الفهرس 
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Abstract
SUMMARY
Two experiments were carried out at Sids Agricultural
Research Station, Beni- Suef Governorate, during 1987 and
1988 seasons to investigate the effect of intercropping
cotton and maize, under different population densities as
well as different planting dates, on growth, yield and yield
components of cotton (cv. Giza 80) and maize (cv. Giza 2).
In each season two separate experiments were undertaken
!~_!~~_!!!~!_~!2~!lmco~tEto!n, and maize were planted
in the same date in both seasons. Planting date was on April
26lE and 22nd in 1987 and 1988 seasons, respectively.
!~_!~~_!~~~~~_~!2~!lmco~tEto!nLwas planted 3 weeks
earlier than maize. Cotton was planted on April 261h and_mai~e
on May 17-th in the. first season. In the second season cot ton
planting date was on April 22~ and maize planting was done
In each experiment eleven treatments were applied which
were the combination of three cotton population densities
(50 %, 75 %,and 100 % of the pure stand density) and three
maize population densities (50 %, 15 %, and 100 % of the pure
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stand density), in addition to the sole cropping of cotton
and maize •
The standard population density of pure stand cotton
was 70,000 plants! fad., and for maize 23,333 plants! fad.
Treatments in both experiments were therefore
Cotton density Maize density
1 50 96 50 96
2 50 96 75 96
3 50 96 100 96
4 75 96 . 50 %
5 75 96 75 %
6 75 % 100 %
7 100 % 50 %
•... .n.... rv 75 % 0 J.VV 70
9 100 96 100 96
10 Sole cotton
11 Sole maize
Harvesting was done at maturity. Fertilizer application
and irrigation and other cultural practices were
similar either for intercropps or for pure stand.
The experiments were arranged in a complet~ly randomized
blocks design with four replications.
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nat~ on growl}t, yield components and yield were collected.
Results could be summarized as follows:
1- Cotton plant height was not significantly affected
by intercropping in both experiments.
2- Number of fruiting branchesl plant as well as
number of open bollsl plant were significantly reduced
by intercropping, particularly at higher population densities.
The adverse effect of intercropping on these
characters was more evident in the first experiment where
cotton and maize were planted on the same date.
3- Boll weight, seed index and lint percentage were
not significantly affected by intercropping in both exper
iments.
4- Seed cotton yieldl plant was significantly reduced
as a result of intercropping, particularly at
higher population densities. Planting cotton 3 weeks earlier
than maize reduced markedly the adverse effects of
intercropping.
11- Se!~_~Q!!~~-lie!~_!~~_!l~~~ic~ha!aC!!!!-l
. 1- In both experiments, intercropping significantly
reduced seed cotton yield estimated as the ”actual” yield
produced per plot. In the first experiment, yield ~tion
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due to intercropping reached 61 and 62 % in the first and
second season~ respectively, compared with sole_cropping.
Regarding the second experiment, yield reduction reached
56 and 52 % in 1987 and 1988, respectively.
2- ”Adjusting” seed cotton yield according to unit
area practically grown, indicated that intercropping showed
no marked effect. In the first experiment, sole cropping
slightly out yielded intercropping treatments, whereas
in the second experiment intercropping in some cases insi-
. gnificantly increased seed cotton yield ”adjusted” per
unit area.
3- Intercropping at higher cotton population densities
significantly reduced the percentage of survival cotton
plants at picking, in both experiments, canpared with
sole cropping.
4- Earliness percentage was significantly reduced
by intercopping in both experiments.
111- Gr~~!~_~~!!!~!~!!-!~~_lie!~_~~~~~nt!-2!~!ize_l
1- Intercropping had no significant effect on plant
height, area of the topmost ear leaf, ear weight and 100-
kernel weight in both experiments. Lower values of these
traits were observed when intercropping was done at higher
densities.
2- Number of ears per plant significantly increased
compared with sole cropping when intercropping was done at
lower densities. But at higher maize densities, intercropping
s ign i f Lca’n t ly decreased number of ears per plant in
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2- The percentages of smut infested plants as well
as late wilt diseased plants were not significantly affected
by intercropping in both experiments~
3- Weed density in maize either after 35 or 50
days from planting was not significantly affected by intercropping
in both experiments.
VI- g~~E~11!!y~_!~!!!1~~~n!E!_!~~_!1~!~-!~!!~!!g~_l
1- In the first experiment ItLERtIexceeded one in
all treatments of 1987 season and in three treatments out
of the nine in 1988 season, indicating no definite increase
in land productivity. The best result was obtained with
intercropping cotton and maize at 100 % :50 % of pure stand
den s ity, respec t ive Iy, in both seasons. fiLER” was 1. 19 and
1.04 in 1987 and 1988 season, respectively.
2- Maize contributed more than cotton in ”LER” in
both seasons in the first experiment.
3- With the second experiment, tiLER” exceeded one
in all systems in both seasons, showing promising result
when cotton planting preceded maize planting by 3 weeks.
Land equivalent ratio (LER) of 1.21 and 1.19 were obtained
in the first and second season, respectively.
4- In the second experimentllMlize was the best cootributer
in all sJstems in the first seaSOD, but an
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opposite treated was observed in the second season where
cotton was the best contributer in five systems out of
nine.
5- Relative crowding coefficient showed yield advantage
with intercropping in all systems of the first
experiment in 1987 season, but only in three systems in
1988 season.
6- Earlier cotton planting in the second experiment
proved promising where yield advantage was recorded wtth
all intercropping systems in both seasons.
7- Maize was the dominant component in all intercropping
systems in the first experiment in both seasons,
while cotton was the domInated component.
With the second experiment, maize was the dominant
component in all systems in 1987 and in four systems in
1988 season.