Kcntzieky Agrz`c-utturul Eccperiment Station 45
f A condition similar to the lettuce disease has been noted
_ in Chinese cabbage grown in the greenhouse during the season
S of 1920-21. The plants were strong and grew normally for a
h time, the outer leaves attaining full size. The central leaves,
Y however, became stunt·ed and the heads failed to develop. At
11 the same time severe tip burning occurred on the inner leaves
e and on some of the outer ones. eEventually the central axis
n elongated and seed was produced. An examination of the
lg roots showed in all cases severe rotting of the smaller rootlets.
[S Chinese cabbage sown in July and transplanted to the iield in
tg August produced normal heads with practically no sign of tip
gl Mosaic Disease of Potatoes. An attempt was made t·o
It eliminate the mosaic disease from diseased strains of potatoes.
Of The tubers were numbered and tagged and from each tuber a
small seed piece was cut for planting in the spring, the rem-
nants being placed in cold storage for planting in the fall for
M the production of seed stock. Ten strains, including six varie-
i1· ties, were tested, using 100 tube1·s of each strain. The pereeut~-
Sh age of mosaic disease varied from 2 to 05 per eent in the ten
id, lots. Records taken on the test crop included rate of growth.
ut amount of mosaic and the yield per plant.
cd Records maintained from the numbered plants in the field,
lc. made it possible to eliminate from the corresponding numbered
tot seed pieces held in cold storage, all those whose field records
its were unfavorable. 'l`he remnants from the healthy tubers as
oil shown by the behavior of the plants in the spring test, were V
a planted July 26 and showed no signs of mosaic thruout their
rn growth period. The progeny of these will be tested further in
he the hope that this method. with possibly some modification.
)p, may prove a valuable means of securing improved disease-
gf free seed stock.
cd' Potato Fertilizer Tests. A complete series of fertilizer
Hd applications to potatoes grown iu bluegrass sod land gave no
1`€' Coiisisteiit beneficial results on the yield of the irish t`obbler
Wd variety. This is in aeeordance with the results obtained with
i11S' other farm erops on bluegrass soil.