Root fresh weight measurement for rice root system—A proposal for a simple dewatering method of fresh paddy roots using a vegetable drainer

Abstract

The pot experiment is effective for the evaluation of water uptake of plants and the gravimetric method is used to assess the water uptake of plants. For an accurate gravimetric assessment of the water uptake of plants, it is essential to evaluate the fresh weight of the stems, leaves and root system as a percentage of the total weight. The fresh weight of stems and leaves can be easily measured after cutting at the ground level, but the fresh weight of the root system is difficult to measure, especially when the growth of the plant has become more complex, because the process of removing water from the surface of the root system after washing the roots out of the soil is difficult. In this study, we proposed a method for measuring the fresh rice root weight that can be provided at a low cost and is relatively easy to use, with little measurement error and relatively little physical burden. It was found that 1) a vegetable drainer as a measuring device could be prepared at a low price, 2) it was easy to determine the rotation speed, 1 rotation/sec, so that measurement error were unlikely to occur and 3) the physical burden of measurement was low. Furthermore, the effectiveness of the proposed method and the significance of fresh rice root weight measurement were both evaluated by using this method in the pot experiments with different irrigation timing.