course or low spot. We frequently see this same trouble on
grape foliage in such locations. This is probably due to a lack of
sufficient iron intake caused by a deficiency of manganese. It can be
cured by either spraying with a 1% solution of magananese sulphate or
applying the dry salt under the spread of the branches. The spraying
method seems to give better and faster results.

It has been reported from British Columbia that some die-back is due to
deficiency of boron. Perhaps some of the die-back we see on nut trees
during the summer is due to this cause and not all to winter injury. The
very erratic results from ground application of borax would indicate
that borax should be incorporated with one of the regular sprays as a 1%
mixture.

Our conclusions therefore are that nut plantations should be placed in
sod as soon as possible and a mulch established the fall of the year the
grass is sown. Each year cut the grass and draw in around the tree to
supplement the mulch. If not enough material is gathered in this way it
can be supplemented by straw or old hay. Manure or nitrate should be
applied each spring and trace elements where needed can be incorporated
in the regular spray program.

* * * * *

Discussion after J. R. van Haarlem's paper.

Dr. MacDaniels: "I realize that there are more trees which are starving
to death than are being overfed."

Silvis: "Do you recommend that freshly cut hay be used as mulch?"

Van Haarlem: "Any crop refuse can be used as mulch. Anything that will
rot down. The pH of the soil should be 6.2 to 6.5."

O'Rourke: "Would you use clean cultivation for the first year?"

Van Haarlem: "There is nothing against it. We use sod mulch at Vineland.
The reason that our growers are not growing nut plantations is that good
land, that is good soil, sells for $1,000 per acre. Nut trees grown on
poor land, cheap land, do not produce."

McCollum: "I am surprised that rain would not go through loose straw and
will go through old straw. Where does the rain go when it falls on the
loose straw?"

Van Haarlem: "It is absorbed before it gets through the straw. Dry mulch
should be 18 inches deep."

Member: "How would you prevent erosion on rolling land?"

Van Haarlem: "Plant on the contour."

Dr. Crane: "How often do you renew mulch under trees?"

Van Haarlem: "After first application additional may be needed but after
that enough is grown under trees which whe