16 
FLORIDA STATE HORTICULTURAL SOCIETY 
Where moisture is present in generous 
amount, no set time can be given for go¬ 
ing over grove; but where maintenance of 
a dust mulch to preserve moisture is prac¬ 
ticed, we find that trees in their first and 
second years should be gone over on an 
average of once every ten days or two 
weeks under ordinary conditions; but in 
case of prolonged drought, they should be 
harrowed every five to seven days. This 
applies to older and bearing trees as well. 
We believe many growers and caretak¬ 
ers fail to acme bearing groves as often as 
they should, apparently believing that the 
size of trees with their larger and more 
penetrating root system make them practi¬ 
cally immune to drought; but if they 
would stop to consider the immense 
amount of water required to support old 
bearing trees, they would readily appre¬ 
ciate the dependency of such trees upon the 
protection of a dust mulch. Where the 
Planet Jr. or similar cultivating harrows 
are used, the frequency of their use will 
ordinarily depend upon growth of grass 
and weeds, but where they are used in 
place of acme harrows, the frequency of 
operation should be approximately the 
same. 
C. The cost of cultivation based upon 
our own experience is as follows: 
i. Plowing.—We find that plowing 
can be done as cheaply by mules as by 
tractors (where the tractor does not pull 
over three or four bottoms), but the speed 
of operation gained by using tractors 
make their use very desirable and neces¬ 
sary in large acreages. This is especially 
true where only enough stock is kept to 
work the tree rows, and tractors are de¬ 
pended upon to do all other work. Plow¬ 
ing or breaking rough land with tractors 
will cost approximately $1.85 per acre, 
and the plowing of cultivated groves only 
about $1.38 per acre. 
Cost of plowing grove is arrived at by 
using 4-bottom plow cutting 40 inches, 
making three rounds to the middle in 25- 
foot middle, cutting a total of 240 inches 
out of 300 inches, which is width of mid¬ 
dle from tree to tree. This leaves 5 feet 
of unplowed ground, or a strip of 2j4 
feet on either side of tree, at a cost of 
$1.18 per acre and figuring depreciation 
at 20 cents, and an average of 9 acres per 
day makes a total cost of $1.38 per acre. 
Cost will decrease with increase in size of 
trees and will cut down cost in proportion 
to number of rounds per middle. This es¬ 
timate is made on a year-old grove. At 
the rate of $1.38 per acre for 3 rounds, 
or 6 trips of a 40-inch plow, the cost per 
round would be 46 cents per acre, and the 
cost per trip 23 cents per acre. Taking 
these figures you can arrive at cost on any 
age of grove, depending on width of mid¬ 
dle you have to plow. A grove of 8 years 
old, having a space of 10 feet in the mid¬ 
dles to be plowed, could be plowed one 
way at 69 cents per acre. The probable 
minimum cost per acre, plowing one time 
around tree row, using $5.00 per day op¬ 
erator on tractor, is 27 cents per acre; two 
times around tree row, 54 cents; solid 
middles 81 cents. Using mules the cost 
for solid plowing rough land runs approx¬ 
imately $2.25 per acre. 
2. Discing.—The cost per acre of 
double discing with tractors, in young 
groves, using 8-inch discs, should run 
