Peaches

SUMMARY
Thirty strains of bacteria were evaluated for their
effect on germination and growth of lettuce (Lactuca
sativa L. var. Longifolia). For germination, highly
significant differences were found among the effects of
the treatments. The strain Hafnia alvei P-3 increased
germination more than 36.5% relative to the control. In
contrast, the Pseudomonas aeruginosa strains 7PS and
11PS inhibited germination. The growth of the plant
was promoted by all of the inoculating strains except
H. alvei P-25, which had the same effect as the control. The largest effect on growth was obtained
with the RIB strain (unidentified), which increased
fresh weight by 277%, dry weight by 371%, leaf area
by 240% and root volume by 300%. The results
suggest that the growth-promoting bacteria are
potentially useful in the production of vegetable
seedlings.

Index words: Rhizosphere, rhizobacteria, isolation,
propagation.

In the present work, chilling injury (CI) incidence and quality parameters were analyzed in peaches stored at 0 °C, 2 °C, 5 °C and 8 °C for 28 days, to evaluate the effects of four different temperatures on the keeping quality of 'Okubao' peach. The extreme susceptibility of 'Okubao' peach to CI at 5 °C was confirmed by extensive woolliness and decay. Peaches stored at 5 °C develop noticeable CI symptom after one to two weeks, while significantly less woolliness occurred after storage 8 °C, the temperature at which the highest rate of decay was found. Minimum loss of weight and firmness, optimum sensory quality were obtained by the prolonged storage at 0 °C. 0 °C was the most effective treatment in alleviating chilling injury by controlling membrane permeability, inhibiting respiration rate and slowing down polyphenol oxidase (PPO) and peroxidase (POD) activities. Results indicated that fruit held at 0 °C can be stored for at least four weeks, and possibly five weeks without much injury.

The effect of red photoselective net on yield per tree (g), yield efficiency (g·cm-2) leaf surface (cm2), fruit diameter (mm), fruit mass (g), fruit firmness (kg·cm-2) and soluble solids concentration (SSC) (%Brix) on young peach (‘Sugar Time’) and nectarine (‘Big Bang’) trees was studied. No significant differences were recorded for yield, yield efficiency and SSC on peach as well for all fruit quality parameters on nectarine.
Both peach and nectarine trees grown under red net had significantly higher leaf surface (37.82 and 40.72 cm2, respectively) than in control (23.85 and 26.14 cm2, respectively). Peach fruits grown under red net had significantly higher fruit diameter (70.97 mm), fruit mass (163.73 g) and lower fruit firmness (2.12 kg·cm-2) than in control (65.24 mm, 135.84 g, and 3.04 kg·cm-2, respectively). It was concluded that red
photoselective net has a positive effect on vegetative growth of peach and nectarine, and on majority of fruit quality parameters of peach, while on nectarine fruit quality there are no evident differences. Further research must be continued to verify these preliminary findings.

Since 2007, an orchard of old fruit varieties has been developed at the village of Kojsko in the Goriška Brda region, designed by Gregor Božič, a young film director. It is conceived as a genetic bank, which enables preservation and dissemination of indigenous fruit varieties. It currently comprises about a hundred and fifty standard-size trees of various ages (from seventy to three years) and over a hundred varieties of cherries, apricots, figs, peaches, plums, pears and apples. Deliberately selected old varieties that are fairly resistant to diseases and have commercially interesting characteristics have been planted. The orchard, where all the trees have identifying labels, has been developed with the encouragement of two international projects: with the financial support of the Swiss contribution to the enlarged European Union and the European Agricultural Fund for Rural Development. The results of the project are two publications: the brochure Stare sadne sorte na Goriškem (Old fruit varieties in the Goriško region, in two parts) and the illustrated book Sadje sonca: bogastvo starih briških sadnih sort (The Fruits of the Sun: the Wealth of Old Fruit Varieties in Goriška Brda).

Polyphenol oxidase (PPO) was extracted from whole peaches and its catecholase activity was studied spectrophotometrically against three substrates: catechol (Cat), 4-methyl catechol (4MC), and chlorogenic acid (CA). Peach PPO specificity was: CA > 4MC ≈ Cat. 4-hexylresorcinol (4HR, 0.5 mM) inhibited oxidation of Cat and CA by 50% or more, at all substrate concentrations, but had no effect on the oxidation of 4MC, suggesting that laccase-like activity was present in the extract. β-cyclodextrin (β-CD, 10 mM) inhibited only CA oxidation and this effect was not abolished when free substrate concentrations were calculated suggesting a mechanism, additional to substrate complexation, in β-CD action. Combination of 4HR and β-CD had only a weak inhibitory effect on CA oxidation. In conclusion, β-CD and specially 4HR could be used as browning inhibitors in peach products and also as tools for studying different phenol oxidases. Combination of both compounds is not recommended for peaches.Se extrajo la enzima polifenoloxidasa (PPO) a partir de duraznos completos y se estudió su actividad catecolasa, espectrofotométricamente, frente a tres diferentes sustratos:catecol (Cat), 4-metilcatecol (4MC) y ácido clorogénico (CA). La especificidad de la PPO fue: CA > 4MC ≈ Cat. El 4-hexilresorcinol (4HR, 0,5 mM) inhibió, en un 50% o más, la oxidación de Cat y CA, pero no tuvo ningún efecto sobre la oxidación del 4MC, lo cual sugiere que el extracto posee actividad lacasa. La β-ciclodextrina (β-CD, 10 mM) inhibió únicamente la oxidación del CA, aún si se consideran las concentraciones libres del sustrato, lo cual sugiere que la acción de la β-CD depende de un mecanismo adicional a la complejación de sustrato. La combinación de ambos inhibidores tuvo un efecto débil sobre la oxidación del CA. Se concluye que la β-CD y especialmente el 4HR pueden ser usados como inhibidores del oscurecimiento enzimático en productos de durazno, así como para estudiar los diferentes tipos de fenoloxidasas. La combinación de ambos agentes no es recomendable en duraznos.

Da bi vsaj v obrisih ugotovili, katere sadne sorte so na Goriškem obstajale in kje se nahajajo drevesa z uporabnimi cepiči različnih starih sort, smo v letih 2012 in 2013 izvedli pilotno terensko raziskavo, ki naj bi dala približno sliko stanja in bila tudi podlaga za bolj sistematične in obširnejše nadaljnje raziskave. Prvi del terenske raziskave je potekal individualno, in sicer najprej s preučevanjem tuje in slovenske (predvsem starejše) literature, potem pa z obiskovanjem posameznih vasi, iskanjem informatorjev in opazovanjem starih sadovnjakov. Predvsem nekateri starejši sadjarji so bili dragocen vir podatkov, ki so omogočali širjenje kroga informatorjev, preverjanje že dobljenih informacij o starih sadnih sortah, njihovih značilnostih in možnostih uporabe, predvsem pa tudi nabiranje cepičev za vzgojo dreves v matičnem sadovnjaku. Pri drugem delu terenske raziskave so sodelovali predvsem dijaki Biotehnične šole iz Šempetra pri Novi Gorici, Škofijske gimnazije iz Vipave in Srednje ekonomske in trgovske šole iz Nove Gorice, njim pa se je pridružilo še nekaj posameznikov. Naloga popisovalcev je bila, da v posamezni vasi poiščejo starejšega informatorja, poznavalca starih sort, skupaj z njim izpolnijo vprašalnik in ga v določenem roku oddajo svojemu učitelju. Informacije o starih sadnih sortah so bile zbrane v naslednjih petdesetih naseljih (največ iz Goriških Brd in Vipavske doline) Sledila je analiza, ki je prinesla zanimivo sliko ohranjenosti in nekdanje razprostranjenosti starih sort na Goriškem. Najprej se je pokazalo, da ima lahko ista sadna sorta več različnih imen (npr. pastorjevka ali rončarca ali zimka), isto ime pa ne pomeni nujno tudi iste sorte. V Brdih so npr. uspevale štrnivke, rdeče-rumene drobnejše jesenske hruške, ki so jih sušili na soncu in izvažali celo na Dunaj, vendar so se z leti izgubile. Štrnivka je bila po popisu najdena tudi v Čadrgu, in sicer gre za staro drevo, ki pa ima drobne zeleno-rumene poletne hruške, podobne tepkam. Šele dodatna terenska raziskava, pri kateri bi si v vseh obdelanih naseljih ogledali posamezna drevesa in preučili njihove sadeže, bi omogočila zanesljivo določiti različna poimenovanja za isto sadno sorto. Največ starih sort smo našli pri hruškah (okoli devetdeset), jablanah (okoli petdeset), češnjah (okoli petintrideset), figah (okoli trideset) in breskvah (okoli petindvajset). Našli smo še okoli petnajst sort sliv in le osem sort marelic. Te razlike v številu sort so razumljive, in sicer zato, ker so sveže in posušene hruške nekoč gotovo predstavljale najpomembnješe prehransko dopolnilo, ker so sorte hrušk po času zrelosti razporejene od zgodnjih poletnih do poznih jesenskih in ker hruškova drevesa lahko dosežejo zelo visoko starost. Podobno je pričakovano veliko število sort jablan, čeprav se ta po življenjski dobi dreves ne morejo meriti s hruškami. Po drugi strani so češnje po času dozorevanja omejene na dober mesec, drevesa marelic in breskev pa propadejo že po nekaj desetletjih.

Since 2007, an orchard of old fruit varieties has been developed at the village of Kojsko in the Goriška Brda region, designed by Gregor Božič, a young film director. It is conceived as a genetic bank, which enables preservation and dissemination of indigenous fruit varieties. It currently comprises about a hundred and fifty standard-size trees of various ages (from seventy to three years) and over a hundred varieties of cherries, apricots, figs, peaches, plums, pears and apples. Deliberately selected old varieties that are fairly resistant to diseases and have commercially interesting characteristics have been planted. The orchard, where all the trees have identifying labels, has been developed with the encouragement of two international projects: with the financial support of the Swiss contribution to the enlarged European Union and the European Agricultural Fund for Rural Development. The results of the project are two publications: the brochure Stare sadne sorte na Goriškem (Old fruit varieties in the Goriško region, in two parts) and the illustrated book Sadje sonca: bogastvo starih briških sadnih sort (The Fruits of the Sun: the Wealth of Old Fruit Varieties in Goriška Brda).

To evaluate the effects of water stress at various phenological stages of peach fruit development on fruit characteristics, an experiment was conducted during two years period at the experimental orchard of Agricultural college, Tehran university, in Karaj. A split–plot design arranged in randomized completely block with four replications was used. Four cultivars (G.H.Hale,Red Haven,  White Mashhad and Red–white Mashhad) were put in main plots and five water stress treatments (Water stress in stage I of fruit growth, Water stress in stage II, water stress in stage III, water stress in stage I plus stage II and control) in Sub-Plots.
The results indicated that water stress at stage III of fruit growth significantly decreased the mean fruit weight, fruit size and fruit water content while total soluble solids (T.S.S) and fruit acidity were increased. Water stress at stage II of fruit growth (Pit hardening) increased fruit weight significantly (at 1% level) compared with other treatments.

Florida peaches (Prunus persica) typically are picked and placed in a cold room on the day of harvest, then packed and shipped the next day. This room cooling (RC) is slow, requiring %24 hours or more for the fruit to reach optimal temperature (6 to 7°C). There is currently limited research on the effect of cooling practices on microbial quality of peaches, yet this study is essential for decision making in areas such as upgrading packing house facilities and the implementation of improved handling procedures. This research compared the efficacies of post-harvest cooling by RC, forced-air cooling (FAC), and hydrocooling with sanitizer (HS) treatment of peaches to reduce their surface microbial population and to determine the effect on shelf life and microbial quality. Three trials for RC and two trials each for FAC and HS were performed. Following cooling, fruit were stored at 1°C. The average aerobic plate count (APC) from field samples was 5.29 log cfu/ peach, which remained uncha...

Florida peaches (Prunus persica) typically are picked and placed in a cold room on the day of harvest, then packed and shipped the next day. This room cooling (RC) is slow, requiring %24 hours or more for the fruit to reach optimal temperature (6 to 7°C). There is currently limited research on the effect of cooling practices on microbial quality of peaches, yet this study is essential for decision making in areas such as upgrading packing house facilities and the implementation of improved handling procedures. This research compared the efficacies of post-harvest cooling by RC, forced-air cooling (FAC), and hydrocooling with sanitizer (HS) treatment of peaches to reduce their surface microbial population and to determine the effect on shelf life and microbial quality. Three trials for RC and two trials each for FAC and HS were performed. Following cooling, fruit were stored at 1°C. The average aerobic plate count (APC) from field samples was 5.29 log cfu/ peach, which remained unchanged after RC or FAC but was reduced significantly (P < 0.05) to 4.63 log cfu/peach after HS. The average yeast and mold counts (Y&M) from field samples (6.21 log cfu/peach) were reduced highly significantly (P < 0.001) to 4.05 log cfu/peach after HS. Hydrocooling significantly (P < 0.05) reduced the APC and Y&M counts from the peaches and showed promise in maintaining the microbiological quality of the fruit throughout storage. However, at the end of the 21-day storage period, there was no significant difference in APC or Y&M counts from peaches, irrespective of the cooling methods. Peaches that went through the hydrocooling process and were subsequently packed showed an increase (P < 0.05) in both APC and Y&M counts, while fruit that were not hydro-cooled showed no such increase. Information obtained will be used to recommend the best temperature management practices for maintaining the postharvest quality of peaches. A detailed cost-benefit analysis of different cooling methods and the time interval between harvest and shipment are both necessary for a more conclusive recommendation.