Interaction of cultivars of Cymbopogon species with the levels of irrigation frequencies on the variability of secondary metabolite production, essential oil productivity and economics in drought prone Bundelkhand region, India

In the present study, three cultivars of Cymbopogon species viz., Lemongrass var. CKP-25, Himrosa var. IIIM(J)CK-10 and Jamarosa var. RRL(J)CN-5 were assessed with five levels of irrigation frequencies viz., 0.20 IW, 0.40 IW, 0.60 IW, 0.80 IW and 1.00 IW, in three consecutive years (2019-2022). In the study, irrigation was scheduled at 5 cm depth and performed as per the IW: CPE ratio. The amount of water was applied as per the levels of irrigation frequency from lower to higher and to meet the ratio of cumulative pan evaporation (CPE). Furthermore, increase in the levels of irrigation frequency increased the essential oil yield. Interaction among the cultivars of Cymbopogon species with the different levels of irrigation frequencies, Lemongrass var. CKP-25 proved significantly the highest essential oil yield (209.97, 389.12 and 406.57 kg ha(-1)) during 1(st), 2(nd )and 3(rd )year, respectively. Similarly, in 2(nd) and 3(rd) years the net returns were found to be highest in Jamarosa var. RRL(J)CN-5 (Rs. 454627.00 and 502990.30 ha(-1)), respectively at same levels of irrigation frequency. The benefit: cost ratio was found to be superior with treatment receiving irrigation at 1.00 IW. However, percentage of essential oil content, secondary metabolite production viz., Lemongrass, citral (citral a + citral b) content percentage (82.47 +/- 2.12), Himrosa and Jamrosa, geraniol and geranyl acetate percentage (76.23 +/- 1.46 and 8.49 +/- 1.03) and (61.12 +/- 1.58 and 25.88 +/- 1.11), respectively, highest at 0.20 & 0.40 IW, while both decreases at higher levels of irrigation frequency (1.00 IW) in all the three consecutive years.