16 RESULTS OF COTTON EXPERIMENTS IN 1911. 



Egyptian cotton has the habit of forming subterranean shoots when 

 the stalks are frozen to the surface of the ground below the level of 

 the original seed leaves. The new shoots appear in the form of irreg- 

 ular nodules, "wdth a superficial resemblance to crown galls. They 

 probably represent the development of dormant root primordia, for 

 they always arise from the four grooves where the lateral roots come 

 out from the taproot, never from other parts of the surface. The 

 first leaves of these regenerated shoots are very irregular in shape, 

 but the normal form is soon attained and the new stalk makes an 

 entirely normal development.^ 



The readiness of the Egyptian cotton in forming these subterranean 

 buds on the overwintered roots suggested the idea that cuttings 

 would callous and root readily under the same conditions and thus 

 open up a third possibility of utilizing hybrids by propagation from 

 cuttings. The first attempt of this kind was made by IVIr. McLachlan 

 in May, 1911, with cuttings of new- wood branches that had developed 

 on overwintered plants. Notwithstanding the lateness of the season 

 and the absence of any special care or precaution to induce the root- 

 ing of the cuttings, about 10 per cent survived and grew into very 

 vigorous and productive plants. The jDOssibility of carrying such 

 cuttings through the winter by different methods of protection and 

 handling is being tested at Bard, Cal. 



CONTROLLING THE FORMATION OF BRANCHES IN EGYPTIAN 



COTTON. 



Pre\nous experiments having demonstrated the possibility of pro- 

 ducing Egyptian cotton of high quality in the irrigated districts of 

 Arizona and southern California, it becomes necessary to understand 

 the cultural peculiarities of tliis type of cotton. The most obvious 

 cultural difference between the Egyptian and Upland types of cotton 

 is the greater vegetative vigor or luxuriance of the Egyptian. Though 

 the Upland cotton is similarly affected by combinations of fertile 

 soil, moisture, and heat, the Egyptian cotton is much more suscep- 

 tible and often grows two or tlu-ee times as tall as Upland cotton 

 planted in adjacent rows. 



In addition to the greater height of the plants, the Eg}q)tian cotton 

 also produces a much larger number of large "wood limbs" or vege- 

 tative branches. Under field conditions these branches grow in an 

 upright or ascending position, forming so dense a mass of foliage that 

 no normal fruiting branches can develop on the lower part of the 

 plant. The result is that fruiting is largely confined to the top of the 

 plant, making the crop very late in comparison with Upland cotton. 



1 Arrangement of Parts in the Cotton Plant. Bulletin 222, Bureau of Plant Industry, U. S. Dept. of 

 Agriculture, 1911, p. 23. 



[Cir. 96] 



