Lecture 6: SPECIAL PRACTICES TO CONTROL GROWTH AND DEVELOPMENT

Question 1

D objEctivEs In CConTrolling growth

Answer 1

*control direction of growth
*to restrict plant size in the case of ornamentals
*easier cultural management practices
*earlier flowering
*control timing and synchrony of flower or fruit
*induce rooting or shoot
*delay senescence or inhibit germination

Question 2

APPROACHES TO CONTROLLING PLANT GROWTH AND DEVELOPMENT

Answer 2

1. use of chemicals like Plant Growth Regulators (PGRs)
2. physical methods
   -training
   -pruning
   -girding
   -smudging

Question 3

organic compounds other than nutrients which in minute amount promote, inhibit, or modify plant growth development

Answer 3

Plant Growth Regulators (PGRs)

Question 4

naturally occurring PGR’s

Answer 4

phytohormones

Question 5

(PGR) auxins promote what?

Answer 5

rooting of stem cuttings

Question 6

used to promote rooting of stem cuttings in mussaenda, guava, bougainvillea, and rose

Answer 6

Indole-3-butyric acid (IBA)

Question 7

used to promote rooting of stem cuttings in black pepper

Answer 7

naphthaleneacetic acid (NAA)

Question 7

a combination of IBA and NAA mixed with talcum powder, the powder mixtures adhere to the stem cuttings when dipped

Answer 7

quick root

Question 8

stands for alpha-napthaleneacetic acid; a synthetic auxin

Answer 8

ANAA solution

Question 9

(PGR) promote seed germi in mussaenda seeds

Answer 9

gibberellic acid (GA)

Question 10

(PGR) increase fruit set in citrus

Answer 10

2,4-dichlorophenoxyacetic acid (2,4-D)

Question 11

(PGR) reduce stem elongation in chrysanthemum

Answer 11

paclobutrazol

Question 12

(PGR) induce/modify flowering of pineapple

Answer 12

ethrel, calcium carbide

Question 13

(PGR) induce/modify flowering of mango

Answer 13

ethepon

Question 14

special practice for mango using foliar spray

Answer 14

1- 3% KNO3

Question 15

(PGR) induce flowering of crop by substituting for envi reqs in cabbage and gladiolus

Answer 15

gibberellic acid (GA)

Question 16

(PGR) modify flowering in cucumber

Answer 16

gibberellic acid (GA) or ethepon

Question 17

(PGR) stimulate latex flow in rubber and papaya

Answer 17

ethephon

Question 18

(PGR) accelerate priming of uniform ripening for easier/synch harvesting in coffee

Answer 18

ethephon

Question 19

use of PGR in postharvest

Answer 19

1. hasten/acce ripening
2. inihibit sprouting

Question 19

to maintain a high level of reliability, commercial products must be registered with the ______________

Answer 19

Fertilizer and Pesticide Authority

Question 20

product registration involves _________ and _________ as to guaranteed analysis of active ingredients

Answer 20

bioefficacy testing and correct labelling

Question 21

techniques that direct/modify the growth of plant in terms of canopy size, shape, and direction

PHYSICAL METHOD OF CONTROLLING GROWTH

Answer 21

training

Question 22

objectives in training

Answer 22

1. To improve yield and quality
2. To facilitate cultural practices

Question 23

one technique of training

Answer 23

trellising (staking)

Question 24

provision of support to viny crops and other crops and other crops that could not stand without support

Answer 24

trellising

Question 25

types of trellis

Answer 25

a-type t-type fence type teepee type overhead singular pole

Question 26

judicious removal of plant parts to achieve specific objectives PHYSICAL METHOD OF CONTROLLING GROWTH

Answer 26

pruning

Question 27

pruning benefits

Answer 27

-control the size of the plant -control the form (structural make-up of the plant) -better quality fruits by better light distribution -remove diseased & broken branches -remove the non-productive parts -proper proportion of root-shoot ratio

Question 28

techniques in pruning

Answer 28

A. topping/cutting back/pinching B. bending

Question 29

TECHNIQUE IN PRUNING removing terminal shoot of young plant to encourage spreading canopy growth and/or keep the tree dwarf

Answer 29

topping/cutting back/pinching

Question 30

TECHNIQUE IN PRUNING to produce multiple vertical shoots, thus increase the number of bearing lateral branches

Answer 30

bending

Question 31

KINDS OF PRUNING

Answer 31

1. preventive – removal of DEAD plant parts 2. formative – to MODIFY SHAPE of canopy 3. corrective – removing EXCESS shoots 4. rejuvenative – removing most of the shoots to reinvigorate an old or unproductive tree

Question 32

special kind of pruning done in banana to remove excess suckers

Answer 32

desuckering

Question 33

tips in pruning

Answer 33

-use sharp and proper tools -cut as close to the stem as possible -prune after harvest -disinfect the tools when transferring from plant to plant -for large wound ( >1 inch diameter), apply fungicide prevent the entry of microorganisms

Question 34

TYPES OF PRUNING BASED ON PRUNING CUT removal of entire branch or shoot such as in corrective and preventive pruning

Answer 34

cutting out

Question 35

TYPES OF PRUNING BASED ON PRUNING CUT removal of portion of branch or shoot such as in formative pruning

Answer 35

cutting back

Question 36

TYPES OF PRUNING BASED ON PRUNING CUT a severe form of cutting back such as in rejuvenative pruning

Answer 36

stubbing

Question 37

why is rejuvenation required?

Answer 37

-unproductive -wasted investment

Question 38

cause of unproductivity in overlapping canopy

Answer 38

growers did not follow the concept of “Allotted Space”

Question 39

how to solve overlapping canopy

Answer 39

1. thin out by eliminating the trees in the middle 2. prune by heading-back

Question 40

ANOTHER SPECIAL PRACTICE TO CONTROL GROWTH AND DEVELOPMENT (except PGR and physical methods)

Answer 40

windbreak establishment

Question 41

Adverse effect of strong wind (typhoon)

Answer 41

1. Damages among leaves, shoot and fruits 2. Defoliation 3. Breakage of branches 4. Blow down of whole tree

Question 42

effectiveness of windbreak depends on

Answer 42

1. height 2. canopy density

Question 42

most important role of windbreak

Answer 42

to reduce windspeed and to protect the crop from damage