138 EXPERIMENT STATION RECORD. [Vol. 41 



the Guam Experiment Station is said to liave shown considerable resistance. 

 Several standard varieties of corn received from the Bureau of Plant Industry, 

 U. S. Department of Agriculture, failed to produce any grain, while certain 

 other varieties varied in yield from 10.9 bu. per acre of shelled corn for 

 Northwestern Dent to 39.2 bu. for Creole, as compared with 46.7 bu. for 

 Native Guam. Cuban Red, introduced by the College of Hawaii, also showed 

 raai'ked resistance to leaf-hopper attack but possessed somewhat inferior 

 drought-resistant qualities. 



Of six varieties of button clover tested, Medicago saitellata and M. orbiciil- 

 ans alone made promi.slng growth. M. scutellata, although attaining consid- 

 erable size, was killed off by aphids, while M. orbicularis gave the best results 

 when the trailing stems were supported and partially shaded bj'^ Bermuda 

 grass. Plantings of annual types of white sweet clover, received from the 

 U. S. Department of Agriculture and from the Iowa Experiment Station, have 

 made favorable growth. Duplicate plantings of so-called Proliflkeeno grass 

 received from Fabens, Tex., produced at the rate of 1.5.3.5 tons of green forage 

 per acre from 55 to 60 days after planting. It is said to resemble .Johnson 

 grass closely in the appearance of underground suckers shortly after cutting. 



In fertilizer and manurial experiments with edible canna (Canna edulis) the 

 maximum yield of tubers, 42.83 tons per acre, followed an application of 250 

 pounds each of ammonium sulphate, superphosphate, and sxdphate of potash, 

 as compared with a yield of 28.43 tons from the check. Observations on the 

 utilization of spherical and cylindrical types of tubers for sets resulted in 

 yields amounting to 32.02 and 37.13 tons per acre, respectively. 



Further observations of the effect on the yields of different forage crops of 

 soil heating and manuring at Castner again demonstrated the high value of 

 stable manure on manganese soils, crop yields being considerably increased 

 over all other methods of handling. Spraying Peruvian alfalfa with copperas 

 the first and second week after each cutting resulted in increases in yield in 

 the succeeding cuttings ranging from 4.9 to 228.4 per cent over the unsprayed 

 crop. Japanese cane sprayed every 2 weeks for a period of 6 months showed an 

 increase in yield of 43.5 per cent when harvested 6 months after the spraying 

 was discontinued. Spraying alfalfa with copperas and fertilizer compounds, 

 including lime, sulphate of potash, and superphosphate, resulted in decided 

 increases in yield in almost every case over drilling in the fertilizer. 



Hill selection of potatoes both to increase the yield and to seciire a blight- 

 resistant type at the Haiku (Maui) substation is said to have given some suc- 

 cess. Dibble Russett produced 180 bu. of marketable tubers as compared with 

 100 bu. from iniselected seed. The potato industry is reported to be increas- 

 ingly affected by the potato mite. Lime-sulphur spray or sulphur alone has 

 proved to be an effective remedy. 



Work with alfalfa on the Glen wood (Hawaii) substation indicates that 

 seeding may be done in the field instead of in seed plats or nursery seed beds, 

 as was formerly deemed essential to successful alfalfa production, providing 

 care is exercised to plant when cutworms are not plentiful. In variety tests 

 with potatoes, yields have been secured amounting to from 35.7 I)ags (100 lbs. 

 each) per acre for Vermont Gold Coin to 108 bags for Hamakua Hybrid (light 

 variety). In an effort to develop a fiber industry for areas near Glenwood 

 which can not be used for sugar-cane production, trials have been made with 

 sisal, New Zealand flax, hemp, flax, and Manila hemp, all but the last giving 

 some promise for the future. 



[Report of field crops work in New Mexico, 1917—18] (Neio Mexico Sta. 

 Rpt. .1918, pp. 27-29, 32, 33, U-47, figs. ,3).— The progress of work previously 

 noted (E. S. R., 38, p. 633) is briefly described, including observations on 



