1913.] PUBLIC DOCUMENT — No. 31. 99 



ber mildew {Flasmopara Cubensis (B, & C.) Humphrey) in Massachu- 

 setts; the muskmelon blight; an apple leaf spot; a strawberrj' disease; 

 plum " yellows ; " spraying of linden and elm trees for leaf spot ; crops 

 under tent cloth; experiments in heating soils; influence of sterilized 

 soil on seed germination. 



Sixteenth report, 1903 : influence of current electricity on plant 

 growth ; influence of atmospheric electrical potential on plants. 



Seventeenth report, 1904: crops as related to weather conditions; 

 testing of seed ; the practice of soil sterilization ; influence of electrical 

 liotential on the growth of plants; some important literature relating 

 to disease of crops not generally believed to be caused by fungi or 

 insects. 



Eighteenth report, 1905: downy mildew of tomato {PhijioplUliora 

 infestans DBy.) ; potato rot [Pliytophthora infestans DBy.) ; cucumber 

 and melon blight; sun scald; burning of conifers and evergreens; winter 

 killing; relation between soil aeration and germination and growth; 

 comparison of sterilized loam and subsoil; influence of soil sterilization 

 on seed germination; an application of the copper sulfate treatment; 

 a comparison of the numbers of bacteria in sterilized and unsterilized 

 soils. 



Nineteenth report, 190G : outline of work; seed work; prevalence of 

 fungi, etc.; bacterial disease of cucumbers; bacterial disease of lettuce; 

 bacteriosis of geraniums; tobacco troubles; monilia on peach stem; 

 the lime and sulflir mixture as a fungicide; potato-spraying experi- 

 ments; banding substances for trees; effects of escaping illuminating 

 gas on trees; germination and growth in soils of different texture; 

 texture of Massachusetts soils. 



Twentieth report, 1907: outline of the year's work; seed work; 

 seasonal peculiarities; sun scald; sun scorch premature defoliation of 

 trees; asparagus rust; asparagus Fusarium; peony troubles; i^otato 

 diseases; experiments with fungicides; influence of various potash salts 

 on potato scab (Oospora scabies Thaxter) ; investigations relating to 

 mosaic disease ; some factors which underlie susceptibility and immunity 

 to disease. 



Twenty-first report, 1908 : brief notes on the weeds of Massachusetts ; 

 results of seed separation ; examination of onion seeds for fungous 

 spores; bacterial rot of cabbage and cauliflower; crown gall; the pres- 

 ei'vation of mai)le syinip ; onion rot ; onion smut ; a disease of the radish ; 

 celery crown rot; eel worms {Heterodera radicicola (Greef.) Miill.) on 

 lettuce; influence of water on eel worms; influence of lime on eel worms; 

 effects of chemicals on vegetation ; substances and methods used in 

 exterminating weeds ; seed work ; common weed seeds in grass seed 

 and cattle foods. 



Twenty-second reiK)rt, 1909: diseases more or less common to ci'ops 

 during the year; shade tree troubles; malnutrition; calico or mosaic 



