No. 2, September. 1920) AGRONOMY 155 



they are naked and given all ordinary conditions favorable to germination. The optimum 

 temperature for the process of after-ripening lies in the region of 4 to 5°C, and a constant 

 temperature in these limits is very much more favorable than alternations between it and 

 higher or lower temperatures. At freezing temperatures, after-ripening of these embryos 

 progresses very slowly if at all, while temperature periods above 10°C. are especially detri- 

 mental to the process. The facts disclosed by the invest igation raise the question whether 

 nurserymen who layer their seeds to produce after-ripening would not do better to put the 

 seeds in cold storage houses at optimum temperatures of 4 to 5°C., which would lead to a 

 much more rapid and complete after-ripening than is attained in layering under fluctuating 

 temperatures. It is the belief of the author that such methods should give returns in a 

 greater percentage of seeds producing plants and in the general high vigor of the plants 

 resulting from completed after-ripened embryos. — M . T. Munn. 



1124. Cross, W. E. The Kavangire cane. Louisiana Planter and Sugar Manufacturer 

 63 : 397-399. 1 Jig. 1919— See Bot. Absts. 5, Entry 2113. 



1125. Day, James W. The relation of size, shape and number of replications of plats to 

 probable error in field experimentation. Jour. Amer. Soc. Agron. 12 : 100-105. 1920. — Varia- 

 tion is reduced by increasing the size of the plat to one-twentieth of an acre or over. Most 

 accurate results are obtained from plats that are long and narrow and extend in the direction 

 of greatest variation of the soil. An increase in the number of replications of a plat of given 

 size increases the accuracy of the results. — F. M. Scherlz. 



1126. Deem, J. W. Pasture top-dressing test in Waipukuraw county. New Zealand Jour. 

 Agric. 19: 295-296. 1919. — Sheep were used in these experiments and the results for two 

 seasons indicate that it is well worth while to top-dress. — N. J. Giddings. 



1127. Descombes, Paul. Le reboisement et le developpement economique de la France. 

 [Reforestation and the economic development of France.] M6m. Soc. Sci. Phys. Nat. Bordeaux 

 VII, 2: 103-217. 2 fig. 1918. 



1128. Descombes, Paul. Installation d'exp6riencesprolongeessurleruissellement. {Pro- 

 tracted experiments upon stream-flow.] Mdm. Soc. Sci. Phys. Nat. Bordeaux VII, 2: 17-35. 

 2 fig. 1918. 



1129. Doblas, Jose Herrera. El trigo tremesino. [Three-months wheat.] Bol. Assoc. 

 Agric. [Espafia] 12 : 47-52. 1919. — Discusses a variety of wheat known as "Tremesino" (three- 

 months) secured by selection from the common fall type planted in Spain. Yields were much 

 less than with the fall variety and it is not recommended for planting except where planting 

 at the usual time has been impossible. The variety yielded in four experiments an average 

 of 10.75 hectoliters per hectarea. — John A. Stevenson. 



1130. Doblas, Jose Herrera. Estudio sobre el cultivo de la almorta. [Studies in the 

 cultivation of the grass pea (Lathyrus sativus).] Bol. Assoc. Agric. [Espafia] 11: 665-674. 

 1919. — Botanical classification, uses, varieties, cultivation and yields of Lathyrus satimif 

 (grass pea). — John A. Stevenson. 



1131. Duncan, J. Noxious weeds. New Zealand Jour. Agric. 19: 366-368. 1919. — It is 

 urged that more attention be given to the destruction of noxious weeds. Weeds should be 

 destroyed before seeding and the assistance of the public should be enlisted to destroy weeds 

 as soon as they are observed. Methods of weed dissemination are discussed and means of 

 prevention are indicated. It is suggested that in sowing to pasture the best of seed and 

 plenty of it should be used in order to obtain a good close sod. This tends to choke out and 

 prevent growth and spread of weeds. Farmers should not admit thrashing machines to their 

 farm9 until the machines have been thoroughly cleaned. — N. J. Giddings. 



