CONTENTS. 



Department Bulletin No. 741. — Effect of Grazing uroN Aspen Repro- 

 duction — Continued . 



Comparative injury to aspen sprouts by sheep and cattle Iff 



Height at which reproduction is exempt from grazing injuries 18 



Height to which sheep browse 18 



Height to which cattle browse 21 



Rate of growth of aspen reproduction 21 



Silvicultural management of aspen 23 



Methods of cutting 23 



Methods of brush disposal i 24 



Summary 25 



Recommendations • 27 



Department Bulletin No. 742.- — Production of American Egyptian 

 Cotton: 



Community production of cotton 1 



Sources of long-staple cotton 2 



Character and supply of Egyptian cotton 3 



American consumption of Egyptian cotton 4 



Production of Egyptian cotton in America 5 



Future possibilities of the industry 7 



Comparison of American and Egyptian conditions 8 



Early attempts to establish Egyptian-cotton growing in the United States. 10 



Beginning of experiments in the Southwest 10 



Unsatisfactory character of the original stocks 11 



Development of more uniform varieties 12 



Solving the problems of commercial production 13 



Cooperative organization of the growers . 14 



Labor for picking 15 



Community credit for financing the crop 17 



Ginning in relation to production 17 



Grading the crop 18 



Marketing the crop 19 



Maintenance of the seed supply 19 



Agricultural relationships of the crop 21 



Tillage methods 22 



Late thinning and close spacing 22 



Undesirability of ratooning Egyptian cotton 24 



Enemies of the crop 24 



Conditions of successful Egyptian cotton production 25 



Conclusions 26 



List of publications bearing on Egyptian cotton growing in the South- 

 western States 28- 



Department Bulletin No. 743. — The Avocado in Guatemala: 



Importance of the avocado 1 



Extent of avocado culture in Guatemala 2 



Popular uses of the avocado 4 



Climatic zones of Guatemala 6 



Classification of avocados 8 



Avocado culture in the Guatemala highlands 10 



The West Indian race of avocados in Guatemala 3ff 



The Mexican race of avocados in Guatemala 37 



The coyo . 37 



Select Guatemalan avocado seedlings introduced into the United States. . 42 



Department Bulletin No. 744. — Cooling Milk and Storing it and Ship- 

 ping it at Low Temperatures: 



Scope of experimental work 1 



The principle of cooling 1 



Cooling milk on the farm 4 



Effect of low temperatures on bacterial count of milk 4 



Cooling efficiency of various kinds of tanks. 5 



The construction of milk tanks 15 



How to cool milk quickly 18 



Efficiency of different kinds of cans for holding milk 21 



Transporting milk at low temperatures 24 



Summary 28 



