Growth and Yield of Wheat (Triticum aestivum L.) as Affected by Mulching and Irrigation

Abstract

The experiment was conducted at the Agronomy Field Laboratory, Department of Agronomy and Agricultural Extension, University of Rajshahi Campus, Bangladesh during the winter seasons (November to March) of 2008-2009 to 2009-2010 to study the growth and yield of wheat (Triticum aestivum L.) as affected by mulching and irrigation. The study considered three factors viz. four levels of irrigation (0 cm=I0; 2 cm=I1; 4 cm=I2 and 6 cm=I3), four types of mulching (no mulching=M0; water hyacinth=Mw; rice straw=MS and black polythene=MP) and two BARI released wheat varieties (Prodip=V1 and Sufi=V2). The experiment was laid out in split-split plot design assigning irrigation to the main plot, varieties to the sub-plot and mulching to the sub-sub-plot. There were three replications for each treatment. The highest TDM, LAI and CGR were obtained from the highest level of irrigation (I3) and the lowest values were obtained from control in both the years. With few exceptions LAR and SLA showed the highest values at I3 treatment every year. At the initial stage of growth, LWR showed the highest value in I0 but from 50 DAS it was reversed and I3 treatment showed the highest values in both the experimental years with a few exceptions. RGR, RLGR and NAR did not show any clear pattern in both the growing seasons. Between the two varieties, Prodip showed higher values in TDM, CGR and NAR and Sufi was superior over Prodip in producing higher values of LAR and LWR in both the years. RGR, RLGR and SLA did not follow any clear trend of superiority between the two varieties. Results also revealed that, the highest values of TDM, LAI and CGR were obtained from MP followed by MS, MW over no mulch treatment in both the years. With some exceptions the highest RGR values were found in MP but the difference between MP and MS were too narrow. NAR, RLGR and SLA did not show any fixed trend in the highest and the lowest values. MP showed the highest values in LAR with some exceptions in both the years. LWR almost showed the same values as influenced by MP and MS treatments. Moisture retention capacity (MRC) of the flag leaf was increased with increased irrigation levels. The highest MRC was found in I3 treatment over the control treatment. Prodip showed higher MRC than Sufi at each time of the experimental day. In case of mulching treatments, MP showed the highest MRC followed by MS and MW. The highest value of MRC was always shown by I3×MP treatment combination. Non-irrigated plants showed lower relative leaf water content (RLWC) at each time of the experimental day. The highest RLWC was observed in I3 followed by I2, I1 and I0. I3×MP treatment combination always had the highest value of RLWC. Chlorophyll content of the flag leaf was increased with increasing levels of irrigation. I3 treatment produced plants containing the highest amount of chlorophyll a, chlorophyll b and total chlorophyll followed by I2, I1 and I0. The highest amount of chlorophyll a: b ratio was produced by I0 treatment in both the years. All the yield components such as plant height, total tillers plant-1, effective tillers plant-1, non-effective tillers plant-1, spike length, extrusion length, number of spikelets spike-1, number of fertile spikelets spike-1, number of sterile spikelets spike-1, 1000-grain weight, grain yield, sraw yield, biological yield and harvest index were observed with their highest values in I3 (irrigation level) and MP (mulching treatment). Thus, it is concluded that growth, development and yield of wheat can be increased by using the combined treatment of 6 cm of irrigation and black polythene.