Irrigation scheduling for potted gerbera (Gerbera jamesonii Bolus.) under rain shelter

Abstract

The study entitled “Irrigation scheduling for potted Gerbera (Gerbera jamesonii Bolus.) under rain shelter’’ was undertaken with the objectives of evaluating different methods of irrigation and standardizing of irrigation schedule for the quantity of water and frequency of application. The study was conducted at the Department of Floriculture and Landscaping, College of Agriculture, Vellayani. Tissue culture plantlets of gerbera variety ‘Samara’ were planted in polybags (40cm×40cm) containing soil, sand, and coir pith mixed in a ratio of 1:1:1 as substrate. Fertilizer dose of 1.6g N, 1.6 g P2O5, and 1.6 g K2O were applied at monthly basis. Bimonthly application of 30 g dried cow dung manure and foliar application of 13:27:27 (0.4%) @ 100 ml per plant was also done. The experiment was laid out in Completely Randomized Design with two factors ie, irrigation method and water deficit level. Drip irrigation, wick irrigation, wick+supplementary overhead irrigation and overhead irrigation were the irrigation methods and 100%, 80% and 60% field capacity were the levels of water deficit. The daily water consumption of plants was calculated using gravimetric and the computed amount of water was added to compensate the transpiration loss to keep the plants at their appropriate soil moisture levels. Vegetative parameters, floral parameters, physiological parameters, yield, analysis of irrigation and computed parameters like survival percentage, water use efficiency and leaf area observations were taken at monthly intervals. Among the treatments, M1 (drip irrigation) recorded the higher for vegetative parameters like number of leaves (15.67) at 10 MAP, breadth of leaves (11.58cm) at 10 MAP and sucker yield (3.94) at 10 MAP. Overhead irrigation was significantly superior in plant spread (69.28cm) at 10 MAP. Highest leaf length was observed (32.76 cm) in wick and supplementary overhead irrigation at 5 MAP. The water deficit level at 60% field capacity produced significantly highest plant spread (68.57cm) at 10 MAP, number of leaves (14.08) at 9 MAP, length of leaves (31.68) at 6 MAP and breadth of leaves (9.93cm) at 9 MAP. The water deficit level at 100% field capacity was significantly superior in sucker yield. Plants provided with drip irrigation at 60% field capacity recorded significantly highest plant spread (75.73cm) at 6 MAP, number of leaves (20.67) at 10 MAP, breadth of leaves (14.20cm) at 10 MAP and sucker yield (4.83) at 9 MAP. Wick and supplementary overhead irrigation at 60% field capacity was significantly superior in leaf length (35.80cm) at 5 MAP. Regarding floral characters, drip irrigation with 60% field capacity recorded lowest value for number of days taken for bud initiation (23.82 days). Wick irrigation with 80% field capacity recorded lowest value for number of days taken from bud initiation to harvest (10.43 days). Highest flower longevity was observed in drip irrigation with 60% field capacity (8.14days). Highest flower characters were exhibited by drip irrigation at 60% field capacity (flower diamter-15.63cm, length of ray floret- 4.67cm,width of ray floret-1.10cm, length of flower stalk-55.83cm and girth of flower stalk-2.20cm). Most visually appealing flowers were produced in drip irrigation at 60% field capacity. Regarding yield parameters, highest flower yield (7.40) per plant per month was observed for drip irrigation with 60% field capacity at 9 MAP. There was no significant effect of irrigation methods and water deficit level on flower yield in relation to season. Among physiological parameters, no significant effect was observed on relative water content. In irrigation analysis, the highest irrigation frequency was exhibited for overhead irrigation with 60% field capacity (4.01days) at 9 MAP. The highest cumulative water transpired per plant (24940 ml) was observed in overhead irrigation with 100% field capacity at 10 MAP. Among computed parameters, the plants treated with drip irrigation at 60% field capacity showed 100% survival percent in two weeks and 90% in four weeks after planting. The highest interaction effect on water use efficiency (343.04g/ml) was observed in drip irrigation with combination of 60% field capacity at 10 MAP. Highest leaf area was observed in the treatment combination of drip irrigation at 60% field capacity (99.00cm²) at 10 MAP. The most economically feasible treatment combination was drip irrigation at 60% field capacity which recorded B.C ratio of 1.53. The results of the present study suggested that application of water at 60 % field capacity through drip irrigation system improved vegetative characters, flowering characters, flower yield and visual appearance of flowers in gerbera (Gerbera jamesonii Bolus.) variety ‘Samara’ growing under rain shelter followed by drip irrigation at 80% field capacity. The future line of work may be development of an automated precision farming technique and standardization of fertigation using different water-based nutrients in gerbera