24 MASS. EXPERIMENT STATION BULLETIN 427 



9 



same year March-propagated plants benched on July 10 and July 20 yielded the 

 same; those benched on July 1 and June 20 increasingly less. In 1932-33 the 

 effect of time of benching on yield of No. 1 Matchless carnations per square 

 foot of growing area from October to February inclusive is shown in the follow- 

 ing table. 



December Plants..— 



January Plants 



February Plants 



March Plants 



In 1936-37, housing on July 7 in contrast to September 4 increased the yield 

 of No. 1 Boston Ward carnation flowers by approximately 42 percent. Early 

 propagation plus late housing would appear to encourage more disease and a 

 depreciation in growth and yield of flowers. If, under the grower's particular 

 conditions, a limited period of outside culture is desirable, the plants should all 

 be housed b}- the second week in July or even earlier. When Alternaria blight 

 was first recognized as a serious carnation disease (14, 62, 81, 82), it was trouble- 

 some only on outside-grown plants. Where losses fro.m blight have been re- 

 peatedly common, growers should abandon outside culture entirely. 



CONTINUOUS GREENHOUSE CULTURE 



Some of the young stock may be carried along in pots after rooting. This 

 method of culture is desirable if the grower has sufficient help to give pot culture 

 the care it requires. There are advantages, notably that less loss is encountered 

 in transplanting and practically no injury. The shortage of labor and the added 

 cost of culture would favor growing the young plants in 4-inch flats, and this is 

 the common practice in New England. A limited stock ma\' be carried along in 

 greenhouse benches spaced 4x4 inches and transplanted later into permanent 

 beds as the old producing stock is removed. 



If the plants are not going into the field, they must be planted directly from 

 the flats to the benches. While continuous inside growing contributes to the 

 control of certain diseases, nevertheless it does not produce the kind of plant 

 growth derived from a few weeks of outside culture. Since numerous factors 

 are involved in determining the kind of growth under the two sets of conditions, 

 it would not be fair to claim that one method is better than the other so far as 

 flower production is concerned. The loss attendant upon one method might be 

 turned into a gain by the advantage of some other contributing factor. Inside 

 culture for the entire range would deprive some growers of a substantial income 

 from the harvest of cut flowers in June and July, which other growers would 

 regard as a false gain because of loss from disease resulting from the delay in 

 replanting. 



SEGREGATION OF YOUNG STOCK 



Continuous inside culture raises the problem of plant growth control. The 

 flats of soil planted to rooted cuttings are placed on supports above the flowering 

 beds and along the eaves where growth conditions cannot be satisfactorily con- 

 trolled and the detection of disease is obscured and delayed. The flats must be 

 taken down in May, and sometimes it is a problem to decide how to handle the 

 plants, especially when prices for carnations are high. Either the plants must 

 be set in the field or in the benches, or they must be carried along in the flats 



