ANNUAL REPORT, 1930 247 



and usually 100 per cent germinaticMi was obtained. Experiments have 

 shown that corms properly stored may be kept in cold storage two years, 

 and positive blossoming results have been obtained after three winters 

 and two summers in storage. The corms should be in shallow trays to per- 

 mit free circulation of air. An experiment is now under way to determine 

 the maximum time corms may be stored. 



Influence of Light Quality on Plant Growth. (A. V. Osnuin). The ex- 

 periment to test the effect of Vita glass on plant growth and development 

 has been continued with somewhat contradictory results. In one test, 

 radishes grown under Vita glass averaged 1.7 grams or 10 per cent less in 

 weight than those grown under ordinary glass; while in another test, the 

 difference was 3.5 grams or 14 per cent in favor of the Vita glass. Lettuce 

 under ordinary glass weighed 3 per cent more than that grown under 

 Vita glass. Compared with previous tests in which radishes under Vita 

 glass increased 71 per cent in weight and lettuce 76 per cent over the plants 

 under ordinary glass, the results are very inconsistent. The tests will 

 be continued. 



The Effect of Decomposing Paper on Plant Growth. (L. H. Jones). 

 Nitrogen deficiency in a plant may result from decomposing paper in a soil 

 or from a plant container made of paper in contact with the soil mass. 

 This has been well established by incorporating paper mulch in a soil and 

 also with improperly water-proofed paper flower pots. When paper mulcfi 

 is incorporated in a soil, nitrogen starvation may ensue unless an available 

 form of nitrogen is supplied to the plant. LTsing tomato seedlings in 

 four-inch pots with and without paper mulch in the soil, it was noted that 

 all plants made equally good growth for one month. At the end of the 

 second month, the plants in the soil containing no mulch were 33 per cent 

 taller than plants in a soil with mulch, and averaged nine axillary shoots. 

 The plants in the soil containing mulch were without axillary shoots and 

 were more yellow in color, indicating a lack of nitrogen due to decompos- 

 ing cellulose. 



The problem of obtaining good plants from paper pots is not one of 

 soil acidity nor lack of porosity. It has been demonstrated that better 

 plants can be grown in undrained glass containers than in porous clay 

 pots. When plants become yellow in paper pots, they can be made to re- 

 sume normal growth by an application of sodium nitrate. If the fibers in 

 the paper pot are so protected that decay is impossible, plants equal to 

 those grown in porous clay pots may be grown in these pots. 



Chlorosis of Snapdragon caused by an Excess of Lime. (L. H. Jones 

 and H. D. Haskins). Snapdragon iilants grown in a greenhouse soil made 

 from a sandy subsoil mixed with manure and lime became very chlorotic. 

 As the new leaves were yellow in the early stage of development the cause 

 seemed related to a deficiency of iron in the plant. When tested for re- 

 action, the soil was decidedly alkaline (pH 7.9). Pot work indicated that 

 the trouble could be overcome by leaching the soil with a 1 per cent 

 ."solution of sulfuric acid at the rate of one gallon per square foot. The 

 soil so treated was leached of acid with an equal volume of water and then 

 supplied with a complete fertilizer mixture. In the absence of the sul- 

 furic acid treatment, fertilizer materials of superphosphate, potassium sul- 

 fate, and ammonium sulfate, either alone or together, were ineffectual. 

 The iron of ferric chloride was not assimilable. Although snapdragons 



