The Dry Root-Rot of the Bean 1025 



In studying this table several points should be taken into consideration 

 which have or might have a disturbing effect on a proper interpretation 

 of the data. In all instances these points deal with individual rows. 

 Since the first row served as a buffer, the yield was not determined, and 

 hence the check percentage of row 1 was calculated from only one check 

 row. In all other cases the average of the check rows on both sides of 

 the diseased row was used. In check row 6 it may be seen that the ' 

 yield was far below the normal. The cause of this is unknown. It 

 resulted, however, in unfair calculated check percentages for rows 5 and 7. 

 If rows 4 and 8 only had been used, the check percentages would not 

 have been above one hundred. Row 25, which shows a very low yield 

 and therefore a low check percentage, had a small number of plants. 

 Row 27 also had a small number of plants, but this was not evident on 

 the yield. The writer appreciates the fact that rows of equal length may 

 have vaiying numbers of plants without affecting the yield of these rows. 

 For this reason it is considered best to use rows in an experiment of this 

 type instead of a certain number of plants. Just how much thinning 

 a row may permit before a noticeable decrease in yield occurs is not 

 known. 



In consideration of these disturbing factors, very few data are presented 

 which show that the black root-rot reduces the yield of beans to any 

 extent. The weather, no doubt, was as favorable as possible for this 

 disease and the root-rot approached its maximum in severity. The 

 injury from the black root-rot was brought about to a large extent by 

 the destruction of the plants in the seedling stage. The remaining plants, 

 therefore, had a better opportunity to develop and offset this injury. 

 The calculated check percentages for the dry root-rot on the whole are 

 high. This is to be expected, however, when the soil retains a large 

 amount of moisture throughout the growing season. With the combina- 

 tion of the diseases there appears to be a consistent reduction in the 

 yield. 



A further experiment to determine the effect of the dry root-rot on 

 the yield of the bean was conducted during the season of 1918. The 

 plot of land selected, although not so advantageous for beans, was located 

 on higher ground than that used in the experiment of 1917. The soil 

 contained a considerable amount of clay. The plan of the experiment 

 was the same as in 1917 with the exception that only the fungus Fusarium 



