ROOT GROWTH, HYDROULIC CONDUCTANCE AND YIELD OF RICE (BRRIdhan28) UNDER LIMITED WATER AND GROWTH REGULATOR

Abstract

A field experiment was carried out to study the effect of different doses of IAA alone or in combination with soil water on root growth, hydraulic and yield performance and to determine the effective dose for IAA for boro rice cv. BRRIdhan28. The treatments were concentrations of IAA i.e. 50, 100 and 150, ppm alone and with water. The root dry weight, root fresh weight, root volume, root surface area, root length, root diameter at soil base were increased markedly for 100 ppm IAA under flooded water condition. It was also observed that the combined application of IAA and flooded irrigation were more effective and found to be superior to others treatments for root growth parameters. There is no marked variation in root anatomy and suberin lipid deposition in root cell endodermis layer. The hydraulic conductance of rice cv. BRRIdhan28 under flooded condition had higher than that of drought condition. In case of morphological characters, the maximum plant height was recorded 90.56 cm in the treatment of 100 ppm IAA+ continuous flooded irrigation. The highest NAR was found in 100 ppm IAA+ continuous flooded irrigation. The maximum Leaf dry weight, stem dry weight, root dry weight and total dry matter was recorded at 40 and 80 DAT in 100 ppm IAA+ continuous flooded irrigation over control. The highest yield was observed (3.42 kg/plot) in 100 ppm IAA+ continuous flooded irrigation.