than any trees there located. Nuts from that tree might well be
tested and compared with nuts from other trees.
2) The Banana Blight
The banana blight in Central America threatened for a while to be as
destructive as the chestnut blight in this country. It was due
admittedly to an attack by soil fungi, but no fungicide to foliage or to
the soil served its purpose. However, the proper restoration of
bacterial life in soils to keep the soil fungi in check proved
effective. This was a matter not of the presence or absence of any one
inorganic nutrient, but of restoring to soils the balance of fertility,
an abundance of organic matter as food for bacteriae. Dr. George D.
Scarseth, West Lafayette, Ind.[4], is one of those largely responsible
for correcting this epidemic. His experience may prove useful to nut
growers, so that they may not live in constant fear of another blight
epidemic such as the one that exterminated our chestnuts only a
generation ago.
3) Tree Nutrition, Microbial
From England comes interesting information about "Tree Nutrition"[5].
Evidence shows that the healthy growth of trees such as pines and
spruces is intimately bound up with an association between their roots
and fungi present in woodland soil. Poverty in mineral nutrients is no
longer regarded as a necessarily critical factor in the failure of
growth of trees of this kind, since the associated fungi have at their
disposal sources of supply inaccessible to the roots of higher plants.
Experiments carried out during the past ten years at Wareham in England
fully confirm the opinion expressed long ago by Professor Elias Melin,
Upsala, Sweden, that the growth of trees and other plants on poor soils
of the raw humus type is greatly influenced by the root-fungus
association. By fostering the appropriate combination it has been
possible to carry out successful afforestation of heathland so poor that
ordinary cultural methods prove inadequate for the least exacting tree
species. Satisfying the mineral requirements of the trees by direct
application of fertilizers is not in itself sufficient treatment to
ensure continued healthy growth; biological factors also play an
essential role in promoting soil fertility. The experiments have shown
that failure of the trees to establish a satisfactory biological
equilibrium with the necessary fungi is due in this case, not to the
absence of these fungi in the soil, but to their inactivation by toxic
|