Table 9 

 Peas. Average number of pods per plant (Atabekova's data, 1933*) 



a more accurate evaluation of the quality of the 

 obtained yield of peas, the irradiated and control 

 seeds were weighed on a torsion scale in batches 

 of 525. 



In 1935 3 the irradiated pea seeds were planted 

 out on plots of the Timiryazev Academy with a 

 quadruple replication of the experiment. As an 

 index of X-ray effect, we selected the average 

 weight of seeds collected from a single plant. 

 These data are compared in Table 10. 



From this table we can see that as far as the 

 increase of the weight of seeds is concerned the 

 dose of 350 r had a particularly beneficial effect. 

 From this we can deduce that for peas, just as 

 for rye, irradiation of the seeds before planting 

 leads to an increase in yield (Fig. 9). 



Five years of experimentation with the effects 

 of radiation on plants permit us to express our 

 convictions concerning the significance of this 

 factor in the stimulation of growth, development, 

 and yield of plants. The negative results obtained 

 by many investigators are to be explained, in our 

 view, by insufficient work on the dosages, which 

 are specific for every species and variety of 

 plant. Let us take an example from our own ex- 

 perience. Despite three years of experience 

 with spring wheat, we are still unable to obtain 

 stimulating doses for it. We do not draw from 

 this the pessimistic conclusion that stimulating 

 doses are non-existent for wheat; we merely 



^Translator's note: This date should probably be 

 1933 to correspond with the table below, or vice versa. 



consider that we have not discovered them as 

 yet. Nevertheless, our experiments with this 

 plant are rather interesting. 



Wheat ( investigations of Afanas'eva) . For 

 our experiments we used a pure line of soft 

 wheat whose seeds were irradiated in air -dry 

 and soaked conditions, and finally, in the form 

 of sprouts. The air-dry seed was discovered to 

 be resistant to the action of X rays; it did not 

 react in any way on exposure to small and 

 medium doses of X rays, whereas exposures 

 to heavy doses produced a depressing effect on 

 the first phases of development of the plant. 

 In order to study the effects of X radiation on 

 soaked seeds they were planted in the laboratory 

 and in field plots. This last experiment was 

 performed with quadruple repetition, using hand 

 planting by row. The seeds planted under lab- 

 oratory conditions all came up at the same time 

 [regardless of dosage] as the controls. The 

 percentage of irradiated seeds which germinated 

 in no way differed from the controls. During 

 further development obvious depressing effects 

 were noted with a dose of 16, 000 r (just as in 

 the previous experiment). Under field condi- 

 tions it was possible to observe that as the 

 dosages increased, the viability of the plants 

 went down. The dose of 16, 000 r, which under 

 laboratory conditions produced identical germi- 

 nation as the other dosages and the controls, 

 under field conditions made a 50% lower show- 

 ing. This is explained by the loss of a certain 

 percentage of the developing plants during the 

 entire growing season of the plant. Not a single 



Table 10 

 Peas. The weight of seeds per plant (based on Atabekova's data, 1933*) 



23 



