Abstract:
Two sets of experiments were conducted at Adet and Burie in 2011 main cropping season
with the aim of comparing the traditional sowing practice (broadcasting) with drill method of
sowing, and of determining the effect of seed and fertilizer rates on the infestation of weeds,
and growth and yield of bread wheat. Totally fifteen treatments (combinations of three
seeding rates and five NP fertilizer levels) were tested under factorial experiment with
Randomized Complete Block Design (RCBD) at three replications. The seeding levels were
125, 175 and 225 kg/ha, and JOO, 150 and 200 kg/ha for broadcast and drill/row methods of
planting, respectively. NP fertilizer levels were 92-46, 138-46, 138-92, 184-92 and 230-92
kg/ha N-P205. Plant height, stand count, tiller number, biomass and grain yield, thousand
seed weight, hectoliter weight, wet gluten, grain and flour protein and SDS test were among
the important data taken. Composite soil samples were also taken before planting and after
harvesting from each treatment's plots. Analysis of variance (ANO VA) for all parameters was
computed with SAS 12. 0 software and mean separation was done using Duncan's Multiple
Range Test (DMRT). As result from Broadcast planting method indicated only the main
effects of seeding rate on grain yield and weed biomass; and the main effect of NP rates on
stand count, weed biomass, biomass and grain yield were significant (P<O. 05); whereas the
interaction was significant (P<O. 05) for all growth and yield traits except seeds per spike
, 1000 seed weight, hectoliter weight. The main effect of seeding and NP on weed biomass
was only significant for drill planting method; while plant height, tiller number and grain
yield were significantly (P<O. 05) influenced by the interaction. The study revealed that
drill/row method of planting has 56.2 % grain yield advantage and 69. 6 % weed biomass
reduction over broadcast planting. Under broadcast method of planting, a seeding rate of 125
kg/ha and fertilizer rate of 230 192 kg/ha NIP20s were found to be the best economically
profitable combinations with net benefit value of 30642. 06 Birr/ha. Under drill/row planting
method seeding rate of 150 kg/ha and fertilizer rate of 138 192 kg/ha NIP20s were the best
profitable combinations with a net benefit value of 46071.2 Birr/ha. There was no significant
difference among treatments for bread wheat quality traits. Indeed, the highest wet gluten
content was found at ·the highest NP level (230 N kg/ha and 92 P205 kg/ha), whereas the
lowest gluten content was found at the lowest NP combination (92 N kg/ha and 46 P205
kg/ha). Broadcast planting method gave the largest amount of weed biomass amounted 22983
kg Iha from 125 kg/ha seeding rate and 138192 kg/ha NIP205 level, while drill/row planting
method the largest 14750 kg/ha weed biomass was obtained from 150 kg/ha seeding rate and
184192 kg/ha NIP205 level. In both planting methods, tiller number, stand count, spike length,
biological and grain yield were found to increase linearly.pvi~k.tKte i¥ffease of NP levels, and
they were found contrarily to decrease with the increase.if~<Jttii~~