Effects of reduced plant height on breeding requirements and ...

f or this parameter dir¡rinished as i{ increaeed (fab1e 4l-4 ) .
1ng a re sponse to applied N while r-Ìo Õther genotype did
(îable &28). Again we see the trend toward equalÍt1, 6¡
genotypes as N increased (Table bZn ).
fsscent Barley t:¡itrqs . The .{NOVA (fable 4l) indicated
that applied N significantly affeeÌ;ed this parameter at al-l
sites except Portage, 1pf6. The lack <strong>of</strong> response at that
síte was probabry due to roid to late season moisture stress,
It will be noted that, at the Carman site, where the inj_tial
soil nitrogen level was low in both years, barley nitrogen
increased progressivel-y with higher fertilizer l{ increraents
(Table 44C). .A,t Portage in Ig?5, on the other hand, the
grain nitrogen was rel"atively high, probably reflecting
higher ínitial fertålity, and there was little response to
added fertilizer (Tabte 44Á.)" Sirnilar results vrere reported
by Gardener and Rathjen (ISZS) and Kirby (1968).
Á.lthough significant differences between genotypes
were shown for all locations, the data (Ta¡1e &4A) in¿icate
these differences were inconsistent across locations.
A significant F x G interaction was shown at Carman,
!9?6" This resulted from the fâct that the differences
between genotype s at u ero N appl-ied, n r^,,ere mininized through
additions <strong>of</strong> fertilizer, indicatíng that the initially 1ow
genotypes showed a greater response to N than did the
others (TabLe tr5A ) .
118