Tuberose is an important flower crop grown in India for its beautiful and fragrant flowers. Flower spikes have varied uses in bouquets and vases, while loose flowers are used for making garlands/ ‘venis’ and other floral arrangements. Maharashtra enjoys a congenial climate for tuberose cultivation. Tuberose (Polyanthes tuberosa Linn.) needs an improved package of practices for better yield and quality of flowers. Irrigation schedule and quantity of water applied are important factors deciding production. Scarcity of water has compelled the stakeholders to think seriously about water management in the crop. Pressurized irrigation system comprises drip, micro-sprinklers, spray guns, etc. The suitability of a method depends upon the crop and its planting density. To study the performance of tuberose under different irrigation systems, a trial was conducted at the Precision Farming Development Centre, M.P.K.V., Rahuri. The experiment was conducted at the experimental farm of Precision Farming Development Centre, Rahuri. Three treatments, viz., Drip irrigation, Micro-sprinkler and Surface irrigation (conventional) were studied. The experiment was laid out in Randomized Block Design, with seven replications. Tuberose cv. Suvasini (Double) was Short communication Effect of various irrigation methods on growth, flowering and yield of tuberose (Polyanthes tuberosa Linn.) M.R. Deshmukh Precision Farming Development Centre, Dr. A.S. College of Agricultural Engineering, Mahatma Phule Krishi Vidyapeeth, Rahuri-413722, India E-mail: mrdesh101@yahoo.co.in ABSTRACT Tuberose flower has very good fragrance and is suitable for loose and cut flowers. Although crop improvement has been researched upon in various institutes and state agricultural universities, irrigation management in this crop has not been given much emphasis. This factor is important and crucial in crop production. A field trial was conducted at Precision Farming Development Centre, Rahuri, with the objective of studying performance of tuberose cv. Suvasini Double under three irrigation systems, viz., drip, micro-sprinkler and surface irrigation (conventional method). Irrigation through drip and micro-sprinkler was applied at 0.85 PE; and in the conventional method of irrigation, the interval was set at 60 mm CPE with 6 cm depth of irrigation. Micro-sprinkler system proved to be the best and gave a flower yield of 6.77 lakh spikes/ ha with better flower quality, than drip or surface method of irrigation. B:C ratio was also higher under micro-sprinkler (2.68 ). Key words: Tuberose, micro-sprinkler, drip planted at 40 x15 cm spacing in 1.60x12.0 m size beds. Recommended dose of 200:300:300 kg NPK / ha was applied. Before planting, the bulbs were treated with 0.2% Carbendazim for 30 minutes. Irrigation through drip and micro-sprinkler was applied at 0.85 PE and, in the surface- method of irrigation, the interval was set at 60 mm CPE with 6 cm depth of irrigation water. Details of the irrigation methods are as under: Irrigation system/ Drip Micro- Surface parameters sprinkler method Lateral size 16mm 16mm Border irrigation, Lateral spacing 2.2 m 2.2 m Size of border Emission spacing 60 cm 2.0 m = 12x 1.6 m Average discharge 4 LPH 44 LPH Operational pressure 1 kg/cm2 1 kg/cm2 Uniformity coefficient 90% 94% Average discharge and emission uniformity were computed by the formula of by Keller and Karmelli (1974). Recommended dose of fertilizer was given in 30 splits. Irrigations were scheduled for every alternate day. Depth of water to be applied per plant was calculated using the equation J. Hortl. Sci. Vol. 7(1):94-97, 2012 95 Irrigation methods influencing tuberose cultivation D = PE x Kc x Kp Where D = depth of water to be applied (mm) Kc = Crop co-efficient (0.8, 1.0 and 1.2 for 3 months, respectively) Kp = Pan factor (0.7) PE = Sum of pan evaporation for two days (mm) Volume of water to be applied for the treatment was computed by the equation V = D x A x N Where V = volume of water (l) Table 1. Performance of tuberose under various irrigation methods Parameter Year (T1) Drip (T2) Micro- (T3) Conven- CD at 5% (Microtube) sprinkler tional method Average plant height at bud 99-00 59.179 63.439 50.619 4.859 stage (cm) 00-01 59.107 64.446 49.909 0.288 01-02 59.158 63.978 48.460 0.236 pooled 59.148 63.954 49.663 1.695 Average no. of leaves/plant at 99-00 96.094 106.136 91.800 6.140 onset of flowering 00-01 95.766 108.129 90.978 0.349 01-02 96.032 107.663 89.944 0.459 pooled 95.964 107.309 90.907 2.181 No. of flowers/spike 99-00 49.206 55.460 44.381 2.053 00-01 49.259 55.617 44.421 0.596 01-02 49.618 56.184 43.972 0.412 pooled 49.494 55.986 44.124 0.212 Average spike length (cm) 99-00 107.774 110.374 99.456 3.086 00-01 107.970 111.316 99.689 1.768 01-02 107.869 110.989 99.446 0.161 pooled 107.880 111.009 99.485 0.450 Length of rachis (cm) 99-00 48.571 51.570 41.857 2.997 00-01 49.353 52.010 35.809 0.473 01-02 48.842 51.915 38.786 0.336 pooled 48.922 51.832 38.817 4.365 Wt. of spike (g) 99-00 36.226 39.143 30.803 3.126 00-01 36.796 39.934 30.657 0.692 01-02 36.637 39.799 30.378 0.448 pooled 36.677 39.829 30.466 0.238 Yield of bulbs (t/ha) 99-00 36.106 45.201 31.039 8.731 00-01 37.803 47.564 31.073 2.709 01-02 36.967 46.469 30.865 0.252 pooled 36.973 46.477 30.867 0.160 Yield of bulblets (t/ha) 99-00 13.641 16.147 10.034 4.032 00-01 14.256 17.144 9.910 1.256 01-02 13.930 16.669 9.758 0.139 pooled 13.934 16.674 9.760 0.009 Spike yield (lakh/ha) 99-00 5.241 6.650 4.423 0.760 00-01 5.241 6.817 4.530 0.314 01-02 5.192 6.763 4.390 0.112 pooled 5.198 6.767 4.395 0.007 Duration of opening of 99-00 20.071 22.500 19.071 0.750 flowers from 1st to last 00-01 19.960 22.453 18.976 0.425 On the spike in field (days) 01-02 19.997 22.532 18.840 0.310 pooled 19.993 22.504 18.906 0.151 Bulb diameter (cm) 99-00 2.689 3.140 2.090 0.268 00-01 2.683 3.339 2.019 0.247 01-02 2.692 3.254 1.967 0.128 pooled 2.690 3.252 1.995 0.007 Average amt. of water applied/year (cm) — 156.97 156.97 196.0 — J. Hortl. Sci. Vol. 7(1):94-97, 2012 96 D = depth of water (mm) A = area of one plot (m2) N = number of plots or replications per treatments Time of operation (hr) of drip irrigation system for each treatment was calculated using the equation To = V / q. Eu.n. N Where To = Time of application of the operation of drip irrigation unit for the respective treatment (hr) V = Volume of water to be applied for each application for all three replications of treatment (l) q = Average discharge of emitters in the respective treatments (lph) Eu = Emission uniformity of the drip irrigation unit n = Number of emitters per treatment N = Number of plots per treatment Observations on plant height, number of leaves, number of flowers per spike, average spike length, length of rachis (cm), weight of spike (g), yield of bulbs (t/ha), yield of bulblets (t/ha), spike yield, days for opening of flowers and, diameter of bulb (cm) were recorded. Results presented in Table 1 depict significant effect of various irrigation systems on growth and yield in tuberose cv. Suvasini. Pressurized irrigation, viz., sprinkler and drip, proved better than the surface method of irrigation. Micro- sprinkler was the best and gave significantly better values [mean plant height at bud stage (63.95 cm), number of leaves per plant at onset of flowering (107.30), number of flowers per spike (55.98), spike length (111.00 cm), length of rachis (51.83 cm), weight of spike (39.82 g), yield (6.76 lakh spikes / ha), yield of bulb (46.47 t/ha) and bulblet yield (16.67 t/ha) and bulb diameter (3.25 cm)]. Flower spikes lasted longer under micro-sprinkler irrigation. Results obtained in micro- sprinkler were superior over the other irrigation systems because of maximum area wetted and better microclimate. The active root zone in tuberose lies at 30 cm soil depth. Micro-sprinkler created favourable conditions for bulb development, bulblet multiplication, better growth and yield of spikes, etc. These results are in agreement with Beattii et al (1993) who reported very marked differences in response to irrigation methods in Asiatic lilies. Table 2. Cost economics in tuberose cultivation Cost economics Drip (Microtube) Micro- sprinkler Conventional Fixed cost (Rs./ha) 40000 85000 — a) Life (seasons) 7 7 — b) Depreciation 5143 10929 — c) Interest 5600 11900 — d) Repairs & Maintenance 800 1700 — e) Total (b+c+d) 11543 24529 — Cost of cultivation (Rs./ha) 55391 55391 55391 Seasonal total cost (1e + 2) (Rs./ha) 66934 79920 55391 Water used (mm) 1569.7 1569.7 1960.0 Yield of produce ( spikes/ha) 519800 676700 439500 Selling price (Rs./ spike) 0.15 0.15 0.15 a) Income from produce (5 x 6) (Rs.) 77970 101505 65925 b) Income form bulbs (Rs.) 93750 112500 75000 c) Total (a + b) 171920 214005 140925 Net seasonal income (7-3) (Rs.) 104986 134085 85534 Additional area cultivated due to saving of water (ha) 0.25 0.25 — Additional expenditure due to additional area (3rd x 9th) (Rs.) 16734 19980 — Additional income due to additional area (7 x 9) (Rs.) 42980 53501 — Additional net income (11 - 10) (Rs.) 26246 33521 — Gross cost of production ( Rs.) (3+ 10) 83668 99900 55391 Gross income (7+11) (Rs.) 214900 267506 140925 Gross B:C ratio (14/13) 2.57 2.68 2.54 Net extra income due to irrigation system over conventional 45698 82072 — (12 + 8 drip - 8th conventional) (Rs.) Net profit per mm water used (8/4) 66.88 85.42 43.64 WUE (5/4) (spikes/ha - mm) 331.15 431.10 224.23 Deshmukh J. Hortl. Sci. Vol. 7(1):94-97, 2012 97 Overhead method of irrigation produced plants with greater height and good yield. Similar results were reported by Shillo (1992) who stated that tuberose was a popular garden plant besides its use on cut flower; each rhizome of the plant has a potential to produce one flower; but, flowering percentage is related to rhizome size and the irrigation method. In field trials on cv. Pearl, it was observed that plants irrigated with micro-sprinklers had maximum height and number of leaves. Each spike had as many as 60 flowers/ spike and averaged 115 cm in length. Performance of tuberose under drip irrigation was found to be better than in conventional irrigation system. Low performance of these systems compared to that with micro-sprinkler can be attributed to the growing conditions and soil water status which, in these methods, is not as congenial. Ramaswamy et al (1979) also reported similar results in their study on influence of various methods of irrigation on flowering and yield in tuberose. Total amount of water applied through micro-sprinkler and drip was 156.97 cm/ year as against 196.0 cm /year in the surface method of irrigation. Cost economics presented in Table 2 reveal that maximum B:C ratio of 2.68 was obtained with micro-sprinkler method of irrigation. REFERENCES Beattie, D.J., Blodgett, A.M. and Holcomb, E.J. 1993. Effects of root removal, irrigation methods and ancymidol on flowering of Asiatic lilies. Plant growth regulator society of America (Quarterly) 21:64-72 Keller, J. and Karmeli, D. 1974. Trickle irrigation design parameters. Part II, Hort. Rev., 17:678-684 Ramaswamy, N., Paulraj, C. and Chocklingam, P. 1979. Studies on the influence of different irrigation methods on flowering and yield of tuberose (Polyanthes tuberosa L.). Annamalai. Univ. Agri. Res. Annua, 7:29-33 Shillo, R. 1992. The tuber community holds the answer to flowering problems in Polyanthes tuberosa. Acta Hort., 325:139-148 (MS Received 03 August 2010, Revised 17 April 2012) Irrigation methods influencing tuberose cultivation J. Hortl. Sci. Vol. 7(1):94-97, 2012