Affect of Fertilization and Irrigation on Tobacco


yield and quality of the tobacco most with the half inch rate of
irrigation.

TABLE 20.-BREAKDOWN OF THE ANALYSIS FOR FERTILIZERS, INTERACTION
 OF FERTILIZERS AND IRRIGATION AND FERTILIZERS AND "VARIETY" ON
 THE YIELD AND QUALITY OF TOBACCO IN 1951.
 Degrees
 Source of Variation of Mean Square
 Freedom Yield I Quality

 I Fertilizers ................................ 3 20.87** 12.47**
 Time of application ................. 1 33.01** 20.49**
 Rate of application ................-...- 1 22.55** 12.79**
 Rate x time of application ........... 1 7.05** 4.12**
 II Fertilizer x irrigation ................ 6 2.42** 3.17**
 Time of application x irrigation 2 11.20** 13.41**
 Rate of application x irrigation ... 2 2.68** 5.37**
 Time x rate x irrigation -_........ 2 .62 .24
 III Fertilizer x "variety" ...-...-....... 3 1.13**
 Time of application x "variety".... 1 1.55*
 Rate of application x "variety" .... 1 .04
 Time x rate x "variety" ............... 1 1.79**
 Error (e) ..................................-... 72 .25 .31

 Significant at .05 percent level.
 ** Significant at .01 percent level.

 DISCUSSION OF RESULTS FOR THREE YEARS
 Yield and quality of tobacco were increased by irrigation in
 1949 and 1951 but not in 1950. However, the yield of good
 quality tobacco was significantly influenced in 1950 by many
 of the treatments and treatment interactions. The total amount
 of rainfall, its distribution, and the accumulative total of irriga-
 ion plus rainfall for the tobacco growing season are presented in
 Figures 4, 5, and 6.
 On April 6, 1949, there were approximately seven inches of
rainfall and with it there was leaching of soluble nitrogen.
This loss of nitrogen probably accounts for the split application
of fertilizer being more beneficial than the single application in
1949. The tobacco recovered from the heavy rainfall and grew
very rapidly for a few days, after which practically no growth
was made for several weeks on the non-irrigated plots because of
dry weather. The plants were severely stunted on the non-
irrigated plots. However, the irrigated tobacco continued to
grow and produced a fairly good leaf.
 The early growth of the tobacco on the non-irrigated plots in
1950 and 1951 was not as severely retarded as in 1949 because