26o 



Journal of Agricultural Research 



Vol. XII, No. s 



by the fact that in a given area, as the size of the plot increases the 

 number of plots necessarily decreases, and thus lessens the reliability 

 of the comparisons. Thus, these exceptions may be due to chance in a 

 small population and might not hold true with a larger number of variants. 



Table III. — Effect of increasing the number of adjacent trees per plot 



Kind of tree. 



Navel oranges (Ar- 

 lington) 



Do 



Do 



Do 



Do 



Do 



Navel oranges (An- 

 telope Heights) 



Do 



Do 



Do 



Do 



Do 



Valencia oranges 



Do 



Do 



Do 



Do 



Do 



Eureka lemons. 



Do 



Do 



Do 



Do 



Do 



Num- 

 ber of 

 trees 

 per 

 plot. 



Seedling walnuts. 



Do 



Do 



Do 



Do 



Do 



Jonathan apples. . 



Do 



Do 



Do 



Do 



Do 



Num- 

 ber of 

 plots. 



,000 

 500 

 250 

 125 

 60 

 40 



495 



247 



125 



61 



30 



20 



240 

 120 

 60 

 30 



364 



280 

 140 



224 



112 



56 



28 



14 



Acre- 

 age per 

 plot. 



o. on 

 . 022 



.044 

 .088 

 .176 



. 264 



. on 

 . 022 

 .044 

 .088 

 .176 

 . 264 



.011 

 . 022 

 .044 



Mean yield 

 per plot. 



Pounds. 



137- 6i 1.2 



275. 6i 2.9 



551. 6i 7.4 



1, 100. 8i 19. 2 



2, 220. oi 56. o 



3.343-8i 92.5 



186. 2i 1. 7 



373- oi 4-2 



742. 7i 10. o 



1,460. 7± 26. 7 



2,973. 3 ± 68.4 



4,450. oi 121. 6 



246.3 i 4.3 

 487. 92 i 10. O 

 991- 7 i 23. 9 

 1,966. 7 i 59-4 

 176 3,813.3 ii58.6 

 264 5,880.0 i243. o 



•013 

 . 026 



. 211 



•317 



.057 

 . 114 

 . 228 

 .456 

 . 912 

 1.368 



.oil 

 . 022 

 .044 

 .088 

 . 176 

 . 264 



270. 7 i 2. 9 

 544. 3 ± 6. 8 

 1,081. o ± 17. 3 

 2, 172. o i 46. 7 

 4,395-o ii2i. 7 

 6,692.0 ii53. 5 



86.4 i 1.6 



178. 7 i 3. 6 



353- 6 i 8. 6 



717. I i 20. 7 



1,409. 4 i 58. O 



2,154.6 il03.3 



303-9 ± S-6 



6og. 8 i 12. 3 



I, 210. 7 i 28. 8 



2,414.3 i 76.9 



4,864.3 ii75-S 



7,277.8 i3l3-9 



Standard 

 deviation. 



Pounds. 



54. 42i 0.82 



95. 6oi 2. 03 



173- 89i 5- 24 



319. ooi 13.60 



642. 6oi 39. 58 



867. 70i 65.43 



S5-33± I- 19 

 97. 2ii 2.95 

 164. 37± 7.07 

 309. 05 i 18.90 

 555- 55 i 48.38 

 806. 54i 86.01 



97- 84i 3- 01 

 161. 8oi 7- 04 

 275. 2oi 16. 92 

 482. 6oi 42. 02 

 910. 58iii2. 13 

 i,l40.ooil7i.90 



81. 38i 2. 03 

 135- 40i 4- 78 

 245. 35 i 12. 27 

 448. 50i 33. 01 

 827. ooi 86. 07 

 820. 30i 108. 50 



40. io± 1. 14 



62. 40i 2. 52 



106. 40 i 6. 06 



181. 24i 14. 60 



354- 40i 41.00 



508. ooi 73.05 



125. 30i 4- 00 

 193. ooi 10. 44 

 319. 40 i 20. 40 

 603. 38i 54.38 

 973. 68 i 124. II 

 1,396. ooi 221.90 



CoelBcient 



of 

 variability. 



39.55±o. 68 

 34.68io. 82 

 31. 52ii.o5 

 28. 98ii.30 

 28. 95 i I. 92 

 2S-95±2.oS 



29. 72 ±0.69 



26. o6±o. 84 



22. I3il. 00 



21. i6ii. 35 

 18. 68ii.68 

 18. ioil.91 



39- 72 ±1.40 

 33- i6ii.6i 



27. 75ii.84 



24. 54i2. 26 



23. 88i3. 10 

 I9-39±3.03 



30. 06 io. 81 



24. 88 i 0.93 



22. 70il. 19 

 20. 65 i I. 57 



18. 82 i 2. 02 

 12. 26ii. 65 



46. 41 i I. 58 

 34-92ii. 57 

 30. 09ii. 86 



25. 27i2. 16 



25. I5i3. 07 

 23- S8i3. 53 



41. 23il. 52 

 31.65i1.87 



26. 38il. 80 

 24. 99i2. 39 

 20. 02 i 2. 65 



19. i8i3. 16 



Probable error. 



Pounds. f^J- 

 ' centage 

 of 

 mean. 



per 

 tree. 



26.67 



23-39 

 21. 26 

 19.55 

 19.53 

 17- SO 



20.05 

 17-58 

 14-93 

 14.27 

 12.60 

 12. 21 



26.79 

 22.37 

 18.72 

 16.5s 

 16. II 

 13-08 



20. 28 

 16.78 

 IS- 31 

 13-93 

 12.69 

 8.27 



31.30 



23- ss 

 20.30 

 17.04 



16.96 



15.90 

 27.81 



21- 3S 

 17.79 

 16.86 

 13.50 

 12.94 



SUMMARY 



