Maya;. i9i8 BOYOfl A^l 



boron, either as borax or as calcined colemanite, had exerted no ill effects 

 on the growth of these crops. Samples of onions were taken from the 

 various plots for analysis for boron in July, 191 5. They had gone to 

 seed; and the flowering tops, as well as the tops and roots, were tested. 

 The flowering tops from the borax treated plot, where the manure had 

 been applied at the 40-ton rate showed 0.00004 per cent of boric acid. 

 The rest of the plants or portions of plants gave negative results for 

 boron. Jay (6) reported that he found considerable amounts of boron 

 in onions. As will be seen later, none of the plants grown at Bethesda 

 absorbed much boron. 



EXPSRIMEXTS OF THE SECOND YEAR, 1915 



The plots were cleared, and a second application of manure was made 

 to all plots on July i, 191 5, with the same quantities of borax and cole- 

 manite and three different rates of manure application as the first year — 

 that is, the plots received exactly the same amounts of boron as in 

 September, 1914. The manure was harrowed into the ground, not 

 plowed, so as to have the boron in the upper 3 or 4 inches of soil in order 

 to obtain the maximum effects. On July 12, 191 5, Golden Bantam 

 com, green stringless beans, table beets (Beta vulgaris), and McCormick 

 potatoes were planted. On July 29 the com, beets, and beans were up, 

 and a potato plant was seen here and there. The beans showed a yellow- 

 ing on the borax-treated and colemanite-treated plots, even where the 

 manure was applied at the 16-ton rate. During August the beans 

 growing on the 40-ton borax-treated plots showed decided injury, while 

 those on the 16- and 24-ton plots showed some injury. Colemanite pro- 

 diuced much less injury to the beans than the borax. There were fewer 

 potato plants on the plot where borax manure was applied at the 40-ton 

 rate than on the other plots. It was very noticeable during August that 

 no weeds were growing on the colemanite plots, while weeds grew luxuri- 

 antly on the control and the borax treated plots. 



On August 20 the beets, as well as the beans, showed that they had 

 been injured by the borax. The com on the control plots had the 

 highest stand, but no injury was apparent to the corn on the borax or 

 colemanite plots. The potatoes on the 40-ton borax-treated plot showed 

 a slight yellowing of the leaves. The potatoes on the other plots were 

 apparently normal. 



On this date the beans on the 16-ton borax-treated plot had outgrown 

 the initial injury, and the three other crops on this plot were normal. 

 The colemanite-treated manure at the 16-ton rate caused no injury to 

 any of the vegetables. On the 16-ton control plot all the plants were 

 normal, but the beets were thinner than on the 16-ton colemanite-treated 

 plot. 



