Agriculture Reference
In-Depth Information
Hogy and Fangmeier (2009) studied the effect of high CO
2
concentra-
tions on the physical and chemical quality of potato tubers. They observed
that increase in atmospheric CO
2
(50% higher) increased tuber malforma-
tion in approximately 63%, resulting in poor processing quality, and a
trend towards lower tuber greening (around 12%). Higher CO
2
levels (550
μmol CO
2
/mol) increased the occurrence of common scab by 134% but no
significant changes in dry matter content, specific gravity and underwater
weight were observed. Prolonged exposure to CO
2
concentrations could
induce higher incidences of tuber malformation, increased levels of sugars
in potato and diminished protein and mineral contents, leading to loss of
nutritional and sensory quality.
Exposure of crops with ozone changes the carbon transport system in
the underground storage organs (e.g., roots, tubers, bulbs). Normally car-
bon gets accumulated in the form of starch and sugars, both of which are
important quality parameters in both fresh and processed crops. If car-
bon transport to these structures is restricted, there is great potential to
lower quality in such important crops like potatoes, sweet potatoes, car-
rots, onions and garlic (Felzer et al., 2007). High concentrations of at-
mospheric ozone can potentially cause reduction in the photosynthetic
process, growth and biomass accumulation. Ozone-enriched atmospheres
increased vitamin C content and decreased emissions of volatile esters
on strawberries. Tomatoes exposed to ozone concentrations ranging from
0.005 to 1.0 μmol/mol had a transient increase in β-carotene, lutein and
lycopene contents (Moretti et al., 2010).
Due to heavy rain the loss of essential nutrient like Ca and Mg is a
common problem with the toxicity of heavy metals. Recently the empha-
sis has been placed on N and Ca, the nutrients most closely associated
with fruit quality. Possible responses include precision horticulture with
more targeted nutrient management. This in turn will require improved
understanding of application efficiencies and the timing and magnitude
of nutrient demand in order to synchronize fertilization more closely with
plant requirements (Neilson et al.
,
2010). Higher concentrations of atmo-
spheric carbon dioxide (CO
2
), for example, may actually benefit potatoes
as increased CO
2
stimulates the development of underground biomass in
potato plants, with tuber weight and number both increasing significantly.
Higher levels of atmospheric ozone (O
3
) also seem to benefit the crop,
resulting in more of the antioxidant ascorbic acid in tubers.
