8. Sorghum

Question 1

Sorghum is the ___ biggest Field crop in Australia after ____

Answer 1

4th, wheat barley and canola

Question 2

Sorghum seed formation of a black layer is shown on the seed by

Answer 2

A black spot becoming larger as the seed develops.

Question 3

Taller genotypes, often with bigger stems require more

Answer 3

Nitrogen

Question 4

Leading producer of sorghum in Aus (which state?) and how many tons?

Answer 4

Queensland with 1 million tons.

Question 5

Sorghum is often planted on what soil type?

Answer 5

Heavy clay soils. Good moisturise retention

Question 6

Early Sorghum plantings, growers aim for temps atleast

Answer 6

12 degrees c absaloute minimum, at 8 am.

Question 7

Soil temps between ___ and___ are generally ideal

Answer 7

16-18 degrees celcius

Question 8

No till farming produces what quantities compared with conventional

Answer 8

No till produces 0.5 -1ton more per ha

Question 9

Prussic acid poisoning

Answer 9

Release of hydrocyanic acid HCN, in sorghum type forages. Animals are able to de-toxify a certain amount of HCN

Question 10

450kg cow can de-toxify around____mg per___

Answer 10

0.5mg, Hour.

Question 11

What soil nutrition increases prussic acid potency?

Answer 11

High N couple with low P

Question 12

WUE crop factor of sorghum is generally

Answer 12

15

Question 13

Kg of crop produced per mm of rain

Answer 13

15kg/mm/ha

Question 14

Simulation modelling is a more accurate prediction of water use in sorghum an example is

Answer 14

APSIM

Question 15

APSIM is a model that takes into account

Answer 15

Seasonal rainfall distribution, temp, radiation, and soil condition.

Question 16

Seed calculators are used for seeding rates of sorghum, what impacts these?

Answer 16

variety and irrigation design specific.

Question 17

Skip row refers to?

Answer 17

A practice of saving water during the vegetative stage for the use during flowering.

Question 18

Target plant population for dryland sorghum.

Answer 18

40,000-60,000 plants/ha

Question 19

Target plant population for irrigated sorghum

Answer 19

100,000-250,000

Question 20

Where can i find a plant density calculator

Answer 20

pacificseeds.com.au

Question 21

In favourable seasons (yield potential 6 t/ha), 100 cm solid plant row spacings may provide up to ___ percent greater yield than double skip setups.

Answer 21

50%

Question 22

Early sown sorghum results in

Answer 22

same or higher yield/ha, longer vegetative period, moving flowering window forward, less plant density. earlier harvested, but longer entire season. potential for double cropping with chickpea’s.

Question 23

Sorghum is a non-host for? (2)

Answer 23

crown rot and a type of nematode.

Question 24

Benefits of sorghum in a rotation (5)

Answer 24

• non-host for crown rot
• resistance to root lesion nematode
• splitting labour
• Increased cashflow
• management intensity is low

Question 25

well timed dessication of sorghum can save up to

Answer 25

24mm of soil moisture in the profile

Question 26

There are three main benefits of timely desiccation

Answer 26

- Modify harvest timing and aid in paddock harvest scheduling - Maximize soil water potential for the next crop by decreasing late-season transpiration losses - Lengthen the effective fallow time in order to maximise future cropping prospects

Question 27

Lodging occurs when ......

Answer 27

plant stems weaken to the point they can no longer support the weight of the grain causing it to fall over.

Question 28

sorghum is most susceptible to temperature stress over ___ and is best performing in temperatures around _____

Answer 28

flowering, 28-35 degrees over most of its life-cycle.

Question 29

In a single day, sorghum will utilise between_____millimetres of water at its maximum rate of transpiration.

Answer 29

80 and 95 ml/day

Question 30

The rule of thumb for daily waterlogging loss is

Answer 30

0.2 t/ha/day of waterlogging

Question 31

Khapra Beetle summary (6)

Answer 31

- Exotic pest of stored grains, inside a grain silo. - not yet in australia - tiny beetle, produces thousands of eggs. - hide under small spaces including paint, - can live for up to 12 months without food - feed on sorghum, and most type of grains.

Question 32

grain _____has higher correlation to increased yield than grain ____

Answer 32

grain number has higher correlation to increased yield than grain size

Question 33

Each sorghum grain is a caryopsis

Answer 33

a fruit containing a single seed with the fruit wall (pericarp) and seed coat (testa) fused.

Question 34

developments required for improved Sorghum production in the face of climate change in Australia? (3)

Answer 34

- Improved heat tolerance over flowering - improved emergent percentage in cooler weather/soil temps - improve fundamental WUE