Affect of Fertilization and Irrigation on Tobacco


(irrigation and rainfall combined) was received by the 1950 crop
than by either the 1949 or 1951 crop. It appears that in 1950
the lack of rainfall was not the limiting factor in amount of
tobacco produced. However, it does appear that the improve-
ment in moisture distribution, by supplementing the rainfall
with irrigation water, did increase production of high quality
tobacco.
 In addition to effects of irrigation, the sub-plot treatments
 of cropping practices, lupine and fallow and corn and peanuts
 differed. In 1949 cropping practices did not affect total yield.
 However, improvement of quality approached significance when
 tobacco grown on the corn plots showed an outstanding increase
 in yield under irrigated conditions. The cropping practice which
 included lupine and corn together with irrigation produced best
 yield and highest quality tobacco for all three years. There were
 no apparent economic losses from disease either year.
 Yield of tobacco was significantly increased by both time and
rate of fertilizer applications in 1949 and 1951, while time was
more important in 1950. The 800-pound single application of
fertilizer produced a significantly lower yield than either of the
split applications or the 1,600-pound single application. The
800 + 800-pound split application was better than the 400 + 400-
pound split application or the 1600-pound single application. To-
bacco growth following these treatments is shown in Figure 8.
The 400 400-pound split application of fertilizer was equal to
the 1,600-pound single application in 1949 and 1951. This re-
sponse indicates the importance of split applications of fertilizer
and suggests that split applications are more desirable than in-
creasing the rate of fertilizer when irrigation is used. With irri-
gation a more uniform rate of plant growth is obtained and this
enables the tobacco plant to utilize fertilizer more efficiently.
 One-half inch of irrigation water per application with split ap-
plications of fertilizer increased yield on the average more than
any other treatment for two of the three years.
 Tobacco quality was much lower on the non-irrigated tobacco
for all three years. However, quality was much higher in 1951,
on the average, from all treatments than in 1949 and 1950. This
fact indicates that good yields and high quality are possible
with continuous (for at least three years) tobacco culture on
the same land, provided certain cultural practices are used. It
is believed that among these cultural practices, irrigation and
soil fumigation are two of the more important. This is of
primary concern to the grower where water and suitable tobacco