NORTH CAROLINA. 207 



study of lettuce diseases was continued and the results prepared for 

 publication. A method of treatment based on the laboratory investi- 

 gations was worked out. In connection with the studies in nitrifica- 

 tion, samples of the different soil types existing in the State were se- 

 cured and the nitrifying and ammonifying efficiency was determined. 

 It appears from the data accumulated that the associative action of 

 other bacteria with the nitrifying organisms is an important factor. 

 The chemical work done on this project showed that the results ob- 

 tained when Avorking witli soils are not the same as those secured 

 with solutions. Work was also pursued in the improvement of 

 methods for comparing the nitrifying efficiency of soils and making 

 colorimetric and (jualitative tests for nitrates. 



The study of the relation of geology and chemistry of soils to fer- 

 tility was continued actively, and the chemist, cooperating with the 

 department of agronomy, analyzed about 200 samples of soil in con- 

 nection with this work. Considerable work was also done on the 

 investigation of the cause of the development of suckers on corn and 

 its influence on the yield. 



The horticulturist continued to study the cause of " double flower " 

 and sterility in blackberries and dewberries. Results secured in 

 studying the Muscadine grapes and published in Bulletin 209 of the 

 station have brought out the fact that these grapes are generally self- 

 sterile and that male vines must be planted in the vineyards to insure 

 satisfactory fruiting. The study of the transmission of characters in 

 hybrids of the Rotundifolia grapes was taken up in continuation of 

 the work with this species. 



In entomology, special attention was given to the investigation on 

 the pickle worm and work was taken up on the life history of the 

 corn billbug and allied species. The investigation on the toxicity of 

 cottonseed meal, in which the chemist, animal husbandman, and vet- 

 erinarian cooperated, was actively carried forward. Among other re- 

 sults secured, it was found that meal from certain kinds of sea-island 

 cotton seed is as toxic as the meal from upland seed. 



Numerous lines of station work, some of them having been taken 

 up during the year, were supported by Hatch funds. The work in 

 agronomy included variety, culture, and rotation tests with a number 

 of cereal and forage crops, selective breeding experiments with cot- 

 ton and wheat, a study of the dropping of squares of different varie- 

 ties of cotton under different seasonal and soil conditions, and a com- 

 parison of various cover-crop combinations. Canada field peas and 

 Burt oats, and hairy vetch and wheat gave excellent results as green 

 forage crop combinations for hogs. It was also found that velvet 

 beans mature in the Piedmont section of the State and that they pro- 

 duce a very satisfactory groAvth of vines. The results of fertilizer 

 tests indicated that all fertilizer treatment hastened the maturity of 

 cotton and corn on a poor type of Cecil sandy loam soil, and further. 



