22 Florida Agricultural Experiment Stations

 Total yield and good quality yield were higher, on the average,
on the corn plots. This result was the same for each of the
three years of the experiment. This fact is difficult to explain
because cropping ("variety") influence was residual.

 TABLE 15.-ANALYSIS OF VARIANCE FOR YIELD AND QUALITY OF
 TOBACCO IN 1951.
 Degrees
 Source of Variation of Mean Square
 Freedom Yield Quality

 Total ... .....- ...........- .................. 143
 I Irrigation ............ .... ........... 2 24.61** 50.67**
 Blocks .......................................... 2 1.91 4.94
 Error (a) ........-.... ......--...--- 4 .92 1.07
 II "Cultivation"t (lupine-fallow) .... 1 1.89 2.00*
 "Cultivation" x irrigation .......... 2 .53 .56
 Error (b) ....................... .............- 6 .54 .24
III "Variety" (corn-peanuts) ......- 1 7.02** 2.88*
 "Variety" x irrigation ..... --. 2 .35 .25
 Error (c) .....................-- .....- .-._....... 6 .13 .48
IV "Variety" x "cultivation" .......... 1 .10 .22
 "Variety" x "cultivation" x
 irrigation ...................................- 2 .03 .59
 Error (d) .....................-...........- ... 6 .28 .47
 V Fertilizers ..........-...... --....------..... 3 20.87** 12.47**
 Fertilizers x "variety" .................. 3 1.13** .14
 Fertilizers x irrigation ............. 6 2.42** 3.17**
 Fertilizers x "cultivation" .......... 3 .46 .21
 Fertilizers x "variety" x
 "cultivation" ......---.. --..--------.- 3 .29 .29
 Fertilizers x "variety" x irrigation 6 .76 1.80''
 Fertilizers x "cultivation" x
 irrigation ............................ ...... ..6 .43 .36
 Fertilizers x "variety" x
 "cultivation" x irrigation ....... 6 .62 .35
 Error (e) ........................................ 72 .25 .31

 Significant at .05 percent level.
 ** Significant at .01 percent level.
 t "Cultivation" refers to lupine or fallow for cover crops.
 $ "Variety" refers to corn or peanuts in the rotation following the cover crops.

 Total yield and high quality yield data, based on irrigation
and rate and time of fertilizer applications, are shown in Tables
16 and 17. Each entry is based on a total of 12 plots.
 The 800-pound single fertilizer application was significantly
lower in total production and good quality production than the
400 + 400, 1,600 and 800 + 800-pound applications. Sixteen
hundred pounds of fertilizer in one application did not signi-
ficantly increase yield or improve quality over the split applica-