HANDBOOK OF CONNECTICUT AGRICULTURE. 2 7 



prevention by the use of suitable devices for ventilating by 

 means of artificial heat, have been studied. Studies on the 

 curing and fermentation of wrapper-leaf tobacco are now in 

 progress. 



Investigations are in progress with the object of determin- 

 ing the cause of " calico," a destructive disease of growing 

 tobacco. It has been ascertained that the disease is purely 

 physiological, and experiments indicate that the use of lime 

 upon soils where " calico " is liable to occur is attended with 

 good results. 



The effect of shading growing tobacco plants has also 

 been under trial, and some interesting and possibly important 

 results with respect to the texture of the leaf have been ob- 

 tained. 



Experiments with fertilizers in the culture of carnations 

 have been a prominent line of work in the horticultural di- 

 vision. 



For several years the disease known as onion smut, due to 

 the fungus Urocystis cepulae, which seriously threatens onion 

 growing in Connecticut, has been a subject of study. In 

 1889 Dr. Thaxter found that when onion seed was sown in 

 soil that has been impregnated with Urocystis cepulae, the 

 young plants were infected underground, and if the fungus 

 did not become manifest in them shortly after they appeared 

 above the soil, they were not subsequently affected by it. Dr. 

 Thaxter noted that " the fact of subterranean infection is 

 further confirmed by the absence of smut on sets and seed 

 onions, as well as on transplanted seedlings." Dr. Sturgis 

 has more recently shown that when onion seed is sprouted in 

 clean soil in hotbeds, and the seedlings transplanted into 

 smutty land, the onions entirely escape infection. 



Extensive studies have been made on the chemical com- 

 position of maize as affected by fertilizers and by open and 

 close planting. For six years the availability of various 

 forms of nitrogen has been studied in a large number of pot 

 cultures, with various soils, fertilizers, and conditions. 



