Lecture 19 - Sugarcane

Question 1

where was sugarcane originally cultivated and developed

Answer 1

originally cultivated in New Guinea
mainly developed in India

Question 2

3 cultivated species of sugarcane (all polyploids)

Answer 2

Saccharum officinarum
Saccharum barberi
Saccharum sinense

Question 3

Nobelization of sugarcane

Answer 3

S. officinarum x S. spontaneum = F1 high sugar cultivar

Question 4

best climate for sugarcane

Answer 4

1000mm of annual rainfall, temps above 27C and needs high levels of fertilization

Question 5

morphology of sugarcane

Answer 5

C4 perennial grass that grows 4-5m with solid stem and nodes

Question 6

what has the highest growth rate of any plant

Answer 6

sugarcane

Question 7

when is the highest sugar concentration reached in sugarcane

Answer 7

12-20% are reached just as flowering is initiated

Question 8

sugarcane will _____ after harvest to produce

Answer 8

ratoon

Question 9

what is required for sugarcane to flower

Answer 9

short days

Question 10

what is the inflorescence of sugarcane

Answer 10

loose panicle

Question 11

which part of sugarcane is highest in sugar

Answer 11

bottom

Question 12

which part of sugarcane is used for propagation

Answer 12

the top

Question 13

how are sugarcane propagated

Answer 13

stem cuttings (2-3’ sections) that are laid in furrows and covered with soil

Question 14

growth phases of sugarcane

Answer 14

1. germination and establishment phase
2. Tillering phase
3. Grand growth phase
4. Ripening phase

Question 15

germination and establishment phase of sugarcane

Answer 15

from planting to germination of buds
lasts about 30-35 days
optimum temp is 28-30 and warm moist soil

Question 16

tillering phase of sugarcane

Answer 16

starts at day 40-120 days
provides crop with good number is stalks
light is the most important factor

Question 17

grand growth phase of sugarcane

Answer 17

day120-280days. only 50% tillers survive
most important phase

Question 18

what is the most important growth phase of sugarcane

Answer 18

grand growth phase

Question 19

ripening phase of sugarcane

Answer 19

3months-360 days
sugar synthesis and rapid accumulation of sugar

Question 20

bacterial diseases of sugarcane

Answer 20

gumming disease
leaf scald

Question 21

fungal diseases of sugarcane

Answer 21

red rot
root rot
pineapple disease

Question 22

viral diseases of sugarcane

Answer 22

mosaic virus
ratoon stunting virus
chlorotic streak
Fiji disease

Question 23

pests of sugarcane

Answer 23

stem borers, termites, white grubs

Question 24

harvest of sugarcane

Answer 24

leaves are stripped or burnt, tops cut off
cane cut close to ground
lower stem has highest sucrose concentration and is harvested

Question 25

what is the leading crop in the world in terms of dry matter productions

Answer 25

sugarcane

Question 26

how much sugar does the average stalk yield

Answer 26

150grams

Question 27

uses of sugarcane

Answer 27

cane syrup, sugar, molasses, wax, rum, alchohol

Question 28

processing steps of sugarcane

Answer 28

1. cane is cut, sampled, weighed, and washed
2. shredded and milled to extract juice
3. heated and clarified
4. filtered
5. concentrated into syrup, form crystals
6. centrifuge to separate crystals
7. dried and cooled for packaging

Question 29

raw sugar of sugarcane

Answer 29

sugar crystals that are yellow/brownish, covered in molasses, and contain impurities

Question 30

refined sugar of sugarcane

Answer 30

refined raw sugar that is bleached and filtered. Made into concentrate and crystals broken to uniform size

Question 31

t/f: all modern cultivars of sugarcane are interspecific hybrids

Answer 31

t

Question 32

why is sugarcane burned

Answer 32

preharvest burning promotes pest control and lowers harvest costs
postharvest burning eliminates trashy residue and facilitates plowing and replanting