Abstract:
Afield study was conducted to known the effect of three
tillage types (harrowing, disking, chiseling and control
(zero tillage)) and two sowing methods (Ridge and flat)
and irrigation water levels (100%ETc, 85% ETc and 75%
ETc) on sunflower crop (Helianthus annuus L.) hybrid
hysun33 in summer season during (2011- 2012) in Faculty
of Agricultural Science farm, University of Dongola,
.Northern State by
A two-year field experiment was carried out using a strip-
split plot arranged in randomized complete block design
12
with four replications in two seasons 2011 – 2012.
Recognized standard methods were used for assessing
yield, vegetative growth, soil physical properties and field
:water regimes. Results can be summarizing as follows
Significant differences in yields were obtained at 100%ETc
irrigation water levels. This indicates the sensitivity of the
crop to water stress. Analysis of variance, in both seasons,
showed significant differences due to tillage treatments.
The highest values in yield were obtained under harrowing
treatments and lowest values were obtained under no-
tillage treatment. This may be attributed to the fact that
sunflower plant is a tap rooted plant that penetrates well
in tilled soils. The number of seed per head was not
affected by tillage treatments, water stress and sowing
methods. It seems that these characters are genetically
.control rather than environmentally affected
Sunflower is well known for its empty seeds problem.
100% ETc irrigation water level showed no improvement in
the reduction of the number of empty seeds, but, on the
reverse the number of empty increased. This implies that
the number of empty seeds phenomenon is associated
with level of irrigation at a certain growth stages of the
plant life duration. On the other hand there was no
.significant difference due to sowing methods
Full 100%ETc should be given to the crop to get maximum
yield. Empty seeds should be studied under different
.deficit irrigation levels at mid stage of plant growth
