Eiji Kanda

• Kagoshima University

In recent years, the increased incidence of sudden heavy rains in Japan has enhanced the occurrences of surface runoff from sloping farmlands. These runoff events negatively affect the ecosystems due to leaching of fertilizer components and/or heavy metals into local watersheds. Water-level meters installed at the bottom edge of sloping farmlands h...

Rice blast disease occurs in rice production areas all over the world and is the most important disease in Japan. Remote sensing techniques may provide a mean for detecting disease intensity for large area without being subjected to raters. This study evaluated the use of airborne hyperspectral imagery to measure the severity of panicle blast in fi...

In recent years, the increased incidence of sudden heavy rains in Japan has enhanced the occurrences of surface runoff from sloping farmlands. These runoff events negatively affect the ecosystems as a result of the fertilizer components or heavy metals present in the runoff water that flows into local watersheds. A conventional method for measuring...

Maps for forecasting heading dates of the forage rice cultivars ‘Bekogonomi’ and ‘Yumeaoba’, direct-seeded in paddies in the Tohoku region were created by using models to estimate the developmental stages of rice plants, and 1-km-mesh temperature data. The developmental-stage models were prepared by using growth and temperature data obtained from t...

We analyzed the impact of climate change due to global warming on the risk of cool summer dam-age to paddy rice in the Tohoku region of Japan. We downscaled the atmospheric general circulation model of the Meteorological Research Institute (MRI AGCM) to 10 km, and we used monthly aver-age temperatures and their standard deviations to correct the bi...

Cold northeasterly winds, called Yamase, which cause the summertime weather of northern Japan to be unusually cool, have often damaged the rice crop in northern Japan, both historically and recently. To estimate future Yamase event occurrences, we used the new version of the MIROC5 atmosphere-ocean general circulation model and predicted the freque...

The effects of climate conditions during vegetative growth on cold tolerance of rice at the booting stage were examined. Rice cultivar 'Hitomebore' was grown in Hokkaido-Tohoku region at six locations in 2008 and seven locations in 2009, where the soil and applied fertilizer were identical. A cold tolerance test was conducted during the reproductiv...

A method for estimating the suitable time and area for transplanting or direct-seeding rice to avoid the incidence of marked dull endosperm was investigated by predicting the amylose content of low-amylose rice varieties using a model for estimating developmental stages. Three low-amylose rice varieties were transplanted or direct-seeded at three l...

The major carbohydrates of rice straw samples were determined in order to evaluate the potential of using rice straw as a feedstock for ethanol production in Japan. Straw samples were harvested by cutting the plants at ground level when the grain was mature and immediately heating or chilling the samples. In all cases, significant amounts (62–303 g...

We examined genotypic variation in the effect of rice (Oryza sativa L.) responses to water temperature (T(w)) during vegetative growth on cold tolerance during reproductive growth in pot and field experiments. Cold tolerance was evaluated based on the percentage spikelet sterility induced by a cool and deep irrigation treatment during the reproduct...

With meteorological data of Harbin City and Jiamusi City during 1951-2005 combined with the characteristics of rice production, the impacts of global warming on chilling damage, spring's drought, high temperature injury and diease and insect pests of rice were studied in this paper. Based on the research, a series of practical strateges to deal wit...

To evaluate the incidence of cool summer damage as early as possible, we made a model to estimate the sterility percentage from the cool degree days in the consecutive developmental stages of young panicles. For estimation of the sterility percentage, we used nonparametric regression with, the limitation that the values of the adjoined partial regr...

Spikelet sterility of rice (Oryza sativa L.) results from low temperatures during panicle development. However, this temperature alone cannot fully explain the fluctuations in sterility observed in the field, since the susceptibility of rice plants to low temperature often changes according to its physiological status during sensitive stages. In th...

The variation of developmental stages in rice-producing areas makes it difficult to estimate cool weather damage. We made a method to estimate the percentage of productive panicles and glumaceous flowers at a specific stage such as meiosis, in the areas around automated meteorological data acquisition system (AMeDAS) points. In this method, the var...

水稲冷害早期警戒システムで作成した発育モデルを拡張し, 圃場内における有効穂や穎花が減数分裂期などの特定の発育ステージにある割合を推定する手法を作成した. この手法は発育に内在する形態形成の規則性に起因する変異を対象とし, 移植時の個体葉齢変異, 有効穂の幼穂形成期変異, 穎花の開花日変異を発育モデルの初期値とすることで取り扱う. この手法を1999年, 2001年, 2003年の東北農業研究センターと青森県十和田, 八戸, 青森の生育診断圃場に適用し, この手法の実用性を検討した. 1穎花の危険期間を設定して危険期にある穎花割合を推定すると, 穎花レベルの危険期のピークは有効穂レベルの減数分裂期のピークよりも2～3日遅かった. また, 冷害年である2003年は冷温で発育が緩慢となり, 減数...

 Rice reflectance was measured to determine the spectral regions most sensitive to leaf blast infection with a multispectral radiometer. As disease severity increased, reflectance also increased in the 400–500 nm (blue), 570–700 nm (red), and 900–2000 nm regions but decreased in the 500–570 nm and 700–900 nm regions. The increased reflectance in th...

An early warning system for preventing the decrease in rice yield by cool summer damage in the whole Tohoku area is constructed. This needs to predict the developmental stages of rice plants from the effective accumulative air temperature above 10°C. The panicle development model, which predicts the time of pollen mother cell differentiation, meios...

ABSTRACT Rice reflectance was measured to determine the spectral regions most sensitive to panicle blast infection. Reflectance increased in the 430- to 530-, 580- to 680-, and 1,480- to 2,000-nm regions at the dough stage both in the laboratory and the field as the percentage of diseased spikelets increased. The wavebands of the greatest sensitivi...

We are building an early warning system for preventing the decrease in rice-yield by cool summer damage. To monitor the developmental stage of rice plants in the whole Tohoku area, we constructed a model for estimating the plant age in leaf number. In the model, the sum of effective cumulative air temperature for l0-24°C necessary to advance the le...