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PubMed2002

Changes in the HPLC phenolic profile of virgin olive oil from young trees (Olea europaea L. Cv. Arbequina) grown under different deficit irrigation strategies.

The HPLC phenolic profile of virgin olive oils obtained from young olive trees (Arbequina cv.) grown under different deficit irrigation strategies was studied. Deficit irrigation (RDI) did not affect all the phenolic compounds in the same way. Lignans, vanillic acid, vanillin, and the unknown phenolic compound named P24 increased in the oils from the most irrigated treatments. The secoiridoid derivatives and the unknown phenolic compound named P19 increased in the oils from the most stressed irrigation treatments. The period of growth where a water stress significantly affects the phenolic profile of oils was between pit hardening and the first stages of fruit growth and oil accumulation, independently of the water applied during the previous period to harvest. The phenolic profile and those parameters related to phenol content, oxidative stability, and the bitter index were significantly affected only in the most severe RDI strategies. Other strategies produced important savings in irrigation requirements and an increase in the water use efficiency without noticeably affecting the phenolic profile.

Agriculture↗
PubMed2006

Phenolic and volatile compounds of extra virgin olive oil (Olea europaea L. Cv. Cornicabra) with regard to fruit ripening and irrigation management.

This study investigated the effect of both the degree of ripening of the olive fruit and irrigation management-rain-fed, two different regulated deficit irrigations (RDI), the method proposed by the Food and Agriculture Organization of the United Nations (known as FAO), and 125 FAO (125% FAO)-on the phenolic and volatile composition of Cornicabra virgin olive oils obtained during two crop seasons. Secoiridoid phenolic derivatives greatly decreased upon increase of both irrigation and ripening, for example, the 3,4-DHPEA-EDA content decreased from 770 to 450 mg/kg through fruit ripening under rain-fed conditions and from 676 to 388 mg/kg from rain-fed conditions to FAO irrigation treatment (at a ripeness index of approximately 4). Moreover, secoiridoid derivatives of hydroxytyrosol decreased more than those of tyrosol. The levels of major volatile components decreased in the course of ripening but were higher in irrigated olive oils: for example, the E-2-hexenal content ranged between 4.2 and 2.6 mg/kg (expressed as 4-methyl-2-pentanol) over fruit maturation under rain-fed conditions and between 8.0 and 3.5 mg/kg under FAO scheduling. It is important to note that where water was applied only from the beginning of August (RDI-2), when oil begins to accumulate in the fruit, the resulting virgin olive oil presented a phenol and volatile profile similar to those of the FAO and 125 FAO methods, but with a considerable reduction in the amount of water supplied to the olive orchard.

Agriculture↗
PubMed1992

Comparison of responses to air, water, and closed-loop caloric irrigators.

Three types of commercially available caloric irrigation units--air, water, and closed-loop--were evaluated for nystagmus response patterns and comfort. Electronystagmographic recordings were analyzed for slow-phase velocity, response duration, amplitude, frequency, and test-retest reliability. Significant differences were found among the three types of irrigators, between warm and cool irrigators, and between male and female subjects. Test-retest reliability was adequate for all three units. Subjects clearly favored the closed-loop system over the water and air irrigators, but the water irrigator yielded the most robust caloric response.

Adolescent↗
PubMed2001

Lymphatic filariasis in Ghana: entomological investigation of transmission dynamics and intensity in communities served by irrigation systems in the Upper East Region of Ghana.

We conducted an entomological study to document the effect of irrigation on the vectors and transmission dynamics of lymphatic filariasis in the Upper East Region of Ghana. Mosquitoes were collected by indoor spraying of houses in a cluster of communities located around irrigation projects (Tono and Vea) and others without reservoirs (Azoka). Anopheles gambiae s.s. was the dominant species and major vector, followed by An. funestus. Anopheles arabiensis constituted 9--14% of the An. gambiae complex but none were infective. Culex quinquefasciatus was also not infective in these communities. Chromosomal examinations showed that >60% (n=280--386) of the An. gambiae s.s. in irrigated communities were Mopti forms whilst 73% (n=224) in the non-irrigated area were Savannah forms. Infectivity rates (2.3--2.8 vs. 0.25), worm load (1.62--2.04 vs. 1.0), annual bites per person (6.50--8.83 vs. 0.47) and annual transmission potential (13.26--14.30 vs. 0.47) were significantly higher in irrigated communities.

Animals↗
PubMed2005

Sustainability of irrigated agriculture in the San Joaquin Valley, California.

The sustainability of irrigated agriculture in many arid and semiarid areas of the world is at risk because of a combination of several interrelated factors, including lack of fresh water, lack of drainage, the presence of high water tables, and salinization of soil and groundwater resources. Nowhere in the United States are these issues more apparent than in the San Joaquin Valley of California. A solid understanding of salinization processes at regional spatial and decadal time scales is required to evaluate the sustainability of irrigated agriculture. A hydro-salinity model was developed to integrate subsurface hydrology with reactive salt transport for a 1,400-km(2) study area in the San Joaquin Valley. The model was used to reconstruct historical changes in salt storage by irrigated agriculture over the past 60 years. We show that patterns in soil and groundwater salinity were caused by spatial variations in soil hydrology, the change from local groundwater to snowmelt water as the main irrigation water supply, and by occasional droughts. Gypsum dissolution was a critical component of the regional salt balance. Although results show that the total salt input and output were about equal for the past 20 years, the model also predicts salinization of the deeper aquifers, thereby questioning the sustainability of irrigated agriculture.

Agriculture↗
PubMed1995

Prospects and problems of intermittent irrigation for control of vector breeding in rice fields in southern India.

The impact of water management on the abundance and interaction of aquatic stages of mosquitoes and some important groups of their predators was studied in a 22.3-ha plot of rice in southern India. Many pools persisted even in a year when intermittent irrigation (II) was properly implemented (fields being re-irrigated as soon as they were dry) and these acted as microrefuges for the immature stages of mosquitoes and for their predators. Although the abundance of all predators, particularly of Notonectidae, was reduced by II in this year, increased predation efficiency in the confined spaces of the persistent pools resulted in a 75%-88% reduction in the abundance of mosquito pupae, as measured by two independent sampling methods. In another year there was insufficient irrigation water for proper II and re-irrigation took place whenever water was available rather than when it was required, frequently resulting in only partial drying. This reduced predator populations without enhancing their efficiency, and so mosquito abundance was slightly higher than in conventionally irrigated fields. The implications for vector control are discussed.

Agriculture↗
PubMed2003

Irrigated agriculture and soil salinization in the Maltese islands.

In the Maltese islands, soil is one of the most threatened natural resources, being continuously exposed to a multitude of climatic, environmental, and man-induced impacts. The changes in agricultural practices as well as increases in urban development have intensified environmental problems and have accentuated the pressures on agricultural land and fragile semi-natural ecosystems. Between 1956 and 2001, the total agricultural land declined from 20,433 ha to 10,713 ha, however, during the same period, the irrigated land as a percentage of total agricultural land increased from 3.9% to 10.7%. The poor quality of irrigation water sources, and the supply of treated sewage effluent with a high level of salts, contribute to a significant salt input. The extent of salt-affected soils in the Maltese islands is not well-documented, however, field observations and technical reports indicate that soil salinity is a potential constraint for agricultural production. This article gives a comparative review of the salinity status of soils in three case study areas in Malta, the agricultural dryland at Ghammieri, the intensively cultivated irrigated valley of Pwales, and the agricultural land irrigated with treated sewage effluent of the Sant Antnin Sewage Treatment Plant in the South-East of Malta. This analysis is provided in the context of the environmental impact of irrigation on soil quality in the Maltese islands.

Agriculture↗
PubMed2005

Is it time to abandon the use of amphotericin B bladder irrigation?

In this article, we review the issues surrounding funguria and its management. With this background, the value of bladder irrigation with amphotericin B for the management of funguria is directly examined. Amphotericin B bladder irrigation is used frequently in clinical practice. Although its use is not standardized, there are multiple studies that attempt to show the impact on funguria management. These bladder irrigations have been used either for treatment of funguria or (less commonly) as a diagnostic test in attempts to identify upper urinary tract disease. Despite their widespread therapeutic use and relative safety, it is not clear from our experience and a review of the literature that amphotericin B bladder irrigations have any diagnostic or therapeutic value. The patient may be best served by removal of the urinary catheter, if possible, rather than by instillation of bladder irrigation with amphotericin B.

Amphotericin B↗
PubMed2006

Laparoscopic partial nephrectomy with saline-irrigated KTP laser in a porcine model.

PURPOSE: To evaluate the feasibility of using the potassium titanyl phosphate (KTP) laser to perform laparoscopic partial nephrectomy in a porcine model, with saline irrigation to reduce intraoperative smoke formation. MATERIALS AND METHODS: A high-power (80 W) KTP laser was used without hilar occlusion in 14 laparoscopic partial nephrectomies in four pigs. During laser discharge, the cutting plane was irrigated continuously with saline. RESULTS: Thirteen partial nephrectomies were completed. Hemostasis was obtained without the need for any non-laser techniques. Only minimal smoke was produced, not affecting visibility or the progress of surgery. Histologic examination of the resection margin showed only minimal tissue destruction. One procedure failed because the laser fiber broke and occluded the suction during the operation. The mean partial nephrectomy time was 13.14 minutes (range 7-19 minutes) with a mean estimated blood lost of 28.57 mL (range 5-80 mL). The mean saline irrigation used for each operation was 2600 mL (range 1500-3400 mL), and the amount of saline drained out was 1700 mL (range 900-3200 mL). CONCLUSION: Laparoscopic partial nephrectomy using the 80 W KTP laser is feasible and effective in the porcine model. Saline irrigation dramatically reduces smoke formation. The technique is deserving of clinical studies after the laser-application device and suction irrigation are refined.

Animals↗
PubMed1990

Larval survey of surface water-breeding mosquitoes during irrigation development in the Mahaweli Project, Sri Lanka.

A survey of ground water-breeding mosquitoes was done during 1986-1987 in an area undergoing irrigation development in the Mahaweli Project of Sri Lanka. Forty-nine species were collected during the 12-mo phase of humans settlement and infrastructure construction, and 42 species during the succeeding 12-mo period under irrigated rice culture. Development resulted in the elimination of some preexisting breeding habitats, the modification of others, and the creation of new habits. The overall change from uninhabited forest to settled irrigated rice sharply increased the prevalence of Anopheles annularis van der Wulp, An. peditaeniatus (Leicester), Aedeomyia catasticta Knab, Mimomyia hybrida (Leicester), Mansonia uniformis (Theobald), and Culex tritaeniorhynchus Giles. Equally sharp decreases occurred in the prevalence of An. barbirostris van der Wulp, An. barbumbrosus Strickland & Choudhury, Ae, jamesi (Edwards), Ae. vittatus (Bigot), Ae. pseudomediofasciatus (Theobald), Cx. halifaxii Theobald, Cx. malayi (Leicester), Cx. minutissimus (Theobald), Cx. nigropunctatus Edwards, Cx. fuscocephala Theobald, and Cx. mimulus Edwards. Other species that showed smaller positive or negative changes included An. nigerrimus Giles, An. culicifacies Giles, An. jamesii Theobald, An. subpictus Grassi, An. vagus Donitz, An. varuna Iyengar, Mi. chamberlaini (Ludlow), Ma. annulifera (Theobald), Cx. bitaeniorhynchus Giles, Cx. gelidus Theobald, and Cx. pseudovishnui Colless. Irrigation development led to reduced breeding by the majority of species; however, most species that did increase in prevalence were potential vectors of human disease. Components of the irrigation system such as reservoir and canal margins, seepages, and rice fields provided increased breeding sites for some of these species.

Animals↗
PubMed1993

Effect of intermittent irrigation on mosquitoes (Diptera: Culicidae) and larvivorous predators in rice fields.

Effect of intermittent irrigation to facilitate rice production on rice-field mosquitoes and larvivorous predators was studied in Saga, Japan. Mosquitoes and associated taxa were sampled by dipping in two rice fields subject to intermittent irrigation and in one rice field that remained flooded throughout the study period of approximately 1 mo. With the onset of intermittent irrigation, larval mosquito (Culex tritaeniorhynchus Giles and Anopheles sinensis Wiedemann) abundance decreased; reirrigated fields were colonized initially by first instars. Abundance of aquatic arthropod predators and larvivorous fish also decreased drastically. Water from irrigation canals was considered to be a major source of recolonization by these predators with limited breeding seasons and longer developmental periods than mosquitoes. Richness (number of taxa) of aquatic insect communities decreased, but the percentage mosquitoes among insects increased with repeated intermittent irrigation. Manipulation of rice fields and associated canals as a whole is essential to rice-field mosquito control by water management.

Agriculture↗
PubMed1995

Mosquito (Diptera: Culicidae) and predator abundance in irrigated and rain-fed rice fields in north Sulawesi, Indonesia.

Immature mosquito species composition and abundance were studied in irrigated and rain-fed rice fields of North Sulawesi, Indonesia. Irrigated rice fields were characterized by the prevalence of aquatic macrophytes and cyprinodont larvivorous fish, Aplocheilus panchax (Hamilton), but abundance per dip of most aquatic insect predators was lower than that in rain-fed rice fields. Anopheles peditaeniatus (Leicester), Culex vishnui Theobald, and Culex tritaeniorhynchus Giles, were dominant in both irrigated and rain-fed fields, but the abundance of the Culex species was lower in irrigated fields. The effect of irrigation system introduction on regional mosquito abundance cannot be evaluated by the enlarged surface water area alone. Changes in habitat quality, expressed as the abundance per dip (index of density per unit water area), also need to be considered.

Aedes↗
PubMedDate not supplied

Growth and water use of Eucalyptus grandis and Pinus radiata plantations irrigated with effluent.

We studied the growth and water balance of young plantations of Pinus radiata D. Don and Eucalyptus grandis W. Hill ex Maiden irrigated with effluent for 3 years in a climate of high net evaporation. The plantations were irrigated weekly with secondary-treated municipal effluent at the estimated water-use rate, or at nominally twice or half this rate. Control plots were irrigated with bore water at their estimated water-use rate. Both species grew rapidly when irrigated with either effluent or bore water. The eucalypts irrigated with effluent at the estimated water-use rate closed canopy in 24 months, and at 34 months, mean dominant height was 12.1 m, stand basal area was 12.2 m(2) ha(-1), volume was 51.2 m(3) ha(-1), LAI was 5.7, and foliage mass was 6.5 Mg ha(-1). The pines in the corresponding effluent treatment had not closed canopy by 34 months. At this time, mean height was 5.0 m, stand basal area was 9.6 m(2) ha(-1), volume was 29.7 m(3) ha(-1), LAI was 3.5, and foliage mass was 7.3 Mg ha(-1). Water use by eucalypts was consistently higher than by pines, commensurate with their more rapid early growth, but the difference was not in proportion to the difference in leaf area. In the third year (when the eucalypts had a closed canopy), the eucalypts used 22% more water than the pines, but the annual mean LAI of the eucalypts was three times greater than that of the pines. The results suggest that (1) plantation water use by the two species on the same site will be similar for the same stage of canopy development, (2) eucalypts are not inherently more profligate consumers of water than pines when soil water is not limiting, and (3) stomatal control limits growth and water use of E. grandis in arid environments.

Journal Article↗
PubMed1996

Effects of carbon dioxide, fertilization, and irrigation on photosynthetic capacity of loblolly pine trees.

Branches of nine-year-old loblolly pine trees grown in a 2 x 2 factorial combination of fertilization and irrigation were exposed for 11 months to ambient, ambient + 175, or ambient + 350 micro mol mol(-1) CO(2). Rates of light-saturated net photosynthesis (A(max)), maximum stomatal conductance to water vapor (g(max)), and foliar nitrogen concentration (% dry mass) were assessed monthly from April 1993 until September 1993 on 1992 foliage (one-year-old) and from July 1993 to March 1994 on 1993 foliage (current-year). Rates of A(max) of foliage in the ambient + 175 CO(2) treatment and ambient + 350 were 32-47 and 83-91% greater, respectively, than that of foliage in the ambient CO(2) treatment. There was a statistically significant interaction between CO(2) treatment and fertilization or irrigation treatment on A(max) on only one measurement date for each age class of foliage. Light-saturated stomatal conductance to water vapor (g(max)) was significantly affected by CO(2) treatment on only four measurement dates. Light-saturated g(max) in winter was only 42% of summer g(max) even though soil water during winter was near field capacity and evaporative demand was low. Fertilization increased foliar N concentration by 30% over the study period when averaged across CO(2) treatments. During the study period, the ambient + 350 CO(2) treatment decreased average foliar N concentration of one-year-old foliage in the control, irrigated, fertilized and irrigated + fertilized plots by 5, 6.4, 9.6 and 11%, respectively, compared with one-year-old foliage in the corresponding ambient CO(2) treatments. The percent increase in A(max) due to CO(2) enrichment was similar in all irrigation and fertilization treatments and the effect persisted throughout the 11-month study period for both one-year-old and current-year foliage.

Journal Article↗
PubMed2006

Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin.

Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.

Agriculture↗
PubMed1991

Effects of intraocular irrigants on the preserved human corneal endothelium.

Either a simple balanced salt solution (BSS) or a bicarbonate-buffered, glutathione-containing commercial irrigant (BSS Plus, Alcon Laboratories, Fort Worth, Texas, U.S.A.) may be used during the vitrectomy portion of a corneal transplant procedure. To simulate the conditions present in the anterior chamber during the first few hours after vitrectomy and grafting, we performed in vitro perfusions of stored human corneas using each irrigant and measured corneal thickness over a 3-hour period. Irrespective of the preservation medium used (McCarey Kaufman, Chondroin Sulfate or Dexsol, all from Chiron Ophthalmics, Irvine, California) or duration of storage (2 or 4 days), corneas irrigated with BSS Plus exhibited significantly (p less than .05) decreased thickness compared with their paired mates irrigated with BSS. In ultrastructural studies performed on postperfusion corneas, there was a tendency toward improved surface morphology in the in vitro BSS Plus-perfused tissue. This study shows that in vitro corneal thickness after preservation is significantly irrigant dependent, with BSS Plus providing the essential ingredients to promote the corneal endothelial pump function.

Corneal Edema↗
PubMedDate not supplied

The effect of a disinfectant/coolant irrigant on microbes isolated from dental unit water lines.

The purpose of this study was to assess water samples from a hospital dental clinic to determine whether a disinfectant/coolant irrigant containing chlorhexidine (Lines, Micrylium Laboratories) affects the presence of microbial organisms in dental unit waterlines. Water samples from three hospital dental operatories were collected at baseline and after overnight treatment with a disinfectant-containing irrigant followed by sterile water irrigation. Saliva of treated patients and sterile water rinse specimens were collected from the waterlines of these operatories for three consecutive days, then weekly for eight weeks after treatment. Specimens were cultured to identify total heterotrophic plate counts as well as presence of Pseudomonas aeruginosa and Candida species. Baseline organism counts varied from 10(3) to 10(5) colony-forming units per milliliter. After treatment, no organisms were detected in waterline discharge. Decontamination of dental unit waterlines is possible using a disinfectant/irrigant followed by sterile water irrigation. The potential for contamination of the lines from patients' saliva may have been reduced due to use of anti-retraction valves and the disinfectant/sterile water irrigation, as conducted in this study.

Bacteria↗
PubMed2006

A cross-sectional study of the prevalence of intensity of infection with Schistosoma japonicum in 50 irrigated and rain-fed villages in Samar Province, the Philippines.

BACKGROUND: Few studies have described heterogeneity in Schistosoma japonicum infection intensity, and none were done in Philippines. The purpose of this report is to describe the village-to-village variation in the prevalence of two levels of infection intensity across 50 villages of Samar Province, the Philippines. METHODS: This cross-sectional study was conducted in 25 rain-fed and 25 irrigated villages endemic for S. japonicum between August 2003 and November 2004. Villages were selected based on irrigation and farming criteria. A maximum of 35 eligible households were selected per village. Each participant was asked to provide stool samples on three consecutive days. All those who provided at least one stool sample were included in the analysis. A Bayesian three category outcome hierarchical cumulative logit regression model with adjustment for age, sex, occupation and measurement error of the Kato-Katz technique was used for analysis. RESULTS: A total of 1427 households and 6917 individuals agreed to participate in the study. A total of 5624 (81.3%) participants provided at least one stool sample. The prevalences of those lightly and at least moderately infected varied from 0% (95% Bayesian credible interval (BCI): 0%-3.1%) to 45.2% (95% BCI: 36.5%-53.9%) and 0% to 23.0% (95% BCI: 16.4%-31.2%) from village-to-village, respectively. Using the 0-7 year old group as a reference category, the highest odds ratio (OR) among males and females were that of being aged 17-40-year old (OR = 8.76; 95% BCI: 6.03-12.47) and 11-16-year old (OR = 8.59; 95% BCI: 4.74-14.28), respectively. People who did not work on a rice farm had a lower prevalence of infection than those working full time on a rice farm. The OR for irrigated villages compared to rain-fed villages was 1.41 (95% BCI: 0.50-3.21). DISCUSSION: We found very important village-to-village variation in prevalence of infection intensity. This variation is probably due to village-level variables other than that explained by a crude classification of villages into the irrigated and non-irrigated categories. We are planning to capture this spatial heterogeneity by updating our initial transmission dynamics model with the data reported here combined with 1-year post-treatment follow-up of study participants.

Adolescent↗