CULTURAL DIRECTIONS 
459 
a shortage of the mineral elements, invariably result in 
a heavy growth of vine and foliage and a light crop of 
small fruits. While nitrogen is essential, it should be 
used in moderation. Its value is greatest early in the 
season, before the organic forms have had time to be 
changed by nitrification into nitrates. Numerous experi- 
ments show the value of spring applications of nitrate 
for this crop. Such treatment encourages a vigorous vine 
growth before the fruits begin to color and in most in- 
stances has been the means of increasing the yield. Not- 
withstanding the beneficial results arising from the use 
of nitrate of soda, it is admitted that part of the nitrogen 
should be derived from an organic form, as dried blood, 
tankage and fish scrap. For the late crop the soluble 
forms of nitrogen are not so useful, and yet in. thin soils 
they may be employed to advantage. 
The mineral elements must also be supplied in ample 
quantities, for without them the fruits will be small and 
inferior and the crop light. There should be a proper 
proportion of the three elements applied. This will 
doubtless vary greatly in different soils, or even on the 
same type, the amount of each to use depending upon 
previous methods of cropping and of soil treatment. 
A knowledge of the composition of the fruit and the 
vines assists in the determination of a satisfactory com- 
bination of fertilizing ingredients. Voorhees (“Fertiliz- 
ers,” p. 233) estimates a ton of the fruit and vines to 
contain the following amounts of nitrogen, phosphoric 
acid and potash: 
Composition of Tomatoes 
Nitrogen 
Phosphoric 
add 
lbs. 
Potash 
lbs. 
lbs. 
In fruit 
. . . 3-20 
I. OO 
5-4‘J 
Vines (green) .... 
. . . 6.4O 
I.40 
10.00 
Fie estimates that a yield of 10 tons an acre, with vines 
