Extended Field Storage
Tomato Varieties Offer Hope
The Tomato Magazine
By Lisa Lieberman
One of the big challenges tomato growers struggle with each year is timing
their plantings just right so that at the end of the season, they are able
to harvest their fields and get their tomatoes to the processors without
creating a bottleneck. Bottlenecks frequently occur when they are forced
to harvest too many acres at the same time.
The problem is Mother Nature doesn’t always cooperate.
If it’s raining, you can’t always get into the field to harvest,” notes
Michele LeStrange, a University of California extension specialist. “Or,
if you have cold weather followed by a hot spell, everything speeds up
and is ready at one time and the grower has to figure out which fields
to harvest first, second and third.”
Ideally, growers would have enough leeway so that when their tomatoes
were ready to harvest, they could store them in the field for an extra
or two until they’re able to get to them, explains LeStrange, who
has been conducting experiments with extended field storage (EFS) tomato
varieties this past year.
More Research Needed
Although this was the first year doing the experiment—and more
trials are needed over the next couple of years to come up with conclusive
results—LeStrange is optimistic about the future. So far, at least,
it looks like there are tomato varieties out there that have the EFS
qualities being sought.
Another part of LeStrange’s experiments was to look at how much
extra yield earlier plantings of tomatoes got in comparison to later
planted varieties. Not surprisingly, the earlier planted varieties got
higher yields, LeStrange says. Plantings on April 12 yielded 38 tons
per acre, while April 27 plantings got 33.2 tons per acre and May 17
plantings yielded 21.3 tons per acre.
The results weren’t surprising, but the main point is that, ideally,
growers want to plant, and harvest, throughout the whole season,” LeStrange
says. The trick would be finding a way to plant early and then hold the
tomatoes in the fields knowing the yields will be higher.
For each of the three planting, LeStrange did three different harvests.
For the April 12 planting, the second harvest yielded 36.8 tons while
the third harvest yielded 33.7 tons per acre. Comparing the April 27
planting, which yielded 33.2 acres on the first harvest, to the April
12 yield on the third harvest, the earlier plantings yielded the most
tonnage in all cases. These results seem to corroborate LeStrange’s
finding that it’s often better to plant early and harvest late
than to plant later and harvest earlier.
During her field trials, LeStrange also found that the level of brix
in the tomatoes at all stages of planting and harvesting remained fairly
stable while the general pH increased by only one-tenth with each successive
Looked at Fruit Setting Ability
In addition to testing varieties for EFS qualities, LeStrange also looked
at the ability of different varieties to set fruit during heavy heat
spells. Some of the varieties which did well in the heat but did not
necessarily set a lot of fruit included H 9997, Sun 6368 and U 886.
Finding higher yielding varieties that have EFS and set well during
the heat could ultimately help growers cut costs, LeStrange feels.
“During harvest time, canneries are running 24/7 and want to be filled
to capacity, so they want tomatoes every single day to stay efficient,” the
researcher points out.
“In order to satisfy their demands, a lot of growers will plant more acreage
than they actually need because they know they’re
going to lose some fruit to the heat. This way they end up spending more
money on seed and pest management than they actually need. If they could
get the right varieties that had the right acceptance among processors,
they could end up saving money.”
Richard Ozminkowski, manager of agriculture research for Heinz, notes
that Heinz has also been working on coming up with new EFS and heat-resistant
This past year in California, there was a very strong heat spell in July,” Ozminkowski
says, “and there was considerable yield loss in a lot of standard
varieties that were out there. Because we don’t always know when
heat spells are going to occur, tomatoes that have that heat-setting
ability are a nice kind of insurance.”
While there are heat-setting varieties out there, the problem is not
all have the right viscosity for the processors or high enough yields
for the growers, Ozminkowski points out. Right now, Heinz is working
on creating its own heat-setting varieties, one of which may be good
for a peel-and-dice-type tomato. However, he says it may take another
two to three years of testing before any of these varieties are ready
to be used commercially.
Heinz Varieties Showing Promise
So far, Heinz has come out with several EFS varieties that have done
well commercially, Ozminkowski says. H 9780, H 9665, H 2401 and H 9995
varieties have been some of Heinz’s top performing EFS varieties.
One of the main benefits of EFS varieties that may make growers consider
planting them despite their lower yields is that they generally hold
up better in the rain than some standards do, Ozminkowski says.
In the past couple of years we’ve had rain events in September,
and what happens is that the varieties that don’t have field-storing
abilities are the ones that rot very soon after it rains,” he says. “These
EFS varieties give the grower the potential to let his tomatoes sit for
an extra few days while he’s busy getting the more sensitive varieties
out of the field.”
Although late rains are one reason to utilize EFS varieties, growers
might also want to use them in areas that have high humidity, Ozminkowski
“In areas in Central California where there are more humid environments,
growers have to be careful of mold setting inside of dense canopies,” he
points out. “Field storage varieties aren’t immune to mold,
but they give you that extra bit of time to get the tomatoes off. You
also have less of a problem with mold when it goes through the grading
Even sunburn may become less of a problem for growers using EFS varieties
since moisture is what causes sunburn in the first place, Ozminkowski
Although Heinz’s EFS varieties are mostly for the late season,
the processor would like to come up with EFS varieties for the mid-season
as well, he adds.
“If we can bring the ability of EFS varieties into the field a little
earlier, it would help because you don’t know when you’re
going to get late August rains or when you might run into problems with
crops bunching up,” Ozminkowski says. “Processors can run
a lot of fruit but they still have limited capacity. So, if the weather
doesn’t always cooperate earlier in the season, EFS is a beneficial
management tool for avoiding bottlenecking.”
© 2006 Columbia Publishing
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