Optimum Ratio of Coriander Intercropping with Onion

Aims: The main aim of this study was to find out the optimum plant density of onion for intercropping with coriander for higher productivity and economic return.
Study Design: The experiment was arranged following randomized complete block design with three replications.
Place and Duration of Study: Agronomy Experimental Field of Regional Agricultural Research Station, Jamalpur, Bangladesh during the cropping season rabi 2011-2012 and 2012-2013.
Methodology: We broadcast coriander seeds in different ratio with onion. The seeding ratio includes sole onion i.e., 100% onion seed broadcasting, 100% onion + 50% coriander, 100% onion + 40% coriander, 100% onion + 30% coriander and 100% onion + 20% coriander. Onion var. BARI Peaj-1 and Coriander var. BARI Dhania-1 were used in the present experiment. Randomly five onion plants were recorded earlier to collect the yield and yield contributing characteristics. Yield attributes of coriander were also recorded from five plants selected randomly earlier and yield data was recorded considering the whole plot in case of both crops. Onion equivalent yield (OEY) was calculated considering the local market price during the harvesting time.
Results: During the both year's maximum onion equivalent yield 13.10 t ha-1 and 12.83 t ha-1 was obtained from the treatment of 100% onion + 20% coriander followed by 100% onion + 30% coriander intercropping system during the first and second year, respectively. Onion (100%) + 20% coriander gave the highest benefit cost ratio (BCR) of 5.01 and 4.92 in first and second year, respectively followed by sole onion 4.86 and 4.59, respectively while 100% onion + 50% coriander gave the lowest BCR of 3.50 and 3.37 during the first and second year, respectively.
Conclusion: From two years result it may be concluded that 100% onion + 20% coriander and 100% onion + 30% coriander seeding ration may be extended in the char land (river flood plain) areas of this region.