Assessment of water quality in small agricultural ponds in Nara,Japan

Paddy and Water Environment - In Japan, since ancient times, numerous small- to medium-size agricultural ponds have been constructed to irrigate paddy rice fields. Economic growth and urbanization...     

Water transfer from agriculture to urban domestic users: a case study of the Tone River Basin, Japan

Agricultural water reorganization measures (AWRM) is an approach that has been adopted in Japan for more than 30 years to capture excess water from agriculture for other uses by relying on the modernization of existing irrigation infrastructures. This paper reviews the history and processes of four such permanent water transfers by AWRM in the Tone River Basin, specifically those conducted in the Saitama Prefecture, Japan. The benefit of AWRM for the agricultural sector is the lowering of rehabilitation costs by sharing part of it with the city sector. AWRM does not require saving water at the on-farm level. Instead, the labor requirement of farmers is reduced by the rehabilitation and installation of pipelines. The benefit to the city is the lower cost, when compared with costs for the development of new water resources, and the relatively short duration of the project, which are important factors in an environment of the rapid increase in domestic water demand.

Abnormal auxin distribution and poor berry setting (coulure) in grapes

A constant low auxin level was observed in a normally setting trimmed cluster of the tetraploid grape ‘Kyoho’ (Vitis vinifera L. × Vitis labrusca L.). The basipetal auxin transport in the trimmed cluster was always 2–3 times higher than the acropetal transport during the flowering-period. In a non-treated cluster, showing a tendency towards excessive berry abscission, the auxin level in the apical parts of the cluster fluctuated within the range of 20–70 times that of the auxin content at full bloom. The ratio of basipetal to acropetal auxin transport was nearly unity or less than unity.The results support the hypothesis of apical dominance and auxin gradient in the formation of an abscission zone.     

Clonal variation in heartwood norlignans of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>: evidence for independent control of agatharesinol and sequirin C biosynthesis

• Introduction   

In Cryptomeria japonica, heartwood properties are considered to be affected by specific extractives. It remains unclear whether traits of specific heartwood compounds are under genetic control.     

On-farm irrigation development and management in lower Myanmar: factors for sustainable rice production and collective action

The case study is aimed at assessing impacts of on-farm level irrigation development and management on dry season rice production in the main irrigated rice production area of Myanmar. The study was carried out from 2003 to 2009 in the middle reaches of the Ngameoeyeik irrigation area of 28,000 ha. In addition to collecting information on water management and institutional arrangement of the study area, hydrologic and agronomic parameters were monitored during the study period. Results showed the effectiveness of on-farm level infrastructural development for increasing rice productivity owing to increased amount of water delivery, increased flexibility of water distribution, and improved drainage conditions. Besides, encouraging the involvement of farmers in design and implementation of the development led to improved farmer participation in the operation and maintenance of the irrigation system. The outcomes of this study demonstrated the importance of balancing between infrastructural and institutional development in irrigation systems of Southeast Asia. Such infrastructural development should be in close association with institutional development and capacity building, and the interactions between those two aspects should be well understood.     

Plant regeneration from protoplasts of calamondin (Citrus madurensis Lour.)

Diploid callus cells arose from the hypocotyl region of plantlets differentiated by anther culture of Calamondin (Citrus madurensis Lour.). The callus grew vigorously on Murashige and Tucker's medium containing 10 mg l⁻¹ benzyladenine, and differentiated embryoids on a medium with 5% lactose and no plant growth regulators. This embryogenic potential was transferred to protoplasts which regenerated plantlets.

Preculture of callus in liquid medium containing 5% lactose, for 4–7 days prior to protoplast isolation, effected a high yield of protoplasts. Plating efficiency was increased in a medium solidified with agarose and/or layered with liquid medium.