Intensive Wheat Management

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Intensive Wheat Management

• Should we do anything else?

SOUTH DAKOTA STATE UNIVERSITY
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Intensive Wheat Management
N Rates
Varieties
Seed Treatments
Fungicides
Split N
Seeding Rates
Spray Bars
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Intensive Wheat Management

• Most of these ideas for high yield have merit
  especially if based on conditions for year
• What is the idea behind splitting N and seeding
  rate?

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Intensive Wheat Management

• Premise is that tillers waste energy for the
  plant and main stem heads are more efficient
• Therefore higher seeding rate (more main stems)
  and less tillering is desirable
• Since N deficiency will limit tillering, apply
  lower N rates at seeding and more after tillering

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3/31 planting 4/16 emergence
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3/31 planting 4/16 emergence
Tillering beginning
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3/31 planting 4/16 emergence
Tillering continues Adventitious roots
forming Head size being formed
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3/31 planting 4/16 emergence
First node almost above ground (jointing) Tillerin
g ends Head size is formed
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Intensive Wheat Management

• Wheat development
• Tillering starts at about 2-3 leaf stage until
  5-6 leaf stage (jointing or stem elongation)
• at 4 6 leaf stage, head size being formed
• So dont want N deficiency limiting head size
• Most suggest split N at 4-6 leaf stage
• So a limited window to apply remainder of N

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Intensive Wheat Management

• What is our window?
• Based on average growing degree days we have
  about 10 14 days from 3 leaf to 5 leaf stage.
• For above average temperatures this window can
  decrease to less than a week.
• Problems if too wet to apply N
• Or if rainfall doesnt occur soon after N
  application

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Hall, SDSU, 2002
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Hall, SDSU, 2003
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Lamb and Rehm, Univ. of MN
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(No Transcript)
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(No Transcript)
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Hall, SDSU, 2002
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2003 data, Garrison, ND, McKay S.
rate 90/0/0 45/45/0 0/90/0 0/0/90 -----------
yield, bu/acre------ 1 m 66 64.5 63.6 55.9 1.
5 m 68 64.2 63.9 60.9 LSD 5 6.8 bu No
differences in protein
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Intensive Wheat Management

• Conclusions
• Tillering may be lessened by low pre-plant N
• Tillering may not be increased by large amounts
  of preplant N
• Problems with split N
• Window of application limited
• Tillering tends to spread out head size formation
  period, lessening stress impact
• Mn, SD, ND data would suggest split N is not
  necessary

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Intensive Wheat Management

• Conclusions
• Also if preplant N at low levels, split-N may
  decrease yield.
• Split N if sandy or gravel close to surface
• Most fields,recommend N pre-plant. If yield
  conditions look very good at 5-6 leaf apply
  another 30lb N/a

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Intensive Wheat Management

• Suggestions
• Yield goals use optimistic but yet realistic
  goals.
• Ave. last 3-5 wheat yields from that field,
  use 15 -20 higher as yield goal

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Questions ? Comments