Wire Stem of Cabbage 5 



In 1920 the writer endeavored to arrive at sonic more definite conclusions 

 concerning the actual losses caused by this disease. Counting more than 

 1000 plants on each of three farms, immediately before transplanting 

 into the field, it was found that 55 per cent of the seedlings were healthy, 

 while 23 per cent were slightly diseased, and 22 per cent were severely 

 diseased. This arbitrary classification of the diseased plants was made 

 from the standpoint of the grower, who normally sets the slightly diseased 

 plants and discards those designated as severely diseased. Some of the 

 growers were of the opinion that slightly diseased plants which had appar- 

 ently recovered could be transplanted into the field without any subsequent 

 losses. To demonstrate that permanent injury had resulted to the seed- 

 lings, several hundred of each of the above classes of plants (healthy, 

 slightly diseased, and severely diseased) were planted in adjacent rows 

 on each of two farms. Careful records were kept of the number of heads 

 and the pounds produced by each class. It was estimated that the actual 

 losses on the two farms, considering the healthy plants as yielding normally, 

 were 12 per cent in heads and 10 per cent in pounds for the slightly diseased 

 plants, and 36 per cent in heads and 30 per cent in pounds for the severely 

 diseased plants. If, then, of the 10,000 plants required to plant an acre, 

 23 per cent (2300 plants) were slightly diseased, the actual decrease in 

 yield in heads (12 per cent) from this class only was 276 per acre. Accept- 

 ing five cents a head as the average selling price, the loss per acre was 

 approximately $14. This is a loss of which most growers are probably 

 not aware. In addition to this loss and that of the discarded plants, 

 there is also a loss caused by a delay in maturing of heads produced by 

 the diseased plants. This loss is dependent on the fluctuations of the 

 market, and may assume rather extensive proportions. This is especially 

 true in a season with an early market. In 1920 there was an excessive 

 amount of rainfall throughout the growing season, and this is probably 

 the reason why there were only slight indications of delay in maturing. 

 The following year an attempt was made to duplicate the above experi- 

 ments, but the disease was not severe on any of the farms. On one, 

 however, 32 per cent of the plants were found to be very slightly affected. 

 Several hundred of these were planted, as before. Because of the only 

 slightly diseased condition of the seedlings, the results of the harvest 

 did not demonstrate any actual loss in yield, but a definite delay of a 

 week or ten days in the ripening of the heads was very evident. 



SYMPTOMS 



Wire stem of cabbage is first evident as a typical damping-off . Usually 

 the disease is to be observed when the seedlings are an inch or two in height. 

 A water-soaked area completely encircling the tender stems is found just 

 at the surface of the soil. In a few hours the stem loses its supporting 

 power and the plant topples over. This occurs especially where the soil 



