678 Summary of Agricultural Experiments, [nov., 



acid) per acre, while the effect of sulphate of potash in addition and 

 of ground lime was also tested. 



In 1908 the plots were stocked with newly clipped Cheviot din- 

 monts, the unmanured plot with 11 and the manured plot with 16 

 sheep. The numbers were later increased to 15 and 22 respectively. 

 In 1909 13 and 19 sheep were used, and in 19 10 15 and 21. In this 

 last year several sheep on both plots were fat by August 20th, when 

 they were removed and the numbers made up to 14 and 20. During 

 the winter and spring the plots were grazed along with the rest of the 

 field till the end of the first week in June, and then reserved for the 

 experimental sheep. 



The live weight increases in the three years from the manured and 

 unmanured plots were respectively as follows : — 1908, 518 lb. and 

 253 lb.; 1909, 532^ lb. and 362J lb.; 1910, 545 lb. and 325 lb. This 

 gives an increase due to the use of manures of 655 lb. Valuing this at 

 2^d. per lb., and deducting the cost of the manures (£5 iSs.), the 

 profit is £3 135. for the four acres, or iSs. 3d. per acre. The improve- 

 ment due to the manures was in reality much greater. The effect of 

 the manures was by no means exhausted by 19 10, and the increase 

 of clover, which took place on the manured plots, is likely in addition 

 to have a beneficial influence for a considerable time. Moreover, the 

 experimental period did not cover the whole of the grazing season, and 

 it is estimated that this would bring the profit up to 30s. per acre. 



There were no marked differences in the increases in live weight on 

 the sub-plots due to the addition of lime or omission of sulphate of 

 potash. 



Manurial Experiments (Shepton Mallet Grammar School, nth Ann. 

 Rept., 1910). — These manurial trials have been carried on for eleven 

 years. The crops are mixed grasses without clover, now in its seventh 

 year on the ground, mangolds, and broad red clover, second year. 

 The crops in 19 10 and the results of the continuous manuring are given 

 in this report. Nitrate of lime was used with good results on the 

 mixed grasses and mangolds. 



Field Crops. 



Breeding of Rust-resistant Wheats (/. B. Pole Evans, Jour. Agric. 

 Science, Vol. iv., Pt. 1, May, 191 1 : Cambridge University Press). — 

 This work is concerned with South African cereal rusts, but some 

 of the conclusions reached are of general importance. The Black rust 

 (Puccinia graminis) was the species investigated. Two varieties of 

 wheat which are immune to Black rust in the district where the work 

 was carried on and two susceptible varieties were crossed, and the 

 resulting hybrids, as well as the parents, were inoculated with the 

 rust. A number of experiments showed clearly that the hybrids were 

 even more susceptible than the susceptible parents. This is in accord- 

 ance with the results of Biffen's trials with Yellow rust (Puccinia 

 glumarum). Further, it was found that the rust taken from these 

 hybrids now readily infected the immune parent plants, and also 

 rust from the susceptible varieties which had contracted it from the 

 hybrids behaved in the same way. It appears therefore that a hybrid 

 plant may, by acting as an intermediary, play an important part in the 



