Harvest Year Research Articles

МИНЕРАЛЬНЫЙ СОСТАВ КАК МАРКЕР ТЕРРИТОРИАЛЬНОЙ ПРИНАДЛЕЖНОСТИ ВИН ЗАЩИЩЕННЫХ НАИМЕНОВАНИЙ МЕСТ ПРОИСХОЖДЕНИЯ

The paper discusses methods for identifying wines based on regional characteristics, which consists of establishing a connection between the component composition of wines and soils corresponding to the area where grapes grow. It has been shown that markers of regional affiliation can be components whose content in wines practically does not change during the production process. The results of a study of the mineral composition of wines produced by the winemaking enterprise OOO “Imenie Sikory” are presented. Using atomic absorption spectroscopy using the Kvant Z spectrometer (NPF OOO “KORTEK”, Russia), 12 metal elements (Co, Mn, Rb, Cr, Cs, Al, Ba, Zn, Sr, Li, Na, Mg) were determined in the course of studies on atomic emission and absorption spectra. A study was also conducted of the mineral composition of soil samples from vineyards where grapes used for wine production grew. Using the methods of correlation and cluster analysis, as well as using the “random forest” algorithm (for wine samples, the initial data were the content of elements and their pairwise ratios), it was revealed that the mineral composition can serve as a marker of the regional affiliation of wine products, since the studied wine samples are within each variety have a stable mineral composition, regardless of the year of harvest (correlations between the year and the content of elements are insignificant), determined by the characteristics of the site where the grapes grow. Quantitative determination of the components of the mineral complex in combination with mathematical processing of the results allows us to establish the origin of the wines with a reasonable degree of probability. The mineral composition of the studied wines is unique and is determined by the soil characteristics of the vineyard areas of the “Semigorye” geographical object.

Predicting Bordeaux red wine origins and vintages from raw gas chromatograms

Connecting chemical properties to various wine characteristics is of great interest to the science of olfaction as well as the wine industry. We explored whether Bordeaux wine chemical identities and vintages (harvest year) can be inferred from a common and affordable chemical analysis, namely, a combination of gas chromatography (GC) and electron ionization mass spectrometry. Using 12 vintages (within the 1990–2007 range) from 7 estates of the Bordeaux region, we report that, remarkably, nonlinear dimensionality reduction techniques applied to raw gas chromatograms recover the geography of the Bordeaux region. Using machine learning, we found that we can not only recover the estate perfectly from gas chromatograms, but also the vintage with up to 50% accuracy. Interestingly, we observed that the entire chromatogram is informative with respect to geographic location and age, thus suggesting that the chemical identity of a wine is not defined by just a few molecules but is distributed over a large chemical spectrum. This study demonstrates the remarkable potential of GC analysis to explore fundamental questions about the origin and age of wine.

Germination biology of Hedysarum grandiflorum (Fabaceae) seeds under laboratory conditions

Germination biology of Hedysarum grandiflorum seeds research was conducted using seed material collected in one wild and one cultivated population growing in Rostov region and included an identification of seed laboratory germination degree, seed hardness, endogenic infection degree, and seed pathogens composition. A combinational dormancy type combining physical and non-deep physiological dormancy was identified in Hedysarum seeds. Stably high germination rates under laboratory conditions was demonstrated if mechanical scarification is used whereas efficiency of sulfuric acid treatment varies it relation to seeds harvest year and retention period. A proportion of hard seeds of H. grandiflorum is confirmed to increase during first three month of dry storage and then slowly decrease. A degree of Hedysarum seeds endogenic infection revealed is higher in wild population compared with seed material from cultivated plants. Micromycetes - facultative parasites and saprotrophs prevail among seed pathogens regarding their species diversity, and bacterial pathogens quantitatively.

Essential oil profiles, improvement of enzymatic and non-enzymatic antioxidant systems in different populations of Salvia subg. Perovskia by irrigation management

Salvia subg. Perovskia is an aromatic medicinal plant from the Lamiaceae family. Essential oil (EO) content and composition, along with enzymatic and non-enzymatic antioxidants, were evaluated in 18 plant populations under three levels of irrigation for two consecutive years. Based on the GC-MS analysis, the main components of EO were borneol (1.18–36.53%), followed by camphor (0.54–32.17%), 1,8-cineole (12.44–29.26%), δ-3-carene (0.39–21.20%), myrcene (0.59–16.28%), and α- pinene (0.79–12.87%) in the studied treatment. Except for malondialdehyde and hydrogen peroxide in leaves and roots, all the examined parameters showed lower values in the first harvest year compared to those of the second year. The activities of antioxidant enzymes, total phenolics, and flavonoids of the extracts were substantially enhanced as stress intensified to reach maximum values in leaves under severe stress and in roots under moderate stress conditions. The maximum root tanshinones content was observed under moderate water deficit conditions, while the highest EO content was obtained in plants exposed to severe stress conditions. Taking into account the evidence provided by this study, it can be inferred that the use of water deficit stress can serve as an effective method to stimulate and improve antioxidant properties, as well as the quantity and quality of secondary metabolites in Salvia subg. Perovskia.

Study of grape microorganisms in Moldovan vineyards: influence of human and natural factors

The objective of this study was to investigate the microbial diversity on the grape berries under different climate conditions. Sixteen samples from ten vineyards were taken from three PGI regions in Republic of Moldova Moldova during years 2018–2020. The year of harvest had a significant effect on the amount of yeasts, but the geographical location did not significantly influence this criterion. As natural factors, the influence of temperature and precipitation during both the growing season and the month of grape harvest was studied. The selected methods for vineyard plant protection were as follows: fungicides to control powdery mildew, fungicides to control mange and insecticides. The total yeast population per grape ranged from 3.8E+04 to 2.3E+07 CFU/berry and the culturable yeast population ranged from 1.7E+03 to 8.0E+06. The harvest month temperature affects the yeast population the most, fungicide use in mealybug control reduces the culturable yeast population but increases the total yeast population; insecticide treatment only increases the total yeast population but has no impact on culturable yeasts.In addition, six species yeast have been identified: A.pullulans, M.pulcherrima, H. uvarum, R. Glutinmis, R. graminis and S.cerevisiae. The Saccharomyces cerevisiae strain isolated from the 2020 crop is totally different from the 2018 and 2019 crops. The bacteria population is at a low level, except for a few samples, P. damnosus, L. brevis, L.fermentum, G. oxydants were isolated.

Clark's nutcracker forest community visitation: Whitebark pine maintains a keystone seed disperser.

Clark's nutcrackers (Nucifraga columbiana) are obligate seed dispersers for whitebark pine (Pinus albicaulis), but they frequently use other conifer seed resources because of annual variability in cone production or geographic variation in whitebark pine availability. Whitebark pine is declining from several threats including white pine blister rust, leading to potential population declines in the nutcracker and the pine. We hypothesize that where there are few additional seed resources, whitebark pine becomes the key and limiting resource supporting nutcracker populations. We investigated how nutcrackers use coniferous forest community types within Yellowstone National Park to determine potential seed resources and the importance of whitebark pine. We established sites representing five forest community types, including whitebark pine, lodgepole pine (P. contorta), Engelmann spruce (Picea engelmannii), limber pine (P. flexilis), and Douglas-fir (Pseudotsuga menziesii). Each transect annually generated nutcracker point counts, conifer cone production indices, community composition data, and seed resource use observations. We compared hierarchical distance sampling models, estimating nutcracker density and its relationship to forest community type, seed harvesting time-period, year, study site, and cone seed energy. We found cone production varied across years indicating annual variability in energy availability. Nutcracker density was best predicted by forest community type and survey time-period and was highest in whitebark pine stands during the mid-harvesting season. Nutcracker density was comparatively low for all other forest community types. This finding underscores the importance of whitebark pine as a key seed resource for Clark's nutcracker in Yellowstone National Park. The decline of whitebark pine potentially leads to a downward spiral in nutcrackers and whitebark pine, arguing for continued monitoring of nutcrackers and implementation of restoration treatments for whitebark pine.

Insight into the aroma quality of ‘Callista’ cultivar of hop (Humulus lupulus L.): impact of harvest timing, year, and location

Hops (Humulus lupulus L.) are essential ingredients in brewing, contributing to beer’s flavor, aroma, and stability. This study pioneers an in-depth analysis of the 'Callista' cultivar, aiming to unravel how harvest timing, annual variations, and cultivation location synergistically influence its molecular profile, sensory perception, and biochemistry. Leveraging high-performance liquid chromatography and gas chromatography-mass spectrometry-olfactometry, we identified significant year-to-year and location-based fluctuations in bitter acids—the quintessential aroma constituents in hops. Our comprehensive aroma profiling discerned 55 volatile compounds, marking the first-ever sensory detection of 2-butanone in hops, with its presence showing remarkable interannual variability. This study showed significant differences among the three years tested, whereas hops were perceived “fruitier” and more “citrusy” in 2021, even though the bitter acid and aroma analysis showed that 2022 sticks out due to extremely high lupulone values up to 10% dry cone weight and 78% β-myrcene in the oil fraction compared to 60% and 45% in 2020 and 2021, respectively. Molecular analysis of key enzymes involved in hop aroma biosynthesis revealed no significant associations with location, but a strong diurnal pattern for all genes. The results indicated that especially the hot temperatures of 2022 may have induced significant changes of cone quality, while 2021 was more interesting from the sensory evaluations, which may justify the usage of viticultural terms such as “vintage” for hop marketing. These findings contribute to a better understanding of the factors influencing hop aroma and quality.

Discrimination of Turkish Gemlik virgin olive oils by growing regions and environmental conditions

AbstractGeographic origins together with environmental conditions (temperature, rainfall, humidity, altitude) during harvest, could alter the olive oil quality, nutritional value, and traceability. The impact of geographic region (Bursa PDO, Hatay, Mersin, and Izmir NPDO) and conditions at harvest years (2016 and 2017) on the quality and traceability of Gemlik virgin olive oils were investigated. Environmental conditions (high temperature and relative humidity, low rainfall) resulted in low quality due to increase in FFA, linoleic acid, PUFA, Δ7‐stigmastenol, stigmasterol and total sterols in oils obtained from southeast (Hatay and Mersin) NPDO regions. Bursa PDO and Izmir NPDO Gemlik virgin olive oils were high in oleic acid, MUFA, hydroxtytyrsol, tyrosol, antioxidant activity and, ∆5‐avenesterol and discriminated by 99% accuracy with discriminant analysis. PCA and DA can easily detect and distinguish differences in virgin olive oils quality and purity coming from different growing regions and subjected to inverse environmental conditions. Bursa PDO and Izmir NPDO growing regions have better conditions for Gemlik olives cultivation to obtain high quality and oxidative resistant Gemlik virgin olive oils.

Influence of dextrins and β-glucans on palate fullness and mouthfeel of beer

Palate fullness (PF) and mouthfeel are important sensory attributes influencing beer quality. The molar mass of starch (dextrins) and non-starch (β-glucans) polysaccharides may influence PF (pleasant) or mouthfeel (sliminess, unpleasant), respectively. Therefore, this research aims to generate beer with wide physico-chemical responses based on various raw material characteristics to study its relation to PF and mouthfeel. To accomplish this, ten barley varieties (two harvest locations and years) were classified into three groups based on their modification characteristics. To intensify response variation, barley was malted at two modification levels (parameter steeping degree), generating 55 independent malts used to brew the same number of standardized bottom fermented beers. A trained sensory panel evaluated PF (intensity and quality) and mouthfeel (e.g., slimy) descriptors. Additionally, beers were fractionated by asymmetrical flow field-flow fractionation (AF4) in three different fractions and their molar masses were determined. The average molar mass of big size (> 10 nm) dextrins and β-glucans AF4 fraction increased analogously to barley modification characteristics. For sensory data evaluation, only beer samples brewed with malts inside the recommended brewing specifications were considered (β-glucan content in malt < 350 mg/L, ISO 65 °C). PF quality was lower on samples with β-glucan content < 100 mg/L. This group also contained fewer dextrins (attenuation > 87.4 ± 1.5%), suggesting that the balance of β-glucans and dextrins is important for PF quality. This work indicates that molar mass of starch and non-starch polysaccharides, affected by barley variety and its modification level, influences sensory perception, and hence, beer quality.Graphical

Adjusting nitrogen fertilization to spatial variations in growth conditions in silvopastoral systems for improved nitrogen use efficiency

Grass swards in silvopastoral systems have a lower herbage production near trees than open grassland. This is related to a lower nitrogen (N) uptake in an area close to the tree lines. The N use efficiency for the whole field can then be improved when N input is spatially adjusted and the overall amount reduced. We performed a 2-year field experiment to gain insights into this idea for making savings on N inputs by studying the response of the grass sward to fertilizer N input in relation to the distance from trees. We hypothesized an interaction between N input rate and position to the tree line on grassland herbage production and N uptake and, accordingly, N use efficiency. The field trial was carried out in a silvopastoral system in Germany consisting of the factors year (2019 and 2020), position (2.5, 6.5 and 24.5 m distances to tree line), annual N application rate (0, 15 and 30 g N m−2) and harvest date (four harvests per year). We found significant interactions between position × N rate for all target variables, and usually also in interactions with the harvest date or year. The N application close to trees at a distance < 6.5 m had in most cases no significant influence on herbage production but significantly increased herbage production by up to 35% at positions further away. Omitting the N fertilization in a corridor of 6.5 m near the trees would contribute directly to the saving of fertilizer N without a negative trade-off in herbage production.

338 A Survey of Mycotoxin Occurrence in Us Corn and Corn By-Product Feed Ingredients from 2018 to 2022 Harvest Years

Abstract The aim of this survey was to compare the occurrence and contamination levels of six major mycotoxin categories found in corn and corn by-product feed ingredients harvested in the United States from 2018 through 2022. Mycotoxins are secondary fungal metabolites that can negatively impact animal health and performance and have been routinely found in a variety of feedstuffs including, but not limited to, cereal grains, by-products, silages, dry hays and pasture grasses. Mycotoxin categories evaluated in this survey included: aflatoxins (AFLA), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A (OTA). This study includes data from corn samples labeled as 2022 harvest and corn b-product feed ingredients submitted from October 2022 through March 2023 and were analyzed for 17 different metabolites via the Liquid Chromatography with tandem mass spectrometry (LC-MS/MS) method. Samples that tested above the limit of detection for each mycotoxin group were analyzed using the generalized linear mixed model procedure of SAS (SAS 9.4, Cary, NC) using harvest year as a fixed effect. The effect of harvest year on average contamination level for each mycotoxin is presented in Table 1. For 2022 harvest year, 260 corn samples and 66 corn by-product samples have been evaluated to date. Mean B-Trich, ZEN, FUM and AFLA levels (parts per billion, ppb) for corn grain samples were similar in 2022 as previous years (P &amp;gt; 0.05). However, for corn grain samples, FUM prevalence and concentration were numerically greater in 2022 than in 2021 and 2020. In the 66 samples of corn by-products, FUM was found in all the samples (100%) and B-Trich were found in the majority of the samples (97%). Mean concentration of FUM in 2022 corn by-product samples was greater (P &amp;lt; 0.001) compared with 2021. Preliminary results of this survey suggest mycotoxin occurrence and contamination remains similar to previous harvest years except for greater mean FUM concentration levels in corn and corn by-products feed ingredients.

СОДЕРЖАНИЕ ОРГАНИЧЕСКИХ КИСЛОТ СУСЛА И ВИНА ИЗ ВИНОГРАДА СОРТА ПЕРВЕНЕЦ МАГАРАЧА В ЗАВИСИМОСТИ ОТ ПРИМЕНЯЕМЫХ АГРОТЕХНИЧЕСКИХ ПРИЕМОВ

The influence of shoots load on the qualitative and quantitative composition of organic acids of musts and wines made from Pervenets Magara-cha grapes was studied. The research of influ-ence of agrotechnical measures was carried out on must and wine materials, on the following variants of experiment: load of 30 shoots / shrub; 35 shoots / shrub; 40 shoots / shrub; 45 shoots/shrub. It was revealed that the composi-tion of organic acids in grapes and wine to a greater extent depends on the varietal features of grapes and conditions of the year of harvest, while a clear dependence of the composition of organic acids on the load of bushes with shoots for the variety Pervenets Magaracha as a result of these studies could not be established.

PSVI-20 Trends in Mycotoxin Contamination of the 2022 United States Corn Crop

Abstract Mycotoxins are harmful secondary fungal metabolites detrimental to animal health, even at reduced quantities. Focus on clinical signs such as decreased feed intake and vomiting overlook impacts of mycotoxicosis, including increased disease incidence and severity, immune modulation, inflammation, and gastrointestinal disorders. This study was conducted to compare mycotoxin contamination of initial samples of the 2022 corn crop with previous year trends. Samples were analyzed utilizing the liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for six major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin A (OTA). The 2022 crop year data were compared with the prior four harvest years using GLIMMIX procedure of SAS with harvest year as fixed effect and sample as the experimental unit. A limited number of samples is available thus far (n = 44) as harvest is still progressing, therefore the risk profile of this crop year is likely to change as the sample pool expands. Contamination levels in corn for the tested toxin groups have remained consistent over the survey period. To date, 97% of the samples evaluated contained at least one mycotoxin, compared with 90% that was observed in 2021. The percentage of Afla contaminated samples increased (P &amp;lt; 0.05) in 2022 corn compared with the 2020 and 2021 harvest years (42 vs. 5 and 7%). The percentage of FUM contaminated samples in 2022 corn is greater (P &amp;lt; 0.05) compared with 2020 and 2021 (88 vs. 64 and 64%). The preliminary results of the 2022 US corn crop survey indicate mycotoxin occurrence and contamination levels are similar or greater (Afla and FUM) to the prior crop year and will continue to challenge animal health and performance as these ingredients are fed out.

A guide for quality control of honey: Application of UV–vis scanning spectrophotometry and NIR spectroscopy for determination of chemical profiles of floral honey produced in southern Brazil

This study aimed to determine the chemical profile of floral honey by ultraviolet and visible spectrophotometry (UV–vis) and near-infrared (NIR) vibrational spectroscopy, and via analysis of the total phenolic content, considering the harvest year (2018–2019 and 2019–2020), geographic and botanical origins, and seasonality of samples (n = 116) collected in southern Brazil. The total phenolic content (TPC) of honey showed great variation by geographic origin and for both harvests, with a higher overall average in the 2019–2020 (3.81–7.22 mg/mL) compared to the 2018–2019 (2.49–6.17 mg/mL), which seemed to be related to climatic factors, mainly precipitation. The visual inspection of the UV–vis spectra (280–320 nm) revealed two samples with distinct chemical compositions, being these further confirmed as outlier by PCA. UV–vis (260–360 nm) coupled to PCA was able to distinguish honey with higher and lower TPC. The NIR spectral data set revealed discrepancies among honey according to the harvest seasons, with bands associated with higher water content and lower carbohydrate amounts in the 2018–2019-collected samples; the contrary has been noted for the 2019–2020. Thus, UV–vis and NIR spectroscopies coupled to PCA proved to be a useful approach to distinguish honey samples as to possible adulterations and geographic origin associated with their higher and lower phenolic contents.

Seasonal and species variation in raffinose, short‐chain fructan, and long‐chain fructan accumulation in tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) grown in Central Kentucky

AbstractFructans in cool‐season grasses may have some negative effects on equine health. However, they may have positive effects on ruminant performance, and fructans of different lengths appear to be metabolized differently in the rumen. Hence, seasonal variation in fructan concentrations may impact equine and ruminant performance. Long‐chain fructan with degree of polymerization (DP) &gt; 8, short‐chain fructan (DP 4 to 8), raffinose, and three fructan trisaccharides were profiled and quantified in timothy (Phleum pratense L.) cultivar ‘Clair’ and tall fescue (Festuca arundinacea Schreb.) cultivar ‘Cajun II’ harvested in April, June, August, and October of two consecutive years in central Kentucky. Harvest year influenced concentrations of long‐chain fructan (p = .0017). Harvest date influenced species differences in raffinose (p = .0035), which was most abundant in timothy in June, and in 1‐kestose and neokestose (p &lt; .0001), which were most abundant in tall fescue in April. Harvest date influenced species differences in short‐ and long‐chain fructan (p &lt; .0001). Tall fescue had two‐ to three‐fold more short‐chain fructan than timothy in April, August, and October. Timothy had two‐ to five‐fold more long‐chain fructan than tall fescue in April, June, and October. Species choice and weather patterns may have contributed to relatively low concentrations of all the carbohydrates measured in this study. Fermentation or feeding studies could help to determine if the concentrations present could affect equine health or ruminant performance.

GC-MS evaluation of the essential oils from the newly developed cultivars of Satureja montana grown in southern Ukraine

Satureja montana L. is widely used in traditional medicine and culinary. New varieties of this species are created and grown with different purposes. The essential oil (EsO) samples were obtained from the fresh flowering shoots of four new Ukrainian cultivars of S. montana: 'Krymski smaragd', 'Lunata', '697-1', and 'N3-18'. The EsO of cultivars ''Lunata' and 'Krymski smaragd' were studied in two following harvest years (2019 and 2020). The EsO samples were analyzed using gas chromatography-mass spectrometry (GC-MS). More than 60 components were identified in the studied EsO. Carvacrol was the principal component of all the samples (58.3-87.0% (as GC-MS relative abundances). p-Cymene was the second predominant component (5.0–8.8%) in the EsO of all the cultivars collected in the 2020 year, while cultivars ''Lunata' and 'Krymski smaragd' gathered in 2019 contained it in much fewer amounts (1.7% and 0.5%, respectively). γ-Terpinene was the third main component of EsO of the most studied varieties (0.9% to 6.6%). Only cultivar 'N697-1' contained carvacrol methyl ether at a significant level (11.7%). All the tested samples met the requirements of International Standard Organization (ISO) 79284:1991(E), supposing that the qualitative composition of the S. montana EsO should comprise the following main constituents: γ-terpinene, p-cymene, linalool, terpinen-4-ol, and carvacrol. It can be concluded that we dealt with the carvacrol chemotypes of S. montana. It was also revealed that growth year influenced the EsO composition of 'Krymski smaragd' and 'Lunata' cultivars. Our results afforded to compare the EsO of the S. montana new cultivars

Forgotten Perfumery Plants - Part II: New Insights into the Development of Novel Fragrant Ingredients - Hawthorn Case Study.

Naturalness is gaining ground among perfumers and the use of natural raw materials is spreading in perfumery. Forgotten perfumery plants are of concern to develop innovative and natural ingredients for modern perfume industries. The main purpose of this study was to evaluate the potential interest of Crataegus monogyna Jacq. extracts as fragrance ingredient. To this end, various extractions, phytochemical characterizations and organoleptic evaluations of hawthorn were conducted on fresh, frozen, and dried flowering aerial parts, to identify those most likely to be of interest. More than a hundred compounds, anisaldehyde being the predominant one, were characterized for the first time in the volatile fraction, using HS-SPME-GC-MS technology. Impact of plant treatment and harvest year on the extracts were also discussed. From this work, a new and natural hawthorn-based ingredient was developed to complete the perfumers' palette.

Fate of Planktonic and Biofilm-Derived Listeria monocytogenes on Unwaxed Apples during Air and Controlled Atmosphere Storage.

Multiple recalls and outbreaks involving Listeria monocytogenes-contaminated apples have been linked to the post-harvest packing environment where this pathogen can persist in biofilms. Therefore, this study assessed L. monocytogenes survival on apples as affected by harvest year, apple cultivar, storage atmosphere, and growth conditions. Unwaxed Gala, Granny Smith, and Honeycrisp apples were dip-inoculated in an 8-strain L. monocytogenes cocktail of planktonic- or biofilm-grown cells (~6.5 log CFU/mL), dried, and then examined for numbers of L. monocytogenes during air or controlled atmosphere (CA) (1.5% O2, 1.5% CO2) storage at 2 °C. After 90 days, air or CA storage yielded similar L. monocytogenes survival (p > 0.05), regardless of harvest year. Populations gradually decreased with L. monocytogenes quantifiable in most samples after 7 months. Apple cultivar significantly impacted L. monocytogenes survival (p < 0.05) during both harvest years with greater reductions (p < 0.05) seen on Gala compared to Granny Smith and Honeycrisp. Biofilm-derived cells survived longer (p < 0.05) on L. monocytogenes-inoculated Gala and Honeycrisp apples compared to cells grown planktonically. These findings should aid in the development of improved L. monocytogenes intervention strategies for apple growers and packers.

Texture Properties, Crude Fat, Fatty Acid Profiles, Total Soluble Solids, and Total Polyphenols for 21 Pecan Varieties and the Effects of the Harvest Year

Texture Properties, Crude Fat, Fatty Acid Profiles, Total Soluble Solids, and Total Polyphenols for 21 Pecan Varieties and the Effects of the Harvest Year

Effect of rotational harvesting on the size composition of Cape rock oysters Striostrea margaritacea on the east coast of South Africa

A commercial fishery for the Cape rock oyster Striostrea margaritacea along the north coast of KwaZulu-Natal, South Africa (western Indian Ocean), follows a 4-year rotational cycle, with each harvest year followed by 3 fallow years across four harvest zones. We analysed reported harvesting effort and catch information, and fishery-independent oyster size composition data collected over 18 years (Feb 2003-Feb 2020), to investigate the sustainability of rotational harvesting. Total harvesting effort and catches declined over the study period, but on average, the number of oysters collected per outing increased. Fewer outings in recent years were attributed to incomplete reporting and a progressive loss of access to harvest sites. Generalised linear mixed models were used to estimate trends in oyster mean size in relation to fishing method (divers and intertidal collectors), harvest zone, 4-year rotational cycles, and months spent in a zone. Oyster mean size increased from north to south along the coast. Oysters caught by divers on newly exploited deeper reefs were initially larger than those caught by intertidal collectors. Mean oyster size decreased monthly during 1-year harvest periods but recovered to pre-harvest size over 3 fallow years. The results confirmed that the current rotational harvest strategy is well-suited to oyster biology and is sustainable at the present level of effort. Improved reporting on harvesting effort and catch are required to verify longer-term spatiotemporal trends in this fishery. More effective stakeholder communication is needed to resolve potential user conflict