No. VIII.] 



EXPERIMENTS ON POTATOES. 



40 



2°. The object of the two followmg series of experiments was to ascertmn — 

 1°. The relative effect of different saUri/; subslances applied along wUh f ami-yard 

 manure; and — 2°. Whether tlie effects were greater when mixed with the ma- 

 nure at the time of planting, or when subsequently applied, as a top-dressing, to 

 the growing plants. 



1°. Result of Experiments with saline substances in top-dressing Eoxly American 

 Potatoes. Planted 18tli April, top-dressed 1st June, and lifled 28th Sep- 

 tember, 1842. Low Field, Barochan. T!ie quantity of land in each plot 

 was one-eighth of an imperial acre. 



Remarks. — The soil is a light loam of good quality, subsoil hard, stoney till, and retentive 

 of water. The potatoes were planted with the spade at the distance of 26 inches between 

 drills. The manure, farm-yard dung at the rate of 40 cubic yards per acre, spread in the 

 bottom of the drills — cutsets laid on this and covered up. (The cut tubers planted were 

 the produce of those top-dressed last season (see Appendix, page 20). Came away strong 

 and healthy, of a dark green colour, and were very remarkable fn>m the contrast whicli 

 they presented to the same variety of Potato — planted alongside this experimental ground 

 • — that had not been dressed last season. These last came away weak, and of a yellowish 

 green colour, and, under the some treatment in every respect, did not produce so good a 

 crop by 15 twlls per acre). Nos. 1, 2, 4, 6, 8, and 9, had all the same effect in altering the 

 colour of the stems and leaves to a darker green. Nos 3 and 7 had not that effect, but No. 

 3 added greatly to the produce. No. 7 made no visible SiHerMion^ but hurTied the tops se- 

 verely at, the time of dressing, as did most of the others this dry season ; this burning was in 

 most cases only temporary. 



2°. Results of Experiments with different saline subHances, mixed, with farm- 

 yard dung at the time of planting, in growing Early American Potatoes. 

 Planted 29th April, and lifted 31st i^ugust, 1842. The quantity of land in 

 each plot was one-eighth of an imperial acre. 



' Dung 5s. 6d. per cubic yard, exclusive of cartage and spreading. 



t The silicate of potash or soluble glass was directly prepared from caustic potash an<J 

 sand or silex fug^d together. 



