CARNATION WILT DISEASES 23 



peciall\- desirable. The management of the cutting bench with respect to water- 

 ing, shade, light, and temperature is also of great importance to successful rooting 

 and even more important than the quality of the sand used. 



AGE OF PLANTS IN RELATION TO DISEASE AND YIELD 



The relation of age of carnation plants to disease and yield of flowers during 

 the first producing year has never been clearly established to the knowledge of 

 the writer. Frequent obser^'ations have indicated more disease among the older 

 plants, other conditions being alike. In New England new carnation plants are 

 propagated from cuttings gathered from November to April, and all of the 

 young plants propagated during these months are usually mixed together to 

 constitute the next planting. By April all of the young stock is growing in pots 

 or flats, and that of the earliest propagation has made the greatest growth of 

 root and top. Early in the i history of American carnation culture, rooting in 

 February and March was apparently preferred. More recently, according to 

 Wiggin (80), better results are secured from earh- propagation, i. e., November 

 or December, because a larger plant with more branches is secured. 



In transplanting operations and especially in transplanting from the field to 

 the greenhouse benches, the greatest amount of breakage has appeared to occur 

 among the largest or oldest plants. The close association of disease with injuries 

 and unfavorable growing conditions has been established. Differences in yield 

 of cut flowers of carnation plants made from cuttings taken in different months 

 of the rooting season can be shown in some years. In the year 1931-32, Matchless 

 carnations rooted in February' and March yielded the greatest number of No. 1 

 flowers; December plants, the least. In the year 1932-33, February-rooted 

 Matchless plants yielded slightly more No. 1 flowers than plants rooted in other 

 months. In another year when only Matchless plants of January and March 

 cuttings were compared for yield of cut flowers, there was no significant differ- 

 ence. In still another year, December-rooted plants yielded significantly more 

 than plants rooted in January, February, or March, when all were benched on 

 July 15. The March-rooted plants yielded the least. Factors other than the 

 month of propagation appear to be involved. 



FIELDING AND BENCHING 



The maintenance of the producing stock in the greenhouse much after May 30 

 would require the fielding of the young plants, and it is also a factor in determin- 

 ing the date of benching. The two classes of stock are managed to correspond to 

 each grower's concept of their respective value under his particular conditions. 

 In the field the carnation stock experiences certain hazards from the weather and 

 from disease, notably Alternaria blight, and a certain amount of abuse and injury 

 in transplanting which also introduces a serious hazard from disease, notably 

 Fusarium branch rot. Experience has taught that a long growing period in the 

 field extending into late July and beyond is dangerous. In the shelter of the 

 greenhouse many of the growth factors are under better control; but temperature 

 conditions in the greenhouse in July and August can also be severe enough to 

 check and suspend growth. Practice generally has taught the value of some 

 outside growing and the importance of benching the stock early in the summer 

 season. Delay in housing the fielded plants increases the amount of disease 

 which can be shown in the yield of flowers (Fig. 10). A limited series of tests 

 is suggestive of the idea. 



Our experience in 1932-33 showed a much greater yield from January-rooted 

 plants benched on July 20 than from similar plants benched on July 30. In the 



