FIELD CROPS. 729 



youug plants, and consequeully they are less efl5cieut as photosynthesizing 

 organs. He obtained a formula showing means for determining the age of 

 1". rulpina from its veinage, as the age (age being reckoned from the last repro- 

 duction from seed) of a plant of V. riilinna determines the character of its velu- 

 age. The juvenile veinage is restored only after sexual reproduction. 



The effects of kerosene and other petroleum oils on the viability and 

 growth of Zea mays, J. II. Whittkn (liitL III. Stale Lab. Nat. IIM., 10 (1914), 

 .1/7. 5, pp. 245-27S, pi. 1, fig. 1). — The author reports on several series of 

 studies with Zea mays as affected by kerosene imder different conditions. 



Grains of corn were not injured by immersion in kerosene for from 10 to 20 

 days if they were then freed from adhering oil and given very little moisture 

 during germination and initial growth. Dry, uninjured membranes were im- 

 permeable to kerosene, but moist membranes were not. 



While some uninjured grains of corn may remain in icerosene for eight years 

 without detriment, mechanical injury to the membranes permits destruction of 

 life in the embryo by kerosene within 75 days. 



Kerosene, while harmless in small i)roportions, was above those injurious 

 to germinating grains in proiwrtion to length of time of immersion and increase 

 in water content of the soil above the minimum required for germinaiicn. 

 Older seedlings absorbed safely larger quantities of kerosene. The injurious 

 effects of petroleum oil on germinating seed corn seemed to vary inversely as 

 the volatility of the respective oils. 



It is not considered advisable to treat seed corn with kerosene unless the 

 water content of the soil is under control. 



Injuries to plants by smoke, g'as, and ashes, II. C. Muller et al. (Ber. Agr. 

 Chem. Kontioll u. Vers. Stat. Pflanzcnkrank. Prov. Sachsen, 1913, pp. 21-23). — 

 This is a brief report on the chemical or physical injuries to various classes of 

 useful or ornamental plants by gaseous and solid emanations from locomotives, 

 electric ])lauts, and other .sources of abundant combustion products. The in- 

 juries due to nematodes, etc., attacking the plants weakened by the action of 

 such ])roducts are included. 



FIELD CROPS. 



Beport of the agronomy department, C. K. McClelland and C. A. Sahr 

 (Hawaii Sta. Rpt. 1914, pp. 36-42, pi. 1). — In a test with rice, a Japanese vari- 

 ety, Bezembo, and a Chinese variety, Long Nyah Yin, are noted. 



" In an exi)eriment with a sweet sorghum, a nonsaccharin sorghum, and 

 Japanese cane for yields of forage over a long period, the sweet sorghum has 

 yielded in four cuttings 47.1 tons per acre and the nonsaccharin variety 49.8 

 tons in three cuttings. The Jajtanese cane, cut for the first time, yielded 102 

 tons of forage per acre 4.53 days after planting." 



Sudan grass planted November 22, 1913, is noted as yielding 31 tons of green 

 forage at the first cutting, March 9, 1914, and 30 tons at the second cutting, 

 May 8. Sudan grass seems to be much superior for lower and Tunis grass for 

 higher elevations. Among other grasses " Mitchell grass (-4sfre&?rt triticoides), 

 Judd grass (Lcptochloa' Hrgata), Pa.'ipaluui stolonifentm. molasses gra.ss 

 (Melinis minuti flora), P. rirgatum, Phalaii.s hitlbosa, and Texas blue grass are 

 worthy of mention. The American 'Buffalo grass' (Biilhilis dactyloides) 

 from Kansas seed started very slowly but is making much better growth as the 

 summer months come on." 



Three varieties of saltbushes are montioneil as having shown desirable quali- 

 ties as sturdy, long-period cover crops, namely, Atriplex nummularia, A. lep- 

 tncarpa, and A. halimoides. Trials with buckwheat, flax, and rape show these 

 to be crops of value for Hawaiian conditions. 



