XIV INDEX 



Oklahoma, production of corn in 13-14 



acreage 6-7 



production 13-14 



valuation 22-23 



Osmosis 61 



Oswego 336 



Overhead expenses in production of corn 207 



Oxygen as a plant food 58, 67 



P 



Palatability of corn 355 



Paper from corn stalks 343 



Parts of corn kernel, separation 347 



Peonage system of Mexico 24 



Phosphorus 69 



Photosynthesis 67 



Physical changes caused by water 62 



Pith of corn stalk 43 



Planter, calibrating of 133-135 



Planting corn 159-175 



checking 159 



depth of 162-163 



distance between rows 164-165 



for fodder 366 



for silage 350 



drilling 172 



listing 173-175 



replanting , 172 



thickness of 165-171 



time of 161-162 



Plant foods (see "Soil Fertility") 67 



elements of 67-70 



calcium 70 



carbon 67, 70 



humus 86 



nitrogen 67, 69 



oxygen 58-67 



phosphorus 69 



potassium 69 



other plant foods 70 



from the air 67 



from the soil 68 



in farm crops 70 



Plant selection of seed corn 101 



Plowing 143-153 



deep plowing 146 



depth of 145-147 



fall plowing 147-149 



objects of 143-144 



points of merit in 144-145 



shallow plowing 146 



sod ground 151-153 



spring plowing 149-150 



Pod corn (Zea tunicata ) 36 



Pollination 49 



cross pollination 49, 459-460 



hand pollination 459-460 



Pop corn (Zea everta) 36 



Portugal, production of corn in 9, 32 



Potassium 69 



Precipitation, relation of to corn growing 65,75, 76-83 



