22 Thirty-1*’1`ftlz Annual Report: ’
Fertilizer Experiments on Burley Tobacco. The nitro-
gen tests on tobacco were continued in 1922. The tobacco was
grown in a rotation of wheat, clover, corn and tobacco, ten to
V twelve tons of manure being used on the C01`11. Nitrogen fer-
t tilizers of several kinds in varying amounts failed to give an
‘ increase in yield in 1921. The 1922 crop is not stripped, but;
W _ judging from appearances, the fertilizer has not been of bene-
fit. ln the permanent fertilizer tests on tobacco, nitrogen has
given a ‘suhstantial increase. No manure or crop residues are
returned there. however. This shows that commercial nitro-
. gen ma_v give responses under such conditions. while on land
well manured and where erop residues are returned. the use of
·· eommereial nitrogen may give no increase in yield.
Strains of Stanclup White Burley Tobacco Resistant to
Root-Rot. 'l`:·sts of strains oil tohaeeo resistantto root-rot
eaustd by Y`/t/z/aria l,·rr.~ft`o/u, Zopts have been eontinned on
the lilvperintent Station tarm and on ttppt-tstt.attt»t_i- 200 farms -
in the Hurley seetion. These strains have been derived direct-
Y ly by seleetion from the eommonly grown varieties of Standup
\\lhite l·ln:~ley originated from a small lot of seed sent to Hr.
ll, ii, Kelly ol" l.ant·aster. l{entnelll1 3 lt)   ]`)t‘l' (‘(‘lll` tllltl lll tll|l' ('2l$tl
an entire tield ol` nine 'aeres was dislted and reset except five
rows ot` a resistant strain.
'l`he ouality ol` the best resistant strains appears to be as _
gtmtl as the best standup liurley varieties eonnnonly grown.