HORTICULTURE. 



361 



The influence of electricity on vegetation, F. Paulin {uinn. Sta. Agron. Oise 

 [Fj-nncel, 1903, No. 35, }yp. 35-40). — In the work conducted electricity was con- 

 veyed to the plants by means of urpight rods placed in the ground with a network of 

 wire connecting them below, and placed deep enough in the ground not to interfere 

 with cultivation. Under the influence of the electricity thus generated tiie yield of 

 potatoes was increased 50 per cent. Cauliflowers matured a month earlier than 

 plants not imder the influence of electricity. The yield of beans and peas was 

 nearly doubled. Figs matured perfectly out of doors, as did also grapes for wine. 



In another experiment 50 tomato seeds subjected to the influence of electricity 

 produced 45 plants, while 50 other seeds not thus treated gave but 35 plants. With 

 another variety 49 seeds subjected to electricity produced 45 plants, while 49 

 untreated seeds produced only 33 plants. It is stated in this connection that no dif- 

 ference was noticed in the after-growth of tomato plants whether the seed had been 

 subjected to electricity or not. It is also stated that the seed not subjected to elec- 

 tricity was sown dry, while the other seed had been moistened. 



Preliminary report on the root and stem, development of leaf cuttings, 

 and its importance in plant reproduction, H. Lindemuth ( Gartenflora, 52 {1903) , 

 No. IS, pp. 479-4S5). — The author discusses the propagation of plants from leaf cut- 

 tings, and gives a table showing the length of time required for the rooting of some 

 28 species of plants propagated by leaf cuttings. A list is also given of 13 species 

 which could not be propagated by leaf cuttings. The author states that with the 

 citrus leaf cuttings have often rooted, but in his experience never produced stems. 



Orchard cover crops in Delaware, C. P. Close {Delaware Sta. Bid. 61, pp. 32, 

 Jiga. 9). — This bulletin contains an account of the seeding, growth, and comparative 

 value of a large number of different plants and combinations of plants as orchard 

 cover crops on different soils in Delaware. The work was begun in 1901 and the 

 results secured during 2 seasons are reported upon. The weight of the top growth 

 and the root growth to a depth of 12 in. of the different crops grown at the station 

 was determined. The tops and roots were analyzed and the total amounts of nitro- 

 gen, potash, and phosphoric acid in each are recorded. The moisture content of 

 the soil in which the cover crops grew, as compared with cultivated soil alongside, 

 was also investigated. All these matters are reported in considerable detail, the 

 behavior of each crop or combination of crops in each of the different localities for 

 each of the 2 years being noted under separate headings. 



An idea of the growth and fertilizing value of several of the more prominent crops 

 is shown in the table below. These crops were seeded July 22 at the station on a 

 clay-loam soil and were harvested from November 7 to 22 following: 



]]^eight and composition of orchard cover crops in Delaware. 



Crop. 



Weight 



of green 



tops. 



Cowhom turnip 



Rape 



Crimson c:lover 



Red clover 



Alfalfa 



Hairy vetch 



Cow peas 



Soy beans 



11,297 



20, 020 



1«, «00 



G,909 



5, 430 



13, l.'SO 



5, 933 



10, 952 



Weight 

 of tops 

 and air- 

 dried 

 roots. 



Pouv(h. Pounds. 



31,819 



27,484 



19,213 



8,121 



7,410 



13, 750 



6,327 



11, 708 



Nitrogen in- 



Tops. 



Pounds. 



64.4 

 116.2 

 128. 2 



69.8 



54.8 

 108.0 



65.2 

 130.9 



Tops and 

 roots. 



Pounds. 

 109. 5 

 161.3 

 134.4 

 103.0 

 95.2 

 121.2 

 69.5 

 140. 2 



Potash in — 



Tops. 



Pomids. 

 80.3 

 148. 2 

 84.0 

 46.5 

 32.2 

 78.4 

 47.4 

 46.2 



Tops and 

 roots. 



Pounds. 

 142. 6 

 161.3 

 88.2 

 56.4 

 41.7 

 85.5 

 49.8 

 48.0 



Phosphoric acid 

 in — 



Tops. 



Pounds. 

 14.3 

 41.8 

 59.2 

 18.9 

 13.1 

 22. 5 

 16.6 

 37.8 



Tops and 

 roots. 



Pounds. 

 26.0 

 46.9 

 61.2 

 29.0 

 21.6 

 27.2 

 18.9 

 40.2 



The root growth to depths of 8 and 12 in., respectively, of some of the more 

 important croj^s was determined. The weight of the roots of crimson clover in the 

 first 8 in. of soil was 381 lbs., of red clover 1,185 lbs., of alfalfa 1,972 lbs., of hairy 

 vetch 584 lbs., of cowpeas 301 lbs., and of soy beans 717 lbs. In the next 4 in. of soil 



