Water stress is one of the most limiting environmental factors to plant productivity world wide and can be caused by both soil and atmospheric water deficits. Water stress is one of the most limiting factors for plant survival since it regulates growth and development and limits plant productivity. The effect of water stress varies with variety, degree and duration of stress and the growth of the plant. The effect of water stress on yield decrease of rice is very pronounced during certain period of growth, called the moisture sensitive periods.In an experiment conducted in the Philippines. It has been shown that moisture stress early in the growth of the rice reduced tillering, thereby reduced yield. When moisture stress was extended into reproductive phase, yield loss was significant. examined the effect of varying soil water regime during different growth phaseson rice yield. They reported that the soil water stress applied any of the growth phases reduced rice grainyield, compared to the continuous flooding irrigation. The ripening phase appeared to be most sensitive to compared to the other phases. Soil water stress during the earlier growth phases appeared the production of effective tillers resulting in the reduction of grain yield, while stress during the later growth phases appeared to affect the reproductive physiology by interfering with pollination, fertilization and grain filling in the reduction of grain yield.
The objectives of this study are to examine the effects of water stress on growth and yield of three rice varieties in Sokoto.Pot experiment was conducted during the 2013 dry season at the Botanical garden of the Department of Biological Science, Usmanu Danfordiyo University, Sokoto. Sokoto State is located between latitude 13˚01′ North and longitude 05˚15′ East of about 350 m above sea level. The area has a long dry season that is characterized by cool dry air during harmattan from November to February and hot dry air during hot season from March to May. Relative humidity ranged from 26% – 39% in the dry season. Minimum temperature ranged between 19˚C and 29˚C and maximum temperature ranged from 30 to 40˚C and, livestock fodder system wind speed ranged between 1.8 to 5 MS−1 . Soil sample was collected from 0 – 20 cm soil depth and analyzed for physic-chemical characteristics. The soil of the experimental area is sandy, slightly acidic, low in organic carbon, total nitrogen, exchangeable cations and available phosphorous .The effect of water stress and variety on plant height is presented on Table 1. The result indicated that water stress had no significant effect on plant height at 3 Weeks After Planting . Water at tillering resulted to significant reduction in plant height at 6, 9, 12 and 15 WAP. Control is statistically similar with water stress at flowering and grain filling. The reduction in plant height was as a result of water stress imposed at tillering stage. This is because imposing water stress resulted in law leaf water potentials and reductions in photosynthesis; photosynthetic activity declines because of decreased stomatal opening and the inhibition of chloroplast activity; this reduced the length of the internodes at jointing stage which follows tillering stage. At the time when water stress was imposed at flowering and grain filling, the jointing stage had taken place and plants have reached their maximum height, thus the effect of water stress was ineffective.
Found significant reductions in tillers and panicles numbers as well as plant height and grain yield when water stress was imposed at tillering stage water stress resulted to decreased in plant height, number of tillers per plant, total biomass and grain yield. The effect of variety showed that at 3 WAS varieties did not differ in plant height. But Faro 44 differed significantly with taller plants, while Wheata 4 and Nereca 2 did not differ significantly with shorter plants. The significant differences among genotypes for plant height indicate appreciable amount of variability among the genotypes subjected the varieties to moisture stress at different growth stages particularly during seeding stage. They identified some promising lines had tolerance to the water stress reported varietal differences among the cultivar for moisture stress.The effect of water stress and variety on number of tillers per plantis is presented in Table 2. Water stress at tillering resulted in significantly fewer number of tillers than water stress at flowering or grain filling and control which were statistically at par with each other. The fewer tillers recorded at tillering could be as a result of water stress imposed at tillering because non-availability of water at tillering stage resultedin reduction in the amount of intercepted photosynthetically active radiation . Similarly, during tillering plant produces leaves and due to reduced growth as a result of water stress, the leaf initiation gets decreased and thus, tends to reduce tillering. Reported that significant reductions in tillers and panicles numbers as well as plant height and grain yield were found when water stress was imposed at tillering stage. The effect of variety indicated that.FARO 44 differed significantly with higher number of tillers per plant, while FARO15 and NERICA 2 did not differ significantly with fewer number of tillers plant. The significant differences among genotypes for number of tillers indicate appreciable amount of variability among the genotypes. identified promising lines tolerance to water stress.Decrease in HI could be largely due to water stress which resulted to decrease in translocation of assimilates to the grains, which lowered grain weight and increased the empty grains. High HI indicate the efficient translocation of assimilates towards sink.
Lower HI values under water stress at flowering and grain filling stages indicate that it was more harmful in translocation of assimilates towards the grains.The hazard quotients for lead through the consumption of fish and market garden products are less than 1 in both children and adults. This confirms that the fish species Oreochromis niloticus from Lake Toho in HouinLogbo and Solanum lycopersicum market garden products are not contaminated by lead. The consumption of fish, in particular the Oreochromis niloticus species from Lake Toho in Houin Logbo, exposes the population to the risk of cadmium and arsenic poisoning, while the consumption of market garden products, in particular Solanum lycopersicum, exposes the population to risks cadmium poisoning. With economy rapidly development, gardening has been one of the most important parts of urban infrastructure construction which decorate the city more and more beautiful. More attention is paid to urban construction rather than urban management, which results in low informationized development. This problem has impacted the gardening construction and development. It mainly reflects in the following aspects: 1) Landscaping classification complexity result in difficult management, 2) due to the rapid development of urban construction, information is very difficult to update, 3) traditional management methods can’t accurately statistic various landscaping, such as, old trees, parks, scenic spots, etc, 4) planning and evaluation are mainly based on practical experience. Based on the above reasons, the key technology and construction methods of urban gardening need to be studied and gardening information management system will be studied. By operating this system, the operational level and management efficiency will be improved. Carry out comprehensive evaluation of urban gardening and set urban development strategies for gardening development. Gardening information management system is based on MapGIS data center integrated development platform to build and design on three layer architecture, . The first layer is hardware and software-based layer, which is base for management operation platform. Hardware part includes network equipment, servers, storage, backup devices, network including government special network, Internet, GPRS network, etc. Software part includes operating systems, database management systems, mirror and backup tools, GIS platforms and security software. The second layer is an integrated development platform for data center which is the running environment for gardening information system building and configuration.
The third layer is the applications and services layer which provides business applications and service to users. Integrated development platform for data center is based on the gardening information management requirements, which provides common needs and capabilities. It adopts service-oriented architecture conceptions. It designs and develops corresponding abstraction function module which constituted by several basic function composition. It can be divided into three layers. The first layer is to provide basic and common features, such as basic heterogeneous data view, GIS capabilities, remote sensing capabilities, 3D functions, data processing work space, data security rights management module, etc. The second layer is to provide basic and general landscape features, such as data models management, basic function management, fodder system trays gardening basic method management functions, etc. The third layer is to provide gardening professional functions, such as landscaping assisted analysis, removal and analysis, etc. In addition, as for specific business needs, it provides a standard function module expansion interface, which supports particular business logic integration, specific business function development completion. It can also be incorporated into functional warehouse to be an integral part of a functional warehouse. In addition, data center integrated development module and function module adopts “Loosely coupled” connection approach. This approach which is flexible in structure and powerful expansibility is the best connection method which has minimal environmental impact. Operation adopts “service” approach which converts “data access operation” to “data access service request service”. “Data access service” is an example, which fully embodies the latest “service oriented” design ideas. Digital Elevation Model is an entity ground model which uses an array of values to describe ground elevation. It’s one of branches of Digital Terrain Model . The other digital model uses matrix form to express various non-terrain features, including the natural and geographical factors as well as the ground-related socio-economic and cultural factors, such as soil type, land use types, rock depth, land, commercial advantages district, etc. By using DEM, 3D visual reality technology, establish 3D view model of gardening planning area, such as urban green space system planning models, landscaping professional planning and green space system detailed planning model, landscape greening proportion and distribution models, urban green space and scenic spots of the planning model. Base state with amendments is one of spatial data management method which doesn’t store all the status of researched area, but only the state of some point and also change to relative basic state. Base state with amendments can greatly reduce temporal data amount. Gardening historical data management is based on tuple level which is based on base state with amendments. Generally, the status after construction of urban gardening is taken as “base state”. User most concerned “current state” is the latest update data state.
All the “current state” gardening information will be effectively managed which can fully reflect the change and development of gardening, and reduce historical data of the redundant and facilitate historical data management. Urban gardening information management system professional basic function includes, greening data model, metadata management, gardening basic function warehouse, gardening basic method warehouse, data exchange components, etc. . The basic function library includes data management basic function library, data update basic function library, data analysis basic function library, 3D model, encoding engine, etc. System application function construction includes application function library, business process library, etc. The application function library includes analysis function library, business function library, thematic map function, etc. Analysis function libraries includes landscaping demolition cost accounting, green analysis, greening comparative analysis, index analysis, etc. Gardening business functions includes gardening project management, landscape planning and management, garden maintenance, etc. Both professional basic and industry function support Visual Studio2005. All the plug-ins development is according to the relative interface standards. After completing plug-in functions, find appropriate registration documents and start editing plug-ins register in accordance with registration standards. Phosphorus is recognized as a limiting factor for growth of aquatic organisms in surface water bodies especially in lakes and reservoirs. When excess amounts of nutrients are discharged into surface water, the biomass of phytoplankton starts to increase and shifts to bloom-forming species that may be toxic to stock animals and potentially humans. As biomass of algae increases, water transparency decreases and taste, odor and water treatment problems become a possibility. Microorganisms decompose algae when they die resulting in dissolved oxygen depletion, death of living organisms, fish kills, and deterioration of aesthetic value of water bodies.