FIELD CROPS. 759 



The lands suitable for cotton culture in the Protectorate are estimated at 1,340,000 

 acres, including 1,250,000 acres of coast lands, w hich are best adapted to the crop. 



The specific effect of phosphoric acid on oat plants grown on black peaty- 

 sand, II. Clausen [Jour. Landw. } 53 (1905), No. 3, pp. V18-228, fig. 1).— The 

 ivsults of a series <>t' pot experiments showed that on this soil tin- use of phosphoric 

 acid regularly increased the total yield and decreased tin- relative yield of grain. 



Dryness and aeration of the soil reduced the effect <>n the yield of grain, while 

 moisture and a lessened aeration so increased it that even the absolute yield of -rain 

 was largely diminished. The average data also indicate a reduction in the yield of 

 grain when the total yield is increased by means of phosphoric acid. The applica- 

 tion of this element seem- to interfere with t he translocation of material w it hill the 



"at plant, and the fact that it favors the production of new. -hoots from the lower 

 node after the main stem ha- headed is considered a good basis for this conclusion. 

 The growth of these younger shoots is made at the expense of -rain development. 



It was also observed that the plants receiving phosphoric acid had bluish-red 

 stems while the stems of those grown without an addition of this element were light 

 yellow in color. It was shown by chemical analysis that the bluish-red plant- con- 

 tained much more lime hut considerably less ox id of iron than the light yellow one-. 



The effect of soil compression on the development of oats, ('. vox Seelhoest 

 and Kezymowsk] [Jour. Landw.,53 {1905), X". ./, pp. ?69-278). — Field experiments 

 in this line have been previously reported I E. S. If., 13, p. 541). 



In the work here described plants were grown in vegetation boxes and the effect 

 of compacting the soil was noted. Oats were sown April 14, and on May 11 the .-oil 

 was compacted in one box while in the other the surface was hoed. From the 

 results secured it is concluded that rolling reduces the tendency to lodge mainly 

 because it retards the general development of the plant by lessening the air supply 

 of the roots, decreasing nitrification in the soil, and reducing root growth. The 

 reduction in the general growth of the plant is especially marked in the early vege- 

 tative period. 



This soil treatment also retards heading, and it is believed that this results in a 

 shortening of the lower internode and possibly a thickening of the >tems and a 

 st ren-t helling of the cell walls. A top-dressing of nitrate of soda is recommended to 

 counteract a possible reduction of the yield through rolling. 



The influence of soil moisture on the development of oats at different stages 

 of growth, (\ vox Seelhoest and Krzymowski (Jour. Landw., 53 (1905), X<>. .;, pp. 

 857-370). — Oats were grown in 24 pots, each filled with 22 kg. of soil adequately 

 fertilized. 



Sixteen kernels were sown in each pot, hut the stand was later thinned to8 plants. 

 The pots wen' divided into 2 series, the first being kept dry in the beginning and 

 watered later on. and the second being kept moist at tiist with no waterapplied dur- 

 ing the later stages of growth, [n the first series the check pot- received no water 

 and in the second they were supplied with moisture during the entire period of the 

 te-t. 



The results showed that when water v\as supplied in the first series beginning with 

 July 1, the increase in total yield was 27.7 per cent; beginning with June 15, 48.8; 

 June 1, 103.2; May 15, L36.3; and .May 1, L78.9 per cent. The corresponding 



increases in the yield of grain were 21.4. 40. I. L07, L26.3, and 158.7 per cent. In the 

 second series, in which the water supply was discontinued on these dates, the total 

 yields based on the yield of the check test as l(l() pel' cent, were a- follows: .Inly 1. 

 B5 - percent; June 15, 67.3; June 1. 52.3; .May 15, 44.:;; and May 1, 41.:; percent. 

 The corresponding yields of grain amounted to 74.4. 62.3, 48.6, 44. s. and 40.8 per 

 cent of the yields in the check te-t-. 



The influence of the moisture content of the soil on the structure of the plant, and 

 particularly the development of the panicle, is also briefly noted. 



