Brownsville herald. [volume] (Brownsville, Tex.) 1910-current, 1917-10-08

itli.itiuE afst'tiit IHtd~tblteN WITH IAN
guage which can be understood and made
use of by the person who has no time to
devote 10 scientific discussion. IL would
seem only reasonable 10 expect the begin
ner Ia grasp a general knowledge of the
causes which underly his daily difficult
ties. Without this knowledge of funda-
mental principles no person can succeed
in any line of human effort. and it Is not
IL he expected that the citrus industry j.
in any way different from other industries.
The protection of the industry depends
upon a study of the phenomena associ-
atcd with the menace. In the ease of the
protection of citrus trees what might seem
a mysterious or incxplicable occurrence
10 the beginner, might seem but natural
phenomena To the old sub-tropical horti-
culturist.
1t should he recollected by the horticul-
turist that nature has provided a means
whereby the a~cculmaicd heat collected nv
the soil. or more correctly bv the earth,
from the sun during the day. j. gwen back
into space during the night, thus making
II possible Ia produce vegetable life a.
well a. animal life. Some soils in some
climates are more pronounced in this Civ
ing up Of heat than others.
HEAT GATHERING STATUS OF SOIL.
Some soils are receptive Ia the heat
gathering process during the day. while
other soils are not. Some soils n wei a.
their environment are slow Ia gather heat
IN the day and are equally slow ia give
away the heat already gathered by radia-
iIon during the night. All other require
ments being present. the latter type or
condition Of soil i usually the most favor
able Ia the propagation of sub-tropical
fruit trees.
A. the soil can only gather a certain
amount of heat during the day and must
part with il during the night unless under
exceptional climatic conditions, IL must
readily he understood that the period be
fore sun rise must be the time nj which
the lowest temperature are a. H. expected.
That H.. at the time the soil has given up
by radiation most Of its heat accumulated
the day before aud iu>t before II begins iu
again replcniSh il store.
This j. the princii,le underlying the
short freezes which visit the Valley and
which nearly always do their destructive
work IN the mornings. Only under ex
ceptIonal circumstances DO freezes visit
the Valley orchards in the evening or early
night, and when this happens II j. most
often due 10 ~vagar,c~ of the wind~.
ACTIONS or THE ATMOSPHERE.
After radiation has been active Tor some
time and the >oil and trees have become
cooled off. should "A slightly moving wind
pass over the surface there may result a
condensation Of the moisture in the air
and we may observe what We call dew on
the leaves and branches Of the trees. But
should the opposite take place-should
the earth not have given up all it, heat.
and should a severely cold atmosphere of
the nature 81 a frcez fall over the soil and
the trees. then instead of the cold. dry at
mospherc giving off moisture ~ condcn-
sation the trees will give off their heat nv
radiation and their moisture by cvapora-
tion. The loss of this moisture NAV bring
about the Reorganization or death ~ the
living matter IN the cells: the result /, a
dried out frozen back tree. Sometimes.
where the freeze has been IT short ,lura-
ton. the application of water a. a spray
will permit the tree to again take back
sufficient moisture before permanent in
jury ha, been done. bat tins can only he
done before the temperature has raised To
IT. normal stage. This plan i not practi-
cable and can only be tried in the ease Of 4
few trees ~ a yard. and excn then II can
not H. well recommended.
About the same thing happens In u tree
when passing through = freeze ~ hap
pens Ia u tree when passing through a.
fire "r through An exceptionally de-trnc-
tive drought. About the same remedies
are nceded and about the same chances
OF recovery exists.
"AIR DRAINAGE" SAVES TREES.
Where there - a good air drainage. a.
some people call Il. there J. always n bet
ter chance of saving trees IN a severe
freeze. III Is well known that trees suffer
the most from 4 freeze IN hollow places
In such places the loss of heat by radia-
ton = excessive a. "A result of the atmo~-
phere lifting ~ soon a II l. heated by,
radiation and being replaced by a colder
atmorphtr' continuously. III the land j.
elevated efficiently To permit this move
ment ot AIR to the lower places the trees
may receive sufficient heat by conductIon
or convection 10 offset the loss by radia-
ton at least 10 some extent. Large fires
IN the path Of the moving atmosphere may
supply much connective heat. Int would
not be of service in an orchard owing tol
the fact tina, their heat j. mostly thrown
into the moving atmosphere by their draft.