Volatiles of peach (Prunus persica L., cultivar, Gleason Early Elberta) fruit were studied by gas-liquid chromatography , thin-layer chromatography, and infrared spectrometry. Hard mature , firm mature, soft mature , tree ripe, and artificially ripened hard mature fruit obtained from four seasons , 1964 to 1967, were used. A total of 86 peaks were observed in the chromatogram of the tree ripe peach volatiles. Major components of the volatiles identified were mainly esters, gamma and delta lactones , aldehydes, alcohols, and terpenes. In general, concentration of the volatile components were found to increase with the maturity of the fruit. However, that of the artificially ripened fruit did not reach the same level of the tree ripe fruit.

The objective of this research was to determine the effect of stage of maturity at the time of harvest for barley and oat whole-crop forage on feed intake, ruminal fermentation and digestibility, and the impact forage allocation has on intake and ruminal fermentation. In the first 2 studies, whole-crop barley (Study 1; c.v. CDC Cowboy) and oat (Study 2; c.v. CDC Weaver) forage were harvested at the late milk (LM), hard dough (HD) and ripe (RP) stages and offered ad libitum to ruminally cannulated heifers. Diets were supplemented in an attempt to balance crude protein (CP) among treatments. Heifer performance, dry matter intake (DMI), ruminal fermentation parameters, ruminal digestibility, and total tract digestibility were evaluated. In Study 3, whole-crop oat (c.v. CDC Weaver) forage harvested at HD and RP was offered ad libitum to ruminally cannulated heifers in either daily (1-D) or 3 d (3-D) allocations. Dry matter intake and ruminal fermentation parameters were measured. In Study 1, harvest maturity of barley did not affect DMI (P = 0.70; average 5.4 kg/d) or average daily gain (ADG; P = 0.64). Total tract digestibility was decreased for barley harvested at HD (P = 0.003), but harvest maturity did not affect daily digestible energy (DE) intake (P = 0.52). Minimum ruminal pH for heifers fed the barley forage was lowest for LM (6.09), intermediate for RP (6.13), and greatest for HD (6.25; P = 0.016). Total short chain fatty acid (SCFA) concentrations were not affected by harvest maturity (P = 0.36). In Study 2, harvest maturity of whole-crop oat did not affect DMI (P = 0.26; average 8.1 kg/d) or ADG (P = 0.52). There were no effects of harvest maturity of oat forage on total tract digestibility (P = 0.78) or daily DE intake (P = 0.68). The minimum ruminal pH from heifers fed oat forage was lowest for HD (5.84; P = 0.012), intermediate for RP (5.94) and greatest for LM (5.99). There was no effect of harvest maturity of oat forage on total SCFA concentrations (P = 0.21). The quantity of forage allocation (Study 3) had no effect on total or forage DMI over a 3-d duration (P ≥ 0.47). Throughout the 3-d feeding period, 3-D allocated heifers had a reduction in the area pH was under 5.8 (214.4, 79.5 and 10.9 pH × min/d, for d 1, 2 and 3, respectively; P = 0.003). Total SCFA concentrations were not affected by forage allocation or harvest maturity (P ≥ 0.14), however there was an interaction of forage allocation and day in the feeding cycle (P = 0.046). Heifers allocated 1-D had no change iii in total SCFA concentration over the 3-d feeding period (averaged 122 mM), but 3-D allocation had elevated concentrations on d 1 (138 mM) intermediate on d 2 (135 mM) and decreased on d 3 (117 mM). These data suggest that harvesting barley and oat at the HD stage improves DM yield without negatively affecting cattle DMI and ADG. These data also suggest that providing 3-d allocations of forage does not affect DMI, but can increase daily fluctuations of ruminal pH and ruminal SCFA concentrations.

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Thompson Seedless and Regal Seedless are two white seedless table grape cultivars widely produced in South Africa. Both cultivars are susceptible to berry browning, especially Regal Seedless. Browning leads to annual financial losses for table grape growers. Although a correlation between harvest maturity and the occurrence of browning seems to exist, it is still unclear whether maturity levels are the actual contributing factor. The aim of the study was to establish if harvest maturity and crop load could influence the occurrence of browning of both cultivars. The impact of harvest maturity and crop load on phenolic compound concentration in the berry skin of both cultivars was also investigated. Total external browning of Regal Seedless and Thompson Seedless occurred in much higher percentages than internal browning. Regal Seedless showed a tendency to decreased total external browning with harvest maturity. The main reason for this is that net-like browning, which is the greatest contributor to total external browning, decreased with harvest maturity, in all three seasons. External browning of Thompson Seedless increased with harvest maturity in both seasons. Contact browning was the greatest contributor to total external browning of Thompson Seedless. Crop load did not significantly influence berry browning of Regal Seedless or Thompson Seedless grapes. The flavan-3-ol concentration (catechin, epicatechin, procyanidin B1 and procyanidin B2) in Regal Seedless generally increased with harvest maturity, whereas in Thompson Seedless the general tendency was a decrease in the flavan-3-ol concentration with harvest maturity. The development of phenolic compound concentration with maturity could not be correlated with the occurrence of berry browning. Crop load did not affect flavan-3-ol concentration. When the flavan-3-ol concentration of Regal Seedless and Thompson Seedless were compared at different harvest maturities the concentrations of flavan-3-ols were clearly much higher in the skin of Regal Seedless than in the skin of Thompson Seedless (for both the 2008 & 2009 seasons). Comparison of the browning incidence with harvest maturity for these two cultivars (see above) clearly reveals that external browning of Regal Seedless occurred in much higher percentages than on Thompson Seedless. Regal Seedless had much higher levels of external browning than Thompson Seedless. The concentration of flavan-3-ols in the skin of white seedless cultivars may be an indication of the cultivar’s susceptibility to external browning. / AFRIKAANSE OPSOMMING: Thompson Seedless en Regal Seedless is twee wit pitlose tafeldruif kultivars wat ekstensief in Suid-Afrika verbou word. Verbruining kan ‘n probleem wees by beide kultivars, spesifiek Regal Seedless. Die faktore wat aanleiding gee tot verbruining is nog nie duidelik bepaal nie. Alhoewel dit lyk of daar ‘n korrelasie tussen rypheidsgraad van die oes en verbruining kan wees is dit steeds onduidelik of oesrypheidsvlakke die werklike oorsaak van verbruining is. Die doel van die studie was om vas te stel of die rypheidsgraad van die oes en oeslading verbruining van beide kultivars kan beïnvloed. Die effek van oes rypheidsgraad en oeslading op konsentrasie van fenoliese verbindings in die korrelskil van beide kultivars is ook ondersoek. Totale eksterne verbruining van Regal Seedless en Thompson Seedless het in baie hoër persentasies voorgekom as interne verbruining. Daar was ‘n tendens by Regal Seedless dat totale eksterne verbruining verminder het soos die oes ryper geraak het as gevolg van netagtige verbruining, wat die grootste bydrae tot totale eksterne verbruining veroorsaak het. Netagtige verbruining se voorkoms het verminder oor al drie seisoene. Eksterne verbruining van Thompson Seedless het toegeneem met oes rypheid in beide seisoene. Kontak verbruining het grootste byrdae gelewer tot totale eksterne verbruining van Thompson Seedless. Oeslading het nie ‘n betekenisvolle invloed op verbruining van Regal Seedless en Thompson Seedless gehad nie. Die flavan-3-ol (katesjien, epikatesjien, prosianidien B1 en prosianidien B2) konsentrasie van Regal Seedless het met oes rypheid toegeneem. By Thompson Seedless was daar ‘n afname in die flavan-3-ol konsentrasie met oes rypheid. Daar was geen korrrelasie tussen die konsentrasie van fenoliese verbinding en die voorkoms van verbruining vir beide kultivars. Oeslading het nie ‘n betekenisvolle effek op die konsentrasie van fenoliese verbindings gehad nie. Vergelyking van die flavan-3-ol konsentrasie van Regal Seedless en Thompson Seedless by verskillende rypheidsgrade wys dat die konsentrasie baie hoër in die korrel skil van Regal Seedless as in die van Thompson Seedless (vir beide 2008 & 2009 seisoene). Die vergelyking van die voorkoms van verbruining met oesrypheid van beide kultivars wys duidelik dat eksterne verbruining van Regal Seedless in baie hoër persentasies voorkom as in Thompson Seedless. Flavan-3-ol konsentrasie in die skil van wit pitlose kultivars kan ‘n aanduiding wees van die kultivar se moontlike risiko vir die voorkoms van eksterne verbruining.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: ‘Triumph’ persimmon production in South Africa is export driven and the profitability of the industry is largely dependent on consumer demand and supermarket shelf space in the European market. In order to realise high returns, it is important to advance harvest maturity to attain early fruit that arrives on the market prior to European summer fruits. In addition, market feedback suggests that fruit picked during the second half of the harvesting period stores poorly and rapidly softens during shelf life. It is important to establish whether this is the case. The effect of paclobutrazol (PBZ) application rate on fruit maturity and keeping quality, return bloom and vegetative growth was investigated over two seasons. Advanced harvest maturity was attained at a compromise of reduced fruit storage quality and stunted growth with the severity of the compromise increasing with increasing PBZ application rate. To advance harvest maturity while maintaining acceptable keeping quality, PBZ application at 0.75 ml per plant is recommended although effects on harvest maturity will not persist into the subsequent season as found at higher application rates. Prohexadione-calcium (P-Ca) as an alternative for PBZ in advancing harvest maturity was evaluated over two seasons. A positive response to three foliar applications of P-Ca at 200 mg·L-1 was noticed in the first season. In the second season, a single application of P-Ca at 300 mg·L-1 two weeks before harvest significantly advanced harvest maturity. Due to the rapid metabolism of P-Ca in the plant, it is unlikely that growth in the subsequent season will be affected. Based on these results, the persimmon industry will undertake commercial trials in the 2012 season to further assess the efficacy of P-Ca application in advancing harvest maturity. The effect of various rest breaking agents (RBAs) on bud break, flowering, fruit maturity and quality as well as vegetative growth was assessed for one season. RBAs did not increase or advance bud break and flowering. Consequently, yield and harvest maturity were unaffected by the treatments. The ineffectiveness of the RBAs could be due to the low application rates used or the fulfilment of the chilling requirement prior to treatment application. An experiment was carried out to determine whether storability and shelf-life differ between “early” and “late” production areas in South Africa as well as between orchards within these areas. The data indicated that fruit colour is a good maturity parameter and indicator of fruit storability. However, “late” fruit were about 1 kg softer than “early” fruit at the same colour chart value. We therefore recommend that fruit from late regions are harvested at colour chart values of 5 and 6 (yellow-green) instead of 3 and 4. Fruit from “late” orchards as well as GA3-treated fruit with a colour chart value of 3 and less should be culled due to the high propensity (>20%) of these fruit to become soft during storage and shelf life. A delay in 1-MCP treatment and interruption of the cold chain considerably increased fruit softening during storage and shelf-life. Further research is required to verify this result. / AFRIKAANSE OPSOMMING: ‘Triumph’ persimmon produksie in Suid-Afrika is uitvoergedrewe en die winsgewendheid van die bedryf is grootliks afhanklik van verbruikervraag en supermark spasie in die Europese mark. Ten einde hoë pryse te realiseer, is dit belangrik om ʼn vroeë oes te verkry sodat vrugte voor die Europese somervrugte op die mark beland. Mark terugvoer dui verder daarop dat vrugte wat tydens die tweede helfte van die oesperiode gepluk word, swakker opberg en vinnig sag word gedurende op die rak. Dit is belangrik om vas te stel of hierdie waarneming juis is. Die effek van paklobutrazol (PBZ) toedieningshoeveelheid op vrugrypwording en - houvermoë, opvolgblom en vegetatiewe groei is oor twee seisoene ondersoek. Oesrypheid is vervroeg, maar tot nadeel van vrughouvermoë en vegetatiewe groei. Die omvang van die negatiewe effekte van PBZ het toegeneem met ʼn toename in toedieningshoeveelheid. Ten einde oesrypheid te vervroeg terwyl aanvaarbare houvermoë behou word, word toediening van PBZ teen 0.75 ml per plant aanbeveel alhoewel die effek op oesrypheid anders as die geval met hoër toedieningshoeveelhede nie in die opeenvolgende seisoen sal voortduur nie. Proheksadioon-kalsium (P-Ca) as alternatief tot PBZ om oesrypheid te vervroeg is oor twee seisoene gee-valueer. ʼn Positiewe effek op vrugrypwording is in die eerste seisoen verkry met drie blaartoedienings van P-Ca teen 200 mg·L-1. In die tweede seisoen is oesrypheid betekenisvol vervroeg deur ʼn enkel toediening van 300 mg·L-1 P-Ca ʼn maand voor oes. Vanweë hierdie resultate gaan die persimmonbedryf in die 2012 seisoen kommersiële proewe onderneem om die effektiwiteit van P-Ca om oes te vervroeg, verder te ondersoek. Die effek van verskeie rusbrekende middels (RBAs) op bot, blom, vrugrypheid, vrugkwaliteit en vegetatiewe groei is vir een seisoen ondersoek. RBAs het bot en blom vervroeg of vermeerder nie en het daarom ook geen effek op produksie en oesrypheid gehad nie. Die oneffektiwiteit van die RBAs kan moontlik toegeskryf word aan die lae toedieningsvlakke wat gebruik is of aan die kouebehoefte wat bevredig is voor toediening van RBAs. ʼn Eksperiment is gedoen om vas te stel of die opberging- en houvermoë van vrugte verskil tussen “vroeë” en “laat” produksieareas in Suid-Afrika en ook tussen boorde in hierdie areas. Die data dui daarop dat vrugkleur ʼn goeie rypheidsparameter en indikator van opbergingsvermoë is. Vrugte van laat areas was egter omtrent 1 kg sagter as vrugte van vroeë areas van dieselfde kleur. Ons beveel gevolglik aan dat vrugte van laat areas by ʼn kleurkaartwaarde van 5 tot 6 (geelgroen) geoes word eerder as by 3 tot 4. Vrugte van laat boorde sowel as vrugte wat met GA3 behandel is met ʼn kleurkaartwaarde van 3 en laer moet afgradeer word weens die hoë geneigdheid (>20%) van hierdie vrugte om sag te word tydens opberging en op die rak. Uitstel van 1-MCP behandeling en die onderbreking van die koueketting veroorsaak ʼn aansienlike toename in sagte vrugte tydens opberging en op die rak. Verdere navorsing word benodig om hierdie resultaat te verifieer.

Thesis (MScAgric (Horticulture))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT: Climatic differences between production areas or seasons directly affect the rate of fruit maturation and the eating quality following storage and ripening. South African ‘Forelle’ pears are harvested at an optimum firmness of 6.4 kg and have mandatory cold storage duration of 12 weeks at -0.5°C to ensure even ripening. The firmness variable alone, however, is not a good indicator of ripening potential. Hence, various maturity variables (ethylene production, ground colour, firmness, total soluble solids (TSS) titratable acidity (TA), and starch breakdown) and their rates of change were evaluated to identify consistent maturity indices that can be reliably used in a prediction model to determine optimum harvest maturity (Chapter 2). This was then related to the ripening potential (Chapter 3) and eating quality (Chapter 4), defined by optimum ‘edible firmness’ (3.5 kg), presence or absence of astringency or mealiness. Fruit were harvested from three main producing areas: Warm Bokkeveld (WBV), Elgin and Koue Bokkeveld (KBV). Harvesting was done biweekly on five harvest dates over three successive seasons (2007-2009). At harvest, 20 of 240 fruit per block were used to determine maturity using all the mentioned parameters in order to understand their changes and behaviour pre-harvest. The remaining 220 fruit were stored at -0.5°C for three storage durations followed by ripening at 15°C. At harvest, the 2007 season’s fruit were more advanced in ground colour and were significantly softer (6.7 kg) than the 2008 (7.0 kg) and 2009 (7.1 kg) seasons. Firmness, ground colour, TSS and TA, all displayed a linear relationship with days after full bloom. For the firmness and ground colour, more than 90% and 73%, respectively, was explained by the variation in the linear model, while for the TSS and TA less than 70% could be accounted for by the model. Fruit harvested before commercial harvest (pre-optimum) in 2007 and 2009 failed to ripen to an ‘edible firmness’ when stored for eight weeks at -0.5oC plus 11 days at 15oC. In 2008, eight weeks storage was sufficient to induce ripening changes in pre-optimum harvested fruit. The development of ripening potential in the 2008 earlier harvested fruit, corresponded with a higher rate of change (3.15 µL.kg-1.h-1.day-1) in ethylene production at 15oC compared to the 2007 (1.98 µL.kg-1.h-1.day-1) and 2009 (1.87 µL.kg-1.h-1.day-1) seasons. The 2007 season fruit experienced maximum incidence of astringency (36.7%) on the first harvested fruit. In all three seasons, fruit harvested at commercial harvest time and later (optimum and post-optimum), required an eight week storage period to induce ripening. However, the eight weeks storage period developed highest mealiness. More than 40% of the last harvested fruit were mealy after eight weeks at -0.5°C plus seven days at 15°C. Mealiness significantly reduced with prolonged storage at -0.5°C. Fruit from the WBV and Elgin, warmer areas than the KBV, were more prone to mealiness. In conclusion, firmness was the most consistent variable at harvest and could be used in conjunction with ground colour to determine ‘Forelle’ harvest maturity. Furthermore, the study does not support shortening the current mandatory 12 weeks period at -0.5°C due to the higher incidence of astringency and mealiness. / AFRIKAANSE OPSOMMING: Klimaats verskille tussen produksie areas of seisoene affekteer die tempo van vrugrypwording en eetkwaliteit na opberging en rypwording direk. Suid-Afrikaanse ‘Forelle’ word ge-oes by ‘n optimum fermheid van 6.4 kg en het ‘n verpligte opbergingstydperk van 12 weke by -0.5°C om egalige rypwording te verseker. Die veranderlike ‘fermheid’ is egter nie ‘n goeie aanduiding van die rypheidspotensiaal op sy eie nie. Dus is verskeie rypheidsparameters (etileen produksie, agtergrond kleur, fermheid, total oplosbare vaste stowwe (TOVS), titreerbare suur (TS) en stysel afbraak) en die tempo van verandering ge-evalueer om konstante rypheidsverwysings te identifiseer wat met vertroue in ‘n voorspellingsmodel gebruik kan word om optimum oes rypheid te kan bepaal (Hoofstuk 2). Dit is dan in verband gebring met die rypwordingspotensiaal (Hoofstuk 3) en eetgehalte (Hoofstuk 4), wat gedefiniëer is deur “eetbare fermheid” (3.5 kg), frankheid en melerigheid. Vrugte is ge-oes uit drie, hoof verbouingsareas: Warm Bokkeveld (WBV), Elgin en Koue Bokkeveld (KBV). By oes is 20 van die 240 vrugte per blok gebruik om die vrug rypheid te bepaal, deur al die bogenoemde parameters te gebruik, om die verandering en reaksie voor oes te begryp. Die oorblywende 220 vrugte is opgeberg by -0.5°C vir drie opbergingstye, gevolg deur rypmaking by 15°C. By oes was die vrugte van die 2007 seisoen verder gevorderd in agtergrond kleur en betekenisvol sagter (6.7 kg) as die van 2008 (7 kg) en 2009 (7.1 kg). Fermheid, agtergrond kleur, TOVS en TS het almal ‘n lineêre verband getoon met dae na volblom. In geval van fermheid en agtergrond kleur, is meer as onderskeidelik 90% en 73% verklaar deur die variasie in die lineêre model, terwyl in geval van die TOVS en TS, minder as 70% deur die model verklaar kon word. Vrugte wat voor die kommersiële oes (pre-optimum) ge-oes is in 2007 en 2009, het nie daarin geslaag om ryp te word tot by ‘eetbare fermheid’ na ag weke by -0.5°C en 11 dae by 15°C nie. Daarteenoor kon vrugte wat pre-optimum ge-oes is in 2008, wel geïnduseer word om ryp te word met ag weke opbeging. Die ontwikkeling van die rypwordingspotensiaal van vrugte wat vroeër ge-oes is, stem ooreen met die hoër tempo van verandering (3.15 µL.kg-1.h-1.dag-1) in etileen produksie by 15°C in vergelyking met seisoene 2007 (1.98 µL.kg-1.h-1.dag-1) en 2009(1.87 µL.kg-1.h-1.dag-1). Die 2007 seisoen vrugte het die maksimum voorkoms van frankheid (36.7%) getoon vir vrugte van die eerste oes datum. In al drie seisoene waar vrugte wat by kommersiële oes of later (optimum en post optimum) ge-oes is, was ‘n ag weke periode van opgeberging voldoende om rypwording te inisiëer, alhoewel die ag weke opberging ook gelei tot die hoogste voorkoms van melerigheid. Meer as 40% van die laat ge-oeste vrugte was melering na ag weke opberging by -0.5°C en sewe dae by 15°C. Melerigheid is betekenisvol verlaag met ‘n verlengde opbergingsperiode by -0.5°C. Vrugte vanaf die WBV en Elgin, warmer areas as die KBV, was meer onderhewig aan melerigheid. Opsommend was fermheid die reëlmatigste veranderlike by oes en kan tesame met agtergrondkleur, gebruik word om vrugrypheid van ‘Forelle’ te bepaal. Verder het die studie nie ‘n verkorting van die huidige, verpligte 12 week opberingsperiode by -0.5°C gesteun nie, weens die hoë voorkoms van frankheid en melerigheid.

Der Verzehr von Pflaumen ist derzeit sehr gering. Häufig wird unbefriedigende Fruchtqualität aufgrund unreif geernteter Früchte als Ursache genannt. Um eine hohe Fruchtqualität zu erzeugen ist es nötig, Vorerntebedingungen wie Fruchtbehang und Bodeneigenschaften optimal zu gestalten und die Früchte im richtigen Reifestadium zu ernten. Die Ziele dieses Projektes waren daher 1. die Untersuchung des Einflusses und interaktiver Effekte von Bodeneigenschaften, Fruchtbehang und Baumwasserzustand auf die Qualität von ''Jojo'' und ''Tophit plus'' Pflaumen. 2. den Effekt unterschiedlicher Pflücktermine auf die innere und äußere Fruchtqualität zu bewerten. 3. das Potenzial der Laserlichtrückstreubildanalyse als neues zerstörungsfreies Verfahren zur Bewertung der Fruchtqualität abzuschätzen. Die Untersuchungen wurden 2011 bis 2013 durchgeführt. Zur Bewertung der Vorernteeinflüsse wurden Früchte dreimal vor sowie am kommerziellen Erntetermin geerntet und im Labor untersucht. Dann wurden sie für 28 Tage bei 2°C und zusätzlich 2 Tage bei 20°C bei 90% rF gelagert. Während dieser Zeit wurden Früchte jeder Behandlungsgruppe nach 0, 7, 14, 21, 28 und 30 Tagen analysiert. Früchte von Bäumen mit geringerem Fruchtbehang von Böden mit geringen ECa Werten wiesen die höchsten SSC und Trockenmassegehalte, solche von Bäumen mit geringem Fruchtbehang und von Böden mit hohem ECa die höchste Frischmasse auf. Gut wasserversorgte Bäume hatten niedrigere Fruchterträge, ihre Früchte transpirierten verstärkt und hatten geringere Zucker- und Trockenmassegehalte als Pflaumen von Bäumen mit schlechter Wasserversorgung. Die späten Ernte von ''Jojo'' Pflaumen, vorzugsweise ca. 137 Tage nach der Vollblüte, ergab die beste Fruchtqualität. Diese Früchte besaßen die höchste Frischmasse und die geringste Transpiration. Laserlichtrückstreumessungen bei 532 und 785 nm zeigten, dass diese zerstörungsfreie Methode für die Analyse von Qualitätsparametern wie Anthocyangehalt und Fruchtfleischfestigkeit gut geeignet ist. / Plum consumption does not meet its potential, most probably because of a non-uniform fruit quality and lack of fully-mature fruit. It is necessary to manage preharvest conditions such as crop load and soil properties optimally in order to obtain high quality plums and to harvest the fruit in ripe stage. In this study, (1) the effects of soil ECa, crop load and maximum daily trunk shrinkage (MDS) on various fruit quality parameters of two European plum cultivars ''Jojo'' und ''Tophit plus'') (2) the internal and external fruit quality as it relates to harvest time were investigated. The investigation of plums was carried out in an experimental orchard in 2011, 2012 and 2013. Fruit of selected trees were sampled and subjected to laboratory measurements three times before and at the commercial harvest. At the commercial harvest, plums were stored at 2 °C and 90% RH for up to 28 days plus 2 days at 20 °C. During storage, fruit of each treatment were sampled after 0, 7, 14, 21, 28 and 30 days in order to analyse the physicochemical quality. In addition, the optical properties of samples were non-destructively evaluated through laser light backscattering imaging (LLBI). Fruit from low crop load trees grown under low ECa had the highest SSC and dry matter content, while those from low crop load trees under high ECa showed the highest fresh mass in 2013. Moreover, low MDS trees had lower total fruit yield, and fruit had higher transpiration, lower SSC, and dry matter content than those grown on trees with high MDS. Fruit quality was best when plums had been harvested late, preferably at the 3rd harvest date (137 DAFB) in this study. These fruit had the highest fresh mass and lowest transpiration. Furthermore, the results of LLBI measured at 532 nm and 785 nm showed an encouraging potential to predict quality parameters of plums such as anthocyanin content and fruit firmness.

There has been increased interest in utilizing switchgrass (Panicum virgatum) as biomass. There are several challenges to developing this industry, and these have led to the potential use of switchgrass as hay for feeding beef cattle in Kentucky. The effect of increasing maturity on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and nutritive values of switchgrass hay has been well documented, but few in vivo intake and digestibility trials have been conducted to assess this effect on animal performance when feeding beef cattle. Two in vivo intake and digestibility trials were conducted in 2011 in which Angus x Hereford beef steers (200-265 kg) were fed Alamo and Cave-in-Rock switchgrass harvested as late vegetative, boot, and early flowering hay. The objectives of these trials was to evaluate the effect of increasing maturity on apparent dry matter intake (DMI), digestible dry matter intake (DDMI), and dry matter digestibility (DMD); and to discuss potential challenges that producers might face if incorporating switchgrass hay into their forage program for feeding beef cattle. Observed decreases in nutritive value, DMI, DDMI, and DMD indicate that producers should harvest Alamo and Cave-in-Rock switchgrass before it reaches the boot stage of maturity.