TITLE:
Photosynthetic Water Use Efficiency of Heritage and Modern Potatoes under Limited and Unlimited Water Environments
AUTHORS:
Isaac R. Fandika, Peter D. Kemp, James P. Millner, Dave Horne
KEYWORDS:
Taewa, Photosynthesis, Stomatal Conductance (gs), Transpiration (T), Irrigation, Internal Carbon concentration (Ci), Vapour Pressure Deficit (VPD), Leaf Water Potential, and Photosynthetic Water Use Efficiency (Photosynthetic WUE), Solanum tuberosum, Solanum andigena
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.14,
December
24,
2014
ABSTRACT: Photosynthetic capacity for heritage (Taewa)
and modern potato cultivars were compared at different water and nitrogenregimes
in the glasshouse and field. The glasshouse was 2*2*4 factorial design with two
irrigation: 100% ET and 60% ET; two applied N: 50 kg N ha-1 and 200
kg N ha-1, two Taewa (Moe Moe, Tutaekuri) and two modern potatoes
(Moonlight, Agria). The 2009/2010 field experiment was a split-plot, with
irrigation and rain-fed regimes as the main treatments: four potatoes above
were sub-treatments. The 2010/2011 field experiment was a split-split-plot, with
three water regimes as the main treatments: three cultivars (Moe Moe,
Tutaekuri, and Agria) were subplots; two N rates were sub-sub-treatments.
Gaseous exchange was measured by CIRAS-2 at different days from emergence. Leaf
water potential was measured using pressure chamber method. Taewa achieved
high photosynthetic WUE in glasshouse and 2010/2011 experiment by maintaining
high An, low gs and low Ci compared to modern cultivars
(p The
An, gs and T
increased with irrigation and N increase while decreasing Ci (p n and
photosynthetic WUE in Moonlight in the glasshouse. The leaf water potential for
Taewa was very tolerant while modern potatoes were weakened by water stress.
The study indicated that Taewa can be scheduled at partial irrigation without
more detrimental effects on photosynthetic
capacity while modern potatoes need full irrigation to avoid detrimental
effects on photosynthetic capacity.