136 Knight and Priestley . — The Respiration of Plants 
Attention has been for some time directed to the apparent acceleration 
of growth and maturation reported in field trials, because this phenomenon 
rendered it impossible to gauge the extent to which increased yield was 
a direct result of electrification. If a crop matures earlier, and particularly 
if it is therefore harvested earlier, it may mean that the plants are not 
exposed to a period of bad weather, during which the yield, instead of 
improving, may actually decrease in amount. If acceleration is a result 
of treatment, it needs to be considered in all cases where the causes of an 
increased yield have to be analysed. It therefore seemed desirable to arrive 
as soon as possible at a decision as to the possible cause of such an 
acceleration as has been reported in many field trials. The results obtained 
in these trials have been given at length elsewhere, 1 but in view of the 
importance of the question of acceleration in relation to the subject-matter 
of the present paper, it will perhaps be advisable to extract from the 
previous reports the data which formed the foundation for this research, and 
to subject them to further criticism in the light of later work. 
Analysis of Results of Field Trials. 
In the earliest experiments at Bitton, with an inefficient influence 
machine driven by an oil engine as the source of electrical power, and with 
the overhead wires close to the plants to be treated, the following results, 
amongst others, were obtained : 
Broad beans. Decrease in yield of 15 per cent., but ready for picking 
five days earlier than the control. 
Spring cabbages. Ready for cutting ten days earlier. 
In all the other experiments from which data have been taken, the 
Lodge-Newman system of electrification, described in previous papers, 2 has 
been used. 
At Evesham in 1906 the Canadian wheat under electrical treatment 
was ready for cutting some three or four days before that of the control 
area. In the case of the English wheat, the time of ripening was unchanged 
by electrification, and it is perhaps significant that the yields in the two 
cases were as follows : 
Bushels per acre : 
Electrified. Non-electrified. Increase . 
Canadian (Red Fife) 352 25^ 39 % 
English (White Queen) 40 31 29 % 
Results which indicate a greater increase in yield in the crop showing 
acceleration in rate of growth. 
1 Journal of the Board of Agriculture, loc. cit., and also vol. xx, p. 582. 
2 Journal of the Board of Agriculture, loc. cit., also Journal of the Royal Horticultural Society, 
vol. xxxvii, p. 15. 
