Maharashtra HSC Horticulture (Vocational) cheat sheet

Horticulture is divided into pomology (fruit), olericulture (vegetables), floriculture (flowers) and landscape gardening; plantation crops (coconut, arecanut, cashew, tea, coffee, rubber) are grouped separately.

Photosynthesis: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2; chlorophyll a absorbs maximally near 430 nm and 662 nm, chlorophyll b near 453 nm and 642 nm.

C3 plants fix CO2 into 3-phosphoglycerate via RuBisCO; C4 plants use PEP carboxylase in mesophyll (first product oxaloacetate, 4-carbon); CAM plants open stomata at night and store malate in vacuoles.

Transpiration pull (cohesion-tension theory) moves water through xylem; phloem translocation follows the pressure-flow (Münch) hypothesis from source to sink.

Essential elements: 17 recognized (C, H, O, N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B, Mo, Cl, Ni); deficiency of a mobile element such as N or Mg appears first in older leaves, immobile elements such as Fe and Ca in young leaves.

Growth regulators: auxins (IAA, IBA, NAA) promote rooting and apical dominance; gibberellins elongate internodes and break dormancy; cytokinins promote cell division; ethylene ripens fruit; ABA closes stomata and induces dormancy.

Seed germination requires water imbibition, oxygen, suitable temperature and, for some species, light; epigeal germination lifts cotyledons above soil, hypogeal keeps them below.

Apical dominance, photoperiodism (short-day, long-day, day-neutral) and vernalization are used to schedule flowering in horticultural crops.

Soil texture triangle classifies soil by proportions of sand (2.0–0.05 mm), silt (0.05–0.002 mm) and clay (<0.002 mm); loam is the most desirable horticultural texture.

Soil pH ranges: strongly acid <5.5, acid 5.5–6.5, neutral 6.6–7.3, alkaline 7.4–8.5, strongly alkaline >8.5; most horticultural crops prefer pH 6.0–7.0, and availability of Fe, Mn, Zn falls as pH rises above 7.5.

Cation exchange capacity (CEC) rises with clay and organic matter content; smectite and vermiculite clays have high CEC, kaolinite and sand low CEC.

Liebig's law of the minimum: growth is limited by the nutrient in shortest supply relative to need; excess of one nutrient can induce deficiency of another (e.g., excess K induces Mg deficiency).

Fertilizer grade N-P2O5-K2O expresses oxide form, not elemental P and K; to convert P2O5 to P multiply by 0.44, K2O to K multiply by 0.83.

Urea (46-0-0), DAP (18-46-0), MOP (0-0-60), SSP (0-16-0 plus 11% S) and ammonium sulphate (20.6-0-0 plus 24% S) are common straight fertilizers; NPK complexes supply two or three nutrients per bag.

Fertigation applies soluble fertilizers through drip irrigation; it is suited to protected cultivation and to crops where split N and K applications are required.

Green manuring (e.g., sunhemp, dhaincha) and FYM (approximately 0.5% N, 0.2% P2O5, 0.5% K2O) improve organic carbon, structure and water-holding capacity.

Sexual propagation uses seed and produces variation; it is preferred where seed is cheap, where the crop is annual, or where rootstocks are raised for grafting.

Asexual (vegetative) propagation clones the parent: cuttings, layering, grafting, budding, suckers, rhizomes, tubers, bulbs and tissue culture.

Cuttings: hardwood cuttings root best with high carbohydrate and low N status; softwood cuttings need high humidity and mist; rooting is promoted by IBA or NAA at 1,000–5,000 ppm.

Layering: in air layering (gootee) a ring of bark is removed and the wound is wrapped in moist rooting medium; in stool or mound layering, shoots are etiolated and earthed up to root.

Grafting success requires cambial contact between scion and stock, compatible species, and a tight, clean union; grafting is used to combine a vigorous rootstock with a superior scion and to confer soil-borne disease resistance.

Budding types: T (shield) budding, patch budding (for thick bark), ring budding and chip budding; T budding is standard for citrus and mango.

Nursery standards: raised beds 15–20 cm high, sterilized media (solarization, formalin, steam), 40–50% shade nets for tender seedlings, and hardening of seedlings 7–10 days before transplanting.

Apical meristem culture produces virus-free planting material; micropropagation through axillary buds maintains clonal fidelity better than callus culture.

Mango: propagated by veneer or stone grafting and inarching; flowering is induced by cool nights and dry weather; mango malformation and hopper are major problems; fruits are harvested at maturity and ripened at 20–25°C.

Banana: a giant herb propagated by sword suckers or tissue culture; requires high N and K; bunch weight is improved by desuckering and propping; Panama wilt (Fusarium oxysporum f. sp. cubense) is soil-borne and management relies on resistant varieties and clean planting material.

Citrus: propagated by T budding on rough lemon or Rangpur lime rootstock; citrus decline, tristeza virus and citrus psylla are key constraints; avoid waterlogging at the collar.

Grape: trained on bower, Y or telephone trellis; pruning is the key manipulation - forward pruning for back pruning in tropical viticulture; berry thinning and GA3 are used for seedless varieties.

Papaya: dioecious or gynodioecious; one male per 10–15 female plants is standard; papaya ring spot virus and waterlogging are limiting; fruits are harvested at colour break.

Coconut: propagated by seed nuts from high-yielding mother palms; root (wilt) disease and rhinoceros beetle are major; copra and coconut oil are the chief products.

Arecanut, cashew, tea, coffee and rubber are plantation crops; cashew is propagated by softwood grafting, rubber by bud grafting on seedling rootstock, tea by vegetative cuttings.

Orchard planning: planting density, windbreaks, pollinizer rows, irrigation layout and intercropping are fixed before planting; spacing determines plant population per hectare.

Vegetables are grouped as solanaceous (tomato, brinjal, chilli), cucurbits (cucumber, bitter gourd, watermelon), cole crops (cabbage, cauliflower), bulb crops (onion, garlic), root crops (carrot, radish) and leafy vegetables (spinach, coriander).

Nursery raising followed by transplanting applies to tomato, brinjal, chilli, cabbage and cauliflower; direct sowing applies to okra, cucurbits, root crops and leafy vegetables.

Tomato: staking, pruning of side shoots, and boron and calcium management prevent cracking and blossom-end rot; fruit borer and early blight are major.

Onion: bulb formation is governed by day length and temperature; long-day varieties are grown in northern latitudes, short-day in the tropics; curing before storage reduces storage rots.

Cauliflower: curd initiation is temperature-sensitive; early, mid and late groups are chosen by temperature requirement, and buttoning follows exposure of young plants to low temperature.

Cucurbits are monoecious; bee activity and hand pollination improve fruit set; bitter gourd and bottle gourd are trained on pandals for better quality.

Vegetable seed rate and spacing determine plant population; closer spacing raises yield per area but reduces fruit size and increases disease pressure.

Integrated nutrient management for vegetables combines FYM, green manure, biofertilizers (Azospirillum, PSB, Rhizobium for legumes) and balanced inorganic fertilizer in split doses.

Flower crops are grouped as loose flowers (marigold, chrysanthemum, jasmine, crossandra, rose) and cut flowers (rose, carnation, gerbera, chrysanthemum, gladiolus, tuberose).

Marigold: propagated by seed; pinching and disbudding increase flower size; African marigold is taller and larger-flowered than French marigold.

Chrysanthemum: short-day plant; flowering is controlled by blackout (short-day) and lighting (long-day) treatments; propagated by suckers and cuttings.

Rose: propagated by budding (T or shield) on rootstock such as Rosa indica; pruning and disbudding determine stem length and flower grade.

Gladiolus and tuberose: propagated by corms and bulbs respectively; corm size determines spike quality; harvesting at the right bud stage extends vase life.

Jasmine: propagated by cuttings and layering; flowers are picked in the early morning for higher essential oil content; jasmine concrete and absolute are value-added products.

Post-harvest handling of cut flowers: harvest in cool hours, pulse with sugar plus biocide, precool, and store at 2–4°C with high humidity; ethylene causes petal drop and leaf yellowing.

Grading of flowers follows stem length, flower diameter and freedom from blemishes; loose flowers are graded by size and freshness.

Landscape styles: formal (symmetrical, axial, geometric), informal (asymmetrical, naturalistic) and free style; Mughal gardens (e.g., charbagh layout) are formal, Japanese gardens are informal.

Principles of design: scale, proportion, balance, rhythm, harmony, unity and focal point; a focal point is created with a specimen plant, statue or water body.

Garden components: lawn, hedge, edge, path, pergola, arbor, trellis, rockery, water garden, bedding and herbaceous border.

Lawn grasses: doob (Cynodon dactylon), Korean grass (Zoysia), carpet grass and Bermuda grass for warm climates; cool-season grasses include perennial ryegrass and Kentucky bluegrass.

Lawn establishment by seed, turf (sodding) or dibbling; mowing height and frequency, rolling, top dressing and weeding determine lawn quality.

Hedges are classed as formal (clipped, e.g., Duranta, Clerodendron) and informal (unclipped, flowering shrubs); edges are low borders of Alternanthera or similar.

Bonsai is a dwarfed container-grown tree shaped by pruning, wiring and root restriction; it is a distinct art form, not a garden style.

Landscape planning steps: site survey, functional analysis, concept plan, planting plan and maintenance schedule.

Pest categories: chewing insects (caterpillars, beetles), sucking insects (aphids, hoppers, thrips, mites), borers, and nematodes; sucking pests are managed with systemic insecticides, chewing pests with stomach poisons.

Disease triangle: susceptible host, virulent pathogen and favourable environment must coincide; management removes any one leg, and the disease pyramid adds time and human activity.

Fungal diseases: powdery mildew (white powder), downy mildew (yellow patches with grey growth beneath), wilt (vascular discolouration), damping-off (seedling collar rot).

Bacterial diseases often show water-soaked lesions, oozing and vascular wilting; viral diseases cause mosaic, mottling, leaf curl and stunting and are spread by vectors such as aphids and whiteflies.

Weed classification: grasses (monocots), sedges (triangular stem, e.g., Cyperus), broadleaf weeds; parasitic weeds include Striga and Cuscuta.

Herbicide terms: selective vs non-selective, pre-emergence vs post-emergence, contact vs systemic; glyphosate is non-selective systemic, pendimethalin is pre-emergence.

Integrated pest management (IPM) sequence: cultural, mechanical, biological, chemical, with economic threshold level (ETL) as the decision trigger.

Pesticide safety: read the label, observe pre-harvest interval (PHI), wear PPE, follow resistance management by rotating modes of action, and never spray against the wind.

Fruit ripening is climacteric (mango, banana, tomato) with a respiration and ethylene peak, or non-climacteric (citrus, grape, pineapple) with no ripening peak.

Respiration rate and ethylene production determine shelf life; cooling immediately after harvest and maintaining the cold chain slows both.

Controlled atmosphere (CA) and modified atmosphere (MA) storage lower O2 and raise CO2; controlled atmosphere requires precise gas control, modified atmosphere relies on packaging films.

Post-harvest losses arise from mechanical injury, water loss, disease, and physiological disorders such as chilling injury and sunscald.

Value addition: jam, jelly, marmalade, squash, syrup, RTS beverage, ketchup, chutney, pickle, dried and dehydrated products, and essential oils.

Jam sets by pectin-sugar-acid gel; jelly is made from clear fruit extract; marmalade includes peel; TSS is measured with a refractometer in °Brix.

Preservation principles: reduce water activity by drying, lower pH by acidification, use sugar or salt to bind water, heat-process with proper sealing, and add permitted preservatives such as potassium metabisulphite or sodium benzoate within legal limits.

Grading and packaging: size grading, cushioned CFB boxes, perforated films and cold storage at crop-specific temperature and humidity extend market life.

Protected structures: plastic low tunnel, walk-in tunnel, shade net house, insect-proof net house, plastic film greenhouse (polyhouse) and glasshouse; polyhouse types are naturally ventilated or fan-and-pad cooled.

Shade net percentage determines light reduction: 35%, 50%, 75% and 90% nets are chosen by crop requirement; insect-proof nets (40–50 mesh) exclude vectors.

Drip irrigation applies water at the root zone with 90% or higher application efficiency; sprinkler irrigation suits close-grown crops but wets foliage and favours disease.

Fertigation and soilless culture (cocopeat, perlite, rockwool) are used in polyhouses for tomato, capsicum, cucumber, gerbera and rose.

Greenhouse climate control: ventilation, fan-and-pad cooling, thermal screens and CO2 enrichment; temperature and humidity management prevent condensation-related disease.

Farm mechanization: tractor-mounted implements (MB plough, disc harrow, cultivator, rotavator), power tillers, seed drills, transplanters, sprayers, and post-harvest machines (grader, pulper, drier).

Sprayer calibration: output per hectare depends on nozzle flow rate, pressure, boom width and forward speed; nozzles are selected for droplet size and drift control.

Safety and maintenance: PTO guards, hydraulic checks, and regular servicing of engines and pumps reduce breakdowns and accidents.

Enterprise types in horticulture: nursery, cut-flower unit, vegetable production, protected cultivation, fruit processing, cold storage and custom-hiring of machinery.

Project formulation: objectives, market survey, technical feasibility, capital cost, working capital, and returns; key ratios are benefit-cost ratio (BCR), net present value (NPV), internal rate of return (IRR) and payback period.

A project is viable when BCR is greater than 1 and NPV is positive at the chosen discount rate; IRR is the discount rate at which NPV equals zero.

Marketing channels: producer–consumer, producer–retailer–consumer, producer–commission agent–wholesaler–retailer–consumer; each intermediary adds a margin and reduces the producer's share.

Market functions: assembling, grading, standardization, storage, transport, financing, risk-bearing and price discovery; AGMARK and FSSAI are relevant standards and licences.

Extension methods: individual (farm and home visit, office call), group (demonstration, field day, method demonstration) and mass (radio, television, print, social media).

Extension teaching steps: identify needs, plan, execute, evaluate and follow up; adoption follows awareness, interest, evaluation, trial and adoption stages.

Cooperative societies, farmer producer organizations (FPOs) and self-help groups improve bargaining power, input purchase and collective marketing.

Horticulture branches: pomology (fruits), olericulture (vegetables), floriculture (flowers) and landscape gardening; plantation crops are treated separately.

Photosynthesis equation: 6CO2 + 6H2O + light → C6H12O6 + 6O2, catalysed by chlorophyll in chloroplasts.

C3, C4 and CAM pathways differ in first CO2 fixation product and in stomatal behaviour; C4 plants are efficient in high light and temperature.

Transpiration pull moves water through xylem; phloem translocation follows the pressure-flow (Münch) hypothesis from source to sink.

17 essential elements; mobile nutrients (N, P, K, Mg) show deficiency first in older leaves, immobile ones (Fe, Ca, B) in young leaves.

Growth regulators: auxins for rooting and apical dominance, gibberellins for elongation, cytokinins for cell division, ethylene for ripening, ABA for dormancy and stomatal closure.

Seed germination needs water, oxygen and suitable temperature; epigeal germination lifts cotyledons, hypogeal keeps them below ground.

Photoperiodism and vernalization are used to schedule flowering and to select varieties for a given latitude.