W2 - Lecture 2A - Optimising Grain Yield And Crop Physiology Flashcards
what are the 4 yields in cereal crops
- Economic Yield
- Biological Yield
- Potential Yield
- Actual Yield
what is economic yield
grain yield
what is biological yield
total biomass yield
what is potential yield
perfect crop/weather
what is actual yield
~ 60-65 % of potential
what is definition of Harvest Index
gives an indication of the relative size of the grain yield (economic) to the rest of the plant (biological)
what is the equation of Harvest Index
Harvest Index = Economic Yield /(divided by) Biological Yield
Yield Components of Old and New
Cultivars
table
slide 6 & 12
Yield Components for two modern Winter Wheat varieties - Madrigal and Savannah in a very high yield trial at UCD Lyons farm
Variety - Madrigal :
Ears/m2
Grains/ ear
1000 Grain Wt
Yield(t/ha)
Variety - Madrigal
Ears/m2 - 460
Grains/ ear: 54
1000 Grain Wt: 62
Yield(t/ha): 15.4
Yield Components for two modern Winter Wheat varieties - Madrigal and Savannah in a very high yield trial at UCD Lyons farm
Variety - Savannah
Ears/m2
Grains/ ear
1000 Grain Wt
Yield(t/ha)
Variety - Savannah
Ears/m2: 500
Grains/ ear: 52
1000 Grain Wt: 60
Yield(t/ha): 15.6
what has happened UK wheat yields 1885-2010
increased
UCD Spring Oats Trial 2021
Heritage Lines v Modern
Cultivars
Lodging Issues(2)
- Lodging levels were extremely
high on many of the heritage
lines. - All were salvageable but
caused a lot of mechanical
problems. 4 breakdowns due to
lodging, all attributable to older
genetic material.
Name the 3 crop improvements in cereal crops
- technical progress
- genetics
- mechanisation
Technical progress - 5
Varieties
Fertilisers
Insecticides
Herbicides
Fungicides & PGRs
Genetics
Genetic Improvement – crop breeding
Underpinned by the Recommended List variety testing program
Mechanisation -3
Cultivations
Spraying
Harvesting
Role of harvest index improvement in
yield improvement
Harvest index rises as yield ()\t/ha rises
eg
Har. Index Yield(t/ha)
36, 5.22
42 5.86
51 7.10
55 8.25
Apical development
- floral (spikelet) initiation phase
def: biological yield
total crop yield of wanted and
unusable components
what is the Leaf Area Index (LAI) ratio
ratio of leaf area to ground area,
def:
Net Assimilation Rate (NAR)
dry matter production / leaf area
what does LAI stand for
Leaf Area Index
what does NAR stand for
Net Assimilation Rate
crop growth rate equation
LAI x NAR
what is the Leaf Area Index
This is the crop canopy
what is the optimum LAI FOR CEREALS
optimum for cereals is 4-5
Potential Yield for GS30(end of tillering)
tillers - 8 per plant
spikelets - 19 per plant
florets - 5 per spikelet
what is GS30
END OF TILLERING
Potential Yield at GS75 (mid-grainfilling)
tillers - 2 per plant
spikelets - 15 per plant
florets - 2.5 per spikelet
what is GS 75
mid-grainfilling
Breakdown of Grain Site Losses
diagram slide 22
