Affect of Fertilization and Irrigation on Tobacco 15

 Irrigation and fertilizer had a very marked influence upon
 the production of high quality tobacco. The effects of fertilizer
 and "variety" and those of fertilizer and irrigation were inter-
 dependent.
 Fertilizer applications consisted of a 2 x 2 factorial design
 with respect to rate and time of fertilizer application. The
 effect of rate of irrigation and of time and rate of fertilizer
 application for yield and for quality are presented in Tables
 4 and 5, respectively. Each entry is based on a total of 12
 plots.
 There was no difference between the 400 + 400-pound split
 application and the 800-pound single fertilizer application on
 yield of irrigated tobacco. The 1,600-pound single application
 did not produce significantly higher yield or quality, on the
 average, than the split application of 400 + 400 pounds of fer-
 tilizer per acre. Maximum yield and quality were obtained
 with the 800 + 800 pound split application.
 Under dry conditions the 800-pound single application pro-
 duced higher yields and quality than the 400 + 400 split appli-
 cation. Also the 1,600-pound single produced higher yields
 and quality than the 800 800-pound split application.
 The data have been organized on the basis of time and rate
 of application to facilitate the interpretation of the effects of
 these two factors on yield and are presented in Table 6. Data
 on yield of high quality tobacco are presented in Table 7. Each
 entry is based on a total of 24 plots.
 An analysis for fertilizers and interaction of fertilizers and
irrigation and fertilizers and "variety" on yield and quality of
tobacco is shown in Table 8.
 Both time and rate of fertilizer application affected yield and
quality, with effects of the two treatments being independent.
The split application, at both 800-pound and 1,600-pound levels,
and the 1,600-pound single application fertilizer gave superior
results, on the average. However, effects of rate and time of
fertilizer applications were found to depend upon the rate of irri-
gation as is evident from the mean squares for the interaction of
these factors.
 Superior yields and quality were obtained from the split ap-
plication of fertilizer only under irrigated conditions. Without
irrigation no advantage was realized from the split application.
The high rate of fertilizer application produced the best yield
and the largest amount of good quality tobacco at both rates
of irrigation, but at the high rate of irrigation the increase from