CONTENTS. 



Department Bulletin No. 957. — Investigations of the White-pine 



Blister Rust: Page. 



Scope of investi,s:ations 1 



Origin and distribution of Cronartium ribicola 3 



Host^ of Cronnrliuin ribicola 11 



Pines infected and likely to become infected 11 



Inoculations of Cronartiu'in ribicola on pines 12 



Species of Ribes tliat have l)een infected naturally 14 



Inoculations of Cronnrtinnt. ribicola on Ribes 16 



Susceptiljility of Ribes species and varieties to Crouiriinni ribicola.. . 23 



Life Jiistory of ('ronartiwjn ribicola 24 



The Peridermium stage on pine? 24 



The Cronartium stage on Ribes 40 



Overwintering of Cronariium ribicola 68 



Important dates in tlio life history of Cronartium ribicola 72 



Control of the wJiito-pine blister rust 73 



Significant factors wliich determine control 73 



Experiments in control in Europe 76 



Experiments in control in^orth America 80 



Statu=i of the control of white-pine blister rust 89 



Literature cited 90 



Department Bulletin No. 958. — -Development op Tubers in the Potato: 



Scope of the experiments 1 



Work of previous investigators 1 



Description of the tuber-bearing parts 4 



Details of the experiments 4 



Summary 25 



Literature cited 27 



Department Bulletin No. 959. — Experiments and Suggestions for the 

 Control op the Codling Moth in the Grand Valley op Colorado: 



The Grind Valley of Colorxdo. ._. 2 



Comoiri^on of the climatic conditions of Grand Junction, Colo., and 



Rochester, N. Y 2 



Spraving experiments in the Grand Valley 3 



Sm'aving experiments in 1915 4 



Sorxving experiments in 1916 7 



Soriving experiments in 1917 11 



Sor xving exr)erimonts in 191 8 25 



Summarv of results 29 



Suggestions for control of the codling moth in the Crind Valley of Colorado . SO 



Avoid presence ot spray residue on harvested fruit 33 



Soriv materials 34 



Sorxving equipment 34 



Supplemental control measures 35 



Banding 35 



Codling-modi trap 35 



Department Bulletin No. 960. — ^The Relation of Water-raking to the 

 Keeping Quality op Cranberries: 



Methods of harvesting cranberries 1 



Storage conditions 2 



Present practice in water-raking 3 



Important factors in drying cranberries 3 



Injurv during submergence 4 



Age of the berrv at the time of submergence 4 



Temperature of the water 5 



Oxvgen content of the water 5 



Oxygen content of waters used in flooding cranberrv' marshes in Wisconsin. 6 



Experimental tests of the keeping quality of water-raked cranberries 7 



Summarv 11 



Practical suggestions 11 



Literature cited 12 



