12 MASS. EXPERIMENT STATION BULLETIN 388 



followed. A marked deficiency of normal rainfall occurred following application 

 of the borax. Evidence that borax may contribute to longevity of alfalfa is 

 indicated by plant response t j two seasons' applications compared with the check 

 in two fields. 



Borax was broadcast at 25 pound rates in strips on a variety of crops growing 

 on six market garden farms. The treatments were made early in May, without 

 regard to planting time and seedling stage. In no case did growers observe any 

 injurious effects from the borax. 



Fertilizer containing 20 pounds of borax per ton was drilled in bands at a ton 

 rate on an acre of Cobbler potatoes planted by D. Wilson Smith, Scituate. There 

 were no symptoms of plant injury which could be attributed to the borax. 



Oat Variety Tests. (W. G. Colby.) Eleven named varieties of oats, including 

 several of the recently developed, smut-resistant strains, were grown at Amherst 

 during the past season. The results are reported in Control Bulletin 111, Seed 

 Inspection (pages 92-93), where these named varieties are compared with a 

 number of lots of commercial seeds. 



The Effect of Arsenious, Arsenic, and Antimony Oxides on Soil and Plant 

 Growth. (Walter S. Eisenmenger and Hrant M. Yegian.) Pot culture studies 

 under greenhouse conditions on the effect of arsenious, arsenic, and antimony 

 oxides on Merrimac fine sandy loam and subsequent crop growth are being con- 

 tinued. Six successive crops, barley and buckwheat alternating, were grown in 

 the same soil in pots during 1939 and 1941. On June 11, 1941, tobacco seedlings 

 were transplanted to these treated pots. The tobacco was harvested Novem- 

 ber 14, 1941. 



Arsenious oxide, 500 p. p.m., retarded the growth of tobacco and prevented 

 blossoming; while 500 p. p.m. with organic matter produced a fully mature, 

 normal plant. Concentrations of 1000 p. p.m. or over of arsenious oxide were 

 very toxic even in the presence of organic matter. 



Arsenic oxide, 750 p. p.m. reduced the growth of tobacco and prevented blos- 

 coming; 750 p. p.m. with organic matter, however, produced a fully maturCf 

 normal plant. Concentrations of 1000 p. p.m. or over of arsenic oxide, with or 

 without organic matter, were very toxic to tobacco. 



The arsenic content of a few of the tobacco leaves, stems, and seeds was de- 

 terminedi by the micro Gutzeit method, modified according to C. C. Cassil. 

 The results of these analyses may be summarized as follows: 



1. At the low concentration of arsenic (240 p. p.m. As) in the soil, the stems 

 and leaves contained 3 to 6 p. p.m. As, while none was detected in the seed. 



2. At the higher concentration of arsenic (480 p. p.m. As) in the soil, the 

 stem and leaves contained 12 to 18 p. p.m. As, and no seeds were produced. 



3. Indications are that the concentration of arsenic in the tobacco leaves 

 exceeds that in the stems. The number of determinations, however, was not 

 great enough to warrant definite conclusions at this time. 



The tobacco plants in pots containing 1500 and 2000 p. p.m. arsenious oxide 

 made no growth during the five-month period. At the end of five months these 

 plants were transplanted to AsgOs free soil. While these plants have resumed 

 growth, it is not a norma! but a rosette growth. This may be due either to the 

 age of the transplants, short daylight conditions, presence of arsenic in the plant, 

 or to a combination of all these factors. 



The antimony oxide treatment did not affect the growth of tobacco at any 

 concentration (250 to 2000 p. p.m. antimony oxide). 



•By John W. Kuzmeski, Senior Chemist, Control Laboratory of the Massachusetts Agricultural 

 Experiment Station. 



