﻿4 DEPARTMENT OF AGRICULTURE BULS. 1376-1400 



Fag« 

 Department Bulletin No. 1378. — Relation of Soil Conditions and 

 Orchard Management to the Rosette op Pecan Trees: 



Effect of soil treatment on the rosette of pecan trees 2 



Norfolk fine sandy loam 2 



GreenviUe sandy loam 7 



Laboratory examination of soils from rosetted and from nonrosetted 



pecan orchards 10 



Orchard soils examined 10 



Discussion 13 



Examination of the soil of good and of poor sections of orchards free 



from rosette 13 



Summary 16 



Department Bulletin No. 1379. — Electroculture : 



Normal electrical state of the atmosphere 1 



Electrical field employed in eleetrocultural experiments 2 



Electrocultural experiments with miscellaneous crops 3 



Eleetrocultural field experiments with grains 4 



Electrocultural experiments in the plant house 13 



Summary of experiments at Arlington Experiment Farm 15 



Review of other investigations in electroculture 17 



Experiments with soil currents 17 



Experiments with modified potential gradients 21 



Literature cited 32 



Department Bulletin No. 1380. — A Pathological Survey of the 

 Para Rubber Tree (Hevea brasiliensis) in the Amazon Valley: 



Preface 1 



General pathological conditions and sanitation 2 



Diseases of Hevea 3 



Host relationships 3 



Regional peculiarities 4 



Intercrops 4 



Destruction of jungle debris 6 



Special diseases 6 



Root diseases 6 



Stem and branch diseases 19 



Leaf diseases 33 



Fruit and flower diseases 61 



Injuries caused by phanerogamic plants 63 



Physiological disturbances and abnormalities 66 



Brown bast 66 



Wounds 58 



Preventltious and adventitious nodule structures 68 



Cortex nodules 70 



Abnormal exudations of latex 72 



Rubber pads 73 



Chlorosis of leaves 74 



Abnormal growths and conditions 74 



Soil and moisture relations 76 



Prepared rubber 77 



Fungi reported on Hevea 7.9 



Mistletoes on Hevea 94 



Algae on Hevea 96 



Bibliography 97 



Department Bulletin No. 1381. — Cost of Producing Hogs in Iowa 

 AND Illinois, Years 1921-22: 



General economic conditions 1 



The area studied 3 



Systems of hog production 4 



Methods of conducting study 6 



Cost of producing pork 7 



Cost of maintaining the breeding herd ^ 11 



Cost of fattening pigs for market 17 



Financial returns from the hog enterprise 29 



