Crop coefficient estimated by degree-days for ‘Marandu’ palisadegrass and mixed forage

Considering profitability in pasture-based systems, investigating parameters affecting crop coefficients for irrigation management becomes important. In this experiment, we determined the crop coefficient of ‘Marandu’ palisadegrass based on accumulated degree-days and estimated plant water consumption under single (‘Marandu’ alisadegrass) and mixed (‘Marandu’ palisadegrass + black oats + Italian ryegrass) cropping regimes. The research was conducted at the Luiz de Queiroz College of Agriculture in Piracicaba, São Paulo, Brazil, between 2016 and 2017. Evapotranspiration was assessed using weighing lysimeters while crop evapotranspiration was calculated using mean weight variation. Reference evapotranspiration and degree-days were estimated. Data were obtained from an automated weather station. Equations and regression models relating crop coefficient with accumulated degree-days were generated for two seasons (spring/summer and autumn/winter) and evaluated for two year-cycles, from 2015 to 2018. The results showed better prediction accuracy for the single cropping system in spring/summer 2017–18. Highlights The model for determinating crop coefficient (Kc) by accumulated degree-days showed efficient for use in determination local. The use of the degree days for determination Kc is more vantage because only necessary to measure the air temperature (maximum and minimum). The equations for determining crop coefficient by accumulated degree days for the spring/summer season in Marandu palisade grass cultive show more precision that in mixture forage system.

Factors of surface thermal variation in high-mountain lakes of the Pyrenees

Thermal variables are crucial drivers of biological processes in lakes and ponds. In the current context of climate change, determining which factors better constrain their variation within lake districts become of paramount importance for understanding species distribution and their conservation. In this study, we describe the regional and short-term interannual variability in surface water temperature of high mountain lakes and ponds of the Pyrenees. And, we use mixed regression models to identify key environmental factors and to infer mean and maximum summer temperature, accumulated degree-days, diel temperature ranges and three-days’ oscillation. The study is based on 59 lake-temperature series measured from 2001 to 2014. We found that altitude was the primary explicative factor for accumulated degree-days and mean and maximum temperature. In contrast, lake area showed the most relevant effect on the diel temperature range and temperature oscillations, although diel temperature range was also found to decline with altitude. Furthermore, the morphology of the catchment significantly affected accumulated degree-days and maximum and mean water temperatures. The statistical models developed here were applied to upscale spatially the current thermic conditions across the whole set of lakes and ponds of the Pyrenees.

Post-mortem Interval Estimation in a Forensic Case with Two Predatory Species: Chrysomya albiceps and Synthesiomyia nudiseta

A forensic case in which two facultative predatory species were found together on a human corpse is presented in this work. Second and third instar larvae of Synthesiomyia nudiseta (van der Wulp, 1883) (Diptera: Muscidae) and Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae) were collected from the dead body of a man on 14th November 2019, but puparia in the autopsy pictures were observed after, but not collected. The corpse was found on the terrace of the third floor of a building located in the town of Elche (SE Spain), and the pathologist confirmed the death as natural. The minimum post-mortem interval was estimated by the time to reach the length of the collected larvae or to reach the pupal developmental stage (in days and accumulated degree-days). In accordance with the influence of the predatory behaviour of each of these species on the developmental data of the other, as described in the existing literature, the effect of a hypothetical competition between both species on post-mortem interval was discussed.

Recognizing the Inherent Variability in Dipteran Colonization and Decomposition Rates of Human Donors in Sydney, Australia

Introduction: Human decomposition is influenced by intrinsic and extrinsic factors including entomological activity, which can result in variability in the decomposition process. In death investigations, forensic entomology, the study of insects in a legal context, is the preferred method to estimate a post-mortem interval after pathologist methods are no longer applicable. The purpose of the current study was to document the primary dipteran colonization and rates of decay during the decomposition processes of human donors with known causes of death. Methods: Five consenting human donors were placed in a forested area at the Australian Facility for Taphonomic Experimental Research (AFTER) in Sydney, Australia, and allowed to decompose in a natural environment. Temperature and humidity were monitored hourly while other factors like colonizers and decomposition stage were recorded at each visit to the site. Thermal summation, called Accumulated Degree-Days (ADD), was calculated to compare the rates of decay. Results: Results show that no two donors followed the same rate of decomposition. There were instances of delayed dipteran colonization, which resulted in slowed decomposition rates. Differences in rates of decay between donors could also have been influenced by intrinsic factors such as size, clothing and peri-mortem treatments. Conclusions: This research supports the larger body of research involving the pre-colonization interval of insects, emphasizing the numerous variables that can affect colonization. Further research into the pre-colonization interval, and factors that affect it, should be performed using human donors to better understand how this knowledge can be applied to death investigations.

The Growth Model of Forensically Important Lucilia sericata (Meigen) (Diptera: Calliphoridae) in South Korea

Development of forensically important Lucilia sericata (Meigen) was analyzed in South Korea. Rearing was replicated five times at seven constant temperatures between 20–35 °C to elucidate changes in accumulated degree hours, based on developmental stage and body length, and 2673 individuals were statistically analyzed. The results indicated that the optimum temperature, the base temperature, and the overall thermal constant were 22.31 °C (±1.21 °C, 95% CI), 9.07 °C, and 232.81 ± 23 (mean ± SD) accumulated degree days, respectively. In the minimum ADH models of each development stage, nonlinear regression graphs were parallel at the immature stages. Based on the scatter plot (n = 973) of immature stages using ADH values and body length, the logarithmic model using Log10ADH as the dependent variable was identified as the best fitting regression model. Additionally, the adjusted R2 value and mean square of error were 0.911 and 0.007, respectively. This is the first forensically focused study on the development of L.sericata for the estimation of minimum postmortem interval in South Korea. In future studies, we intend to study the development of other necrophagous fly species and to identify parameters for the determination of age at post-feeding and pupal stages.

Comparison of Accumulated Degree-Days and Entomological Approaches in Post Mortem Interval Estimation

Establishing the post mortem interval (PMI) is a key component of every medicolegal death investigation. Several methods based on different approaches have been suggested to perform this estimation. Among them, two methods based their evaluation on the effect of the temperature and time on the considered parameters: total body score (TBS)/accumulated degree-days (ADDs) and insect development. In this work, the two methods were compared using the results of minPMI and PMI estimates of 30 forensic cases occurring in northern Italy. Species in the family Calliphoridae (Lucilia sericata, Calliphora vomitoria and Chrysomya albiceps) were considered in the analyses. The results highlighted the limits of the TBS/ADD method and the importance of the entomological approach, keeping in mind that the minPMI is evaluated. Due to the fact that the majority of the cases occurred in indoor conditions, further research must also be conducted on the different taxa to verify the possibility of increasing the accuracy of the minPIM estimation based on the entomological approach.

Creation and Validation of a Temperature-Based Phenology Model for Meloidogyne incognita on Common Bean

The thermal requirements of Meloidogyne incognita on Phaseolus vulgaris in a set of constant soil temperatures were determined and the phenology model was validated at fluctuating soil temperatures. The base temperature (Tb) and the thermal constant (S) from nematode inoculation to females starting to lay eggs were 11.3 °C and 323 accumulated degree days (DD), respectively; Tb = 10.5 °C and S = 147 DD from egg production to emergence of juveniles; and Tb = 11.1 °C and S = 476 DD for life cycle completion. At fluctuating soil temperatures in pots with the minimum lower than Tb and the maximum higher than To (optimal temperature), the DD calculation was carried out by the average daily temperature–Tb (ADTb) and the single sine method over Tb (SSTb) with horizontal, intermediate, and vertical cutoffs. The most accurate were the ADTb and the SSTb with horizontal and intermediate cutoffs (93–106% of the predicted value) but the vertical underestimated the accumulated DD (75–82% of the predicted value). When fluctuating soil temperatures were between Tb and To in a plastic greenhouse, only the ADTb method was used. Life cycle completion was observed around 465 DD (accuracy between 0.95 and 0.99) at four different transplanting dates.

Phenology growth and yield of grafted tomato plants in the high Andean region of Colombia

The BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale is a system that helps producers monitor phenology by employing a uniform methodology across different locations. This study aimed to evaluate the effect of different scion×rootstock combinations on tomato yield and accumulated degree days for each tomato phenological stage. A randomized block design with four repetitions and four treatments was used. Tomato cv. Libertador seedlings were used as a shoot, self-grafted, and over the rootstocks ‘Olimpo’ and ‘Armada’. In addition, there was a non-grafted plant control. There were no significant differences for the accumulated degree days between the treatments since the tomato cultivation required 2,567°Cd-1. The variables, such as plant height, internode number and length, and number of flowers, did not vary significantly between the grafting and non-grafting treatments. The tomato plants grafted over a vigor rootstock produced 39.4 and 20.6% more first category fruits and total fruit yield than non-grafted ones. The heat units necessary to complete the tomato production cycle was not affected by the grafting, and the use of a vigor rootstock had a positive effect on the tomato yield under plastic house conditions.

Satellite Solar-Induced Chlorophyll Fluorescence Reveals Heat Stress Impacts on Wheat Yield in India

With continued global warming, the frequency and severity of heat wave events increased over the past decades, threatening both regional and global food security in the future. There are growing interests to study the impacts of drought on crop. However, studies on the impacts of heat stress on crop photosynthesis and yield are still lacking. To fill this knowledge gap, we used both statistical models and satellite solar-induced chlorophyll fluorescence (SIF) data to assess the impacts of heat stress on wheat yield in a major wheat growing region, the Indo-Gangetic Plains (IGP), India. The statistical model showed that the relationships between different accumulated degree days (ADD) and reported wheat yield were significantly negative. The results confirmed that heat stress affected wheat yield across this region. Building on such information, satellite SIF observations were used to further explore the physiological basis of heat stress impacts on wheat yield. Our results showed that SIF had strong negative correlations with ADDs and was capable of monitoring heat stress. The SIF results also indicated that heat stress caused yield loss by directly impacting the photosynthetic capacity in wheat. Overall, our findings demonstrated that SIF as an effective proxy for photosynthetic activity would improve our understanding of the impacts of heat stress on wheat yield.

Microbial neoformation of volatiles: implications for the estimation of post-mortem interval in decomposed human remains in an indoor setting

The objective of this study was to determine if a relationship between microbial neoformation of volatiles and the post-mortem interval (PMI) exists, and if the volatiles could be used as a tool to improve the precision of PMI estimation in decomposed human remains found in an indoor setting. Chromatograms from alcohol analysis (femoral vein blood) of 412 cases were retrospectively assessed for the presence of ethanol, N-propanol, 1-butanol, and acetaldehyde. The most common finding was acetaldehyde (83% of the cases), followed by ethanol (37%), N-propanol (21%), and 1-butanol (4%). A direct link between the volatiles and the PMI or the degree of decomposition was not observed. However, the decomposition had progressed faster in cases with microbial neoformation than in cases without signs of neoformation. Microbial neoformation may therefore act as an indicator of the decomposition rate within the early decomposition to bloating stages. This may be used in PMI estimation based on the total body score (TBS) and accumulated degree days (ADD) model, to potentially improve the model’s precision.