MARKET DISEASES OF VEGETABLES. 69 



by water-soaked but firm tissue. Later there appears the 

 coarse white mycelium which turns brown and forms scler- 

 otia. The water-soaked areas are often referred to by the 

 trade as "water blisters." 



The fact that this rot is not limited to the blossom-end of 

 the fruit, and is accompanied by a mycelium, differentiates 

 it from blossom-end rot. It may follow blossom-end rot, 

 however. Its solid mat of brown mycelium and its large 

 lesions differentiate it from nail-head spot. The brown mat 

 of fungus and the more regular and more closely arranged 

 markings also differentiate soil rot from the buckeye rot. 

 Furthermore, in the field, soil rot always shows these con- 

 centric rings while buckeye rot may not. Soil rot differs 

 from Phoma rot by the absence of a black center with black 

 pycnidia and from anthracnose by the absence of the 

 orange-pink spore heaps. 



Soil rot is especially severe on Florida tomatoes during 

 rainy weather. It also occurs in early shipments of Cali- 

 fornia tomatoes. 



The original infection takes place from the soil in the 

 field. Fruits touching the ground or hanging low enough 

 to be spattered by the soil during rains are infected. The 

 rot develops and spreads in the pack. 



This disease can be controlled in the field by staking the 

 plants. It is advisable to sort out diseased fruit in the pack- 

 ing house, since affected fruit is unmarketable, unfit for 

 food, and a menace to sound fruit. 



Ref. (56). 



TOMATO: BLOSSOM-END ROT. 



Cause: Non-parasitic (probably irregular water supply). 



In the early stages this disease appears as a small spot at 

 the blossom-end, or it may involve the whole blossom sur- 

 face of the fruit. At this stage the spot looks like a bruise, 

 is dark green in color and water-soaked. Later it becomes 

 darker, and the affected tissue collapses and becomes firm 

 and leathery. Sometimes the collapse is so sharply marked 

 that the lesion appears as a distinct depression. Generally, 

 however, it results only in a flattening of the end of the fruit. 

 The lesions are very shallow and dry ; this, together with the 

 restriction of this injury to the blossom-end, serves to differ- 

 entiate blossom-end rot from the buckeye rot of green toma- 

 toes and the soil rot of both green and ripe fruits with which 

 it might be confused. 



Blossom-end rot is a field disease, and occurs in all tomato 

 growing districts. 



Affected tissue is predisposed to secondary rots, which 

 develop in the field, in transit, and in storage. The non- 

 parasitic injury is, in fact, commonly followed by fungous 

 rots. 



Blossom-end rot has not been successfully controlled. 

 Regulation of the water supply, and the use of varieties 



