The effect of stimulants and environmental factors on resin yield of Pinus merkusii tapping

Oleoresin from Pinus merkusii is one of the most important forest products in Indonesia. The objective of this study was to examine the effects of various stimulants and environmental factors on oleoresin yield. The first factor was the stimulant treatment, i.e., SAEt1 (20% sulfuric acid + 1% Ethephon); SAEt2 (20% sulfuric acid + 2% Ethephon); SR4 (mainly composed by sulfuric acid); ETRAT (mainly composed by ethylene and citric acid); and without stimulant spraying. The second factor was the site with different altitudes, i.e., West Banyumas (326 m asl), East Banyumas (797 m asl), and West Pekalongan (1150 m asl). Through analysis of variance, the relation between stimulant and site was highly significant in regards to the average daily oleoresin yield. The results indicated that the combination of sulfuric acid and Ethephon increased oleoresin production 1.69- to 2.85-fold compared with untreated trees, depending on the sites. The trees with SAEt1 and SAEt2 treatments yielded an equivalent amount of oleoresin compared to that of trees exposed to the SR4. The ETRAT showed the lowest resin yields compared to the other stimulants. The values of daily relative humidity and temperature did not show similar responses in all sites when correlated with daily oleoresin yield.

Modelling evapotranspiration of soilless cut roses ‘Red Naomi’ based on climatic and crop predictors

This study aimed to estimate the daily crop evapotranspiration (ETc) of soilless cut ‘Red Naomi’ roses, cultivated in a commercial glass greenhouse, using climatic and crop predictors. A multiple stepwise regression technique was applied for estimating ETc using the daily relative humidity, stem leaf area and number of leaves of the bended stems. The model explained 90% of the daily ETc variability (R2 = 0.90, n = 33, P < 0.0001) measured by weighing lysimeters. The mean relative difference between the observed and the estimated daily ETc was 9.1%. The methodology revealed a high accuracy and precision in the estimation of daily ETc.

Effects of morning vs. evening inoculation on the development of Neonectria ditissima lesions

The study of Neonectria ditissima causing European canker in apple trees is often dependent on controlled inoculation of tree wounds and development of canker lesions. This makes the success of the initial inoculation crucial for time-efficient research. The effect of morning vs. evening inoculation on the successful development of canker lesions was investigated. Ninety-six ‘Royal Gala’ trees were inoculated on six different days (February—March 2017), which covered several different weather conditions. On each inoculation day, 16 trees were inoculated on four rasp and four picking wounds, at 10:00 and 19:00 hours. These were then assessed over the following 8 months for presence of disease symptoms. Irrespective of rain (0—4.5 mm rainfall at the day of inoculation), temperature (average daily temperature of 14.8—21.3˚C), and humidity (average daily relative humidity of 59.8—94.2% rH), neither the day nor the hour of inoculation affected symptom development. However, more inoculated wounds developed symptoms in rasp wounds (91%) than in picking wounds (63%). Under the environmental conditions tested, inoculation timing (date and hour) had little effect on N. ditissima symptom expression.

Effects of Climatic Conditions on Bovine Semen Characteristics

The present study assessed the effects of climatic conditions and year‑period (month) on both qualitative and quantitative characteristics of bovine semen in Czech Republic. The semen was collected twice a week using artificial vagina at artificial insemination center Hradištko in period 2011 – 2013. The effects of collection month, average daily ambient temperature and average daily relative humidity on volume, sperm concentration and progressive motility above head of collected semen and also on number of produced artificial insemination straws of required quality were analyzed using statistical analysis (procedures: UNIVARIATE, STEPWISE, GLM) in software SAS 9.3 (SAS/STAT® 9.3, 2011). Collection month, average daily ambient temperature, average daily relative humidity, and breed had a significant effect (P < 0.05) on all evaluated characteristics. The maximum values of motility and sperm concentration were found in March and in April. The highest volume of collected semen was found in July and in September and the lowest in November, when also the lowest number of straws was produced. Motility and sperm concentration were significantly influenced by average daily ambient temperature and average daily relative humidity, where the maximum values were recorded in average daily ambient temperature over 14.85 °C and average daily relative humidity over 72.05 %. The results are important to the management of artificial insemination center responsible for planning of semen collection, processing and artificial insemination straws production.

Predicting Fusarium Head Blight Epidemics with Boosted Regression Trees

Predicting major Fusarium head blight (FHB) epidemics allows for the judicious use of fungicides in suppressing disease development. Our objectives were to investigate the utility of boosted regression trees (BRTs) for predictive modeling of FHB epidemics in the United States, and to compare the predictive performances of the BRT models with those of logistic regression models we had developed previously. The data included 527 FHB observations from 15 states over 26 years. BRTs were fit to a training data set of 369 FHB observations, in which FHB epidemics were classified as either major (severity ≥ 10%) or non-major (severity < 10%), linked to a predictor matrix consisting of 350 weather-based variables and categorical variables for wheat type (spring or winter), presence or absence of corn residue, and cultivar resistance. Predictive performance was estimated on a test (holdout) data set consisting of the remaining 158 observations. BRTs had a misclassification rate of 0.23 on the test data, which was 31% lower than the average misclassification rate over 15 logistic regression models we had presented earlier. The strongest predictors were generally one of mean daily relative humidity, mean daily temperature, and the number of hours in which the temperature was between 9 and 30°C and relative humidity ≥ 90% simultaneously. Moreover, the predicted risk of major epidemics increased substantially when mean daily relative humidity rose above 70%, which is a lower threshold than previously modeled for most plant pathosystems. BRTs led to novel insights into the weather–epidemic relationship.

Meteorological factors and El Nino Southern Oscillation are associated with paediatric varicella infections in Hong Kong, 2004–2010

SUMMARYVaricella accounts for substantial morbidities and remains a public health issue worldwide, especially in children. Little is known about the effect of meteorological variables on varicella infection risk for children. This study described the epidemiology of paediatric varicella notifications in Hong Kong from 2004 to 2010, and explored the association between paediatric varicella notifications in children aged <18 years and various meteorological factors using a time-stratified case-crossover model, with adjustment of potential confounding factors. The analysis found that daily mean temperature, atmospheric pressure and Southern Oscillation Index (SOI) were positively associated with paediatric varicella notifications. We found that an interquartile range (IQR) increase in temperature (8·38°C) at lag 1 day, a 9·50 hPa increase in atmospheric pressure for the current day, and a 21·91 unit increase in SOI for the current day may lead to an increase in daily cases of 5·19% [95% confidence interval (CI) 1·90–8·58], 5·77% (95% CI 3·01–8·61), and 4·32% (95% CI 2·98–5·68), respectively. An IQR increase in daily relative humidity (by 11·96%) was associated with a decrease in daily paediatric varicella (−2·79%, 95% CI −3·84 to −1·73). These findings suggest that meteorological factors might be important predictors of paediatric varicella infection in Hong Kong.

Relation between some climate parameters inside and outside the stable in the course of the year

The objective of the present study was to evaluate the relation between some climate parameters inside and outside the stable in the course of the year. Investigations were carried out from 1 July 2007 to 30 June 2008 at the School Farm in Žabčice. We monitored the following micro-climate pa­ra­me­ters: temperature (°C), relative humidity (%) and the temperature-humidity index (THI) inside and outside the stable. We used the statistical programme UNISTAT version 5.1.11 to calculate the average monthly temperatures, relative humidity and the THI inside and outside the stable.Measurements carried out throughout the whole year revealed that the average daily outdoor temperature was always lower than the temperature monitored inside the stable. The differences between the outdoor and indoor temperatures were more marked in winter; in summer the differences were considerably lower. The coefficient correlations confirmed this finding; the temperatures were the highest in July and the lowest in autumn and winter. The same results and tendencies were monitored in terms of the average daily THI values. Much like the temperatures also the differences in high average daily values of relative humidity between the outside and inside environment of the stable were lower. Since the relative humidity was higher in winter than in summer the differences between the indoor and outdoor stable values were more marked in summer than in winter. In contrast to the temperature and THI, in one half of the cases the average daily relative humidity was higher outside the stable than inside and vice versa.