38 FLUE-CURED TOBACCO IN FLORIDA

 E ESTIMATED WATER REQUIREMENT EXPECTED RAINFALL







 I-
 4
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 MARCH 15-31 APRIL 1-30 MAY 1-31 JUNE 1- 2
 PERIOD
Fig. 21: Expected Monthly Rainfall and Estimated Water Requirements
 in Inches for Tobacco Planted March 15
 Tables 9, 10 and 11 show the effect of each of these vari-
ables. The three years encompassed by the experiments repre-
sent what might be commonly called wet, (1953), average
(1954), and dry (1955) year.

 Irrigation was applied in the "medium" treatment at a
rate to equal the amount of water used by the plant as
shown in table 8. In the "low" treatment, irrigation was
applied at a rate to equal one-third less than the amount used
by the plant and in the "high" treatment irrigation was
applied at a rate to equal one-third more than the plant
used. From the first to seventh day the plant used .06 inches
per day. Thus the "medium" application equalled .06 inches
the "low", .04 inches and the "high", .08 inches. The medium
rate of irrigation was equal to or better than other rates of
irrigation for all three years.

 The 1,200 pound rate of 4-8-10 or 4-8-12 produced the
highest yield and quality of tobacco. Rates above 1,200 pounds
of this analysis did not give any increase in dollar value over
the cost of the additional fertilizer.

 The optimum plant population appears to fall within the
7,500 to 10,000 plants per acre range. See table 6 for row
widths and plant spacings.