Rawson has applied five tons of compost peracre to
infested tobacco land.
The vine proved to be amycorrhiza
former.
Careful note of this infection was made and the
cultures were repeatedyear after year.
Oncethe inquiry was begun evidence began to pour
in.
The first of these problems was met with at Pusa in
the case of thepeach.
They were the kind of trees that most people would
have consignedto the bonfire. Only one disease, whichresulted in malformed dwarf
plants, was met with during these nineteenyears.
The plants soon made a complete recoveryfrom virus.
At the beginning of this work an interesting thing happened. No further potato crops
are possible till the filth andfertility of the soils have been re-created. The
results so far obtained, as far aspractice is concerned, are not impressive. Thenext
year infection was noticeably less. We know that thelarge group of leguminous plants
are mycorrhiza formers. But after flowering the crop wassmothered by a mildew; no
seed was harvested. That this is needed is suggested by the fact that the banana is
amycorrhiza former. This disease was much more prevalent on thepopular King Edward
variety than on Majestic.
In suchcases a remarkable change in the flora and
in the soil structureprecedes the outbreak. Only one disease, whichresulted in
malformed dwarf plants, was met with during these nineteenyears. After two or three
years the potatoes of one crop cannotbe used to raise the next. This included
aninvestigation of the factors concerned in the effect of grass on fruittrees. These
two methodsalso affect the leaves as well. No fungicides or insecticides were atany
period used in this work. I spent some time in the Spalding area in the study of the
eelwormdisease of potatoes.
The rest of the plot escaped infection andgrew
normally.
Careful note of this infection was made and the
cultures were repeatedyear after year.