The San Juan County index. (Aztec, N.M.) 1890-19??, 1900-04-13
FoR FRUIT GROWERS.


ive-FOrmatioH OF RrOsts.
Probably the most serious problem
that now confronts the fruit grower Of
this county is whether or not he is goiug
to be able to protect the tender buds and
blossoms Of his fruit trees from the dam
aging effects Of the spring frosts. While
there are many devised means Of protect
ing the fruit from these frosts, providing |
the temperature Of the air does not drop |
too low. yet there are 40 specified rules
laid down by which the orchardist can
be governed and his own judgment must |
be brought in play to determine whether
by combating the frost he can save his
fruit crop, Among other methods now
successfully carried on in California for
protecting the orange groves from the
injurious effects Of the spring frosts,
many Of which if properly performed in
this county would doubtless prove Of
value to the orchardist in aiding his
fruit trees to survive the danger period
of irosts, may be mentioned the irriga-
ten and spraying methods. Such pre-
ventife measures as she dry and wet
smudging and the building Of fires to
raise the temperature of tine air around
the trees to higher degree would hard
~ he practicable or, ,Reeeunt r. Chr ~
pense the orehardist would have to sus-
tain while experimenting in this line.
Although spraying and irrigation can
hardly be considered anything more
than an experiment, yet both are mex
pensive and have repeatedly proven Of
great benefit in other localities. The
following paragraphs taken from Bulle-
tin % of the us. Weather Bureau give
good idea Of the formation Of frosts, also
reasons to believe that preventive meas
ures can be successfully performed in
this county;
| The surface Of the earth is continually los
ing heat by radiation into space, but during
the day it usually receives neat from the sun
more rapidly than it hoses It by radiation, and
consequently it gtows warmer. At night,
however, heat from this Source is cut of and
the continued radiation causes the tempefa-
ture to fall.
Under favorable conditions this fail contin-
ues until condemnation Of vapor begins.
If the condensation takes place at temperaa
tures below ths freezing point Of watet the
moisture is deposited in the form Of frost.
The heat given OF by the condensation Of
vapor is enormous. The condemnation Of
enough Vapor to make pint of water will
evolve enough heat to raise moro than FIVE
pints Of water from the freezing to the boil
ing point.
Radiation takes place most rapidly when
There is nothing to obscure the sky, clouds
acting asascfsen in rOtarding it.
Conditions favorable to frosts are: First-
Clear sky, because radiation of heat Is rapid
under certain conditions. Second DRY air,
because With dry afr, cooling by radiation
will continue to a lower temperature befote
1t is checked by the heat given of by conden-
sation. Third--Stiif nights, because under
these circumstances the air arranges itself
In layers according 70 its density and >hs
colder, dsnser sir COLLECTS near the surface.
Now, by rebortTng to irrigation as a
means Of protecting the fruit buds we
simply increase fhe.aQueous yapol in the
atmosphere, and by 80 doing the dew
poiut is raised to higher degree than It,
formerly was, and hence more latent
heat is liberated in the air surrounding
the fruit trees, thus raising its tempera-
ture and hence partially, if not wholly
neahtralizing the frost.
The above mentioned bulletin refer
ing 10 the amount OF heat consumed in
evaporating water, further continues;
The amount OF heat consumed In svaporat-
ing water is very C 1siderahle. The evapor-
alton Of quart Of water would necesstate |
the expenditure Of ss much energy as would
DO needed IN raising the temperature of the
air 20 Q throughout space 10 feet sauaro ana
dep.
Most Of tho heat thus consGmed is
again liberated in the atmosphere when
condemnation takes place, the moisture
simply serving TO retain the hgat until
the time when the temperature calls.
One that would probably be advanta-
goous to consider when applying water
to the orchard for tho protection Of fruit
from iroel itthe fact that the more sur
face Of exposed the greater will b.
the evaporation and consequently the 4
greater the humidity Of the air. II the
soil beneath The trees that aso Hfsly TO /
be injured islnnihtaiBed 81 ~ wthorouehlv
moist state daring the dtager peri II
the esaporati5A iherefr6n win proba ~
lbesoaae tbsttiatitohun 'it5 81 iB3,ar