°C, germination ceases; optimum 30-35°C maximizes photosynthesis in C4 pathway; >44°C causes pollen sterility and kernel abortion, critical for phenology modeling in subtropical zones.

Correct Answer: a) High rainfall (>2000 mm), red loamy soils, rice-based systems

NARP classification; Zone IIIA (Bihar plateau, Chhattisgarh) supports tribal farming with upland rice, pulses, and millets, prone to soil erosion on undulating terrain.

Correct Answer: c) -0.033 MPa and -1.5 MPa

Field capacity (-0.033 MPa) holds gravitational water drainage complete; PWP (-1.5 MPa) marks unavailable hygroscopic water, defining available water capacity (AWC) of 10-20% vol in loams.

Correct Answer: a) Capillary rise influenced by pore size and soil texture

In fine-textured soils, rise can reach 1-2 m (h = 0.15/r, Jurin's law); critical for subsoil moisture access in dryland crops like sorghum during drought spells.

Correct Answer: b) Reducing soil organic carbon oxidation and enhancing infiltration rate

Residue retention (4-6 t/ha) sequesters 0.3-0.5 t C/ha/year, improves aggregate stability, and cuts irrigation need by 15-20% via better rainwater infiltration in puddled soils.

Correct Answer: b) 30% post-seeding

USDA standard; reduces erosion by 50-90%, conserves soil moisture (20-30 mm extra), and sustains yield in rainfed vertisols compared to conventional ploughing.

Correct Answer: a) Short-duration, fast-growing, sown to utilize residual moisture

E.g., cowpea or radish in delayed monsoon; opportunistic to suppress weeds and provide fodder, common in contingency planning for drylands.

Correct Answer: a) Total productivity advantage over monocropping

LER = (Yab/Yaa) + (Yba/Ybb); >1 (often 1.2-1.5 in cereal-legume) indicates resource complementarity (light, N, water) in systems like maize+pigeonpea.

Correct Answer: a) Sowing second crop into standing first crop before its harvest

Minimizes turnaround time (e.g., wheat into cotton); ensures 10-15 extra days for establishment, critical in rice-wheat where delay reduces wheat yield by 30-40 kg/ha/day.

Correct Answer: a) Potential to germinate under optimal conditions (tetrazolium test)

TZ test stains living tissues red, detecting embryo viability (>90% for certified seed); germinability may be lower due to dormancy or pathogens.

Correct Answer: c) 3.0-3.5 lakh/ha

Achieved at 100-125 kg seed/ha (22.5 cm rows); balances tillering (400-500 spikes/m²) and lodging risk, maximizing grain yield (5-6 t/ha) via compensatory mechanisms.

Correct Answer: b) 4-8 LPH

Matches crop ET (5-7 mm/day peak); fertigation efficiency >90%, saving 30-50% water vs. flood, with uniform wetting (80-90% area) in saline soils.

Correct Answer: a) 0.75-0.90 during tasseling to grain filling

Reproductive phase most sensitive; moisture stress reduces cob size and kernel number by 40-50%, per pan evaporation-based scheduling in subtropical conditions.

Correct Answer: c) Drip (90-95%)

Localized delivery minimizes evaporation/percolation; achieves 2-3 times higher WUE (kg/m³) than flood, vital for water-scarce regions like Maharashtra orchards.

Correct Answer: a) Inhibiting urease and nitrification (20-30% N saving)

Bitter neem triterpenes slow hydrolysis; synchronized N release matches crop demand, improving NUE from 30-40% to 50-60% in rice-wheat.

Correct Answer: a) Organic (FYM, compost) + inorganic + biofertilizers in 4:2:1 ratio ideally

Sustains SOC (>0.5% increase/year), reduces fertilizer dose 25-50%, and enhances microbial activity for long-term productivity in intensive systems.

Correct Answer: b) 0-20 DAT

Coincides with establishment; uncontrolled weeds (Echinochloa) cause 40-60% yield loss; weed-free maintenance beyond 30 DAT yields no further gain.

Correct Answer: d) All of the above

Host-specific pathogens integrated in IWM; reduces chemical load 50-70% in organic systems, though slow action limits standalone use.

Correct Answer: b) 5-6

Beer-Lambert law (I = I0 e^{-k LAI}, k=0.65); beyond LAI 5, mutual shading reduces NAR, shifting assimilate to stems over grain.

Correct Answer: a) Photosynthetic efficiency per unit leaf area

NAR = (W2 - W1)/(t2 - t1) × (log LA2 - log LA1)/(LA2 - LA1); declines with ontogeny due to shading and senescence in dense canopies.

Correct Answer: a) 0.45-0.55 from 0.30 in traditional

Dwarfing genes (Rht) partition more assimilates to grain; HI plateau limits further yield gains without improving total biomass.

Correct Answer: c) Both a and b

Hilum discoloration marks cessation of grain filling; harvesting at 18-20% moisture minimizes field losses while allowing safe storage after drying.

Correct Answer: a) Thinning or ratooning during drought spells

Reduces plant population 20-30% to match available moisture; e.g., sorghum ratoon yields 50-60% of main crop under terminal drought.

Correct Answer: a) Reducing runoff velocity and increasing infiltration time

0.3-0.6 m height bunds store 100-200 mm runoff; graded bunds safe disposal, increasing profile moisture by 50-100 mm in black soils.

Correct Answer: a) Soil biological activity and long-term fertility

NPOP standards; relies on compost (10-15 t/ha), biofertilizers, and crop rotation; yield gap 10-20% initially but stabilizes SOC and microbial biomass.

Correct Answer: a) Component interactions (crop-livestock-fish-horticulture)

E.g., paddy-fish-duck; recycles 60-80% nutrients via pond silt/manure, generating 2-3 times higher net returns than arable farming alone.

Correct Answer: a) Grid soil sampling and yield maps for site-specific input application

GPS-guided applicators save 10-30% fertilizer; NDVI sensors detect variability, optimizing yields in large fields of Punjab wheat.

Correct Answer: d) Intensive tillage

CA triad (no-till, rotation, cover) sequesters 0.4-0.8 t C/ha/year globally; intensive tillage oxidizes SOC and disrupts aggregates.

Correct Answer: a) Productivity, adaptation, mitigation

CSA practices (AWD in rice, agroforestry) reduce GHG 10-20%, enhance resilience to +2°C scenarios, and sustain yields in vulnerable regions.

Correct Answer: a) Understanding growth stages and environmental responses for scheduling practices

Physiological insights (e.g., critical stages, source-sink) guide irrigation, nutrient timing, and harvest for optimizing dry matter partitioning.

Correct Answer: a) Increasing transpiration and mechanical damage at high speeds

>5 m/s causes lodging in cereals; shelterbelts reduce wind speed 50% in 10H distance, cutting ET 10-20% in arid zones.

Correct Answer: a) Favoring spore germination at >80% (e.g., downy mildew)

High RH prolongs leaf wetness (>10 h); critical for epidemic forecasting in grape/millet pathosystems.

Correct Answer: a) Pearl millet, cluster bean, moth bean systems

Rainfall <400 mm, sandy soils, high PET; drought-tolerant crops with moisture conservation critical for 1-1.5 t/ha yields.

Correct Answer: a) Above field capacity (rapid phase)

Mass flow dominates initially; transpirational pull takes over as soil dries, limited by root conductivity in later stages.

Correct Answer: a) Control weeds, aerate soil, and facilitate infiltration during growth

E.g., hoeing in maize 30-45 DAS; reduces competition and breaks crust, improving root proliferation in vertisols.

Correct Answer: a) Aquatic plants and some xerophytes

Enhances CO2 uptake in floating leaves (lotus) or drought adaptation; higher transpiration potential in arid-adapted species.

Correct Answer: a) 250-300%

Rice-wheat-summer mungbean; high irrigation and fertilizer enable 3 crops/year, though sustainability concerns with groundwater depletion.

Correct Answer: a) Thousand grain weight, germination %, and desired plant population

Formula: SR (kg/ha) = (Target plants/m² × 1000-grain wt)/10 × germination %; adjusts for field losses to achieve optimum stand.

Correct Answer: a) Intercrop accommodation and light penetration

30/150 cm pattern allows pulses/vegetables in wide rows; increases system productivity 20-30% in subtropical belts.

Correct Answer: a) Soils with high infiltration rate (>50 mm/h) due to runoff

Lateral movement limited; better for medium textures (10-20 mm/h) like loams to avoid ponding or loss.

Correct Answer: a) Micronutrients (Zn, Fe) under deficiency and alkaline soils

Bypasses soil fixation (Zn-DTPA chelates); 0.5-1% sprays correct chlorosis rapidly, recovery 70-90% vs. 20-30% soil application.

Correct Answer: a) Preventing yield loss by maintaining weed-free up to certain growth stage

E.g., 30-45 DAS in soybean; beyond this, crop canopy suppresses weeds, optimizing herbicide use in IWM.

Correct Answer: a) Exponential vegetative phase

RGR = (1/W)(dW/dt); declines as self-shading increases LAI, shifting from source to sink limitation.

Correct Answer: a) Storage (insects, rodents) at >12% moisture

10-20% national loss; hermetic bags or fumigation reduce to <2%, critical for food security buffer.

Correct Answer: a) In-situ moisture conservation in low rainfall (<600 mm) areas

Small basins hold runoff; increase profile storage 100-150 mm, boosting sorghum yield 30-50% in alfisols.

Correct Answer: a) Soil health indicators (SOC >1%, microbial biomass) above threshold

Prevents degradation (erosion, salinization); CA and INM sustain yields long-term under climate variability.

Correct Answer: a) Tree-crop interactions involve light, water, nutrient management

Agronomic principles guide alley cropping (e.g., Leucaena with cereals) for N contribution (50-100 kg/ha) and microclimate moderation.

Correct Answer: a) Photoperiodism controlling flowering in SDP/LDP

Critical for phenology; e.g., short-day rice varieties flower early under decreasing daylength post-monsoon.

Correct Answer: a) CEC and anion exchange capacity retaining cations/anions

High CEC clays (>30 cmol/kg) buffer nutrient supply; variable charge soils (oxides) dominate in tropics for P fixation.

Correct Answer: a) Reduce energy input (30-50%) and maintain partial residue

1-2 primary operations; balances soil disturbance for seedbed vs. conservation benefits in medium rainfall zones.

Correct Answer: a) Warm-season, high radiation use efficiency crops

RUE 2.5-3.5 g/MJ vs. 1.5-2 in C3; suited to kharif in tropics with high temperature and solar radiation.

Correct Answer: a) Breaking host continuity and altering soil microbe balance

E.g., legume-cereal rotation reduces take-all (Gaeumannomyces) in wheat; improves N economy and yield stability.

Correct Answer: a) 2-3 cm

Ensures contact with moist soil without emergence failure; deeper sowing depletes seed reserves in light-sensitive seeds.

Correct Answer: a) Intercultural operations are mechanized along rows

Wider inter-row (e.g., 90x20 cm cotton) allows tractor movement; yield parity with square if intra-row adjusted.

Correct Answer: a) ~55-60%

Contributes 40-45% food production; dependent on monsoon variability, necessitating watershed management.

Correct Answer: a) Young leaves (e.g., S, Fe, Zn)

Limited retranslocation; apical meristems show chlorosis/rosetting early in growth stages.

Correct Answer: a) Early post-emergence at 2-4 leaf stage of weeds

Lower biomass, higher susceptibility; reduces dose and multiple applications in IWM.

Correct Answer: a) Maximum LAI phase before mutual shading

CGR = (W2 - W1)/(t2 - t1) × area; highest when canopy closure optimizes light capture without senescence.

Correct Answer: a) Grain moisture (optimum 14-18%)

>20% increases damage/cracking; <12% causes grain loss; timely harvest critical.

Correct Answer: a) Antitranspirants (KAOLIN) to reduce cuticular loss

Reflective coating cuts transpiration 20-30%; foliar sprays during stress conserve moisture for grain filling.

Correct Answer: c) Conventional blanket fertilization

Precision replaces uniform with site-specific; sensor-based N application in wheat saves 20-30 kg/ha.

Correct Answer: a) Crop-weather modeling and contingency planning

Agromet advisories use rainfall forecasts for sowing dates; DSS like InfoCrop simulate yield scenarios.

Correct Answer: a) Causing pollen grain bursting or poor dehiscence

>90% RH in tomato/rice leads to sticky pollen; low humidity causes desiccation in self-pollinated crops.

Correct Answer: a) Field capacity and permanent wilting point

Plant-extractable fraction (0.1-0.2 mm/cm depth in loams); depleted in stages (readily, slowly, unavailable).

Correct Answer: a) Pulverization and leveling after primary ploughing

Creates fine seedbed; disc harrow cuts clods, essential for small-seeded crops like mustard.

Correct Answer: a) Sugarcane, sweet sorghum for biofuel

High biomass C4 plants; agronomic management optimizes ethanol yield per hectare.

Correct Answer: a) Risk minimization and resource stabilization

Complementary species (tall-short, deep-shallow roots); insurance against weather aberrations in rainfed areas.

Correct Answer: a) Receding monsoon and optimum temperature decline

Wheat sowing Nov ensures 15-20°C during tillering; delay causes heat stress at grain filling.

Correct Answer: a) Increased competition, lodging, and disease incidence

Intra-specific competition reduces kernel/ear size; optimum balances yield components.

Correct Answer: a) Canals (40%), tubewells (45%), tanks (others)

Groundwater overexploitation in Punjab/Haryana; conjunctive use recommended for sustainability.

Correct Answer: a) Reducing fixation and improving root contact in row crops

P in acidic soils; 10-15 cm below seed enhances uptake 20-30% vs. broadcast.

Correct Answer: a) Releasing phenolics inhibiting germination and growth

Root/leaf leachates reduce alpha-amylase; integrated removal essential in IWM.

Correct Answer: a) Panicles/m², spikelets/panicle, filled grain %, 1000-grain wt

Sequential determination; stress at any stage reduces final yield multiplicatively.

Correct Answer: a) Grain moisture <12% and fumigation (AlP)

Prevents mold and insect proliferation; hermetic storage emerging eco-friendly alternative.

Correct Answer: a) Erratic rainfall, soil erosion, low moisture retention

Mid-season droughts common; watershed approaches address multiple constraints.

Correct Answer: a) Heat/drought tolerance, higher NUE, pest resistance

E.g., Sahbhagi dhan rice; combines adaptation with productivity under variable climate.

Correct Answer: a) Enhancing per unit area productivity sustainably

Bridging yield gaps (50-60% potential unrealized) through better management practices.

Correct Answer: a) Planning Commission (NARP) into 15 zones

Based on rainfall, temperature, soil, cropping pattern; guides region-specific technology transfer.

Correct Answer: d) All of the above

Tensiometer for wet range, gypsum blocks/resistive for drier, neutron for volumetric content.

Correct Answer: d) Higher soil temperature fluctuation

Residue mulch stabilizes temperature; zero till moderates extremes better than conventional.

Correct Answer: a) Climate, soil, water availability, market demand

Agro-ecological suitability primary; economic viability secondary for profitable farming.

Correct Answer: a) Soil nutrient mining, pest buildup

Continuous cereal depletes specific nutrients; rotation breaks cycle.

Correct Answer: a) Precision planting (seed cum fertilizer drill)

Maintains exact spacing/depth; reduces seed rate 20-30% in maize/wheat.

Correct Answer: a) Variety (dwarf vs. tall), soil fertility, moisture

Dwarfs tolerate higher density (less lodging); fertile soils support more plants.

Correct Answer: a) Reduce evaporation (30-50%) and suppress weeds

Straw/dust mulch critical in summer fallow; builds profile moisture for kharif.

Correct Answer: a) Rhizobium, Azospirillum, PSB for N and P solubilization

Fix/mobilize 20-50 kg N/P ha⁻¹; seed inoculation enhances native microbial activity.

Correct Answer: a) Row crops during inter-row cultivation

Hoeing/weeding 20-40 DAS; reduces herbicide dependency in cotton/maize.

Correct Answer: c) Both a and b

HI = Grain DM / Total above-ground DM; breeding target >0.5 in cereals.

Correct Answer: a) Loss of green color, hard dough, moisture <25%

Ensures maximum dry matter accumulation; mechanical harvest possible.

Correct Answer: a) Intercropping and sequential systems for stability

E.g., pearl millet + cluster bean; hedges against rainfall variability.

Correct Answer: a) Nutrient mining and soil degradation

Balanced fertilization and residue return maintain long-term land productivity.

Correct Answer: a) Remote sensing for crop monitoring

Drones/satellites assess NDVI, guide precision interventions for resource efficiency.

Correct Answer: a) Runoff and erosion more than total amount

>25 mm/h exceeds infiltration in many soils; contour farming mitigates splash erosion.

Correct Answer: a) SPAC concept for water movement from soil to atmosphere

Gradient from soil (-1.5 MPa) to leaf (-2 to -3 MPa) drives flow; stomatal regulation key.

Correct Answer: a) Weeds, residues, incorporate manures

Mouldboard plough; controls perennials but exposes soil to erosion if not followed timely.

Correct Answer: a) Rice, wheat, maize, pulses, oilseeds

Staples covering >70% food production; agronomy focuses on their management.

Correct Answer: d) Uniform pest attack

Diversity often dilutes host-specific pests; e.g., marigold in chili repels nematodes.

Correct Answer: a) Soil science, meteorology, plant physiology, and genetics

Agronomy applies multidisciplinary knowledge for crop management; e.g., soil for nutrient supply, weather for scheduling, physiology for growth analysis, and genetics for variety selection in sustainable production systems.

Correct Answer: a) Bridging yield gaps via improved crop management practices

Potential yields are 2-3 times current; agronomic interventions (timely sowing, balanced nutrition, water management) close 30-50% gap without genetic changes, as per ICAR estimates.

Correct Answer: a) Energy flow is subsidized, and nutrient cycling is incomplete

Harvest removes 30-50% nutrients; fertilizers/fuel inputs maintain high NPP harvest index, unlike closed cycling in natural systems.

Correct Answer: a) Cumulative temperature above base threshold for phenological development

GDD = Σ (Tmax + Tmin)/2 - Tbase; e.g., maize base 10°C, total 1500-2000 GDD to maturity; predicts sowing and harvest dates accurately.

Correct Answer: a) High rainfall (>2000 mm), acidic soils, shifting cultivation

Zone covers NE states; terracing and agroforestry recommended to combat erosion and sustain rice-maize systems.

Correct Answer: a) Soil texture and structure influencing pore size distribution

Clay soils hold more unavailable water (higher PWP); sandy soils drain faster (lower FC), affecting irrigation scheduling.

Correct Answer: a) Transpirational pull creating negative pressure gradient in SPAC

Cohesion-tension theory; leaf ψ -2 to -3 MPa vs. soil -0.03 MPa at FC, driving xylem flow during daylight.

Correct Answer: a) Dryland farming to conserve moisture and control erosion

Residue left on surface reduces evaporation (30-40%) and wind erosion; chisel plough maintains stubble in wheat fallows.

Correct Answer: a) Soil organic matter depletion, structure destruction, erosion acceleration

Repeated ploughing oxidizes SOM (0.5-1% loss/year), forms plough pan, and exposes soil to raindrop impact in tropics.

Correct Answer: a) Vigorous growers suppressing weeds (e.g., cowpea, sunflower)

Dense canopy shades weeds; used in cultural control, reducing herbicide need in intercropping systems.

Correct Answer: a) Growing 4-5 crops/year with short-duration varieties and irrigation

E.g., rice-rice-potato in peri-urban; high input but risks soil fatigue without rotation.

Correct Answer: d) Uniform nutrient mining

Diverse root depths and nutrient demands prevent depletion; e.g., legume restores N for cereal.

Correct Answer: a) Purity, germination, moisture, vigor

Certified seed >98% pure, >85% germination, <12% moisture; tetrazolium for quick viability test.

Correct Answer: a) Light interception and reduces weed competition

Equidistant plants optimize canopy architecture; ideal for broadcast crops like wheat when drilled square.

Correct Answer: a) High percolation and runoff losses (40-60%)

Border/furrow methods; laser leveling improves uniformity, saving 20-30% water.

Correct Answer: a) Wide-spaced crops like cotton (IW/CPE 0.8-1.0)

Replenishes 75-100% CPE; accounts for ET demand in non-rice systems.

Correct Answer: d) Flood irrigation

Rainfed depends on rainfall; in-situ conservation key, flood requires external source.

Correct Answer: a) <0.1 kg/ha, critical for enzyme activation

Zn, Fe, Mn; deficiencies widespread in calcareous soils, corrected by soil/foliar application.

Correct Answer: a) Banding near roots

Reduces fixation by oxides/clays; starter dose enhances early growth in maize.

Correct Answer: a) Dependency on crop association

Obligate (Striga) need host; facultative grow independently, critical for parasitic weed management.

Correct Answer: a) Reduce herbicide resistance and environmental impact

Rotation of MOA, cultural practices, biological agents; sustainable long-term.

Correct Answer: a) Maximum cell division and RGR

Exponential increase; nutrient/water abundant, ideal for sampling in growth analysis.

Correct Answer: a) Low tillers compensated by more grains/spike

Plasticity; stress at one stage shifts assimilate to surviving sinks in cereals.

Correct Answer: a) Respiration, transpiration, microbial spoilage

Low temperature, controlled atmosphere storage extends shelf life in grains/fruits.

Correct Answer: a) Frequent mid-season and terminal droughts

Affects critical stages; drought escape/avoidance varieties key adaptation.

Correct Answer: a) Weed control and better rainwater infiltration

Breaks clods, reduces weeds; stores off-season rain in profile.

Correct Answer: a) Increased microbial biomass and SOM buildup

Vermicompost, green manuring; long-term yield stability despite initial drop.

Correct Answer: a) Higher benefit-cost ratio and employment generation

Diversified components recycle waste; 2-4 times returns vs. monocropping.

Correct Answer: a) Enhancing aggregation, infiltration, and biodiversity

No-till + residue + rotation; sequesters C, reduces runoff.

Correct Answer: a) CSA pillars for resilient systems

Productivity + adaptation + mitigation; e.g., drought-tolerant varieties + CA.

Correct Answer: a) Weather-based advisories and crop insurance

FASAL, IMD integration for timely interventions like frost protection.

Correct Answer: a) Reducing photosynthesis and promoting etiolation

Cloudy monsoon limits rice yield; high radiation favors C4 crops.

Correct Answer: a) Anchorage, nutrients, water, aeration

Root zone 0-30 cm critical; compaction reduces O2 diffusion.

Correct Answer: a) 20-30 cm for inversion

Disc/mouldboard plough; deeper for root crops like potato.

Correct Answer: a) Monsoon sown (June-Sept), harvested post-rainy

Rice, maize, cotton; temperature >25°C, rainfall dependent.

Correct Answer: a) Wheat into standing cotton

Utilizes residual moisture; common in irrigated North India.

Correct Answer: a) Lower germination % and higher tillering varieties

Adjusts for field establishment; bold seeds lower rate.

Correct Answer: a) Microclimate, disease spread, yield

Wide rows increase humidity favoring blight; narrow reduce lodging.

Correct Answer: a) Water saving 40-70%, weed reduction, fertigation

Lateral wetting; ideal for orchards, saline areas.

Correct Answer: a) High K reduces Mg uptake

Competitive inhibition at root surface; balanced ratios critical.

Correct Answer: a) Light, nutrients, water in early stages

Critical period determines yield loss threshold for control.

Correct Answer: a) Understanding dry matter partitioning and stress effects

CGR for canopy productivity, NAR for efficiency.

Correct Answer: a) Timely harvesting at physiological maturity

Avoids shattering in cereals, cracking in groundnut.

Correct Answer: a) Supplemental irrigation, antitranspirants, mulching

Life-saving irrigation at critical stages boosts yield 20-50%.

Correct Answer: a) Resource use efficiency and ecosystem services

Low input, high output; biodiversity conservation.

Correct Answer: a) Desiccation of pollen in anemophilous crops

Windbreaks in maize protect silk receptivity.

Correct Answer: a) Reproductive stages (flowering, grain filling)

Reduces sink strength; 50-70% yield loss possible.

Correct Answer: a) 20-40 DAS in row crops

Earthing up, weeding; improves aeration.

Correct Answer: a) Two years (vegetative + reproductive)

Carrot, beet; vernalization required for flowering.

Correct Answer: a) Higher land use efficiency, income stability

>200% intensity; diversified production.

Correct Answer: a) Coincidence of critical stages with favorable weather

Late wheat faces terminal heat.

Correct Answer: a) Parabolic curve (optimum then decline)

Competition vs. compensation; asymptotic in some.

Correct Answer: a) >60% via tubewells

Leads to depletion; sustainable management needed.

Correct Answer: a) Improve soil structure and microbial activity

FYM + urea 50:50; higher NUE.

Correct Answer: a) Bioherbicides, insects, pathogens

Sustainable; e.g., Zygogramma for Parthenium.

Correct Answer: a) Partitioning efficiency

Modern varieties >0.5 HI.

Correct Answer: a) <12% moisture, aeration, pest control

Safe storage >1 year.

Correct Answer: a) Low water requiring crops and conservation

Millets, pulses; watershed development.

Correct Answer: a) 10-30% via site-specific application

Sensors, GPS; economic and eco-friendly.

Correct Answer: a) Resilient practices and varieties

CSA, contingency plans.

Correct Answer: a) Vapor pressure deficit (low RH increases rate)

High RH closes stomata partially.

Correct Answer: a) Mass flow to diffusion/capillary

Dry soil limits hydraulic conductivity.

Correct Answer: a) Timely sowing, moisture conservation

Happy seeder; avoids puddle delay.

Correct Answer: a) Cotton, jute

Bast/spinning fibers.

Correct Answer: a) Rotation and diversity

Breaks cycles, balances nutrients.

Correct Answer: a) Emergence and seedling vigor

Too deep exhausts reserves.

Correct Answer: a) Sugarcane for intercrops

Wide space for companions.

Correct Answer: a) Light soils, undulating land

Uniform, no leveling needed.

Correct Answer: a) Slow release nutrients, improve soil physical properties

FYM 10-20 t/ha base.

Correct Answer: a) Leaf shape, venation

Selective herbicide target.

Correct Answer: a) Increased respiratory load, shading

Maintenance respiration rises.

Correct Answer: a) Pod dry, leaf yellow

Avoids shattering.

Correct Answer: a) Runoff harvesting, groundwater recharge

Farm ponds, check dams.

Correct Answer: a) Lower initial yield but better soil health

Transition period 3-5 years.

Correct Answer: a) GIS, remote sensing for decision support

Crop monitoring, yield forecasting.

Correct Answer: a) Pollination, dispersal, mechanical stress

Anemophily in maize.

Correct Answer: a) Cell expansion first (turgor loss)

Vegetative growth sensitive.

Correct Answer: a) Rice wetland preparation

Reduces percolation.

Correct Answer: a) Economic viability, farmer preference

Market, profitability key.

Correct Answer: a) Advantage over sole cropping

Efficient resource use.

Correct Answer: a) Rice, tobacco for uniformity

Overcomes establishment issues.

Correct Answer: a) Tall, weak stems, lodging

Light competition etiolation.

Correct Answer: a) Deficit irrigation in some crops

Regulated deficit in grapes.

Correct Answer: a) Cereals below seed

Better contact.

Correct Answer: a) Timing of control measures

Economizes inputs.

Correct Answer: a) Photothermal units

Phenology models.

Correct Answer: a) Bulk grain aerobic

Large scale.

Correct Answer: a) Delayed monsoon (short duration crops)

Alternate crops.

Correct Answer: a) Crop diversification, INM

Resilience.

Correct Answer: a) Technology transfer to farmers

KVKs, demonstrations.

Correct Answer: a) Crop success in rainfed

Dry spells critical.

Correct Answer: a) Upper soil layers initially

Density higher top.

Correct Answer: a) Fuel cost, erosion

Partial conservation.

Correct Answer: a) Groundnut, mustard, soybean

Edible oil source.

Correct Answer: a) Spatial and temporal arrangement

Yearly sequence + arrangement.

Correct Answer: a) Spacing and area

Plants/ha = 10000 / (row × plant spacing m).

Correct Answer: a) Tensiometer, gypsum block

Soil moisture based.

Correct Answer: a) N fixation, P solubilization

Reduce chemical 25%.

Correct Answer: a) Delays resistance, eco-friendly

Holistic approach.

Correct Answer: a) Threshing, drying, storage

Minimizes losses 10-20%.

Correct Answer: a) Rainfall, temperature, soil type, and cropping pattern

The Planning Commission (now NITI Aayog) delineated 15 agro-climatic zones under NARP for region-specific planning; integrates biophysical factors to tailor agronomic practices like variety selection and nutrient management.

Correct Answer: a) Light intensity where photosynthesis equals respiration

Below compensation point, net CO2 uptake is negative; critical for shade-tolerant crops in intercropping systems, influencing LAI management.

Correct Answer: a) Driving gradient between leaf and atmosphere

High VPD (>2 kPa) accelerates transpiration, risking dehydration; mulching or antitranspirants mitigate in dryland agronomy.

Correct Answer: a) Breaking hardpan to improve root penetration in compacted soils

Depth 40-60 cm; enhances water infiltration and root exploration in vertisols, boosting drought tolerance in deep-rooted crops like cotton.

Correct Answer: a) Animal feed (green/dry fodder)

E.g., berseem, lucerne, oats; integrated in IFS for livestock nutrition and soil N enrichment via legumes.

Correct Answer: a) Successive crops without overlap in growth periods

E.g., rice-wheat; maximizes annual productivity but requires quick turnaround, addressed by zero tillage.

Correct Answer: a) Enhance germination and vigor in aged/low-quality seeds

Techniques like osmopriming; improves field emergence in vegetables and pulses under stress conditions.

Correct Answer: a) Yield plateaus beyond optimum density due to compensation

Plastic crops like wheat adjust tillers/grains; guides spacing recommendations.

Correct Answer: a) Minimizes weeds, evaporation, and deep percolation

90-95% efficiency; fertigation synchronizes nutrient delivery, reducing leaching in sandy soils.

Correct Answer: a) Leaf color chart or soil test for real-time adjustment

Improves NUE 15-20%; SSNM in rice uses QUEFTS model for balanced fertilization.

Correct Answer: a) Chemical exudates inhibiting growth (e.g., sorghum sorgoleone)

Exploited in cover crops; Parthenium phenolics reduce wheat germination.

Correct Answer: a) NAR and LAR for unit dry matter increase

RGR = NAR × LAR; early growth indicator, declines with ontogeny.

Correct Answer: a) Drought stress, reducing kernel set

ASI >5 days causes barrenness; stay-green hybrids minimize under terminal drought.

Correct Answer: a) Harvesting runoff for supplemental irrigation

Life-saving irrigation at flowering; increases yield 20-50% in millets/pulses.

Correct Answer: a) Variable rate application and yield mapping

Reduces input costs 10-20%; NDVI-guided N in wheat optimizes zones.

Correct Answer: a) Daylength for photoperiod-sensitive crops

Better predicts phenology in rice/sorghum; accounts for latitude effects.

Correct Answer: a) Accumulation of solutes to maintain turgor

Proline, sugars; enables water uptake at low ψ, key trait in breeding.

Correct Answer: a) High rainfall areas for drainage and erosion control

Ridges 20-30 cm; warms soil faster, suits soybean in vertisols.

Correct Answer: a) Short-duration catch crops in rice fallows

E.g., toria, lentil; utilizes residual moisture in Eastern India.

Correct Answer: a) Erosion control on slopes by alternating dense/close crops

Contour strips; dense (grass) traps sediment from row crops.

Correct Answer: a) Add nutrients/protectants to small seeds

Rhizobium in legumes; improves handling and establishment.

Correct Answer: a) Limited moisture to reduce competition

1:1 or 2:1 skip; conserves water for boll development in rainfed.

Correct Answer: a) Row crops with medium infiltration soils

Efficiency 60-80%; graded furrows minimize runoff.

Correct Answer: a) N, P, K, Mg (retranslocated)

Deficiency symptoms in older leaves; guides foliar application timing.

Correct Answer: a) Before weed/crop emergence

Soil-active; pendimethalin in soybean controls early flush.

Correct Answer: a) Impaired assimilate translocation and harvest losses

PGRs like trinexapac-acid shorten internodes in wheat.

Correct Answer: a) Cylinder-concave separation

Speed adjustment minimizes grain damage; moisture 14-18% optimal.

Correct Answer: a) Trenches filled with residue for infiltration

30-50 cm deep; channels water to subsoil in alfisols.

Correct Answer: a) On-farm holistic approach integrating components

Farmer participatory; optimizes resource recycling in IFS.

Correct Answer: a) Crops with both temperature and daylength influence

Refines phenology prediction in photoperiod-sensitive varieties.

Correct Answer: a) 0.33 to 15 bar (available)

Plant roots extract; depleted progressively under drought.

Correct Answer: a) Direct drilling in rice residue without burning

Conservation agriculture tool; reduces air pollution in NW India.

Correct Answer: a) Grain legumes

High protein; N-fixing, key in rotation for soil health.

Correct Answer: a) Intercultural operations and intercrops

30/90 cm; accommodates vegetables for higher income.

Correct Answer: a) Scarification, stratification, GA3

Hard seed coat in legumes; ensures germination timing.

Correct Answer: a) Level land for uniform distribution

Laser leveling improves efficiency 20-30%.

Correct Answer: a) Match crop demand, reduce losses

NUE >60%; suited for flooded rice.

Correct Answer: a) Trap crops, suicidal germination

Desmodium in push-pull; host-specific in sorghum.

Correct Answer: a) Assimilate partitioning to economic yield

Grain number/size in cereals; breeding for higher HI.

Correct Answer: a) Terminal heat stress

1 day/°C above 30°C; early sowing or heat-tolerant varieties mitigate.

Correct Answer: a) Small basins for in-situ conservation

2x2 m grids; retains runoff in low rainfall.

Correct Answer: a) CA, diversified systems, water harvesting

Triple win: adaptation, mitigation, productivity.

Correct Answer: a) >Critical photoperiod (e.g., wheat)

Spring wheat needs long days for reproductive phase.

Correct Answer: a) Unavailable, held tightly >31 bar

Adsorbed on soil particles; not extracted by roots.

Correct Answer: a) Uniform water distribution, saving 20-30% irrigation

Precision agriculture tool; improves WUE in rice-wheat.

Correct Answer: a) Root drugs

Withanolides; dryland suited, rotation crop.

Correct Answer: a) Trees in rows with alleys

Hedgerow intercropping; prunings as mulch/N source.

Correct Answer: a) Pre-germinated seeds in gel

Uniform emergence in vegetables under cool conditions.

Correct Answer: a) Daily or alternate for constant moisture

Pulse irrigation; prevents stress in fruits.

Correct Answer: a) Targeted delivery, higher uptake efficiency

Slow release; reduces environmental impact.

Correct Answer: a) Rotation of MOA groups

IRAC classification; delays evolution in weeds like Phalaris.

Correct Answer: a) Assimilate supply < sink demand

Shading/defoliation reduces yield; post-anthesis stress.

Correct Answer: a) Dockage, impurities for quality

Air-screen cleaners; improves storability and market value.

Correct Answer: a) 150 cm bed for drainage and conservation

Vertisols; excess water drains, moisture conserved.

Correct Answer: a) Biodiversity, natural regulation over inputs

Mimics ecosystems; resilience to climate extremes.

Correct Answer: a) Phytochrome pigment

Red/far-red reversible; controls flowering in SDP/LDP.

Correct Answer: a) < Management allowed depletion (MAD)

MAD 0.5 for many crops; guides irrigation timing.

Correct Answer: a) >30% residue on surface

Conservation practice; temperature moderation.

Correct Answer: a) Spices like coriander, cumin

Flavoring; seed spices in arid zones.

Correct Answer: a) Trees + pasture + livestock

Fodder trees; sustainable in degraded lands.

Correct Answer: a) Precision singulation in large seeds

Pneumatic planters; uniform spacing in maize.

Correct Answer: a) Advance rate in long fields

Intermittent flow; higher efficiency in clay soils.

Correct Answer: a) Polymer coatings for diffusion-based release

Temperature/moisture triggered; matches crop curve.

Correct Answer: a) Spreading, retention, uptake

Surfactants; better efficacy at lower doses.

Correct Answer: a) Grain number per unit assimilate at flowering

Critical for yield potential; stress sensitive.

Correct Answer: a) 10-20% volume

O2 diffusion; compaction reduces root respiration.

Correct Answer: a) Weed kill and moisture storage

Summer plough; evaporates less, stores rain.

Correct Answer: a) Plantation crops

Perennial bushes; shade management key.

Correct Answer: a) Fruit trees + pasture

Grazing under orchards; multi-layer income.

Correct Answer: a) Precision placement at high speed

Vacuum/pressure; uniform depth in row crops.

Correct Answer: a) Heavy rainfall for drainage

Avoids waterlogging; suits vegetables in humid zones.

Correct Answer: a) Delay NH4+ to NO3- conversion

Reduce leaching/denitrification; with urea in rice.

Correct Answer: a) Pathogens like fungi (e.g., Colletotrichum)

Host-specific; eco-friendly for organic farming.

Correct Answer: a) Crop water status (cooler = well-watered)

Thermal imaging; scheduling tool in precision.

Correct Answer: a) Heated/low temperature for quality

LSU dryer; prevents cracking in rice.

Correct Answer: a) Runoff collection for recharge

Tied at ends; conserves water in contours.

Correct Answer: a) No external inputs, cow-based preparations

ZBNF; Jeevamrutha for microbes.

Correct Answer: a) Minimum, optimum, maximum daylength

Beyond ceiling, delay in LDP; breeding for insensitivity.

Correct Answer: a) Compaction, reduced porosity

>1.6 g/cc restricts roots; subsoiling corrects.

Correct Answer: a) Secondary tillage and residue mixing

Fine tilth; puddling in rice.

Correct Answer: a) Sugarcane, sugarbeet

Sucrose source; ratoon management in cane.

Correct Answer: a) Trees + crops

Boundary/taungya; boundary for windbreak.

Correct Answer: a) Direct seeding in untilled soil with residue

Inverted-T opener; CA essential.

Correct Answer: a) Orchards, level fields

Ring basins; tree crops like citrus.

Correct Answer: a) Ammonia volatilization from urea

Surface application; 30-50% loss prevention.

Correct Answer: a) Touch, non-translocated

Paraquat; quick burn-down.

Correct Answer: a) Anther dehiscence failure

Boro rice; cold-tolerant varieties.

Correct Answer: a) Air-tight seals to control insects via low O2

PICS bags; smallholder grains.

Correct Answer: a) Safe disposal of excess runoff

Bench for cultivation; outward slope for drainage.

Correct Answer: a) Zoning, stacking, perennial focus

Mimics natural ecosystems; long-term sustainability.

Correct Answer: a) 4-5°C

Cool-season; accumulates slowly in rabi.

Correct Answer: a) Sandy soils initially

Decreases with time; steady-state higher in structured.

Correct Answer: a) Fracturing hardpan without inversion

Conservation tillage; deep non-inverting.

Correct Answer: a) Regulated stimulants

Latex source; licensed cultivation.

Correct Answer: a) Mango + vegetables

Multi-tier; shade-tolerant understory.

Correct Answer: a) Metering medium seeds

Groundnut, maize; cell-fill accuracy.

Correct Answer: a) Large circular fields

Automated; uniform in plains.

Correct Answer: a) Waterlogged, high C, nitrate

N2/N2O loss; AWD in rice mitigates.

Correct Answer: a) Specific weed types (broadleaf/grass)

2,4-D for dicots in cereals.

Correct Answer: a) Physiological maturity

Abscission at kernel base; harvest timing.

Correct Answer: a) Land required to sustain crop production systems

Assesses sustainability; intensive systems have lower footprint per unit yield due to higher productivity, guiding eco-efficient practices.

Correct Answer: a) Phenotypic plasticity and genetic traits for stress tolerance

E.g., deeper roots in drought; breeding + management for resilience in changing environments.

Correct Answer: a) Frost-free period and temperature accumulation

Critical for crop selection; lengthening under warming allows double cropping in temperate zones.

Correct Answer: a) Soils with compacted subsoil layers to improve drainage

Occasional (every 3-5 years); avoids in conservation systems to prevent SOM dilution.

Correct Answer: a) Natural colorants

Leaf-derived; sustainable alternative to synthetics in organic textiles.

Correct Answer: a) Relay cropping with partial growth overlap

E.g., maize into wheat before harvest; extends land use in short seasons.

Correct Answer: a) Soaking-drying cycles for stress tolerance

Osmohardening with KCl; improves drought resistance in seedlings.

Correct Answer: a) 15% more plants than square

Equilateral triangle; denser orchards with uniform light.

Correct Answer: c) Furrow

Gravity-based; pressurized for uniformity and efficiency.

Correct Answer: a) Leaf burn risk and low translocation for some nutrients

Ca immobile; urea best for N quick correction.

Correct Answer: a) Vegetative propagation (rhizomes, stolons)

Cynodon, Cyperus; require systemic herbicides like glyphosate.

Correct Answer: a) Total dry matter via canopy longevity

Stay-green trait; prolongs photosynthesis in sorghum.

Correct Answer: a) Faster, uniform, weather-independent

Batch/continuous dryers; preserves grain quality in humid regions.

Correct Answer: a) Grass strips for erosion control

Vetiver; stabilizes bunds, fodder bonus.

Correct Answer: a) IoT, AI for real-time decisions

Sensors for VRT; future of precision agronomy.

Correct Answer: a) C3 crops than C4

C4 concentrate CO2; higher RUE in tropics.

Correct Answer: a) 2-3 days drainage post-saturation

Gravitational water lost; tension ~ -0.033 MPa.

Correct Answer: a) Zone tillage with residue retention

Band for seedbed, undisturbed inter-row; fuel saving.

Correct Answer: a) Seed beverages

Theobromine; fermentation key post-harvest.

Correct Answer: a) Trees on field edges for windbreak

Eucalyptus; reduces evaporation in arid crops.

Correct Answer: a) Sloppy lands contour sowing

Prevents erosion; paired row in hills.

Correct Answer: a) Large area coverage like sprinkler

Traveler type; high volume for fodder crops.

Correct Answer: a) Extra water to flush salts below root zone

LR = ECw / (5(ECe threshold - ECw)); maintains ECe low.

Correct Answer: a) Phloem to growing points

Glyphosate; kills perennials systemically.

Correct Answer: a) C4 crops (3-4 g/MJ)

No photorespiration; maize > wheat.

Correct Answer: a) Insect cross-infestation

Super grain bags; farmer level.

Correct Answer: a) Green manure N source

50-100 kg N/ha; alley cropping.

Correct Answer: a) Soil regeneration via biology, minimal disturbance

Cover crops, compost; rebuilds SOC.

Correct Answer: a) Low temperature for flowering induction

Winter wheat; 0-10°C for 30-60 days.

Correct Answer: a) 40-60% volume

Macro + micro; aeration vs. water holding.

Correct Answer: a) Heavy residue incorporation

Stubble mulch; primary-secondary.

Correct Answer: a) Latex crop

Tapping management; perennial plantation.

Correct Answer: a) Multi-tier mixed cropping around house

Kitchen gardening; nutrition security.

Correct Answer: a) Small seeds precision

Vegetable seeds; low rate accuracy.

Correct Answer: a) Arid zones localized water

Porous pots; slow release.

Correct Answer: a) High C:N ratio residues (>30:1)

Microbes tie up soil N; wheat straw.

Correct Answer: a) Auxin mimics (2,4-D)

Growth disruption in broadleaf.

Correct Answer: a) Fraction of assimilate to economic yield

Increases with modern varieties.

Correct Answer: a) Aluminum phosphide for insects

PH3 gas; sealed stacks.

Correct Answer: a) Small ties for pocket storage

Every few meters; in-row water harvesting.

Correct Answer: a) Cosmic rhythms, preparations

Steiner method; horn manure 500.

Correct Answer: a) 40-50°C varying by crop

Pollen viability lost above in many.

Correct Answer: a) Coarse textures

Drainage fast; leaching risk.

Correct Answer: a) Residue sizing without inversion

Prepares for no-till; aerates lightly.

Correct Answer: a) Leaf distillates

Temperate; distillation post-harvest.

Correct Answer: a) Trees + crops initial years

Forestry + agriculture; shifting later.

Correct Answer: a) Hill sowing large seeds

Manual; maize in hills.

Correct Answer: a) Field crop herbicide/foliar

Flat fan nozzles; uniform coverage.

Correct Answer: a) Uptake beyond need (K in grasses)

No yield increase; affects quality.

Correct Answer: a) Weeks-months controlling germination

Atrazine; carryover risk.

Correct Answer: a) Grain filling under stress

Stem reserves in wheat; 20-40% contribution.

Correct Answer: a) Greenhouse effect for grains

Low cost; poly tunnels.

Correct Answer: a) Small basins around plants

Negarim; tree establishment in arid.

Correct Answer: a) Synthetic pesticides, GMOs

EU standards; biodiversity focus.

Correct Answer: a) High temperature, low CO2 in C3

25-50% loss; Rubisco oxygenase activity.

Correct Answer: a) Moisture at -1.5 MPa

Permanent wilting; crop specific slightly.

Correct Answer: a) Shallow tillage aeration

Improves oxygen in compacted.

Correct Answer: a) Natural insecticide flower

Chrysanthemum; pyrethrins from florets.

Correct Answer: a) Trees + fish ponds

Mangrove or fruit on dykes.

Correct Answer: a) Hardening, root dipping

Phosphorus dip; quick recovery.

Correct Answer: a) Rectangular fields

Linear move; efficient land use.

Correct Answer: a) Variable charge soils (oxides)

P, SO4 retention in tropics.

Correct Answer: a) Glyphosate pre-plant

Non-selective burn-down for zero till.

Correct Answer: a) Panicle number/sink

Productive tillers; N timing influences.

Correct Answer: a) <15°C, low RH

Long-term; inhibits insects/mold.

Correct Answer: a) Individual trees on slopes

Semi-circular; runoff capture.

Correct Answer: a) Soilless nutrient management research

NFT, aeroponics; precise studies.

Correct Answer: a) Day-night temperature alternation for growth

DIF in protected; controls height.

Correct Answer: a) Impervious layer causing perched water

Drainage issue in layered soils.

Correct Answer: a) Small farms puddling/tilth

Walk-behind; wetland preparation.

Correct Answer: a) Wattle for bark extract

Leather industry; agroforestry.

Correct Answer: a) Pollination + honey

Bees enhance fruit set 20-30%.

Correct Answer: a) Level fields tree crops

Square/rectangular; orchard irrigation.

Correct Answer: a) Ca, Mg, K, Na in soils

Base saturation; liming increases Ca.

Correct Answer: a) Cell level dehydration resistance

Resurrection plants; rare in crops.

Correct Answer: a) High moisture grains in layers

Aeration prevents spoilage.

Correct Answer: a) Summer short-duration

Mung, cucumber; irrigated.

Correct Answer: a) Recharge on hills

Staggered; water infiltration.

Correct Answer: a) Mulberry + silkworm

Leaf feed; reelable silk.

Correct Answer: a) 25-35°C

Enzyme activity peak; varies slightly.

Correct Answer: a) Excess water removal rate

Subsurface design; mm/day.

Correct Answer: a) Surface leveling, weed kill

Secondary light; clod breaking.

Correct Answer: a) Tree exudates like gum arabic

Acacia; industrial uses.

Correct Answer: a) Waste substrate utilization

Paddy straw; protein supplement.

Correct Answer: a) Single tree irrigation

Circular; fruit orchards.

Correct Answer: a) Nutrient reserve status

>50% fertile; low in acid soils.

Correct Answer: a) Early maturity before stress

Short-duration varieties; terminal drought.

Correct Answer: a) Steaming before milling for nutrient retention

Gelatinization; higher head rice.

Correct Answer: a) Runoff diversion

Safe disposal on slopes.

Correct Answer: a) Earthworm composting

Vermicompost; nutrient rich.

Correct Answer: a) CO2 diffusion in high temperature

Emerging constraint in C3 under warming.

Correct Answer: a) Loam soils

Balanced pores; 15-25 cm/m.

Correct Answer: a) Inter-row weeding

Shovels/ sweeps; secondary tillage.

Correct Answer: a) Host trees like palas

Insect resin; stick lac.

Correct Answer: a) High density organic small plots

French intensive; raised beds.

Correct Answer: a) Alternate furrows

Saves water; root pruning.

Correct Answer: a) Nutrient indexing, soil test

Critical limits; recommendation.

Correct Answer: a) Reduced transpiration (stomatal closure)

Early response; conserves water.

Correct Answer: a) 65-70% head rice

Drying, parboiling improves.

Correct Answer: a) Steep slopes cultivation

Level platforms; hill farming.
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