Abstract

 Field experiments were conducted to explore possibility of introducing Acorus calamus (Sweet flag) under rice ecosystem either as an Intercrop or main crop for optimizing maximum return. In the first experiment, Sweet flag was intercropped with two rice cultivars early IR-64 and late MTU-7029 “Swarna” in additive series where sweet flag was introduced between two normal rows of rice and in replacement series where sweet flag was planted with rice in 1:1 ratio at 20, 30 and 40 cm spacing and were compared with sole crops after one year. Further, in the second experiment, Sweet flag was intercropped only with early maturing variety (IR-64) in 20 cm spacing with a crop cycle of 1 and 1.5 year to evaluate comparative performance of Intercrops and sole crops. Results revealed that intercropping of sweet flag with rice had a significant effect on yield and yield attributing characteristics of both crops. Numbers of effective tillers in rice were increased with widening the space between intercrops as compare to sole crop of rice, while, rhizome length and width of sweet flag registered highest in sole crop and showed declined trend with decreasing spacing of intercrops. Intercropping of Sweet flag with early and late maturing cultivars of rice did not give significant effect on rhizome yield of sweet flag. Sole crop of sweet flag with a crop cycle of one year was found to be superior and gave significantly maximum equivalent yield (233.75 q ha^-1). Whereas, EQY of rice recorded from different series of intercropping were significantly at par. The inclusion of sweet flag with paddy decreased the rice yield with increasing spacing. In contrast, rhizome yield of sweet flag was in opposite trend and increased with increasing spacing from to 20 to 40 cm. Gross return and net profit incurred more from all series of intercropping compared to rice as sole crop irrespective of both early and late maturing cultivars of rice. Sweet flag planted as sole crop incurred highest gross return (Rs 248820.00 ha^-1) and net profit (Rs 187320.00 ha^-1) among different treatments. Data of another experiment revealed that sole crop of sweet flag taken for one and 1.5 year gave maximum equivalent yield (EQY) of 229.54 q ha^-1 and 347.83 q ha^-1 respectively. Intercropping of Sweet flag with rice found to be economical when it was grown as sole crop for a period of one year after rice harvest with 1.5 year of crop cycle (EQY253.23 q ha^-1). Sweet flag planted in between rows of rice and allowed to grow even after rice harvest for one year gave EQY of 268.06 q ha^-1 and at par with inter cropping of sweet flag at spacing of 20 cm with a crop cycle of 1.5 years (253.23 q ha^-1). Moreover, equivalent yield of rice calculated from different treatments was higher as compared to grain yield of sole cop of rice. Maximum gross return of Rs 431472.00 ha^-1 and net profit of Rs 364972.00 ha^-1 incurred from sweet flag taken as sole crop for a period of 1.5 years. All series of intercropping with crop cycle of 1.5 years were superior in terms of getting higher net profit.

Key words: Intercrop, equivalent yield, cost benefit ratio, sweet flag.