Maximizing land utilization efficiency and competitive indices of roselle and cluster bean plants by intercropping...

To maximize the land utilization efficiency of Hibiscus sabdariffa L. (roselle) and Cyamopsis tetragonoloba, Taub (cluster bean), this experiment was executed successfully at Experimental Farm, Fac. Agric., Zagazig Univ., Egypt during 2018 and 2019 at summer season. Intercropping pattern treatments as main plots (sole planting of each component as control, 1: 2, 1: 3 and 2: 3 of roselle: cluster bean as row ratio, respectively), lithovit as sub-plots (CO2 nano-material) at various rates (0.0, 2.0, 4.0 and 6.0 g/l) as well as their interaction effects were estimated. In addition, from calculating competitive indices, it was clear that, the highest land equivalent ratio (abbreviated as LER), area time equivalent ratio (abbreviated as ATER), land utilization efficiency percentage (abbreviated as LUE%) and relative crowding coefficient (abbreviated as RCC) values 1.24 and 1.12, 1.16 and 1.03, 120.57% and 108.06% as well as 0.82 and 0.41 were achieved by the treatment of intercropping pattern of 1 row of roselle alternating with 3 rows of cluster bean during the 1st and 2nd seasons, respectively. The highest values in this concern were achieved with 1: 3 planting pattern combined with 0.0 lithovit rate in the first seasonas well as 1: 2 planting pattern combined with 6.0 g/l lithovit rate in the second one. Also, the highest values of competitive ratio for roselle (Crr) were achieved by combination between 4.0 g/l lithovit rate under 1: 3 pattern, in contrary, the highest values of competitive ratio for cluster bean (Crc) were recorded by combination between 1: 2 pattern with 2.0 g/l lithovit rate in first season. Regardless of the planting patterns combined with different lithovit rates, aggressivity, based on the results, therewas a positive sign for roselle and a negative sign for the intercropped cluster bean, indicating that roselle was dominant, while, cluster bean was dominated.