OMEX USA - 4

4
steps to better yields in tomato,
pepper and melon crops.
Growing row crops like tomato,
pepper and cucurbits is a difficult
job, with yield strongly effected by
growing conditions. Nutrition has
the potential to increase yield, but
get it wrong and yield and quality
can be reduced. Here David Marks
of Levity Crop Science discusses
how good understanding of plant
physiology can teach us how to use
fertilizers better and how this can
drive improvements in yield and
quality. Let's start by identifying
four key targets for getting high
production:
1. Good establishment
2. Managing growth habit
3. Setting and holding fruit
4. Reducing stress
Establishment
Getting a crop off to a good start
can have a dramatic effect on yield
potential, young plants (especially
when transplanted) are highly
susceptible to stress until a good
root system is established. Cell
Power®
SizeN®
Ca contains amine
N stabilized using Levity's LimiN
technology, this holds the N in
a form that gives good rooting,
allowing row crops to develop a
strong even stand.
Growth habit
Once a crop is well established and
has an even size distribution, we
need to build canopy, but use too
much conventional nitrogen can
result in leggy plants with excess
vegetative growth. Here we need to
understand the effect of N form on
plant architecture.
Nitrates are processed in the leaf and
encourage a build up of the growth
hormone auxin, other forms of
nitrogen like amine do not promote
auxin production and instead
encourage cytokinin production
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Figure 1: Lancaster University study. Standard N (left), SizeN (right).
leading to a different growth habit.
Unfortunately, farmers gain no
advantage from using different N
forms from conventional fertilizer
as N is unstable in the environment
and taken up predominantly as
nitrate regardless of the form it was
applied as.
Cell Power®
SizeN®
products use
a chemistry developed by Levity
Crop Science to stabilize N in the
amine form, which allows farmers
to improve growth portioning
whereby the crop invests more of
its growth in reproductive growth
and less in vegetative growth.
So what does this mean from a
practical perspective? Lets look at
an experiment on pepper (Fig. 1).
Here we see how nitrates
encourage investment in vegetative
growth giving taller 'leggy' plants,
but the same quantity of N
supplied by Cell Power®
SizeN®
produces shorter plants with more
investment in fruit production.
In field experiments in Spain on
cucumber Lono (Cell Power®
SizeN®
) reduces internode distance
(bushier habit), impacting positively
on fruit number, fruit size, and total
yield. The same principle applies to
tomato, pepper, melon, eggplant
where Cell Power®
SizeN®
has
been of great benefit to growers
around the world.
Setting and holding fruit
The third key to good yields in
tomato, pepper, and cucurbit crops
is making sure that flowers turn
into fruit. To ensure good setting
and fruit holding growers need
to get calcium inputs right. Most
growers use too much calcium, but
still struggle to get enough into the
crop in the right place at the right
time to prevent problems.
There is a short window of
opportunity to use conventional
foliar calcium products on fruit,
as calcium transport is dependent
on polar auxin transport. This
means that parts of plants high in
auxin can absorb calcium easily,
but parts of plants low in auxin
struggle to absorb calcium. Flowers
have a short period of high auxin
synthesis, and fruit only have high
levels when very small (0-5mm)
and cells are dividing. This makes
application of calcium hit and
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