Horticulture: fruits, vegetables and flowers

What to remember

• Horticulture is the science of growing fruits, vegetables, flowers, spices, plantation crops and medicinal plants. Fruit trees are mostly propagated vegetatively (grafting, budding, layering) so that the plant is true to type.
• Plant population per hectare = 10,000 m² ÷ (row spacing × plant spacing) in metres, for square or rectangular planting. Close spacing (high density planting) raises early yield.
• Good practice rests on four points: healthy planting material, proper spacing and training, balanced nutrition with drip irrigation, and timely control of pests and virus diseases.

Classification and propagation

Horticultural crops are grouped into fruits (tree, vine, herbaceous), vegetables (root, leafy, fruit vegetables), flowers (loose and cut), spices, and plantation crops.

A rootstock gives roots and gives tolerance to soil problems; a scion gives the top variety. Hardening is slowly acclimatising nursery plants to field conditions.

Fruit crops

Practices common to fruit crops: pit digging and filling with farmyard manure before planting, training (shaping young plant), pruning (removing parts to improve fruiting), mulching, drip irrigation and fertigation (fertiliser through drip), and growth regulators such as GA₃ (cell elongation), NAA (fruit drop control) and ethephon (releases ethylene for ripening).

Vegetable crops

Nursery for vegetables: seeds are sown in raised seedbeds or in pro-trays with cocopeat and transplanted after about 3-5 weeks. Pro-tray seedlings give uniform plants. Mulching with plastic film saves water and controls weeds. Staking supports climbers and tall plants. Integrated pest management includes yellow sticky traps for whitefly, pheromone traps for borers and need-based sprays.

Flower crops

Loose flowers are sold by weight for worship and garlands; cut flowers are sold as stems or spikes with long stalk and need cold chain. Harvest at bud stage or early opening, in cool hours, and pack with care. Post-harvest care for cut flowers includes holding in clean water with preservative.

Cultural operations and worked examples

Plants per hectare:

• Square planting 10 m × 10 m = 10,000 ÷ 100 = 100 plants.
• 5 m × 5 m = 10,000 ÷ 25 = 400 plants.
• 2 m × 2 m = 10,000 ÷ 4 = 2,500 plants.
• 1.8 m × 1.8 m = 10,000 ÷ 3.24 = about 3,086 plants (banana).
• For a farm of 2.5 ha at 10 m × 10 m: 2.5 × 100 = 250 plants.

High density planting uses closer spacing with dwarf or trained plants. Drip irrigation supplies water near the root zone and saves 30-50% water against flood irrigation. In India, the Mission for Integrated Development of Horticulture (MIDH) supports area expansion, nurseries, protected cultivation and post-harvest infrastructure; the National Horticulture Board and the State Horticulture departments also give support.

Pruning of grape is done twice a year: back pruning for vegetative growth and forward (fruit) pruning for bunches. Thinning removes excess fruits for better size. Bagging protects fruit from pests and gives better skin colour.

Soil, nutrition and plant protection in brief

Fruit and vegetable crops grow best in well-drained, fertile soil with good organic matter. Heavy clay with poor drainage causes root rot. Soil testing guides the dose of fertiliser. Fruit trees receive manure in a ring around the canopy edge, since feeder roots lie there. Vegetables are fed in splits: a basal dose at planting and top dressings during growth. Deficiency signs matter in practice: yellowing of older leaves points to nitrogen; purple tint to phosphorus; marginal scorch to potassium; new leaf yellowing to iron; and fruit cracking or blossom end rot (in tomato) to calcium shortage and uneven water.

Flowering and fruit set: mango needs a dry spell and cool nights to flower; heavy rain at flowering reduces fruit set. Hormone sprays can reduce fruit drop. Grape bunches are thinned and sometimes sprayed with GA₃ for berry elongation.

Integrated management: use resistant varieties, healthy seedlings, crop rotation, field sanitation, trap crops (marigold around tomato), sticky traps, pheromone traps and bio-agents such as Trichoderma and neem products before chemical sprays. Cover mulch to reduce weeds and soil splash.

Harvest and handling: pick fruits at the right maturity, use clean crates, avoid dropping, shade the produce and move it quickly to market or storage. Mango is harvested with a short stalk to avoid sap burn on the skin.

Exam traps

• Budding uses one bud; grafting uses a shoot piece (scion).
• Sapota is evergreen; Kalipatti is its variety, not Alphonso.
• Papaya is mostly dioecious; latex gives papain.
• Tomato, brinjal, chilli and potato are Solanaceae; okra is Malvaceae.
• Climacteric fruits ripen off the plant; citrus and grape are non-climacteric.
• Training shapes a plant; pruning removes plant parts.
• Capsaicin gives pungency to chilli; it is not an acid of tomato.
• Yellow vein mosaic is a virus of okra; panama wilt belongs to banana.

One-liners

• Banganapalli and Totapuri are mango varieties.
• Grand Naine is a banana variety suited to tissue culture.
• Banana is commonly propagated by suckers.
• Papain is obtained from papaya latex.
• Capsaicin makes chilli pungent.
• Bhagwa is a pomegranate variety.
• Tomato leaf curl virus is spread by whitefly.
• Onion bulbing is controlled by day length.
• Tuberose and gladiolus are bulb or corm flowers.
• GA₃ is a growth regulator for elongation.
• Ethephon releases ethylene.
• MIDH stands for Mission for Integrated Development of Horticulture.

Practice questions

1. Mango belongs to the plant family

   1. Anacardiaceae
   2. Rutaceae
   3. Musaceae
   4. Myrtaceae
   Answer

   A. Anacardiaceae

   Mango (Mangifera indica) is in Anacardiaceae, along with cashew.

2. Banana is commonly propagated by

   1. Air layering
   2. Suckers
   3. True seeds
   4. Leaf cuttings
   Answer

   B. Suckers

   Banana is raised from suckers or tissue culture plants.

3. Banganapalli is a well-known variety of

   1. Banana
   2. Mango
   3. Sapota
   4. Guava
   Answer

   B. Mango

   Banganapalli is a leading mango variety of Andhra Pradesh.

4. The enzyme papain is obtained from the latex of

   1. Mango
   2. Pineapple
   3. Papaya
   4. Fig
   Answer

   C. Papaya

   Papain comes from papaya latex; pineapple gives bromelain.

5. The pungency of chilli is due to

   1. Curcumin
   2. Solanine
   3. Piperine
   4. Capsaicin
   Answer

   D. Capsaicin

   Capsaicin makes chilli hot; piperine is in black pepper.

6. Yellow vein mosaic is a serious virus disease of

   1. Okra
   2. Tomato
   3. Citrus
   4. Banana
   Answer

   A. Okra

   Okra yellow vein mosaic virus is spread by whitefly.

7. Panama wilt is a major disease of

   1. Banana
   2. Grape
   3. Mango
   4. Papaya
   Answer

   A. Banana

   Panama wilt is a fungal wilt of banana.

8. Citrus canker is caused by

   1. A nematode
   2. A virus
   3. A bacterium
   4. A fungus
   Answer

   C. A bacterium

   Citrus canker is caused by Xanthomonas bacteria.

9. Tomato leaf curl virus is spread by

   1. Honey bee
   2. Spider
   3. Earthworm
   4. Whitefly
   Answer

   D. Whitefly

   Whitefly (Bemisia tabaci) transmits leaf curl viruses.

10. Kalipatti is a leading variety of

    1. Pomegranate
    2. Sapota
    3. Mango
    4. Guava
    Answer

    B. Sapota

    Kalipatti is the common sapota variety.

11. Bhagwa is a popular variety of

    1. Pomegranate
    2. Grape
    3. Citrus
    4. Banana
    Answer

    A. Pomegranate

    Bhagwa is a widely grown pomegranate variety.

12. Thompson Seedless is a variety of

    1. Pomegranate
    2. Guava
    3. Sapota
    4. Grape
    Answer

    D. Grape

    Thompson Seedless is a grape variety.

13. In budding, the scion consists of

    1. A root piece
    2. A whole seedling
    3. A single bud
    4. A long branch with many leaves
    Answer

    C. A single bud

    Budding unites one bud with the rootstock; grafting uses a shoot piece.

14. Gladiolus is propagated mainly through

    1. Suckers
    2. Corms
    3. Stem cuttings
    4. Seeds
    Answer

    B. Corms

    Gladiolus is a corm crop.

15. Late blight is a serious disease of

    1. Sapota
    2. Okra
    3. Potato
    4. Rose
    Answer

    C. Potato

    Phytophthora infestans causes late blight in potato and tomato.

16. Giving a desired shape to a young plant is known as

    1. Hardening
    2. Training
    3. Pruning
    4. Thinning
    Answer

    B. Training

    Training shapes the plant; pruning removes parts.

17. Fertigation means

    1. Applying fertiliser through the irrigation water
    2. Spraying pesticide on flowers
    3. Mixing manure in the nursery
    4. Covering the soil with plastic
    Answer

    A. Applying fertiliser through the irrigation water

    Fertigation is fertiliser supply through drip or sprinkler systems.

18. The bulb formation in onion is largely controlled by

    1. Day length
    2. Soil colour
    3. Wind speed
    4. Rainfall pattern only
    Answer

    A. Day length

    Onion is sensitive to photoperiod for bulbing.

19. Papaya plants are commonly

    1. Monoecious only
    2. Self-pollinated bisexual only
    3. Dioecious
    4. Seedless
    Answer

    C. Dioecious

    Many papaya types have separate male and female plants.

20. Which of the following is a loose flower?

    1. Gladiolus spike
    2. Carnation
    3. Anthurium
    4. Jasmine
    Answer

    D. Jasmine

    Jasmine is sold loose by weight for garlands; the others are cut flowers.

21. How many plants per hectare at 10 m x 10 m spacing?

    1. 1000
    2. 100
    3. 25
    4. 400
    Answer

    B. 100

    10,000 / 100 = 100.

22. How many plants per hectare at 5 m x 5 m spacing?

    1. 100
    2. 200
    3. 625
    4. 400
    Answer

    D. 400

    10,000 / 25 = 400.

23. How many plants per hectare at 2 m x 2 m spacing?

    1. 2500
    2. 5000
    3. 1250
    4. 250
    Answer

    A. 2500

    10,000 / 4 = 2500.

24. Banana planted at 1.8 m x 1.8 m gives about how many plants per hectare?

    1. 2500
    2. 3086
    3. 5555
    4. 1800
    Answer

    B. 3086

    10,000 / 3.24 = 3086.

25. A 2.5 ha mango orchard is planted at 10 m x 10 m. How many plants are needed?

    1. 400
    2. 100
    3. 625
    4. 250
    Answer

    D. 250

    100 plants per ha x 2.5 = 250.

26. How many plants per hectare at 4 m x 4 m spacing?

    1. 400
    2. 250
    3. 625
    4. 1000
    Answer

    C. 625

    10,000 / 16 = 625.

27. Plants per hectare at 3 m x 2 m spacing (grape vines) are about

    1. 3333
    2. 1667
    3. 1000
    4. 2000
    Answer

    B. 1667

    10,000 / 6 = 1666.7.

28. How many plants per hectare at 1 m x 0.5 m spacing?

    1. 10,000
    2. 5,000
    3. 50,000
    4. 20,000
    Answer

    D. 20,000

    10,000 / 0.5 = 20,000.

29. A 0.5 ha orchard is planted at 5 m x 5 m. The number of plants is

    1. 100
    2. 250
    3. 200
    4. 400
    Answer

    C. 200

    400 per ha x 0.5 = 200.

30. 100 fruit trees each give 80 kg. The total yield in tonnes is

    1. 8
    2. 18
    3. 0.8
    4. 80
    Answer

    A. 8

    100 x 80 = 8000 kg = 8 t.

31. An orchard yields 20 tonnes per hectare. The yield from 2.5 ha is

    1. 50 tonnes
    2. 22.5 tonnes
    3. 500 tonnes
    4. 8 tonnes
    Answer

    A. 50 tonnes

    20 x 2.5 = 50 t.

32. In a planting of 400 plants, 5% die and must be replaced (gap filling). How many replacements are needed?

    1. 40
    2. 5
    3. 25
    4. 20
    Answer

    D. 20

    5% of 400 = 20.

33. Plants per hectare at 6 m x 6 m spacing are about

    1. 167
    2. 278
    3. 400
    4. 100
    Answer

    B. 278

    10,000 / 36 = 277.8, about 278.

34. Consider the statements. Which of the statements is/are correct? 1. Budding uses a single bud as scion 2. Grafting uses a piece of shoot as scion

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

35. Consider the statements. Which of the statements is/are correct? 1. Tomato and brinjal belong to Solanaceae 2. Okra belongs to Solanaceae

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Okra belongs to Malvaceae.

36. Consider the statements. Which of the statements is/are correct? 1. Citrus fruits are climacteric 2. Grape ripens only after harvest

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    D. Neither 1 nor 2

    Citrus and grape are non-climacteric.

37. Consider the statements. Which of the statements is/are correct? 1. Papaya is commonly dioecious 2. Papain is obtained from papaya latex

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

38. Consider the statements. Which of the statements is/are correct? 1. Pruning means giving shape to a young plant 2. Pruning is removal of plant parts to improve fruiting

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    B. 2 only

    Shaping young plants is training.

39. Consider the statements. Which of the statements is/are correct? 1. Banana is propagated by suckers 2. Banana is a non-climacteric fruit

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Banana is climacteric.

40. Consider the statements. Which of the statements is/are correct? 1. Okra yellow vein mosaic is spread by aphids 2. Tomato leaf curl virus is spread by whitefly

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    B. 2 only

    Okra virus is also whitefly borne.

41. Consider the statements. Which of the statements is/are correct? 1. Drip irrigation saves water 2. Fertigation means hand application of fertiliser to the soil

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Fertigation is through irrigation water.

42. Consider the statements. Which of the statements is/are correct? 1. Gladiolus is commercially planted from true seed 2. Gladiolus is a corm crop

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    B. 2 only

    Gladiolus is raised from corms.

43. Consider the statements. Which of the statements is/are correct? 1. MIDH supports nurseries and protected cultivation 2. Marigold can be grown from seed

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both are correct.

44. Consider the statements. Which of the statements is/are correct? 1. Onion bulbing is independent of day length 2. Late blight of potato is a bacterial wilt

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    D. Neither 1 nor 2

    Onion is photoperiod sensitive; late blight is caused by a fungus-like organism.

45. Consider the statements. Which of the statements is/are correct? 1. Thompson Seedless is a pomegranate variety 2. Bhagwa is a grape variety

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    D. Neither 1 nor 2

    Thompson Seedless is a grape; Bhagwa is a pomegranate.