CONTRIBUTIONS FROM THE WISLEY LABORATORY. 491 



CONTRIBUTIONS FROM THE WISLEY LABORATORY. 



Y. — The Inoculation op Leguminous Crops (cont.). 



By F. J. Chittenden, F.L.S. 



In the last issue of the Journal (pp. 231-254) an account of the experi- 

 ment carried out at Wisley during 1908 upon the Inoculation of Peas 

 with " Nitro-Bacterine " was given. The results indicated that such 

 inoculation in ordinary garden soil is not likely to prove beneficial. 



A full account of the plan of the experiment and the nature of the 

 soil, &c, is given on pp. 236-242, and the numbers used to designate 

 the plots in the tables which follow correspond with those on the plan 

 (fig. 37, p. 237). 



Of the twenty-four rows of peas grown from inoculated seed on the 

 cultivated land, only five gave a larger crop than the corresponding rows 

 from untreated seed. Of the six plots on which inoculated seed was 

 sown only one gave a larger crop than the corresponding uninoculated 

 plot, and one gave an equal crop. Of the twenty-four rows grown from 

 inoculated seed on the fallowed land, eleven gave a larger crop than the 

 corresponding rows from untreated seed and thirteen a smaller. Of the 

 six plots on which inoculated seed was sown, four gave larger crops than 

 the corresponding uninoculated plots. In all cases the weight of the 

 pods as gathered is taken as the measure of the yield. 



The total weight of produce from the inoculated plots was incorrectly 

 stated in the Summary, though it was given correctly in the body of the 

 Report, and I take this opportunity of rectifying the error. Paragraph 

 9 of the Summary (p. 254) should read : " The total weight of the crop 

 from the whole of the plots receiving inoculated seed was 495 lb. (not 

 450 lb. as stated), while the total from the plots in which uninoculated seed 

 was sown was 515 lb. The uninoculated seed, therefore, gave a crop 4 per 

 cent, (not 14 per cent.) heavier than the inoculated in the aggregate." 



The crop from the inoculated seed (138,123 grammes) on the cultivated 

 ground was 6 per cent, less than that from the uninoculated (146,643 

 grammes) in the aggregate, and on the fallowed ground there was a 

 difference in favour of the inoculated seed of less than 1 per cent. 

 (86,642 grammes from the inoculated seed, 85,942 grammes from the 

 untreated seed). 



All these results are based upon the assumption that, under equal 

 conditions, equal weights of seeds would produce equal crops (see p. 240 

 for the reason for using this as a basis of calculation), but, as pointed 

 out in the Report (pp. 240, 247, 249, &c), in a few cases there was a 

 marked difference in the number of plants growing on the two plots 

 which were to be compared. 



It might, therefore, be thought that this difference in number of plants 

 may have made an appreciable difference in the aggregate results, and on 



