CHAPTER III. PROCEDURE 
Nature of Estimates 
Estimates of losses are included in this report, whether or not they 
arise from causes that are preventable with present technical knowledge. 
It has not been possible, however, to obtain complete estimates of all 
such losses. 
The loss estimates are limited to the more important factors and in- 
cludes: 
(1) Diseases and insects affecting field, forage, fruit, nut, 
vegetable, and drug crops, pastures and ranges, and 
ornamental plants (Chapters IV and V). 
(2) Mechanical injuries, weeds, and hail damage to crops, and 
fire and brush damage to grazing and range lands (Chapter VI). 
(3) Mechanical deficiencies in harvesting field crops, and 
rodent and insect damage during storage of crops or their 
products (Chapter VII). 
(4) Losses in marketing, processing, and distributing agricul- 
tural crops (Chapter VIII). 
(5) Fire, wind damage, insects, and diseases affecting forest 
growth and forest trees (Chapter IX), 
(6) Diseases, internal parasites, and insects affecting live- 
stock (Chapter X). 
(7) Erosion and other causes of deterioration of crop, forest, 
and range lands and damage to watersheds from floodwater 
and sediment (Chapter XI). 
Losses in quantity as well as quality and losses to land are included. 
The land losses, of course, affect production over a period of several 
years. 
Other sources of loss are recognized, although detailed estimates 
could not be made of them. They are discussed in Chapter XII, and 
include (1) loss of calories and other food values due to the discard 
of edible portions of food in the kitchen or to destruction of nutrients 
in cooking, (2) losses caused by birds feeding on agricultural crops, 
and (3) the labor and materials involved in the control of pests and 
other factors. 
Computation of Losses 
Most of the losses are expressed as annual production lost in terms of 
(1) quantity, (2) value, and (3) equivalent acreage. Quantitative 
estimates of losses, in bushels, tons, etc., indicate the extent to which 
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