Late Application Research Articles

Winter Annual Rye Seeding Date Influence on Nitrogen Recovery and Ammonia Volatilization from Late Fall Surface-Applied Manure

Dairy farmers in the northeast face challenges in the application of manure in fall and on-time planting of cool-season grasses to maximize recovery of residual N and nutrients released from fall applied manure. Ammonia emission from animal manure is a serious environmental concern and can be reduced if cover crop is integrated in the farming system. On-time planting of cover crops can reduce ammonia volatilization from fall, surface-applied manure, and prevents N loss to leaching. A two-year study was conducted in 2015 and 2016 to investigate if time of planting of winter annual rye (Secale cereale L.) along with late fall application of manure when air temperature is low can influence ammonia emission and preserve nitrogen (N) to meet the N requirement of forage rape. Three planting dates (16 September, 30 September, and 14 October) of rye cover crop with two manure application treatments including late-fall application and no manure were assessed for mitigating ammonia volatilization, and also yield and recovery of N by forage rape (Brassica napus L.). The highest rates of ammonia volatilization were detected in the first 24 hours after manure spreading regardless of the treatment. The result indicated that cover crop use significantly limited volatilization compared with no cover crop. The earliest planting date produced 3823 kg ha−1 dry matter of winter rye cover crop that was 16 and 35 percent higher than second and third dates of planting, respectively. The manured cover crop accumulated 132 kg N ha−1 when planted early. However, biomass yield of forage rape was more when planted after all cover crop treatments with manure application. Prior to forage planting, the nitrate-N content in all three soil depths (0–20, 20–40, and 40–60 cm) in the plots with manure was higher than plots with no manure. No significant differences in forage rape yield was detected among winter rye planting dates; however, forage rape planted after winter rye was higher than after no-cover crop. The results of this study suggest that when immediate incorporation of manure into soil is not feasible, establishing cover crop early and then applying manure in the late fall, is a practical management to limit nonpoint source pollution from ammonia loss.

Effects on nitrate leaching of the timing of cattle slurry application to leys

AbstractThis study compared the effects on nitrate leaching of slurry application to ley in early autumn (15 September), late autumn (1 November) and spring (April) under Swedish growing conditions. In two separate two‐year experiments, started in autumn 2009 and 2010, on a sandy loam soil in south‐west Sweden, these three application times were compared with no slurry application in grass–clover and grass swards. Soil water was sampled with ceramic suction cups, and nitrate leaching was calculated from water nitrate concentrations and drain discharge. Plant measurements indicated that, during autumn, the grass took up at least 20 kg of the 50 kg nitrogen (N) applied with slurry in September. The mineral nitrogen level in the subsoil (30–90 cm) in December was around 2 kg N ha−1 higher in this treatment. Nitrate leaching was on average 5 and 6 kg N ha−1 year−1 higher after early and late autumn slurry application, respectively, than after spring application (p < .001), but the difference varied from 0 to 10 kg N ha−1 year−1 between experiments and sward types. Nitrate leaching losses in kg N ha−1 were lower from the grass sward, but higher if related to nitrogen inputs and dry matter yield. These results indicate that autumn application can increase the risk of nitrate leaching, but that early/late application within autumn is less important. It is more important to limit the amount of slurry applied in autumn and to consider other risks of nitrogen losses associated with time of application, such as ammonia emissions.

Impact of late-season N fertilisation strategies on the gluten content and composition of high protein wheat grown under humid Mediterranean conditions

The rise in high protein common wheat in humid Mediterranean areas has determined a need to compare specific and effective nitrogen (N) fertilisation protocols in order to increase their end-use value. The aim of the work was to assess the impact of late-season N fertilisation strategies on grain yield and protein content (GPC), gluten fraction composition, and rheological traits. Different applications and types of fertiliser (soil applied ammonium nitrate, soil applied urea, foliar applied urea and a foliar applied commercial fertiliser) were distributed at the same rate (30 kg N ha−1) in a field experiment in NW Italy, during three growing seasons. A control without any late-season N fertilisation was also considered. All the treatments received 130 kg N ha−1 as ammonium nitrate (AN), which was split between tillering and the beginning of the stem elongation growth stages.None of the compared late-season N fertilisations significantly affected canopy greenness and stay green duration during the grain filling period, or the grain yield, test weight, and thousand kernel weight, although the foliar application significantly increased foliage burning (+9.8%). The late application of N consistently increased GPC (+1.1%) and dough strength (W, +21%) in the different growing seasons. The type of fertilisation strategies clearly affected the gluten content and rheological parameters: AN was more effective than urea as a soil top-dressed applied fertiliser in increasing W (+10%), as a result of a higher rise in the GPC content (+0.5%) and extensibility (L, +11%). The foliar application at anthesis, at the same N rate, led to a comparable GPC and W with those of the soil top-dressed granular fertiliser. Only a weak effect of granular urea on y/x type HMW was observed for the gluten composition. Conversely, a notable influence of year was observed (i.e. GS/Glia and y/x type HMW), which in turn resulted in a significant impact on W and P and on the aggregation time and aggregation energy.This study offers a further contribution to the improvement of specific N fertilisation strategies in order to enhance the wheat quality according to its end-use value.

Timing of phenological stages for apple and pear trees under climate change in a temperate-continental climate.

The study examines the consequences of climate change in Malus (apple) and Pyrus (pear) on four phenological stages: bud swelling (code 51 BBCH Monograph), budburst (code 53), beginning of flowering (code 61), and end of flowering (code 69) in the temperate-continental climate of southern Romania. The hypothesis tested is how much the onset dates (TOD) of phenology stages moved earlier due to climate change. Weather and phenological data were collected from 1969 to 2018 and were statistically processed. There was an increase in air temperature (T) during the first 5months in the year, with a significant rise in March and April; significant linear relationships show an advance in TOD with the years elapsed. Inverse linear relationships were found between TOD, maximum (Tmax), mean (Tmean), minimum (Tmin) temperature, and sunshine hours (Sh). The relationships between TOD and Tmax were the strongest. The early stages of flowering phenology are advancing more strongly than later flowering stages. For apple, in the last 50years, there was an advance of 13.8days for stage 51, 14.8days for stage 53, 10.7days for stage 61, and only 7.3days for stage 69; for pear trees, the advance was lower: 10days for stage 51, 9days for stage 53, 6.7days for stage 61, and only 2.1days for stage 69. These findings, which might be extrapolated to similar environments, have important consequences in fruit growing, like the occurrence of climate accidents due to late frost, insect pollination, and application of pesticides and irrigation water.

Effect of late season phosphine application on dried fig quality

Effect of late season phosphine application on dried fig quality

Leaf area development and yield of cassava in response to pruning of shoots and the late supply of nitrogen and potassium

AbstractThis study evaluated leaf area development, leaf nutritional content, and yield of pruned/unpruned cassava supplied with nitrogen (N) and potassium (K) during its second vegetative cycle. Two field experiments were conducted in a randomized complete‐block design with split‐plots and four replications. The treatments consisted of four management approaches that combined pruning/not pruning with or without K as the main plot and four N application rates (0, 50, 100, and 200 kg ha−1 N) as the subplots. The results revealed that an evaluation of the nutritional status of cassava during its second vegetative cycle should be considered if shoot pruning has been conducted because pruned plants had higher concentrations of N, P, and K in their leaves, and unpruned plants exhibited leaves with higher Ca, Fe, and Mn concentrations. Pruning of cassava shoots during the autumn/winter resting phase did not negatively affect root yield and may represent a recommended management practice for cassava cultivation. In soils with a medium level of K availability, K provision during the second cassava growth cycle is unnecessary because the application of K did not increase leaf reconstitution or yield components in either pruned or unpruned plants. The late application of N improved the nutritional status of cassava plants and increased their leaf area during the second growth cycle. Cassava root, starch, and flour yields increased in a linear fashion in response to the late application of N.

Accuracy of NDVI-derived corn yield predictions is impacted by time of sensing

Normalized difference vegetation index (NDVI) data derived from cameras mounted on unmanned aerial vehicles (UAVs) or from tractor-mounted sensors have the potential to aid in quick and accurate decision making for fertility management of corn (Zea mays L.). However, timing of sensing can impact the accuracy of yield predictions and hence nutrient need assessment. In this study the accuracy of yield predictions derived from NDVI data for corn silage and grain was evaluated using (a) an active sensor (GreenSeeker; handheld unit), and (b) a passive sensor (UAV-mounted camera). Two types of replicated trials were conducted in central New York: (a) N rate studies with N applied at V6 at rates ranging from 0 kg N ha−1 to 336 kg N ha−1 (2016, 2017, and 2018); and (b) timing of N application studies, with N applied at V4, V6, V8 or V10 (2017 and 2018). For each of the trials conducted in 2017 and 2018, the crop was sensed and NDVI was determined weekly from V4 through V12. An additional flight was done with the UAV-mounted camera at R2. In addition, the 2016 N rate study and timing of sidedress study in 2018 were sensed at V10 (single day) from 7 am through 5 pm on 2-hour intervals. Results showed that crop growth stage and timing of N application affected the accuracy of yield predictions. Scans within 2 weeks of sidedressing did not result in accurate yield predictions, independent of sensor type. Best yield estimates were obtained with a UAV-mounted camera late in the season (R2 growth stage). For in-season N management, a low-rate (<30 kg N ha−1) starter N application is recommended. Sensing must be delayed until just after initial N deficiencies become visible. Sidedressing at V10 still resulted in a yield increase beyond yields with starter N only, but if such late applications are done, accurate estimates of yield based on NDVI can only be obtained with sensing a second time after V12. Due to the reaction of corn plants to water stress, timing of sensing within a day showed the best yield predictions between 9 and 11 am and at 5 pm, independent of sensor used. For most accurate yield predictions, we recommend scanning between V12 and R2, avoiding early morning (dew) and mid-day hours (1–3 pm) if water stress in the crop is evident.

Adding a late fall application of Proxy (ethephon) before two traditional spring applications improves seedhead control of annual bluegrass

AbstractAnnual bluegrass (ABG) (Poa annua L.) is a prolific seed producer in the spring on golf courses that in turn decreases aesthetic quality and trueness of ball roll on cool‐season putting greens. Proxy (ethephon) applied twice in the spring after green‐up is the current industry standard after the loss of Embark (mefluidide) from the turf and ornamental market. However, plant growth regulators including Proxy have been used for years to help suppress ABG seedheads with inconsistent success. The primary objective of this study was to determine if ABG seedhead suppression is improved by adding a late fall application of Proxy to the two traditional spring applications of plant growth regulators at nine locations with diverse environments. A second objective was to determine the importance of including Primo Maxx (trinexapac‐ethyl) in fall and spring applications. Adding a late fall application of Proxy prior to the two spring applications (F+S+S) improved control of ABG seedheads over the traditional two spring applications (S+S), but the magnitude of improvement varied among locations. When treatments were applied F+S+S, the industry standard tank mixture of Proxy + Primo Maxx provided consistent ABG seedhead control and turf quality, similar to Proxy + Fiata (phosphonate + proprietary pigment) and equal to or better than Proxy alone.

Tamgas and Runic Inscription on Two Vessels from Muruisky Island on the Angara River

The article deals with the attempt to comprehensively study of two metal vessels found in the treasure on Muruisky island on Angara river, which became known to the general public in 2008. Based on a comparative analysis of the findings of similar products torevtics in the memorial and funeral complexes of the Türkic period in Inner Asia, it is concluded that they belong to the category of prestigious objects as attributes of the nomadic social elite of the 8th – early 9th centuries A.D. Сomparing the signs of identity (tamga) applied to the vessels with the famous monuments of the region allows it is possible to identify two of them as belonging to the ruling clans of the Eastern Türks and Uyghurs (the Ashina and Yaγlaqar dynasties respectively), as well as to clans of other important nomadic unions of central areas of Mongolia of the same period. For tamga signs on the neck of vessel 2 it is possible to find analogies mainly among the monuments of Tuva and the Minusinsk depression. The fact of their relatively late application to the surface of the vessel refers to the time of the fall of the Uyghur Qaghanate and the expansion of the Qïrqïz in Inner Asia.A new reading of the runic inscription on vessel 2 is based on the personal direct acquaintance with the artifact at the State Historical Museum in Moscow and subsequent work with its photographs of high-quality. In general, the identification of runic characters does not cause difficulties, the fact of which caused to offer an accurate reading of the inscription without assumptions and grammatical stretches. At the same time, it is possible that part of the inscription, which placed on the damaged field of the surface of the vessel, was created earlier than the rest of the text. Since the inscription was not completely restored, it seems correct to consider any interpretations premature. An analysis of spelling of the inscription shows the possibility to compare it with the monuments of the period of the Uyghur Qaghanate (747–840/847). The fact is partially contradicted by some features of the graphics, which, however, may be explained by the presence here of some signs of the mentioned above the earlier inscription.

An Experimental Investigation on Joining of Copper and Stainless Steel by Induction Welding Technique

The Cu–SS welded structures are widely used in nuclear and power generation industries. Various solid state and fusion welding techniques have been experimented for welding Cu–SS with resultant phenomena of low joining strength in solid state and generation of crack in fusion. Of late application of induction heating as a joining technique is gaining momentum in view of its low maintenance, high production rate and cost effectiveness. In consideration of the above facts, in this study, induction heating for welding Cu–SS is experimented in ambient condition under varied settings of load and current. Although few micro-cracks were observed in SEM images, successful joining between copper and stainless steel was achieved. Some compounds like FeCu4, Cr3Fe, Cu(Fe2O4) and CrO were detected by XRD near the weld interface. The microhardness increased near the interface in comparison to the base metals. The interface microhardness was increased with current and load. Similarly, the tensile strength was also increased for higher values of process parameters. Highest strength of 220 MPa was obtained at 2 kg load and 650 A current. Failure of welded joint under tension took place by ductile–brittle fracture mode.

Application timing of urea supergranules for climate-resilient maize cultivars grown in Northern Ghana

Agronomic effectiveness of urea deep placement (UDP) technology for upland maize production, using urea supergranules (USG) as the supplemental nitrogen (N) source, is affected by USG application time. In field studies conducted in six locations in northern Ghana during 2015–2017 growing seasons, we determined appropriate USG application time(s) for climate-resilient maize (early maturing and medium-maturing drought-tolerant) varieties for increased productivity. USG was applied at a depth of 7-10 cm on either 2, 3, 4, 5, or 6 weeks after planting (WAP). For the medium-maturing maize variety, across all locations and in the three growing seasons, applying USG produced an average grain yield of 4.5 t ha−1, 4.4 t ha−1 and, 4.2 t ha−1 on 2, 3 and 4 WAP, respectively. Applying USG on 5 and 6 WAP produced an average grain yield of 3.4 t ha−1 and 2.8 t ha−1, respectively. For the early-maturing variety, average grain yield when USG was applied on 2 WAP was 4.1 t ha−1, and 4.0 t ha−1 on 3 WAP. Late applications produced an average grain yield of 2.4 t ha−1, and 1.9 and 1.7 t ha−1 on 4, 5, and 6 WAP, respectively. Harvest index, recovery of applied N, and N use efficiency followed similar pattern as grain yields. From the combined results, we conclude that, barring adverse environmental conditions, applying USG as supplemental N within 3 WAP for the early-maturing maize varieties, and 4 WAP for the medium-maturing maize varieties could result in greater agronomic benefits than when applied later.

Survey of rice weed management and public and private consultant characteristics in Southern Brazil

AbstractIdentification of common weeds is fundamental in determining adequate recommendations for management practices. The aim of this study was to identify the patterns of weed management adopted by rice farmers and the perspectives of consultants who work in flooded rice areas in Rio Grande do Sul (RS) State, Brazil. Fifty-three public and 50 private consultants who worked with rice in RS in 2017 and 2018 were interviewed. Data were analyzed by descriptive statistics. Both weedy rice and Echinochloa sp. occurred and escaped more often from chemical control because they remained in the field until harvest in 59% of the area. According to consultants, the main reasons for reduced weed control were related to herbicide resistance and late herbicide application. Fifty-six percent of farmers used imidazolinone herbicides at rates that were greater than those indicated on the label for POST application. The consultants’ main challenges were weed escapes, resistance management, and guidelines on herbicide rates. Survey results show that the use of herbicide rates above label recommendations and consultants’ work on control of weed escapes are directly related to the high occurrence of herbicide resistance.

Difficulties and mistakes in the diagnosis of abdominal tuberculosis in the practice of the general practitioner

Identify clinical features and possibilities of timely AT diagnosis. Medical reports of 116 AT patients. The results of clinical, microbiological, immunological, radiological, endoscopic and morphological studies were analyzed. AT proceeded under the mask of ulcerative colitis and Crohn's disease (26.3%), alcoholic and biliary hepatitis (11.8%), lymphoproliferative and oncological diseases (61.8%), often generalized against the background of HIV-infection. The duration of the diagnostic search for disease verification exceeded 3 months due to incorrect (erroneous) interpretation of intoxication (26.3%) and radiological pattern in the lungs (23.7%), non - application and late application of laparoscopy (39.5%). When diagnosing AT, it is necessary to consider the peculiarities of its clinic and to conduct timely laparoscopy.

Defining Fertilization Strategies for Sorghum (Sorghum bicolor (L.) Moench) Production Under Sudano-Sahelian Conditions: Options for Late Basal Fertilizer Application

Soil nutrient deficiency and rainfall variability impair the production of sorghum (Sorghum bicolor (L). Moench) in Sudano-Sahelian zone. The aim is to study the environmental factors that can determine the effect of fertilizer application on sorghum grain yield and to formulate tailored fertilization strategies according to sorghum varieties (hybrid and open pollinated improved varieties) and environmental context. Field experiments were conducted during the 2015 and 2016 growing seasons in Nioro du Rip and in Sinthiou Malème (Senegal). In a randomized complete block design arranged in a split-plot with four replications, three factors were tested: sorghum genotype (G: Fadda, Faourou, Soumalemba and Soumba with different cycle lengths), environment (E: irrigation and rainfed, different soil types and fertility levels), and fertilization management (M: five different combinations of application dose and application time) including T1 = no fertilizer applied; T2 (recommended practice, 100%) = 150 kg/ha of NPK (15-15-15) at emergence + 50 Kg/ha of urea (46%) at tillering + 50 kg/ha of urea at stem extension; T3 = 50% T2; T4 (100% delay) = 150 kg/ha of NPK +50 kg/ha of urea at stem extension +50 kg/ha of urea at heading ; T5 = 50% T4. Results showed that: (i) in most environments, stressed plants under late application treatments (T4 and T5) recovered biomass once the fertilizer was applied (ii); grain yield with T5 was higher than with T4 under well-watered conditions (sufficient and well distributed rainfall and eventual complementary irrigations) ; (iii) Fadda, a hybrid, responded differently to fertilization than the other varieties only for biomass production, (iv) late fertilizer application treatment (T4) gave higher grain yield than the recommended practice (T2) in the environment with low yield potential, and (v) long cycle duration genotypes benefited better from late fertilization compared to short cycle duration genotypes. This study showed that under Sudano-Sahelian conditions late fertilization of sorghum can be beneficial to grain yield if the rainy season has a slow start, depending on sorghum genotypes (i.e., cycle length), and on the initial N content of the soil.

Effects of Polyhalite Fertilization on Skin Quality of Potato Tuber.

The protective peel of potato tuber consists of periderm tissue, the outmost cell layers of which contain corky cell walls and are termed “skin”. The skin protects the tuber from water loss and pathogen invasion, and its visual appearance is a highly important marketing factor. Physiological skin blemishes are of great concern, mainly russeting disorder and skinning injuries. We previously showed that application of calcium (Ca) reduces the rate and severity of skin russeting. Here, polyhalite fertilization was tested as an alternative source of Ca. The polyhalite mineral is a hydrated sulfate of potassium (K), Ca, and magnesium (Mg), and thus contains additional important nutrients that may contribute to skin quality. Furthermore, in view of the direct interaction of soil mineral elements with the tuber skin, we tested application of polyhalite at the end of the growth period, assuming that providing the mineral at the last stages of skin development may enhance its quality. Accordingly, polyhalite was applied at three time points: preplanting, in-season at around 3–4 weeks prior to haulm desiccation, and 2 days post-haulm desiccation. The experiments included several cultivars and locations. Data indicated that late application of polyhalite, after haulm desiccation, results in reduced concentrations of Ca and Mg and increased concentration of K in the tuber peel of fertilized plants compared to controls. Tuber appearance was improved, and the expression of FHT and CYP86A33, indicator genes for skin suberization, was significantly upregulated. Earlier applications of the polyhalite mineral did not alter mineral elements concentrations in the tuber peel compared to control plants. Overall, polyhalite fertilization positively affected tuber skin appearance and skin-related gene expression. However, the effect was moderate, and the mineral did not fully mitigate skin imperfections. The effect of polyhalite may be dependent on local conditions and cultivar type.

Ethanol sprays to release grapevine bud dormancy: a potential alternative to cyanamides

Aim: Grape growers sometimes use cyanamides (calcium or hydrogen) to release bud dormancy in warm climate regions, where the chilling requirement has not been met during winter. However, these products can cause damage to plants and are dangerous to handle, so alternatives would be welcomed by growers. Connections between metabolisms of ethanol, ethylene and cyanide revealed by previous studies led us to test the potential of ethanol sprays on bud break and early shoot growth.Methods and results: Trials were performed over three years on Vitis vinifera grapevines trained in Guyot or cordon, and on cuttings in growth chambers. Cultivars used in the studies included Cabernet-Sauvignon, Syrah and Ugni blanc. The results show that ethanol can advance bud break of all three cultivars at concentrations ranging from 2.5 to 10 % ethanol in water. Ethanol stimulates bud development in both Guyot and cordon training systems. However, the timing of ethanol application is crucial, and late spring season applications reduce the effectiveness of the treatment.Conclusions: Observations were performed over three different seasons. The trials revealed that ethanol sprays can advance bud break of different Vitis vinifera vines, trained with cane or spur systems.Significance and impact of the study: Climate change impacts dormancy release, making it an increasingly important issue over the next few decades. An alternative to the dangerous use of cyanamides to promote bud break would greatly help growers. These preliminary results with ethanol are promising but should lead to trials in various growing areas and with various cultivars in order to confirm their potential for viticulture.

Year-Round N2O Emissions From Long-Term Applications of Whole and Separated Liquid Dairy Slurry on a Perennial Grass Sward and Strategies for Mitigation

Dairy farms need to improve their environmental performance to justify continued consumption of dairy products. Previous studies have demonstrated improved re-use of dairy slurry nitrogen (N) and phosphorous (P) by separating solid and liquid fractions. This study was conducted to examine the long-term effects of applying whole dairy slurry (WS), separated liquid fraction (SLF), and mineral fertilizer on emission of nitrous oxide (N2O) from a grass sward in a moderate climate, and to identify methods to mitigate emissions. The results show that emission occurs in sharp spikes within a week of N application as well as after some wet/dry cycles and freeze/ thaw cycles even in this moderate climate. Greatest emissions occurred from late spring and summer applications. At the high application rate of total-N emissions were similar for WS and SLF, at the lower rate SLF exceeded WS, whereas at equivalent mineral-N, emissions were greater from WS than SLF. On the basis of crop N-uptake, SLF had similar or lower emissions than WS at comparable N rates, and the same was true on basis of yield except for lower emissions with WS than SLF at the low total-N rate (400 kg ha-1). By not finding pollution swapping, the study helps to support the use of slurry manure separation for its agronomic and environmental benefits. This multi-year field study supports current IPCC default values as cautious emission factors (EF) for dairy slurry and commercial fertilizer on intensively managed grass, though a lower EF may be justified for lower input grassland (<50 kg mineral-N ha-1 per dose). Our results suggest that N2O emissions can be reduced by transferring summer slurry application to early spring but on farms where this is not possible, mitigating summertime peaks should be targeted, possibly with the use of a nitrification inhibitor.

Haspin inhibition delays cell cycle progression through interphase in cancer cells.

Haspin (Haploid Germ Cell-Specific Nuclear Protein Kinase) is a serine/threonine kinase pertinent to normal mitosis progression and mitotic phosphorylation of histone H3 at threonine 3 in mammalian cells. Different classes of small molecule inhibitors of haspin have been developed and utilized to investigate its mitotic functions. We report herein that applying haspin inhibitor CHR-6494 or 5-ITu at the G1/S boundary could delay mitotic entry in synchronized HeLa and U2OS cells, respectively, following an extended G2 or the S phase. Moreover, late application of haspin inhibitors at S/G2 boundary is sufficient to delay mitotic onset in both cell lines, thereby, indicating a direct effect of haspin on G2/M transition. A prolonged interphase duration is also observed with knockdown of haspin expression in synchronized and asynchronous cells. These results suggest that haspin can regulate cell cycle progression at multiple stages at both interphase and mitosis.

Challenges and ways forward in pesticide emission and toxicity characterization modeling for tropical conditions

PurposeIn tropical cropping systems, pesticides are extensively used to fight pests and ensure high crop yields. However, pesticide use also leads to environmental and health impacts. While pesticide emissions and impacts are influenced by farm management practices and environmental conditions, available Life Cycle Inventory (LCI) emission models and Life Cycle Impact Assessment (LCIA) toxicity characterization models are generally designed based on temperate conditions. There is, hence, a need for adapting LCI and LCIA models for evaluating pesticides under tropical conditions. To address this need, we aim to identify the characteristics that determine pesticide emissions and related impacts under tropical conditions, and to assess to what extent LCI and LCIA models need to be adapted to better account for these conditions.MethodsWe investigated the state-of-knowledge with respect to characteristics that drive pesticide emission patterns, environmental fate, human and ecological exposures, and toxicological effects under tropical conditions. We then discuss the applicability of existing LCI and LCIA models to tropical regions as input for deriving specific recommendations for future modeling refinements.Results and discussionOur results indicate that many pesticide-related environmental processes, such as degradation and volatilization, show higher kinetic rates under tropical conditions mainly due to higher temperatures, sunlight radiation, and microbial activity. Heavy and frequent rainfalls enhance leaching and runoff. Specific soil characteristics (e.g., low pH), crops, and cropping systems (e.g., mulching) are important drivers of distinct pesticide emission patterns under tropical conditions. Adapting LCI models to tropical conditions implies incorporating specific features of tropical cropping systems (e.g., intercropping, ground cover management), specific drift curves for tropical pesticide application techniques, and better addressing leaching processes. The validity domain of the discussed LCI and LCIA models could be systematically extended to tropical regions by considering tropical soil types, climate conditions, and crops, and adding active substances applied specifically under tropical conditions, including the consideration of late applications of pesticides before harvest and their effect on crop residues and subsequent human intake.ConclusionsCurrent LCI and LCIA models are not fully suitable for evaluating pesticide emissions and impacts for crops cultivated in tropical regions. Models should be adapted and parameterized to better account for various characteristics influencing emission and impact patterns under tropical conditions using best available data and knowledge. Further research is urgently required to improve our knowledge and data with respect to understanding and evaluating pesticide emission and impact processes under tropical conditions.

Effect of low temperature annealing on the properties of nano Ni–Ti alloys

Binary 1:1 Ni–Ti alloy has been the work horse for many industrial and of late biomedical applications amongst all shape memory alloys. Apart from being employed for endovascular applications like stents and filters, they are also used as orthodontic braces and in endodontic tools. Ni–Ti drills and files are used in a few procedures with sterilization between uses. However, the effect of these sterilizing heat-treatments on the properties of the tools is not clearly investigated. In addition to this, satisfactory metallurgical explanations for the wear resistance of these alloys in absent in the literature. Therefore, this paper attempts to define the transformational temperatures for the Ni–Ti as-received and low temperature heat-treated conditions have been investigated using Differential Scanning Calorimetry (DSC). Attempts are made to justify their suitability for endodontic applications by evaluating their mechanical strength parameters using the Tensile and Wear tests. It was found that the samples showed did not show much variations in strength when subjected to tensile tests whereas the same was not observed for DSC tests. Ambient temperature x-ray diffraction studies indicate the presence of Austenitic and Martensitic phases in all the samples. DSC results are strongly affected by presence of internal stresses but stress-induced-martensitic forms in all the samples with equal facility.