Affect of Fertilization and Irrigation on Tobacco


of fertilizer were made in bands approximately six inches apart,
a week before the tobacco was transplanted.
 The soil of all plots was fumigated in the drill row to control
 nematodes. Ten gallons of dichloropropane-dichloropropene
 (D-D) per acre was applied approximately five weeks before
 transplanting.
 Variety 402 was used in these tests. It is a broad-leaf type
 and commonly produces a high yield of good quality leaf through-
 out the flue-cured tobacco territory. All plants were selected
 for uniformity of size and set March 18, March 25 and March
 30 for the years 1949, 1950 and 1951, respectively. The plants
 were set two feet apart in the row and the rows spaced 38
 inches apart. All weak and missing plants were reset within
 two or three days to insure a uniform stand.
 The test plots were tractor cultivated at intervals of 10 to 14
 days during the growing season. The tobacco was dusted regu-
 larly with 5 percent 'DDT and/or DDD to control insects.
 Leaf harvesting began May 25, 1949, June 6, 1950, and June
 1, 1951. The tobacco from each plot was labeled and kept sep-
 arate throughout the entire harvest. All plots were cured in the
 same barn. After curing the tobacco was removed from the
 sticks and placed in paper bags and stored. Approximately four
 weeks after the storing, the tobacco was sorted into various
 farm grades based on color, length, elasticity and other physi-
 cal characteristics. The various farm grades from each curing
 were weighed and kept separate. A composite sample of simi-
 lar grades was made from each treatment. The samples were
 then graded by official tobacco graders of the United States De-
 partment of Agriculture.
 For evaluation purposes total plot yields were used for yield
 analysis. For quality evaluation the total weight of the top four
 grades from the group classifications, primings, lugs, cutters,
 smoking leaf and leaf, were used as the basis for statistical in-
 terpretations.
 EXPERIMENTAL RESULTS
 Results of this experiment will be discussed for each of the
years, 1949, 1950 and 1951, and for the three years combined.
The yearly variation of uncontrolled factors such as amount of
rainfall, distribution of rainfall and other weather factors, adds
significance to a separate discussion for each of the years.
 Measurement of treatment effects is based on both the total
yield and yield of high quality tobacco. It is important to con-