Agriculture Reference
In-Depth Information
The Suitability of Different Winter and Spring Wheat Varieties for Cultivation in Organic Farming
http://dx.doi.org/10.5772/58351
The highest density of plants was noted in a Smuga throughout the growing season and the
lowest in spelt Schwabenkorn (Table 8). Plant density was the highest in the best weather
conditions of 2008 and lowest in 2010, which was caused by poor winter survival of wheat
(table 1, 4, 8). In 2010 weed infestation was determined more by plant density than by mor‐
phological features of varieties. The largest biomass was produced by Smuga (Table 8) which
could be the reason for its big competitiveness against weeds (Table 6). Bogatka and Kobra
Plus canopies were characterized by the lowest biomass.
Density of wheat plants (plants·m
-2
)
Dry matter of wheat (g·m
-2
)
Cultivar (A)
Years (B)
Years (B)
2008
2009
2010
mean
2008
2009
2010
mean
Kobra Plus
271
214
116
200
684
713
657
685
Bogatka
238
223
102
188
738
610
651
666
Smuga
291
242
156
230
817
860
848
842
Tonacja
246
219
115
193
715
809
590
705
Ostka Strzelecka
253
239
122
205
707
893
536
712
Spelt
234
192
123
183
746
976
680
801
Mean
256
222
122
200
735
810
660
735
HSD (α=0.05) for:
A - 42.1, B - 24.2, interaction AB - ns*
A - 137.6, B - 79.2, interaction AB - 228.0
* ns - non significant differences
Table 8.
Selected features of canopy of winter wheat varieties cultivated in organic system
Competitiveness against weeds is one of the criteria of variety selection for the organic farming
system [7, 13]. The varieties with a rapid growth rate at the initial growth stages, the biggest
height, tillering, the most horizontal (planophile) set of leaves to the soil surface, combined
with a low susceptibility to the disease, which prolongs the duration of the foliage, have the
highest competitive abilities [2, 8]. These features affects the ability of shading the soil surface,
and thus photosynthetically active radiation penetrates into the canopy, which directly
influences the growth of weeds. Some authors suggest that the height of the plants is the main
reason for the differences in competitiveness against weeds [17, 23, 24], but others believe that
this factor has a marginal significance [25, 26]. Recent research on wheat and barley varieties
showed that the differences between plant density influence the competitive ability more than
do plant height and light penetration in the canopy [27]. Furthermore, some authors suggest
that differences between varieties arise from their different allelopathic properties [10, 16].
Moreover, weed infestation suppressing ability of varieties vary because of their combined
