Introduction of micro-sprinkler systems to mango production into theuplands Northern Thailand

In order to asses water saving potentials of advanced irrigation methods in irrigated mango production in Northern Thailand, micro sprinklers have been introduced and compared into the area. Three micro sprinkler treatments were established on two commercial orchards: a. Full irrigation based on climate data, b. Partial Rootzone Drying, c. Farmer?s decision. These treatments were compared to the traditional irrigation methods. It was found that by the introduction of micro sprinklers, farmers were able to increase their water use efficiency, while the fruit size distribution was more favourable for export marketing

Alternate furrow irrigation of four fresh-market tomato cultivars under semi-arid condition of Ethiopia – Part I: Effect on fruit yield and quality

Scarcity of freshwater due to recurrent drought threatens the sustainable crop production in semi-arid regions of Ethiopia. Deficit irrigation is thought to be one of the promising strategies to increase water use efficiency (WUE) under scarce water resources. A study was carried out to investigate the effect of alternate furrow irrigation (AFI), deficit irrigation (DI) and full irrigation (FI) on marketable fruit yield, WUE and physio-chemical quality of four fresh-market tomato cultivars (Fetan, Chali, Cochoro and ARP Tomato d2) in 2013 and 2014. The results showed that marketable yield, numbers of fruits per plant and fruit size were not significantly affected by AFI and DI irrigations. WUE under AFI and DI increased by 36.7% and 26.1%, respectively with close to 30% irrigation water savings achieved. A different response of cultivars to irrigation treatments was found for marketable yield, number of fruits and fruit size, WUE, total soluble solids (TSS) of the fruit juice, titratable acids (TA) and skin thickness. Cochoro and Fetan performed well under both deficit irrigation treatments exhibited by bigger fruit size which led to higher WUE. ARP Tomato d2 showed good yields under well-watered conditions. Chali had consistently lower marketable fruit yield and WUE. TSS and TA tended to increase under deficit irrigation; however, the overall variations were more explained by irrigation treatments than by cultivars. It was shown that AFI is a suitable deficit irrigation practice to increase fresh yield, WUE and quality of tomato in areas with low water availability. However, AFI requires suitable cultivars in order to exploit its water saving potential

Alternate furrow irrigation of four fresh-market tomato cultivars under semi-arid condition of Ethiopia – Part II: Physiological response

Understanding the variation in physiological response to deficit irrigation together with better knowledge on physiological characteristics of different genotypes that contribute to drought adaptation mechanisms would be helpful in transferring different irrigation technologies to farmers. A field experiment was carried to investigate the physiological response of four tomato cultivars (Fetan, Chali, Cochoro and ARP Tomato d2) to moderate water deficit induced by alternate furrow irrigation (AFI) and deficit irrigation (DI) under semi-arid condition of Ethiopia during 2013 and 2014. The study also aimed at identifying physiological attributes to the fruit yield of tomato under different deficit irrigation techniques. A factorial combination of irrigation treatments and cultivar were arranged in a complete randomized design with three replicates. Results showed that stomatal conductance (g_s) was significantly reduced while photosynthetic performance measured as chlorophyll fluorescence (Fv’/Fm’), relative water content (RWC) and leaf ash content remained unaffected under deficit irrigations. Significant differences among cultivars were found for water use efficiency (WUE), g_s, chlorophyll content (ChlSPAD), normal difference vegetation index (NDVI), leaf ash content and fruit growth rate. However, cultivar differences in WUE were more accounted for by the regulation of g_s, therefore, g_s could be useful for breeders for screening large numbers of genotypes with higher WUE under deficit irrigation condition. The study result also demonstrated that cultivar with traits that contribute to achieve higher yields under deficit irrigation strategies has the potential to increase WUE

Rapid phenotyping of different maize varieties under drought stress by using thermal images

The development of maize genotypes with high yields under drought is of pivotal relevance for the International Maize and Wheat Improvement Centre (CIMMYT). Thermal images of the canopy of different 92 maize genotypes were acquired in the time interval between anthesis and blister stage with each picture containing five plots of different genotypes. Mean temperature differences of more than 2°C between different genotypes under water stress were then detected using thermal images. Genotypes better adapted to drought exhibiting lower temperatures. A canopy thermal image is a potential promising method to accelerate the screening process and thereby enhance phenotyping for drought adaptation in maize

Real-time detection of root zone-CO2 and its potential for irrigation scheduling

Als Basis für die Bewässerungsplanung wurde die Eignung von CO₂-Messungen im Wurzelraum (WR-CO₂) untersucht und evaluiert. Die grundlegende Annahme war, dass Pflanzen als Reaktion auf eine defizitäre Wasserversorgung die Wurzelatmung reduzieren. Die Untersuchungen an Apfelbäumen konnten zeigen, dass das WR-CO₂ zu großen Teilen (56–72 %) seinen Ursprung in der pflanzenspezifischen CO₂-Produktion (v. a. Wurzelatmung) hat. Darüber hinaus reagierte das WR-CO₂ deutlich auf Bewässerung und korrelierte bei der Austrocknung mit dem Bodenwassergehalt. Da Veränderungen beim WR-CO₂ sich auch in Veränderungen beim Pflanzenwasserstatus widerspiegelten, besitzt das WR-CO₂ Potenzial zur Ermittlung des Bewässerungsbedarfs der untersuchten Apfelbäume. Die Übertragbarkeit auf weitere Nutzpflanzen wird untersucht

Yield and fruit development in mango (Mangifera indica L. cv. Chok Anan) under different irrigation regimes

Deficit irrigation RDI PRD Alternate bearing Fruit set Fruit drop Thailand

Monitoring physiological responses to water stress in two maize varieties by infrared thermography.

Abstract: Water stress is one of the main causes of yield reductions in crops, especially in arid and semi-arid regions where the water supply is limited. Plant water status is frequently assessed by pre-dawn leaf water potential (Ψ PD ) or leaf stomata conductance (gL) measurements, in support of advanced irrigation scheduling. However, both methods are time and labour consuming. A non-invasive approach to water status detection is the use of infrared thermography (IRT). This experiment was conducted in a greenhouse on two potted maize varieties under irrigated and non-irrigated conditions, and the measurements began when the crop had reached its twelve leaf stage. In order to establish the IRT measurements for detecting the water status of maize, an IRT-based crop water stress index (CWSI) was calculated and compared with simultaneously measured Ψ PD and gL data. Good correlations were found between CWSI and gL data (r 2 =0.71 & 0.81), as well between CWSI and Ψ PD data (r 2 = 0.53 & 0.81). These results highlight the appropriateness of infrared thermal imagery to detect and differentiate between the crop water statuses of different genotypes

Effect of Dust Deposition on Stomatal Conductance and Leaf Temperature of Cotton in Northwest China

The Xinjiang Region in Northwest China is known as the “dust center” of the Eurasian mainland. Dust on the leaf surface affects overall plant development. While emphasis was on studying the impacts of industrial dust particles on crop development, the effect of natural dust deposition on the physiological parameters of cotton had not been studied before. The objective of this study was to examine the effects of dust deposits on cotton leaves and to estimate their impact on crop development and yield. For this purpose, an experiment was set up having two treatments and a control. In Treatment 1, cotton leaves were cleaned with water at three-day intervals or after a natural dust fall. In Treatment 2, 100 g·m−2 of dust was applied at 10-day intervals. The control received neither additional dust nor cleaning. In all of the treatments, stomatal conductance, leaf temperature, biomass and yield were measured. The results show a 28% reduction in yield and 30% reduction in stomatal conductance of the dust treatment compared to the control treatment. This indicates blocking of the stomata on the top of the leaf surface. In addition, the canopy temperature of the dust-applied leaves was always higher than the control and treatment

Varicella zoster virus infections in neurological patients: a clinical study

Abstract Background Varicella zoster virus (VZV) reactivation is a common infectious disease in neurology and VZV the second most frequent virus detected in encephalitis. This study investigated characteristics of clinical and laboratory features in patients with VZV infection. Methods Two hundred eighty two patients with VZV reactivation that were hospitalized in the department of neurology in the time from 2005 to 2013 were retrospectively evaluated. Results from cerebrospinal fluid (CSF) analysis were available from 85 patients. Results Trigeminal rash was the most common clinical manifestation, followed by segmental rash, CNS infection, facial nerve palsy, postherpetic neuralgia, and radiculitis. MRI of the brain performed in 25/33 patients with encephalitis/meningitis did not show any signs of infection in the brain parenchyma. Only one patient showed contrast enhancement in the hypoglossal nerve. General signs of infection such as fever or elevated CRP values were found in only half of the patients. Furthermore, rash was absent in a quarter of patients with CNS infection and facial nerve palsy, and thus, infection could only be proven by CSF analysis. Although slight inflammatory CSF changes occurred in few patients with isolated rash, the frequency was clearly higher in patients with CNS infection and facial nerve palsy. Conclusion Monosegmental herpes zoster is often uncomplicated and a diagnostic lumbar puncture is not essential. In contrast, CSF analysis is an essential diagnostic tool in patients with skin lesions and cranial nerve or CNS affection. In patients with neuro-psychiatric symptoms and inflammatory CSF changes analysis for VZV should be performed even in the absence of skin lesions