USCID 14th technical conference

Presented at Contemporary challenges for irrigation and drainage: proceedings from the USCID 14th technical conference on irrigation, drainage and flood control held on June 3-6, 1998 in Phoenix, Arizona.Includes bibliographical references.Water properties, such as the viscosity and surface tension, can be affected by temperature and surfactants to increase infiltration rates into soils. Specifically, they will change the hydraulic conductivity of the soil. A simple soap solution and the new material PAM (inexpensive polymer chemical) were evaluated as surfactants. Laboratory experiments and field tests on a site in Davis, California were done to quantify the effects of changing the water properties. Additional effects, like the improved soil structure during infiltration and less soil particles in tailwater (reduced erosion due to runoff) were observed and are described in this paper. The conclusions of this study are translated into suggestions for improved on-farm water use in furrows, sprinklers, and drip irrigation

The release of dormancy, a wake-up call for seeds to germinate

Seed dormancy determines the timing of germination, thereby contributing to successful seedling establishment and plant fitness. The induction and release of dormancy are controlled by various regulators like plant hormones and dormancy proteins. The relative strengths of these regulators are influenced by environmental factors during seed maturation and storage. In the last few years additional processes have been identified to be involved in the release of dormancy during seed storage with an important role for non-enzymatic oxidative reactions. However, the relations between the different dormancy regulators are not fully understood yet. Finally, all accumulated information will be processed in the seed during early seed imbibition and lead to the decision to germinate or not

Utilizing shallow ground water

Presented at Contemporary challenges for irrigation and drainage: proceedings from the USCID 14th technical conference on irrigation, drainage and flood control held on June 3-6, 1998 in Phoenix, Arizona.Includes bibliographical references.Shallow ground water in arid irrigated areas has generally been treated as a waste product of irrigation which was to be discharged into an available water course for ultimate disposal in an ocean. This practice is no longer environmentally acceptable and means need to be developed to minimize the environmental impact of uncontrolled discharge of drainage water from irrigated lands. This paper presents the results of field and theoretical studies which demonstrate methods to reduce and minimize the volume of drainage water for disposal. The field studies demonstrated the use of subsurface drip irrigation with modified crop coefficients to increase the water use from shallow ground water, and the use of control structures on drainage systems to control the depth to shallow ground water to improve the water use by the crop from shallow ground water. Application of these techniques resulted in significant use of ground water by cotton and tomato. The theoretical studies demonstrated that using new drainage design criteria will result in less drainage discharge and lower salt loads. Improved irrigation efficiency will have the largest impact on reducing total drainage discharge

Sequence Polymorphisms at the REDUCED DORMANCY5 Pseudophosphatase Underlie Natural Variation in Arabidopsis Dormancy

Seed dormancy controls the timing of germination, which regulates the adaptation of plants to their environment and influences agricultural production. The time of germination is under strong natural selection and shows variation within species due to local adaptation. The identification of genes underlying dormancy quantitative trait loci is a major scientific challenge, which is relevant for agricultural and ecological goals. In this study, we describe the identification of the DELAY OF GERMINATION18 (DOG18) quantitative trait locus, which was identified as a factor in natural variation for seed dormancy in Arabidopsis (Arabidopsis thaliana). DOG18 encodes a member of the clade A of the type 2C protein phosphatases family, which we previously identified as the REDUCED DORMANCY5 (RDO5) gene. DOG18/RDO5 shows a relatively high frequency of loss-of-function alleles in natural accessions restricted to northwestern Europe. The loss of dormancy in these loss-of-function alleles can be compensated for by genetic factors like DOG1 and DOG6, and by environmental factors such as low temperature. RDO5 does not have detectable phosphatase activity. Analysis of the phosphoproteome in dry and imbibed seeds revealed a general decrease in protein phosphorylation during seed imbibition that is enhanced in the rdo5 mutant. We conclude that RDO5 acts as a pseudophosphatase that inhibits dephosphorylation during seed imbibition

Место и роль ценностей в механизме социализации

В статье рассматривается специфика механизма социализации и проблема ценностных ориентаций в условиях социокультурных трансформаций украинского общества. Определяются ценностные ориентиры гражданского общества как приоритетного для Украины.У статті розглядається специфика механізму соціалізації і проблема цінностних орієнтацій в умовах соціокультурних трансформацій українського суспільства. Визначаються цінностні орієнтири громадянського суспільства як приоритетного для України.The article deals with peculiarities of socialization and the problem of value ori-entation under the conditions of socio-cultural transformations of the Ukrainian society. We also define value orientation of the civil society as optimal for Ukraine