Photosynthesis Inhibition as a Tool for Apple Fruitlet Thinning

The possible mechanisms of apple fruitlet abscission are presented in this paper. Prevailing hypothesis on hormonal triggered processes in the event of “correlative dominance effects” of adjacent fruitlets or nearby shoot tips has the opponent theory of assimilate supply dependent fruitlet abscission. Assimilation shortage may also be involved in the correlative auxin processes but the connections of both statements are not clear yet. On last years a lot of evidence is provided in support of assimilation dependent fruitlet abscission process. At the time just after the end of the flowering, a strong competition between fruitlets and shoots for photosynthates exist. Shading experiments comparable for a few days of cloudy weather provoked strong natural apple fruitlet abscission. If the applications of chemical thinners are followed by a few days of shading, much stronger abscission occurs comparing to thinner applications without shade. A photosynthesis inhibitor metamitron has gone into registration for fruitlet thinning purpose and is available in Europe last year. A good thinning results can be achieved up to 14 mm king fruit diameter, but additional studies should be made to adapt dosage for the present and predicted light intensity at the time just after metamitron application

Prorjeđivanje plodova jabuke sorte \u27Gala\u27 pomoću ethephona, NAA i BA te njihovih kombinacija

The thinning response was studied on six years old trees of ‘Gala’/M.9. The treatments of single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter as well as the sequential treatments of ethephon followed by NAA or/and BA and tank mixed NAA + BA treatment were performed. A non significant thinning was obtained in treatments when ethephon, NAA and BA were used separately. No additional thinning occurred even in the combinations when ethephon was applied first at the balloon stage and NAA or BA applied later at 10 mm fruitlet diameter. Significant thinning response occurred only when tank mixed treatment of NAA + BA and sequential treatment of ethephon followed by tank mixture of NAA + BA were carried out. In this experiment, mean fruit weight and the share of bigger sized fruits (>70mm) increased significantly in all thinning treatments compared to the non thinned control trees.Proučavali smo odaziv prorjeđivanja na šest godina starim stablima sorte \u27Gala\u27/M.9. Izvedeni su postupci pojedinačnih aplikacija etefona 200 ppm u fenofazi crvene glavice, naftiloctene kiseline (NAA) 10 ppm ili benziladenina (BA) 100 ppm kada je promjer ploda iznosio 10 mm kao i uzastopni postupci etefonom nakon čega je slijedila NAA, odnosno BA ili u tanku pomiješani NAA + BA. Prorjeđivanje nije bilo signifikantno kod postupaka, u kojima su etefon, NAA i BA primijenjeni pojedinačno. Do dodatnog prorjeđivanja nije došlo ni u postupcima kada je etefon primijenjen najprije u balonskom stadiju, a NAA ili BA primijenjeni kasnije, kada je promjer plodova iznosio 10 mm. Signifikantan odaziv na prorjeđivanje dogodio se samo kada je izveden postupak s u tanku pomiješanim NAA + BA i uzastopni postupak etefonom nakon čega su slijedili u tanku pomiješani NAA + BA. U tom pokusu prosječna težina plodova i udio većih plodova (> 70 mm) signifikantno su se povećali kod svih postupaka prorjeđivanja u usporedbi s neprorjeđivanim stablima kontrole

Metabolomic Profiling and Sensorial Quality of ‘Golden Delicious’, ‘Liberty’, ‘Santana’, and ‘Topaz’ Apples Grown Using Organic and Integrated Production Systems

Apple quality was investigated in the scab-resistant ‘Liberty’, ‘Santana’, and ‘Topaz’ cultivars and the scab-susceptible ‘Golden Delicious’ cultivar. Trees subjected to the same crop load were cultivated using either an organic (ORG) or an integrated production (IP) system. Physicochemical properties, phenolic content, and sensorial quality of fruit from both systems were compared. There were no significant differences in fruit mass, starch, and total soluble solid content (the latter was higher in ORG ‘Liberty’) between ORG and IP fruit, whereas significantly higher flesh firmness was found in ORG fruit (except no difference in ‘Golden Delicious’). Significantly higher total phenolic content in ORG fruit was found in ‘Golden Delicious’, whereas differences in other cultivars were not significant. Targeted metabolomic profiling of multiple classes of phenolics confirmed the impact of the production system on the ‘Golden Delicious’ phenolic profile as higher levels of 4-hydroxybenzoic acid, neo- and chlorogenic acids, phloridzin, procyanidin B2+B4, -3-O-glucoside and -3-O-galactoside of quercetin, kaempferol-3-O-rutinoside, and rutin being found in ORG fruit. The results obtained suggested that scab resistance influenced the phenolic biosynthesis in relation to the agricultural system. Sensorial evaluation indicated significantly better flavor (except for ‘Topaz’) and better appearance of IP frui

Prorjeđivanje plodova jabuke sorte \u27Gala\u27 pomoću ethephona, NAA i BA te njihovih kombinacija

The thinning response was studied on six years old trees of ‘Gala’/M.9. The treatments of single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter as well as the sequential treatments of ethephon followed by NAA or/and BA and tank mixed NAA + BA treatment were performed. A non significant thinning was obtained in treatments when ethephon, NAA and BA were used separately. No additional thinning occurred even in the combinations when ethephon was applied first at the balloon stage and NAA or BA applied later at 10 mm fruitlet diameter. Significant thinning response occurred only when tank mixed treatment of NAA + BA and sequential treatment of ethephon followed by tank mixture of NAA + BA were carried out. In this experiment, mean fruit weight and the share of bigger sized fruits (>70mm) increased significantly in all thinning treatments compared to the non thinned control trees.Proučavali smo odaziv prorjeđivanja na šest godina starim stablima sorte \u27Gala\u27/M.9. Izvedeni su postupci pojedinačnih aplikacija etefona 200 ppm u fenofazi crvene glavice, naftiloctene kiseline (NAA) 10 ppm ili benziladenina (BA) 100 ppm kada je promjer ploda iznosio 10 mm kao i uzastopni postupci etefonom nakon čega je slijedila NAA, odnosno BA ili u tanku pomiješani NAA + BA. Prorjeđivanje nije bilo signifikantno kod postupaka, u kojima su etefon, NAA i BA primijenjeni pojedinačno. Do dodatnog prorjeđivanja nije došlo ni u postupcima kada je etefon primijenjen najprije u balonskom stadiju, a NAA ili BA primijenjeni kasnije, kada je promjer plodova iznosio 10 mm. Signifikantan odaziv na prorjeđivanje dogodio se samo kada je izveden postupak s u tanku pomiješanim NAA + BA i uzastopni postupak etefonom nakon čega su slijedili u tanku pomiješani NAA + BA. U tom pokusu prosječna težina plodova i udio većih plodova (> 70 mm) signifikantno su se povećali kod svih postupaka prorjeđivanja u usporedbi s neprorjeđivanim stablima kontrole

REDČENJE PLODIČEV JABLANE PRI SORTI ‘ZLATI DELIŠES’ Z UPORABO ETEFONA, NAA IN BA TER NJIHOVIH KOMBINACIJ

Thinning of ‘Golden Delicious’ apples was studied after single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter, after sequential application of ethephon followed by NAA or/and BA or tank mixed NAA + BA application. The single application of ethephon, NAA or BA, as well as the sequential application of ethephon applied fi rst at the balloon stage and NAA or BA applied at 10 mm fruitlet diameter did not cause a signifi cant reduction of fi nal crop load nor did it cause an increase of the mean fruit weight. The treatment of tank mixed application NAA + BA at 10 mm fruit diameter and, similarly, the treatment of sequential spray of ethephon followed by tank mixture of NAA + BA had both a signifi cant effect on thinning in the studied year with the signifi cant reduction of fi nal fruit retention and the signifi cant enhancement of fruit weight. No additional thinning due to the ethephon application happened in the sequential treatments when ethephon was applied fi rst and NAA + BA mixture was applied afterward.Proučevali smo redčenje plodičev jablane pri sorti ‘Zlati delišes’ pri samostojni aplikaciji sredstev za redčenje plodičev (etefon 200 ppm v stadiju balona, NAA 10 ppm ali BA 100 ppm v stadiju velikosti plodičev 10 mm) ter pri kombiniranih aplikacijah sredstev, kjer je bil najprej apliciran etefon, nato pa še NAA ali BA, kjer sta bila NAA in BA združena v škropilni mešanici in kjer je aplikaciji etefona nato sledila še aplikacija NAA in BA združena v škropilni mešanici. Samostojna aplikacija etefona 200 ppm v stadiju balona, kakor tudi samostojna aplikacija NAA 10 ppm oziroma BA 100 ppm v stadiju velikosti plodičev 10 mm ni imela statistično značilnega vpliva na redčenje plodičev, ker ni povzročila značilnega zmanjšanja števila plodov ob obiranju, kakor tudi ne značilnega povečanja velikosti plodov. Podoben rezultat brez statistično značilnega učinka na redčenje plodičev je bil dobljen pri obravnavanjih s kombinacijo sredstev, kjer je bil najprej apliciran etefon v balonskem stadiju, nato pa še NAA oziroma BA pri velikosti plodičev 10 mm. Edini statistično značilen vpliv na redčenje plodičev je bil dosežen pri obravnavanju, kjer so bila sredstva NAA in BA nanešena skupaj kot škropilna mešanica pri velikosti plodičev 10 mm, kakor tudi pri obravnavanju z zaporedno kombinacijo sredstev, najprej etefona, nato pa NAA + BA v škropilni mešanici. Iz rezultatov kombiniranih nanosov je razvidno, da predhodni nanos etefona v času cvetenja ni imel vpliva na kasnejša redčenja z NAA ali BA, niti kadar sta bila nanešena samostojno, niti kadar sta bila nanešena kot škropilna mešanica

Učinkovitost aerosolne škatle za preprečevanje okužb pri posegih, pri katerih nastajajo aerosoli

Izpostavljenost okužbi zdravstvenih delavcev zaradi pandemije covida-19 je privedla do razvoja novih oblik osebne varovalne opreme. Ena od njih je aerosolna škatla, ki je bila zasnovana z idejo, kako varneje vstaviti dihalno cevko v sapnik bolnikom, okuženim z virusom SARS-CoV2. Uporaba aerosolne škatle ne sega samo v področje anesteziologije, ampak tudi v druga področja medicine. Številne kritike na račun prvotne zasnove so vodile v izdelavo novih oblik, ki postopoma izboljšujejo prvotne pomanjkljivosti. Razvoj se usmerja predvsem v okoliščino, kako zmanjšati oviranost kirurga (ali izvajalca) pri posegih ter kako zagotoviti varnejšo, enostavnejšo in hitrejšo možnost uporabe. Številnim avtorjem je uspelo pokazati, da uporaba aerosolne škatle pomembno vpliva na hitrost vstavitve dihalne cevke v sapnik, zato v urgentnih primerih odsvetujejo uporabo aerosolne škatle. Ob primerni uporabi ter ustreznem urjenju zdravstvenega delavca pa se je izkazala kot učinkovita osebna varovalna oprema, ker zdravstvene delavce dobro zaščiti pred velikimi in majhnimi vodnimi kapljicami. Pravilno posodobljena oblika aerosolne škatle dobro varuje tudi pred aerosolnimi delci, medtem ko uporaba izvorne oblike lahko tveganje za okužbo zdravstvenega delavca z aerosolnimi delci še poveča

THINNING ‘GOLDEN DELICIOUS’ APPLES USING SINGLE OR COMBINING APPLICATION OF ETHEPHON, NAA OR BA

Thinning of ‘Golden Delicious’ apples was studied after single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter, after sequential application of ethephon followed by NAA or/and BA or tank mixed NAA + BA application. The single application of ethephon, NAA or BA, as well as the sequential application of ethephon applied fi rst at the balloon stage and NAA or BA applied at 10 mm fruitlet diameter did not cause a signifi cant reduction of fi nal crop load nor did it cause an increase of the mean fruit weight. The treatment of tank mixed application NAA + BA at 10 mm fruit diameter and, similarly, the treatment of sequential spray of ethephon followed by tank mixture of NAA + BA had both a signifi cant effect on thinning in the studied year with the signifi cant reduction of fi nal fruit retention and the signifi cant enhancement of fruit weight. No additional thinning due to the ethephon application happened in the sequential treatments when ethephon was applied fi rst and NAA + BA mixture was applied afterward

Comparison of metamitron efficiency for postbloom thinning of young 'Gala' and 'Golden Delicious' apple trees

The aim of this study was to evaluate the thinning efficacy of metamitron applied either alone (single or double application) or in combination with 6-benzyladenine (BA) or naphthalene acetic acid (NAA) in young 'Gala' and 'Golden Delicious' apple trees. The experiment was carried out during the first three crop seasons, 2014, 2015, and 2016, at the commercial orchard located on the mountain Fruska Gora, Serbia. Application of chemical thinners was carried out at two fruit diameter stages (6-9 and 12-15 mm). The number of fruit and yield per tree, fruit size distribution, parameters of fruit ripeness, and return bloom were assessed. Single metamitron treatments were effective when the weather conditions were favourable on the day of application and 3 days after (minimum night temperature >10 degrees C, maximum daily temperature >20 degrees C) regardless of fruit diameter stages. A reduction in fruit number per tree was followed by an increase in mean fruit weight. Double metamitron application at lower concentration caused relatively stable thinning activity during the whole experimental period in both cultivars tested. Metamitron combined with either BA or NAA at standard rates significantly reduced the negative influence of low temperature on metamitron thinning activity in the first experimental year. These treatments slightly influenced overthinning in 'Gala' trees if applied when the air temperature was too high minimum night temperature >15 degrees C, maximum daily temperature >25 degrees C). Repeated metamitron treatment and treatments in which metamitron was combined with BA and NAA resulted in an increase in fruit size and share of large fruit in the total yield during the whole experimental period in both cultivars tested. A reduction in fruit number per tree affected by these treatments was followed by increasing flowering intensity in the subsequent year, with the exception of double metamitron application to 'Golden Delicious' trees in the last experimental year. Fruit maturity parameters were slightly different under the influence of metamitron treatments