Two field experiments were conducted at Nubaria Agric. Res. Station during 2003 and 2004 seasons. The objective of this investigation aimed to study the effect of irrigation intervals (irrigation every 14 and 28 days) and six intercropping patterns: (1) Pure stand of soybean (sown in hills 10 cm distance apart on each side of the ridge and thinned at two plants/hill). (2) Pure stand of sunflower (sown in hills 30 cm distance on side of the ridge and thinned at one plant/hill). (3) Soybean sown on one side of the ridge and sunflower sown on the other side of the ridge (100% soybean+100% sunflower). (4) Soybean sown in 2:2 rows with sunflower. (5) Soybean sown in 2:4 rows with sunflower. (6) Soybean sown in 4:2 rows with sunflower on yield and its components of both crops, as well as the competitive relationships. A split plot in complete randomize design with four replicates was used. The results indicated that Irrigation intervals had significant effects on soybean plant height, number of pods/plant, seed yield/fad. and seed oil percentage of soybean plants. Intercropping patterns had significant effects on all studied traits, except oil and protein content percentages in the two seasons. The highest seed yield/fad. was obtained by irrigation every 14 days and sowing soybean in pure stand. Pure stand gave higher seed yield of soybean than that of all intercropping patterns. Irrigation intervals had significant effects on sunflower plant height, number of leaves/plant, seed yield/plant and seed yield/fad. of sunflower plants in the two seasons. Also, intercropping patterns had significant effects on all studied traits in the two seasons. Pure stand of sunflower gave higher seed yield/fad. than all intercropping patterns. The highest seed yields of sunflower and soybean were obtained by irrigation every 14 days and pure stands in the two seasons. The results indicated that land equivalent ratios (LER) of soybean and sunflower values were more than one. Moreover, it could be concluded that soybean and sunflower sown at pure stands with irrigation every 14 days can be recommended for raising soybean and sunflower productivity as compared with all intercropping patterns under the condition of Nubaria region. Also, sunflower was always the dominant crop, whereas soybean was dominated.

Two field trials were carried out at South Tahrir Research Station (Ali- Moubark). These trials were conducted in 2003 and 2004 to evaluate three planting dates of maize (the over story shade crop) intercropped with groundnut i.e, on 1st June, 10th June and 20th June, and four plant densities of maize intercropped with groundnut, i.e, maize was spaced at 50 and 100 cm apart leaving one or two plants/hill. Groundnut (the main crop) was grown on all rows. The data obtained indicate that ear length, ear diameter, number of rows/ear, number of kernels/row and the weight of 100grains increased with increasing maize spacing as well as with diminishing the number of plants remained per hill after thinning (to one plant/ hill). On other hand dense planting resulted in higher yield of maize whether by narrowing maize spacing or increasing the number of maize plants per hill after thinning. Yield and yield components of maize were significantly decreased by delaying planting date of maize up to the latest date. Yield /fed and yield components of groundnut were associated with maize density and distribution. The more the shade offered by maize the less the values of these traits were obtained. Highest values were obtained when maize was spaced at 100cm. and thinned to one plant/ hill. Increases in the values of yield and yield components of groundnut were associated with delaying the planting date of maize. Delaying the planting date of maize resulted in increases in the values of land equivalent ratio (LER) and the relative crowding coefficient. The treatment effect at any planting date of maize exerted very low competitive pressure when aggressivity was measured. With delaying seeding maize, competitive ratio (CR) diminished to the least. Spacing maize at 50cm. apart and leaving two plants / hill after thinning resulted in highest value of LER and relative crowding coefficient (RCC). Nor any maize density had any heavy competitive pressure on groundnut when aggressivity was measured