W1- Lecture 1B - Grain Yield and Yield Components in Cereal Crops

Question 1

how can grain yield be investigated

Answer 1

grain yield can be investigated through the study of the yield components

Question 2

why is the study of yield components very useful

Answer 2

to compare and contrast the different
cereal crops - wheat v barley v oats and winter-sown v spring-sown

Question 3

what is the different yield potential between winter sown vs spring sown crops

Answer 3

winter-sown > spring-sown by 20-25%

– longer growing season
– higher yield components

Question 4

which crop has good levels of all yield components

Answer 4

wheat crops

Question 5

what ear size has barley

Answer 5

smaller ear size compared to wheat or oats

Question 6

what is the different between wheat > oats >~ barley

Answer 6

• wheat crops have good levels of all
  yield components
• barley has smaller ear size
• oats has typically lower ear number

Question 7

what are the 3 yield components in cereal crops

Answer 7

1. Ears/m2
2. Grains/ear
3. Grain Weight (mean 1,000 grains)

Question 8

Graham (Syngenta)
slide 8

Answer 8

its a trial
- i prob wont look at it

Question 9

Yield and Yield Component
Combinations
Ear — Grains/ear –1000 Grain Wt.

Answer 9

Ears/m2-> Grains/ear-> 1000 Grain Wt.
300 50 50
400 42 45
500 35 43
600 25 50
700 30 36
800 25 38

Multiplied across all the above give a yield of ~ 7.5 t/ha
e.g. ( 300 x 50 x 50 ) / 105

Question 10

What are the important yield sub
components

Answer 10

Plants/m2 and ears/plant are useful sub components

e.g. plants/m2 x ears/plant = ears/m2

Question 11

What are the less important yield sub-
components

Answer 11

tillers/plant and tillers/m2 are not useful sub-components but can be useful in field studies

Question 12

Optimising Yield Components in
Practice

Answer 12

we want to see which of these yield components we can control and optimise in practice

Question 13

what do you need to target for when optimising yield components in practise

Answer 13

we need targets for each yield component e.g. in winter wheat target ear no’s is 500

Question 14

how many grains/ear would you expect

Answer 14

we expect 40-45 grains/ear and if good grain-fill is then achieved yield will be high

Question 15

Table to Compare Yield Components of different crops (6)

Answer 15

• Plants/m2
• Ears/plant
• Ears/m2
• Grains/ear
• 1000 Grain Wt. (g)
• Grain Yield (t/ha)

Question 16

Yield Components - 1. Winter Wheat

Answer 16

• Plants/m2 = 240 and ears/plant = 2.25
• hence Ears/m2 = 540
• Grains/ear = 44
• Thousand Grain weight = 50 grams
• Yield in t/ha = (540 x 44 x 50)/10^5
  = 11.88 t/ha

Question 17

Yield Components - 2. Spring Wheat

Answer 17

• Plants/m2 = 260 and ears/plant = 2.0
• hence Ears/m2 = 520
• Grains/ear = 36
• Thousand Grain weight = 44 grams
• Yield in t/ha = (520 x 36 x 44)/105
  = 8.24 t/ha

Question 18

Yield Components - 3. Spring Barley

Answer 18

• Plants/m2 = 250 and ears/plant = 3.5
• hence Ears/m2 = 875
• Grains/ear = 22
• Thousand Grain weight = 40 grams
• Yield in t/ha = (875 x 22 x 40)/105
  = 7.7 t/ha

Question 19

Yield Components - 4. Winter Barley

Answer 19

• Plants/m2 = 250 and ears/plant = 3.5
• hence Ears/m2 = 875
• Grains/ear = 25
• Thousand Grain weight = 40 grams
• Yield in t/ha = (875 x 25 x 40)/105
  = 8.75 t/ha

Question 20

Yield Components - 5. Winter Oats

Answer 20

• Plants/m2 = 250 and ears/plant = 1.6
• hence Ears/m2 = 400
• Grains/ear (panicle) = 75
• Thousand Grain weight = 30 grams
• Yield in t/ha = (400 x 75 x 30)/105
  = 9.0 t/ha

Question 21

Sample Yield Components for
Various Cereals
table!!
slide 23

Question 22

Yield Structure : Example of a wheat
plant with little competition

Answer 22

slide 24!!
could be helpful for data exam

Question 23

Yield Component Comparision for
2-row and 6-row W. Barley

Answer 23

slide 25!!
could be helpful for data exam

Question 24

sowing winter wheat is difficult in autumn conditions
how much seed should be sown per m2 and what % establishment should you expect

Answer 24

Sowing winter wheat in difficult autumn conditions

• sow 400 seeds/m2 and expect 60%
  establishment to give 240 plants/m2

Question 25

what % of potential yield can be achieved with a plant stand of **/m2

Answer 25

95-98% of potential yield can be
achieved with a plant stand of 150-200/m2

Question 26

To achieve the specific crop management in the spring what is required

Answer 26

achieve target ear no’s
– early spring N application
– good growth regulation practices

Question 27

what are the factors effecting Yield Components and Crop Management (4)

Answer 27

• crop establishment
• Seed rate and % plant establishment

*early crop management
- Plant number and level of tillering (up to GS 30)

• rapid growth phase
• Nitrogen fertilisation (rate and timing)
• Growth regulation
• ear emergence / flowering and grain-fill
• Disease control