Florida Agricultural Experiment Stations


rainfall was more plentiful and distributed more uniformly. In
1949 from April 6 to May 11 there was only an inch and a quarter
of rainfall, while for the same period in 1950 and 1951 there
were approximately three inches. In 1950 from May 11 to June
17 there were three inches of rainfall, while in 1951 only 0.71
inch occurred. Rainfall distribution is very important in to-
bacco production and these data support this fact conclusively.
In 1949 the tobacco plants hardened off and flowered early,
which prevented continued growth after rain began. The unused
plant nutrients became available soon after the rains began and
caused the leaves to turn dark green and become heavily bodied.
This type of growth is typical for growing seasons such as that
which occurred in 1949. Tobacco produced under these condi-
tions is very difficult to cure and invariably produces a poor
quality of leaf.
 Neither the three-fourths nor one-half inch rate of irrigation
significantly increased total yield in 1950. However, both rates
of irrigation did increase production of high quality tobacco
over the non-irrigated treatment. It is believed that the total
amount and distribution of rain and irrigation water explains
the performance of the irrigation treatments in 1950. Total
rainfall during the tobacco season for the three years was ap-
proximately 9, 16 and 9 inches for 1949, 1950 and 1951, re-
spectively. Seven, 12 and nine applications of irrigation water
were made during the 1949, 1950 and 1951 seasons, respectively.
Uneven rainfall distribution is responsible for the larger number
of irrigation applications in 1950. This summary of rainfall
and irrigation shows that approximately 65 percent more water

Fig. 8.-Irrigated tobacco fertilized with 400 + 400 pounds per acre on
 left and 1,600 pounds in one application on right.



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