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EFFECT OF BORAX ON GROWTH AND YIELD OF CROPS, 27 
assimilation of iron, similar to the action of an excess of calcium, or, as observed, with 
an excess of manganese compounds. Injurious quantities of borax cause tipburn; 
in still stronger concentrations wilting ensues, first of the older leaves and then of the 
entire plant. Borax toxicity is also evidenced in the foliage by a banded bleaching 
of the chlorophyll of the leaves especially marked at the margins. The extreme tips 
are often killed, but not the margins. When the injury is less severe the leaves are 
at first streaked with pale green and may later regain their normal color. 
Beans.—Borax is especially injurious to beans and is harmful at germination and 
retards development in the early stages of growth. The injury first appears on the 
margins of the first leaves which unfold, especially the tips. Where injury is severe, 
the entire leaf soon turns yellow, then white, which is followed by a killing of the 
tissues, working from the margin inward. It has been observed that the taproot 
of the bean plant was the most injured portion in the poisoned seedling. The root 
nodules were markedly reduced in size and number. In all cases of borax injury 
to beans, a dwarfed plant resulted with a final reduction of both vines and fruit. 
Cotton.—Cotton plants affected by borax both in pots and under field conditions 
are weak, slender, and frequently die after having made a growth of an inch or two. 
At the time when the first pair of true leaves should appear, the seedlings show no 
apparent growth for several weeks, dead sections appearing along the margins of the 
seed leaves which eventually become dry, and the plant dies. Where injury is less, 
the plant shows a stunted growth and early maturity. The foliage shows a yellowed 
effect, and the leaves become dish shaped. The resultant effect is a broken stand, 
oun plane in the field of the same age vary greatly in size. The yield is greatly 
reduced. 
Tobacco.—Plummer and Wolf (17) describe the effects of borax on tobacco as fol- 
lows: The roots of borax-affected plants are severely stunted, tend to be densely 
clustered near the end of the main root, and are all short and fibrous. The lower leaves 
are pale green, thicker, and less broad. The tissues most distant from the principal 
veins are palest and may become dead and dry. The leaf margins and tips are rolled 
downward and become rimbound. The root development of plants which made 
considerable growth is near the surface of the soil and near the tip of the main root, 
with few or no roots between these two groups. The stand in borax-treated fields 
is broken, and the plants lack uniformity in size. 
It would appear from the symptoms described for the various crops 
that the main characteristics of borax-affected plants are (1) retarded 
germination; (2) general dwarfing of the plant including both roots 
and tops; (3) absence of normal color, which may be characterized 
by bleached and yellowed foliage, especially leaf tips and margins; 
and (4) reduced growth and yield. ’ 
SUMMARY. 
_ The results presented herein show that borax proved to be harmful 
to plant growth. The experimental work was designed in order to pre- 
clude any other possible harmful factors. For one thing, practically 
ure borax was employed to mix with the fertilizers. ‘The fertilizer 
itself was made from practically borax-free nitrogen, phosphoric acid, 
and potash salts. Varying quantities of borax, ranging from 1 to 400 
pounds per acre were mixed with fertilizer and applied to the soil in 
three different ways. In order to properly compare the effect of the 
borax, one application of borax-free fertilizer was made in the same 
way and applied in the same quantity. Fimally it was decided 
essential to carry on the experimental work on a number of soil types 
and with different crop plants as indicators of borax injury. 
The results show that the potato can tolerate a greater quantity 
of borax than plants like corn or beans, which were injured by com- 
paratively small quantities of borax. The degree of injury, however, 
was modified considerably according to the rainfall. Apparently the 
depth and distribution of rainfall is the most prominent factor con- 
cerned. Heavy rainfall in one section caused the borax to leach 
