Abstract: Waterlogging reduces shoot and root growth and final
yield of wheat. Waterlogged sites have a combination of low slope,
high rainfall, heavy texture and low permeability. This study was
aimed the importance of waterlogging on root growth and wheat
yield. In order to study the effects of different waterlogging duration
(0, 10, 20 and 30 days) at growth stages (1-leaf stage, tillering stage
and stem elongation stage) on root growth of wheat cultivars
(Chamran, Vee/Nac and Yavaroos), one pot experiment was carried
out. The experiment was a factorial according to a RCBD with three
replications. Results showed that root dry weight and total root
length in the anthesis and grain ripening stages and biological and
grain yields were significantly different between cultivars, growth
stages and waterlogging durations. Vee/Nac was found superior with
respect to other cultivars. Susceptibility to waterlogging at different
growth stages for cultivars was 1-leaf stage > tillering stage > stem
elongation stage. Under waterlogging treatments, grain and
biological yields, were decreased 44.5 and 39.8%, respectively. Root
length and root dry weight were reduced 55.1 and 45.2%,
respectively, too. In this experiment, decrease at root growth because
of waterlogging reduced grain and biological yields. Based on the
results, even short period (10 days) of waterlogging had
unrecoverable effects on the root growth and grain yield of wheat.
Abstract: Sowing date and density are two important factors in
produce of coriander. A field experiment was conducted with
treatments: sowing time (5 May, 20 May, 4 June and 19 June 2009)
and plant density (10, 30, 50 and 70 plants m-2). The experimental
plots were laid out in a factorial according to a RCBD with three
replications. Results showed that the effect of sowing dates and
densities were significant on grain yield and yield components, but
interaction effects between sowing time and density were non
significant for all of traits in this trial. At sowing times 5 May, 20
May, 4 June and 19 June, grain yield obtained 736.9, 837.8, 1003.1
and 1299.6 kg ha-1, respectively. At 10, 30, 50 and 70 plants m-2,
grain yield were 794.9, 1031.0, 1092.3 and 959.3 kg ha-1,
respectively. In this experiment, sowing at 19 June and 50 and 30
plants m-2 had the most grain yield.
Abstract: The effect of flooding can be a serious problem for
wheat farmers, even at dry land condition. Amount of flooding
damage depends on duration flooding, developmental stage, wheat
type and variety. Therefore as a factorial experiment in randomized
complete design based on winter bread wheat cultivars (Pishtaz,
Marvdasht, Shiraz, Zarin, Shahriar, C-81-4, Sardari, Agosta seed,
FGS and Azar2) at stages (Non- flooding stress, flooding at tillering
and stem elongation stages for 15 days) carried out in Faculty of
Agriculture, Razi University, Kermanshah, Iran. During flooding,
soil environment of plant roots were water saturated. Analysis of
variance showed that flooding had a significant effect on the number
of grains per spike, grain weight per spike and a grain weight. Hence
flooding reduces the number of grain per spike between 27.1 to 42.5
percent, grain weight per spike between 34.7 to 54.4 percent and
single grain weight between 12.1 to 15.1 percent. Effects of flooding
at the tillering stage reduced higher than stem elongation stage on
studied traits. The result also showed that flooding at tillering stage
delayed spikelet primordial and floret. Between wheat cultivars was
significant for traits, but were different reactions. "Shiraz", "Zarin"
and "Shahriar" had the most no. grain per spike, but "Zarin" and
"Sardari" had the most grain weight per spike and single grain
weight, respectively. Also, interaction between start of flooding and
cultivar was significant.
Abstract: To study on effect of PEG and NaCl stress on
germination and early seedling stages on two cultivar of corn, two
separated experiment were laid out at physiology laboratory, faculty
of Agriculture, Razi University, Kermanshah, Iran in 2009. This
investigation was performed as factorial experiment under Complete
Randomized Design (CRD) with three replications. Cultivar factor
contains of two varieties (sweet corn SC403 and Flint corn SC704)
and five levels of stress (0, -2, -4, -6 and -8 bar). The principal aim of
current study was to compare the two varieties of maize in relative to
the stress conditions. Results indicated that significant decrease was
observed in percentage of germination, germination rate, length of
radicle and plumule and radicle and plumule dry matter. On the basis
of the results, NaCl as compared with PEG had more effect on
germination and early seedling stage and sweet corn had more
resistant than flint corn in both stress conditions.