204 Proceedings of Indiana Academy of Science. 



Lafayette the disease was so severe that late in September only tufts of the 

 j^oungest leaves remained on the plants. 



As usual Fusarium wilt was severe in the Indianapolis greenhouses. The 

 wilt-resistant Marvel variety has proved acceptable to one greenhouse 

 grower as a substitute for the Bonny Best. Out of numerous single plant 

 selections made last year with the purpose of isolating a wilt-resistant 

 strain of Bonny Best, two showed good resistance but both came into 

 bearing too late to suit the desires of the growers. 



In the field crop wilt was noted as a rule only on scattered plants. From 

 two to six per cent of wilt was found in 12 out of 14 fields visited near 

 Kokomo July 13. In certain of these fields set with southern-grown plants 

 it was practically certain, judging from the distribution and severity of the 

 disease, that it was introduced with these plants. This illustrates a danger 

 in the use of southern-grown tomato plants by Indiana canners. Wilt has 

 not yet become a serious factor in the Indiana canning crop owing to the 

 fact that so much new soil has been available and crop rotation has been 

 practiced. In gardens and old tomato fields the disease persists and there 

 are indications that it is also harbored in plant beds. The disease is 

 \ery destructive under Indiana conditions and infestation of the soil 

 should be guarded against. 



Mosaic was not as severe as in 1019. although it was very general late in 

 the season. In a late epidemic of this kind the yield is not noticeably 

 reduced but plants infected early in the season are likely to be valueless. 

 In one field near Indianapolis there was practically 100 per cent infection 

 of mosaic, much of it of the dwarfed, fern-leaf type which results in a very 

 marked reduction in yield. In certain fields there was some indication that 

 mosaic was carried with the seed but carefully controlled and rather ex- 

 tensive tests with seed from mosaic plants have so far yielded only neg- 

 ative results. 





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Fiii-. 11. Tomato antliracuose. 



