Evaluation of Yield and Quality from Red Pepper for Application Rates of Pig Slurry Composting Biofiltration Red pepper;pig slurry;Nitrogen;recommendation; The application in agricultural fields of pig slurry composting biofiltraton amending smell and nutrient unevenness, it is important for the appropriate nitrogen nutrient management to promote the availability of the crops and to minimize the risk of adversely environmental effects. The objective of this study was to determine the application rates of the preplant pig slurry composting biofiltration for red pepper(Capsicum annuum L.) by considering the yield response and the fruit quality such as sugar, capsaicinoid content. Red peppers were grown on plastic film ground under five different pig slurry(PS) application rates and mineral fertilizer(MF 100%) as a control. The effects of a single application of five different doses of PS: PS 0%(no kg N $ha^{-1}$), PS 50%(51.5 kg N $ha^{-1}$), PS 75%(77.3 kg N $ha^{-1}$), PS 100%(103 kg N $ha^{-1}$) and PS 125%(129 kg N $ha^{-1}$) were compared with the recommended mineral treatment(103 kg N $ha^{-1}$) in the pre-planting. The sidedressing N application(87 kg N $ha^{-1}$) was applied to the mineral fertilizer in all treatments. Red peppers were harvested at the mature red stage through five times from 72 days after transplanting(DAT) to 133 DAT. The results indicated that the yield of red pepper was increased with the increase of the N application rates from PS 0% to PS 100%. The highest yield was obtained in PS 100% by 20,843 kg $ha^{-1}$, although there were no significant differences in yield among PS 100, PS 125% and MF 100%. In addition, The contents of soluble sugar and capsaicinoids were not significantly different in all treatments. Accordingly, fertilization recommendations of red pepper to substitute PS for the mineral fertilizer were considered to PS 100%.

Recent meteorological variability in winter and spring complicates predicting and managing frost damage in apples and pears. This study investigated the relationship between frost injury during the flowering stages of apples (‘Hongro’ and ‘Fuji’) and pears (‘Wonwhang’ and ‘Niitaka’) and weather conditions across regions at varying altitudes. Orchards were categorized into coastal, inland, mid-mountainous, and mountainous regions, and flowering stages and frost injury were analyzed. The flowering period of apples, from the onset of blooming to full bloom, averaged approximately 15 days, which was about 3 to 5 times longer than that of pears. Furthermore, the total flowering duration of apples was 1.5 to 2.0 times longer than that of pears. Additionally, flowering exhibited a tendency to be delayed at higher altitudes. However, orchards situated in mid-mountainous regions experienced earlier flowering compared to those in other regions. Among the two apple cultivars, the average frost damage was more severe in central flowers than in lateral flowers and was relatively higher in ‘Fuji’ than in ‘Hongro’. In pears, frost damage was most prevalent in the first to fourth flowers within the inflorescence, with ‘Wonhwang’ exhibiting relatively greater susceptibility than ‘Niitaka’. Across different cultivation regions, severe frost damage was observed in orchards located in mid-mountainous areas for both fruit species and cultivars. The severity of frost damage followed the order mid-mountainous, mountainous, plain, and coastal regions. Minimum temperatures were lowest in mid-mountainous and mountainous regions, while daily temperature differences were largest in mid-mountainous regions. Meteorological analysis (1981 to 2022) revealed consistent trends, with an increase in daily temperature range in recent years. These findings highlight the vulnerability of mid-mountainous orchards due to flowering stages overlapping with coastal and plain regions, exposing them to lower temperatures and larger temperature differences. Further studies on temperature variability are essential to mitigate frost damage risks.

Due to recent abnormal weather caused by global warming, peach flowering has gradually accelerated, and spring frost damage caused by premature de-acclimation has increased. In this study, under a simulated spring frost environment using a Soil–Fruit–Daylit–System (SFDS) chamber, we investigated whether treatment with 2% cellulose nanocrystals (CNCs) could enhance the freezing tolerance of the flower buds from 2-year-old whole peach trees. Visual changes in the ice propagation were observed using an infrared camera at the same time. After the peach flower buds in the calyx red stage were placed in the SFDS chamber with a minimum temperature of −4 °C for ~20 h, the percentage of browning in the pistils and stamens was 57.0% in the control group and 14.1% in the group treated with 2% CNCs. During the first pink stage, the percentages of browning in the pistils and stamens in the control group and the group treated with 2% CNCs were 98.2% and 70.3%, respectively. However, when peach flower buds in the group treated with 2% CNCs were exposed to a −6 °C-targeted chamber, they could not mitigate frost injury. Almost all flower buds were damaged. Infrared thermal images showed that the first exotherm in the control group began at 2:33:03 am, whereas that of the group treated with 2% CNCs began at 3:01:33 am. The control started to express exothermic behavior at −4.2 °C, while the group treated with 2% CNCs started expressing exothermic behavior at −5.1 °C. Thus, treatment with 2% CNCs enhanced the freezing tolerance by −0.9 °C and delayed the first instance of exothermic behavior by ~28 min. These results indicate that treatment with 2% CNCs could mitigate the frost damage of peach flower buds in a frost environment of −5 °C.