Lecture 6: Practices to Control Growth and Development

Question 1

IMPORTANCE OF CONTROLLING PLANT GROWTH AND DEVELOPMENT

Answer 1

1. control growth direction
2. restrict plant size (ponsettia and mums)
3. easier pruning and crop protection
4. earlier flowering
5. synchrony of production for year-round supply
6. induce root and shoot formation
7. delay senescence
8. inhibit germination

Question 2

APPROACHES IN CONTROLLING PLANT GROWTH AND DEVELOPMENT

Answer 2

1. chemical (plant growth regulators)
2. physical

Question 3

PLANT GROWTH REGULATORS

Answer 3

1. organic compound
2. used in minute amount
3. promote, inhibit or modify plant growth
4. either synthetic or natural

Question 4

PHYTOHORMONES

Answer 4

1. naturally occurring PGRs

Question 5

TYPES OF PHYTOHORMONES

Answer 5

1. auxin
2. gibberellin
3. cytokinin
4. abscisic acid
5. ethylene

Question 6

USE OF PGRs IN CROP PRODUCTION

Answer 6

1. auxin: promote rooting of stem cuttings
2. seed germination
3. inhibit sprouting
4. control fruit drop
5. reduce stem elongation
6. modify flowering
7. stimulate latex flow
8. accelerate ripening

Question 7

AUXINS

Answer 7

1. guava: IBA, 200ppm
2. bougainvillea: IBA, 600ppm
3. black pepper: NAA, 100ppm
4. rose: IBA, 400ppm
5. mussaenda: IBA, 100 ppm (30 minutes dip)

Question 8

COMMERCIALLY AVAILABLE AUXIN FOR ROOTING OF STEM CUTTINGS

Answer 8

1. QuickRoot
2. ANAA solution

Question 9

QUICKROOT

Answer 9

1. combination of IBA and NAA with talcum powder
2. adheres when dipped

Question 10

ANAA SOLUTION

Answer 10

1. alpha-naphthalene acetic acid
2. synthetic auxin

Question 11

SEED GERMINATION

Answer 11

1. mussaenda seeds: GA, 100ppm

Question 12

INHIBIT SPROUTING

Answer 12

1. sweet potato: methyl ester of NAA (100g/root kg)
2. onion: maleic hydrazide, 500-2500ppm

Question 13

CONTROL FRUIT DROP

Answer 13

1. tomato: BNOA (beta-naphthoxyacetic acid), 50ppm
2. tomato: GA, 100ppm
3. grapefuit: 2,4-D, 60ppm

Question 14

REDUCE STEM ELONGATION

Answer 14

1. paclobutrazol: chrysanthemum, poinsettia, mussaenda
2. maleic hydrazide: bougainvillea

Question 15

INDUCE/MODIFY FLOWERING

Answer 15

1. pineapple: ethrel, 24-240ppm
2. pineapple: NAA, 25ppm
3. mango: ethephon, 15-2000ppm

Question 16

1-3% KNO3 OR Ca(NO3)2

Answer 16

1. foliar spray to modify flowering of mango
2. higher concentration in rainy season

Question 17

INDUCE FLOWERING

Answer 17

1. cabbage and gladiolus: GA, 250ppm (vernalization substitute)
2. aster: GA, 100-200ppm (long day requirement substitute)

Question 18

MODIFY FLOWERING

Answer 18

1. cucumber: GA, 100-200ppm
2. cucumber: ethephon (higher female:male flower)

Question 19

STIMULATE LATEX FLOW

Answer 19

1. ethephon: rubber; papaya

Question 20

PAPAIN

Answer 20

1. enzyme extracted from latex of papaya

Question 21

PGRs IN CROP PRODUCTION: ACCELERATE RIPENING

Answer 21

1. coffee: ethephon, 500-1250ppm
2. banana: ethephon, 1ppm
3. mango: ethephon, 1000ppm
4. tomato: ethephon, 2500ppm

Question 22

TRAINING TECHNIQUES

Answer 22

1.physical method to modify plant growth
2. control canopy size, shape and direction

Question 23

TYPES OF PHYSICAL TRAINING TECHNIQUES

Answer 23

1. trellising (staking)
2. pinching/topping/cutting back
3. bending

Question 24

TRELLISING

Answer 24

1. support to viny crops

Question 25

EXAMPLE OF VINY CROPS

Answer 25

1. cucurbit
2. pole sitao
3. grapes
4. passion fruit
5. vanilla

Question 26

EXAMPLE OF HERBACEOUS CROPS

Answer 26

1. tomato
2. black pepper
3. dragon fruit

Question 27

TYPE OF TRELLIS

Answer 27

1. fence type
2. overhead
3. A-type
4. T-type
5. single pole
6. teepee type

Question 28

TOPPING/PINCHING/CUTTING BACK

Answer 28

1. remove terminal shoot from young plant
2. spread of canopy
3. keep tree dwarf
4. e.g. coffee, lanzones

Question 29

BENDING

Answer 29

1. produce multiple vertical shoots
2. increase bearing lateral branches