Effects of Deficit Irrigation and Temperature Stress on Peanut Production

1
Effects of Deficit Irrigation and Temperature
Stress on Peanut Production Paxton Payton1,
David Tissue2, Wilson Faircloth3, and Diane
Rowland3 1USDA-ARS Cropping Systems Research
Laboratory, Lubbock, TX USA 2Department of
Biological Sciences, Texas Tech University,
Lubbock, TX USA 3USDA-ARS National Peanut
Research Laboratory, Dawson, GA USA
Effect of Soil Surfactant Application on
Irrigation Efficiency
Effects of Deficit Irrigation on Peanut
Physiology and Yield

• Introduction
• Abiotic stresses, particularly water-deficit and
  high temperature, are the primary factors
  limiting crop productivity, accounting for more
  than a 50 reduction in yields worldwide.
  Compounding the problem of reduced yields is the
  prediction that the world population will exceed
  8 billion by 2030, requiring a doubling of world
  food production on current arable hectares.
  Given that most of the Earths arable land is
  already under production and consumes almost 70
  of the available freshwater, it is important that
  we increase food production while reducing water
  consumption.
• Cultivated peanut (Arachis hypogaea L.), is both
  a major food crop and one of the top oilseed
  crops produced in the world. It is grown on 25
  million hectares, with a total global production
  of 36 million tons. In 2004, the U.S. produced
  nearly 2 million tons of peanuts and exported
  over 16,000 metric tons worth 1 billion to
  farmers and 6 billion to the economy overall.
  Texas is the second largest producer of peanuts
  in the United States.
• In the southern High Plains of west Texas and
  eastern New Mexico, low natural rainfall (450 mm)
  requires significant irrigation, and rapid
  depletion of the Ogallala Aquifer is already
  limiting crop production. At current rates of
  water use, it is estimated that this water source
  will be locally depleted within 30 to 40 years.
  Therefore, it is extremely important that we
  develop an irrigation schedule that maximizes
  peanut production while reducing overall water
  consumption.
• Objectives
• Our overall objective is to develop an irrigation
  schedule that maximizes peanut maturity and
  yield, but reduces water consumption, in an
  economically viable fashion.
• Our specific objectives are
• Determine the impact of deficit irrigation on
  peanut yield and maturity.
• Determine whether the yield and maturity response
  to deficit irrigation is influenced by plant
  physiology.
• Determine whether the application of a commercial
  surfactant affects yield and maturity.

The use of soil surfactants to ameliorate water
repellency in managed systems has been well
documented. We tested the effect of a commonly
used soil surfactant, IrrigAid Gold (Aquatrols,
Paulsboro, NJ USA), on peanut production under
deficit irrigation in west Texas for the 2006
growing season.
50
100
75
Figure 1. Effect of deficit irrigation on
photosynthesis and stomatal conductance.
Gas-exchange was measured at 45 (Early), 80
(Mid), and 125 (Late) Day After Planting (DAP).
Treatments included 50 (red bars), 75 (yellow
bars), 100 (blue bars) irrigation for the entire
season. Additionally, 50 (purple bar) and 75
(green bar) irrigation levels were applied
through mid-season, followed by 100 irrigation
during late season pod set and development.
Photosynthesis and conductance were measured
approximately 5 hrs. (solid bars) and 10 hrs
(hashed bars) into the photoperiod to monitor the
diurnal change in A and gs in plants 1 day
post-irrigation (DPI) and 1 week post-irrigation
(7 DPI). Bars represent mean SE, n6.
A.
Figure 5. Effect of soil surfactant application
to peanut yield in West Texas. A. Mid-season
photosynthetic rates under 50, 75, and 100
irrigation. Photosynthesis was measured in both
Control test plots (no product applied red bars)
and test plots with applied surfactant (blue
bars). B. Total yield for the 2006 growing season
for test plots (red bars) and plots with applied
surfactant (blue bars). Irrigation treatments
have been combined into drought period
application (ALL drought throughout the season,
NONE 100 irrigation application E, M, L
signify drought during early, mid, and late
season respectively and combinations of drought
periods. Asterisks denote significant
differences at p lt 0.1 level.

• Summary
• Deficit irrigation results in moderate decreases
  in total yield and maturity.
• Early season deficit irrigation (50 of control)
  up to 80 DAP reduced mature yield approximately
  15 and total yield by 16.
• Mid- to late-season deficit irrigation resulted
  in 20-30 yield and mature yield reductions.
• Reduced yield and maturity are correlated with
  late day reductions in photosynthesis and
  stomatal conductance in the test plots during
  mid- to late-season growth. Photosynthetic rates
  declined as much as 70 in the afternoon for
  plants grown under 50 irrigation rate, compared
  to a 40 decline in control plants and late
  season declines on 45 in the 75 treatment.
• The use of soil surfactants increased yield under
  deficit irrigation compared to plots with no
  surfactant. In several treatments, yield was
  significantly increased compared to the full
  irrigation treatment.

Figure 3. A. Effect of timing and severity of
deficit irrigation on crop maturity and yield in
Texas runner peanuts for the 2005 growing season.
Maturity was determined using the hull scrape
method. Full maturity for Flavor Runner 458 is gt
70 brown/black pods. Irrigation treatments have
been combined into drought period application
ALL 50 irrigation for the entire season NONE
100 irrigation application E, M, L signify
drought during early, mid, and late season
respectively and combinations of drought periods.
Data represent mature yield (percent maturity X
total yield). B. Late-day depression of
photosynthesis in plants under 50, 75, and 100
irrigation during early-, mid-, and late-season
growth periods. Data represent the afternoon
photosynthetic rates as a percentage of
mid-morning (5 hrs. into the photoperiod) rates.
Figure 2. Soil volumetric water content (VWC) was
measured at 8, 16, and 24 inch depths throughout
the growing season for all treatments. Data shown
represent VWC in the 50 and 100 treatments.
Acknowledgements
This project is supported by USDA CRIS
6208-21000-013-00D USDA CRIS 6604-21000-002-00 H
oward Hughes Medical Institute National Peanut
Producers
USDA-CSRL Marie Syapin Kayla McCartor JR
Quilantan Michael Metzler
Texas Tech University Andrew Tredennick Erica
Chipman Blake Watkins Ntaasja van Gestel
USDA-NPRL Larry Powell Chris Butts Manuel Hall