September 1, 1906 



HORTICULTURE 



238 



Blossom End Rot of Tomato 



The Blossom End Eot of tomato is very troublesome 

 in greenhouses, and also causes much injury to out-of- 

 door crops of tomatoes throughout the whole United 

 States. Experiment station workers have given attention 

 to the Blossom End Rot for some time, but from the re- 

 sults of the various spraying experiments, very little of 

 positive value has been discovered relating to the best 

 methods of treating this disease. Some experiments in 

 the South have indicated that spraying with Bordeaux 

 mixture helps to quite an extent in controlling this 

 trouble, while there are many others that have given 

 practically no favorable results. 



Blossom End Eot, as its name indicates, occurs on the 

 blossom end of the fruit. It may make its appearance 

 when the fruit is not more than a half an inch in 

 diameter as a light, brown spot near the blossom end, 

 which continues to grow ajid develop in size as the fruit 

 develops ; and eventually it will cover more or less of the 

 whole fruit. Finally this spot may assume a very dark- 

 colored appearance on the surface. 



There has been about as much difference of opinion 

 regarding the cause of the Blossom End Rot as theie has 

 regarding the control of the same. This rot ha.- been 

 attributed to different species of fungi, also bacteria. It 

 is not unusual . to find such fungi as Altornaria, 

 Fusarium and Cladosporium present. In many instances 

 a species of bacteria has been found and isolated which 

 has given rise to the Blossom End Rot when the fruit 

 has been inoculated. 



Miss E. H. Smith, who has been working on this rot 

 for some time in our laboratory at the station, has found 

 all the various species of fungi which are enumerated 

 above, together with a species of bacillus. Most of her 

 work w^as confined to the greenhouse, and under such cir- 

 cumstances she has found practically all of the Blossom 

 End Rot to be caused by a species of bacillus, although 

 occasionally a fungus known as Fusarium is present. 

 These observations have been confirmed by myself, and 

 we are of the opinion that the Blossom End Rot, at least 

 in greenhouses, is caused by a species of bacillus which 

 gains entrance at the blossom end of the fruit, near the 

 base of the style, and that the other species of fungi ac- 

 company it, owing to certain conditions being estab- 

 lished by the presence of the bacillus. On out-of-door 

 plants, however, cfne is likely to find a whole category of 

 organisms. 



Those who are familiar with tomatoes may have no- 

 ticed that the epidermis of the fruit is frequently 

 cracked near the blossom end of the tomato first, and it 

 is undoubtedly through these cracks that the organisms 

 gain entrance to the fruit, causing the rot. Rot caused by 

 a bacillus is always of a lighter color than that caused by 

 the various species of fungi mentioned. It has been 

 known for some time that touiatoes, when grown out-of- 

 doors, during the dry season, are more susceptible to this 

 rot than during wet seasons. This is undoubtedly ac- 

 counted for by the fact that the fruit, during such sea- 



sons, dues not get water enough, and cracks form which 

 allow the entrance of organisms. It is quite possible that 

 sub-irrigation of tomato plants in the greenhouse may be 

 the means of checking this trouble to a large extent. Ex- 

 periments are being made at the station along this line, 

 but it is too early to draw deductions as to the practi- 

 bility of this practice at the present time. 



"Y <^— - "fdC^^^^Zoi 



An Effective Border 



Seldom has the writer seen a more attractive dis- 

 ])lay than on the estate of Mr. G. Oliver, So. Negley 

 Ave., Pittsburg, Pa., where Mr. R. D. Steven-!, the 

 gardener, who is a great lover of nicotianas, both N. 

 affinis and N. Sandene, has arranged a group of beds 

 in which these two species are the leading subjects. 

 This style of bedding, .so seldom seen in suburban dis- 

 tricts, is quite refreshing to people living in residential 

 sections of large cities where nearly everyone's lawn is 

 the counterpart of his neighbor's. 



These beds are situated almo.'^t nn the top of a hill 

 in full sunshine, yet in the hottest time of th,.- year 

 tliese nicotianas were floriferous and healthy, from 

 which we might reasonably infer that nicotiana-. will 

 stand full sunshine, even in the hottest weather, pro- 

 viding they are given a position where they can have 

 lots of air. Better results can be obtained by planting 

 in such a position than in half shade. The effect o\y- 

 tained by planting the two species together is very 

 pleasing: the "dead" white of N. aflinis is relieved by 

 the varving <l;ades nf pink in \. Sanderse. 



