Effect of Irrigation and Mulching on Growth and Yield of Ginger

Bangladesh Agron. J. 2015, 18(1): 27-36 EFFECT OF IRRIGATION AND MULCHING ON GROWTH AND YIELD OF GINGER M.A. Islam1, M.A. Rahim2 and T.M.T. Iqbal3 1Spices Research Center, BARI, Bogra; 2BAU, Department of Horticulture, Mymensingh 3Department of Horticulture, HSTU, Dinajpur Key words: Ginger, irrigation, mulching Abstract A field experiment was conducted at the Spices Research Center, BARI, Bogra, Bangladesh during 2009-10 to determine the impact of irrigation and suitability of mulch materials on the growth and yield of ginger. The experiment was laid out in the randomized complete block design (RCBD) with three replications. The treatments comprising of two factors viz., two irrigation (I1: irrigation in dry period and I2: control i.e. no irrigation and three mulching material (M0: control (no mulch) M1: water hyacinth and M2: rice straw). Treatment revealed that I1: (irrigation in dry period) showed that early emergence, highest plant height, number of leaves/plant, number of tillers/plant with maximum weight of primary and secondary rhizome, highest dry matter % and weight of old mother rhizome t ha-1. The highest yield of rhizome (21.19 t ha-1) was obtained from I1: (irrigation in dry period). Among the mulch treatments, the highest rhizome yield (22.51 t ha-1) was obtained from M2 (ricer straw mulch). The combined effect of I1M2 (irrigation in dry period with rice straw mulch) produced the highest rhizome yield (25.07 t ha-1). Introduction Ginger (Zingiber officinale Rosc.) is an important spice crop in Bangladesh. It is valued for its diversified uses in various drinks, medicines and culinary purposes (Pruthi, 1998). Beside the varietal factor, the yield of ginger can be increased with the adoption of improved agronomic practices, like irrigation and suitable mulch materials. Mulch and irrigation are the two important aspects of ginger production. Generally, farmers depend on unpredicted rainfall, which results in late planting. In the early season, soil remains dry, and therefore irrigation at the early stage is needed for ginger growth. The crop is affected by weed except when mulching and adequate weed control measures are taken during the early the stage of growth. Generally, ginger is cultivated under the rainfed conditions in Bangladesh. As irrigation facilities are inadequate and early monsoon rain is not certain, conservation of residual soil moisture by artificial means is be very useful for the plants in maximizing the growth and production of the crop. Artificial mulches like water hyacinth and rice straw can be used to serve this purpose. Mulch conserves soil moisture and protects sprouting of seed materials from excessive heat and desiccation (Onwueme, 1978). Application of mulch soon after planting is beneficial for the culture of some root and tuber crops (Awal et al., 1978; Jha et al., and 1986). Mulched plot gives higher yield than non-mulched plot (Nick et al., 1969; Mannan and Rashid, 1983). Since soil moisture becomes a limiting factor for emergence and early growth of ginger, the use of mulch may be beneficial. Irrigation and mulch play an important role to increase the yield potential of ginger. Ginger is generally cultivated in kharif season in Bangladesh. Irrigation facilities are inadequate and the early monsoon rain is also uncertain. Thus irrigation and 28 Islam et al. mulching may be the most important factors of ginger production. So, this experiment was undertaken to investigate the effects of irrigation and mulching on the growth and yield of ginger. Materials and Methods The experiment was conducted at the research farm of the Spices Research Centre, BARI, Bogra, during the period from April 2009 to January 2010. It has sub-tropical climate with an average annual rainfall of 237.13 mm. The soil was Tista polal tract, having a pH value of 5.86.6. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Healthy ginger rhizome Var. BARI Ada-1 was used for planting material. Two irrigation levels viz., I1 (irrigation in dry period: 7days before planting and 60 days after planting) and I2 (no irrigation) were consisted as the first factor and three mulching materials viz., M0 (control), M1 (water hyacinth) and M2 (rice straw) were considered as the second factor. Planting was done on the 1st April, 2009. The crop was fertilized with cowdung, urea, TSP, MP and gypsum at 5 ton, 304, 267, 233 and 111 kg ha-1, respectively. Total cowdung was applied at the time of general land preparation and the entire quantity of TSP, gypsum and half of MP was applied during the final land preparation. Half of the urea was applied 50 days after planting and the remaining MP and urea were applied in two equal splits at 80 and 110 days after planting. Earthing up was done at 60, 90 and 110 days after planting. The data on different growth parameters were recorded from randomly of 10 selected plants of each plot 15 days interval at 50, 65, 80, 110, 125, 140 and 155 days after planting. Yield and yield contributing characters were collected at harvesting time. The Ist irrigation was applied 7 days before planting and the 2nd irrigation after 60 DAP (Days after planting). Irrigation was done at the level of critical point indicated by moisture meter (delta T England). Irrigation water applied twice 80 mm each time. Irrigation water was applied twice at 7 days before planting and at 60 days after planting. The discharge of water through hose pipe (Diameter 2.5 cm) was calibrated before application. The discharge of water through this pipe was 20 mm pipe per minute. The mulch materials were covering with the 4 cm thickness. Water hyacinth and rice straw mulch were placed before the rhizomes started to emerge. A second mulch was added at 60 days after planting as the first one was washed away by rain, wind and irrigation water. Rice straw and water hyacinth were applied at 2.0 and 2.5 kg/m2; respectively. The soil samples were taken from each plot at 0-10 cm depth before each irrigation. The samples were weighed and oven dried at 1000 C for 24 hours. The collected data were analyzed statistically and adjusted with least significance (LSD) at 5% level of probability. Results and Discussion Soil moisture content Soil moisture at the field capacity of the experimental plot was 25.4%. At the beginning, application of mulch in non-irrigated or irrigated plot conserved more moisture compared to non-mulch + no-irrigation plot. At this time, rice straw mulch + no-irrigation conserved about 1.8% more moisture than water hyacinth + no-irrigation treatment. Similarly rice straw mulch + irrigation conserved about 1.14% more moisture than water hyacinth + irrigation treatment. Irrigation applied after two months of planting showed that moisture content in rice straw mulch + irrigation conserved more moisture compared to water hyacinth + irrigation and nomulch + irrigation treatments (Table 1). At this time, rice straw mulch + (...truncated)