ONE NIGHT ON ALERT
This
February 16th, forecasts announce a risk of frost for the next night. Alarms
are set to call at + 1ºC. In orchards, everything is ready to quickly intervene
if necessary. People are warned that we might need them at any time. We call
those who agree, starting with those who live closest to each farm. They are
used to that, this is not the first time that it happens.
I
plan to sleep early, or at least, to try it. It must be said that here in
Andalusia, to bed early is not a usual concept and it’s difficult to implement.
11:25 pm: My phone is already
ringing. I usually do not sleep with it, but in times of risk, I must be
reachable 24 hours / 24. The night has been really short. After a kind of nap
of just over half an hour, I have to get up. This is the orchard manager of a
farm. The alarm just rang. I ask him to have a look to all plots awaiting my
arrival. There is at least one thermometer in each risky plot, sometimes more.
11:40 pm: I leave my house. Just the
time to jump into my clothes. In times of risk, "frost special"
clothes are always ready. We must be able to react very quickly. It is better
to stack the layers. The night will be long and cold.
11:55 pm: I arrive on the first
farm. At this hour, the traffic is fluid, I don't waste time. My colleague
arrives at the same time. He will stay on this farm all night, to make
decisions and to call the staff for lighting paraffin cans. My other colleague
went directly to the third farm. All alarms have called in an interval of half
an hour.
First
work, take a look at temperature records. It continues to decline.
I
still have margin. The alarm is set to call about 2 degrees above the ignition
temperature of the most sensitive plots. It gives in principle enough time to
react.
I
take a walk in the orchard. I love those nights. The sky is always beautiful
and there is usually not a breath of air. One night, okay, I love it, and it's
actually quite pleasant, despite the stress. But it must not exaggerate, I am
clocked to sleep during night! While more than 20 nights, as was the case in
2012 or 2005 ... it's quite a trouble!
We
make a round of control every 20 to 30 minutes while we're away from the
dangerous temperature. As soon as we approach, we tighten the rate to 10 or 15
minutes.
0:20 am: On the second farm, things
start to rush. I'm leaving in a hurry. I chose to take care of this one for
three reasons. On the first hand it is a usually cold farm and quite
complicated for frost management. On the second hand, this is where there are
these days most sensitive surface. At last, the orchard manager is new and
inexperienced for such situations.
There
are many days that we speak of the organization to have, but I've probably forgotten
things. I prefer to be where things are likely to be more complex.
As
soon as I arrived, I review the temperatures. It continues to decline. The dew
point is at -4ºC. This night promises to be lively (the lower the dew point,
the lower the temperature may decrease, till the saturation of the air by
humidity and dew formation). The most sensitive parcels must be lit to -1ºC.
In
addition, on this farm, the wind doesn't stop blowing. It seriously complicates
matters because it reduces the quality of protection and therefore it increases
the evaporation of plant, so its sensitivity.
The
higher is the evaporation, the lower is the internal temperature of the plant,
and more the damage of frost is potentially serious. A frost with a dry air
will always be more serious than the same frost with damp air.
The
night will be hard.
1:10 am: it becomes dangerous. I
call the staff. Yes, this technique has advantages, but it requires a lot of
staff. Those who live closest arrive 20 minutes later. They know where they
have to go. They light a large fire awaiting orders, to keep warm. A pile of
wood was prepared on each holding point.
Video made by Roberto, tractor driver of the company, in february of 2012
1:45 am: the ignition temperature
has been reached in a plot. I do a first lighting of every second can, every
second row. We must stop the temperature drop as soon as possible. In 10
minutes, 8 hectares are under protection. We monitor thermometers. They
stabilize quickly. The staff returns to the holding points.
2:10 am: Another plot must be lit
and then quickly, all temperatures drop and everything rushes. We have to light
all plots as soon as possible.
3:15 am: All plots are on protection.
I make a phone briefing with my colleagues. With some variations, the situation
is much the same on the other farms.
The
staff returns to the holding points to rest. It is a thankless and unpleasant
work. It is night, after a truncated sleep, it is cold. When you have to go,
you have to run but you don't see anything, it's messy, it's tiring. In
addition, this night, with the wind, there is a lot of smoke. A dream…
3:45 am: The staff had barely half
an hour to rest. We already have to light again. Temperatures begin to drop
again. This time, we will start to redouble the ignition, staggered on
intermediate ranks, to distribute heat and improve the quality of protection.
Gradually,
almost all plots must be redoubled, except one that mysteriously remains
stable.
5:00 am: a plot begins to decline
one more time. I wait to see if it is confirmed. Ten minutes later, I decide to
light again. Ignition is therefore threefold. We return to the ranks of the
first ignition, on the unlit cans. It's a long time I had not experienced a so
difficult night. Finally, three plots will be tripled.
7:30 am: The late night is finally
a little quieter, fortunately. The day dawns. This is the moment of the cold
peak. But thermometers remain roughly stable, probably due to the surface
already in protection. There is no need to light more.
8:45 am: control thermometers are
just going back above sensitive thresholds. We can begin to put out. I start
with the least cold plots. It takes 45 minutes to put out everywhere.
What
a night! No forecast had announced it so complicated. I don't remember a lonely
night as long and difficult. They are usually episodes of several nights,
including one or two very problematic. But this time...
I
order the control, in the course of the day, of all thermometers, to note the
absolute minimum temperature of each plot. And surprise, in unprotected plots,
the temperature dropped to -4.8ºC. Incredible, while in view of the forecasts,
it could be expected absolute minimum temperatures from -2 to -2.5ºC.
In
the course of the day, news start arriving from our neighbors who don't
protect, or other production regions in particular Murcia and Valencia, regions
that usually make us a hard competition. The damages are enormous. There will
be probably a large output gap, on early varieties of April and May.
We
were right to protect. If the months of April and May are not overloaded with
fruit, there are good probabilities of good prices.
The
misfortune of some makes the happiness of others. It is a maxim that is
unfortunately often relevant in fruits and vegetables production. They are
perishable products, with short life, extremely sensitive to market
fluctuations. And a small decrease in production often has a big impact on the
market.
But
beware, we passed very close to a catastrophe. Observations made in the
following days showed that some plots were damaged just to the limit. The
thinning work will be oriented to offset the frozen parts. Ultimately, we will
have a full crop.
But it was a near thing.
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