Two field experiments were conducted at Sakha Agricultural Research
Station in 1998 and 1999 seasons to study the effect of plant distribution system on
growth, yield, yield components and water use efficiency of cotton cultivar Giza 70.
Randomized complete blocks design with four replications was used. All treatments
had the same plant density (about 60000 plant/fed) as follows: (A)- Hill spacing 24cm apart on both sides of bed 120cm width.
(8)- Hill spacing 28cm apart on both sides of bed 100cm width.
(C)- Hill spacing 32cm apart on both sides of bed 90cm width.
(0)- Hill spacing 36cm apart on both sides of bed 80cm width.
(E)- Hill spacing 40cm apart on both sides of bed 70cm width. The results revealed that plant distribution system had significant effect on
plant height (cm), internode length (cm), number of internodes on the main stem,
number of sympodia per plant, root dry weight (g) and total dry weight of plant (g) in
favour of wide bed. With respect to yield and its components: the results indicated that
treatment (8) gave the highest seed cotton yield per plant and feddan followed by
treatment (A). On the other hand·, number of opened bolls per plant, boll weight (g),
seed cotton yield' per plant (g) and seed cotton yield per feddan (kent) were
decreased gradually as bed width decreased, while the reverse was true for total
shedding percentage in both seasons. Amount of water supply was increased
gradually as bed width decreased. This increasing was more than cotton plants
requirements and led to increasing the total shedding percentage which reflected on
yield, yield components and water use efficiency in both seasons. Generally, It could be concluded that treatment 8 ( Hill spacing 28 cm apart
on both sides of bed 100 em width) followed by A (Hill spacing 24 cm apart on both
sides of bed 120 cm width) recorded the highest values of yield as well as water use
efficiency and saved about 27.2 - 32.9 % of water supply.