Mill Var Research Articles

An economic analysis of harvest timing to manage the physiological storage disorder firm flesh browning in ‘Empire’ apples

Firm flesh browning of ‘Empire’ apple (Malus sylvestris (L.) Mill var. domestica Borkh.) fruit is a major cause of revenue loss for growers and storage operators. In this study, the economic impact of harvest date on revenue based on percentage pack-out (fruit size/weight and red coloration) and disorder incidence has been investigated using a budgeting model. Fruit were harvested from a commercial orchard weekly for three weeks; H1 (one week before normal harvest), H2 (normal harvest), and H3 (one week after normal harvest). Fruit samples were either untreated or treated with 1-methylcyclopropene (1-MCP) and stored under controlled atmosphere (CA) conditions (2kPa O2; 2kPa CO2) at 0.5°C and 2°C. Field bins of fruit were used to assess pack-out percentages. Flesh browning was low at H1 and unaffected by 1-MCP treatment, whereas incidence was highest in fruit from H3, and especially in 1-MCP treated fruit stored at 2°C. The enterprise budget model shows that net profits for a one hectare high density planting vary slightly between fresh-marketed fruit in the fall, and for fruit stored after nine months in CA storage, both with and without 1-MCP treatment. Net profits from one hectare are higher for H3 when fruit are marketed in the fall, in comparison to the normal harvest (H2), but at harvest, pack-out was substantially lower for fruit from H1. Fruit quality and pack-out percentages after storage depended not only on the harvest date but also on storage temperature and 1-MCP treatment. Therefore, there is an economic tradeoff between harvest date, occurrence of flesh browning, and likely net profits to producers of ‘Empire’ apples.

Physico Chemical Studies during the Ripening of the Fruit of Lycopersicon Esculentum Mill Var. Naveen

A correlative study on physico-chemical changes during fruit ripening in Lycopersicon esculentum has been carried out. The tomato fruit was collected at its four successive stages viz. 1. Mature green, 2. Half ripened, 3. 3/4tth - ripened and 4. Fully ripened for its physico-chemical analysis. The obtained result showed that with advancement of fruit maturation the amount of pigments (total carotenoids, lycopene), total sugars, reducing sugars increase significantly. While that of physio chemical studies of weight of fruit, pulp, peel and volume of fruit decrease gradually. However TSS, titrable acidity, PH, ascorbic acid, tannins as moisture of tomato fruits could be considered as maturity indices to judge the ripening stages of tomato fruits for various value added products preparation.

Physico Chemical Studies during the Ripening of the Fruit of Lycopersicon Esculentum Mill Var. Naveen

A correlative study on physico-chemical changes during fruit ripening in Lycopersicon esculentum has been carried out. The tomato fruit was collected at its four successive stages viz. 1. Mature green, 2. Half ripened, 3. 3/4tth - ripened and 4. Fully ripened for its physico-chemical analysis. The obtained result showed that with advancement of fruit maturation the amount of pigments (total carotenoids, lycopene), total sugars, reducing sugars increase significantly. While that of physio chemical studies of weight of fruit, pulp, peel and volume of fruit decrease gradually. However TSS, titrable acidity, PH, ascorbic acid, tannins as moisture of tomato fruits could be considered as maturity indices to judge the ripening stages of tomato fruits for various value added products preparation.

Effect of Treatment Time of 1-MCP on Ripening of ‘Fuji’ Apples Stored at Low and Room Temperature for a Long Period

The effect of 1-methycyclopropene (1-MCP) treatment at 0, 2, and 4 d after harvest (0 DAH, 2 DAH, and 4 DAH) of apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] was evaluated on several fruit quality parameters for 180-d at 0.5°C in the air, followed by 28-d at room temperature. The 1,000 nl l-1 1-MCP treatments were adequate to maintain fruit titratable acidity (TA) and firmness, inhibiting the rates of ethylene production and respiration during the storage of both cold and the room temperatures, regardless of the 1-MCP treatment time.

Internal ethylene concentrations in apple fruit at harvest affect persistence of inhibition of ethylene production after 1-methylcyclopropene treatment

Factors that affect the efficacy of 1-methycyclopropene (1-MCP) treatment of apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] include cultivar and maturity. In this study, ‘McIntosh’, ‘Cortland’ and ‘Empire’ apples were categorized by internal ethylene concentrations (IECs) at harvest, treated with 1μLL−1 1-MCP, and the IECs of individual fruit followed at 30d intervals during air storage at 0.5°C for 90d. IECs at harvest ranged from <0.5μLL−1 to ≥100μLL−1, 51<100μLL−1, and 10<50μLL−1 for ‘McIntosh’, ‘Cortland’ and ‘Empire’, respectively. 1-MCP treatment resulted in a decrease of IECs in fruit of all cultivars by day 30 after harvest. During subsequent storage IECs remained low in fruit with <1μLL−1 at harvest, but in ‘McIntosh’, ‘Cortland’ increased in proportion to IECs at harvest, but not in ‘Empire’. The importance of initial IECs in fruit on the persistence of 1-MCP inhibition of ethylene production was confirmed in a further experiment, in which IECs in untreated and 1-MCP treated ‘McIntosh’ and ‘Empire’ apples were measured for up to 194d. 1-MCP also decreased 1-aminocyclopropene-1-carboxylic acid (ACC) concentrations in fruit. The results of our study are consistent with the hypothesis that IEC modulates the sensitivity of climacteric fruit to 1-MCP.

Herbal Insomnia Medications that Target GABAergic Systems: A Review of the Psychopharmacological Evidence.

Insomnia is a common sleep disorder which is prevalent in women and the elderly. Current insomnia drugs mainly target the γ-aminobutyric acid (GABA) receptor, melatonin receptor, histamine receptor, orexin, and serotonin receptor. GABAA receptor modulators are ordinarily used to manage insomnia, but they are known to affect sleep maintenance, including residual effects, tolerance, and dependence. In an effort to discover new drugs that relieve insomnia symptoms while avoiding side effects, numerous studies focusing on the neurotransmitter GABA and herbal medicines have been conducted. Traditional herbal medicines, such as Piper methysticum and the seed of Zizyphus jujuba Mill var. spinosa, have been widely reported to improve sleep and other mental disorders. These herbal medicines have been applied for many years in folk medicine, and extracts of these medicines have been used to study their pharmacological actions and mechanisms. Although effective and relatively safe, natural plant products have some side effects, such as hepatotoxicity and skin reactions effects of Piper methysticum. In addition, there are insufficient evidences to certify the safety of most traditional herbal medicine. In this review, we provide an overview of the current state of knowledge regarding a variety of natural plant products that are commonly used to treat insomnia to facilitate future studies.

Fruit Size Affects Physiological Attributes and Storage Disorders in Cold-stored ‘Royal Gala’ Apples

‘Royal Gala’ apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] fruit can be susceptible to the development of postharvest disorders such as flesh breakdown and cracking (splitting) during and after cold storage. The objective of this research was to investigate fruit size and 1-methylcyclopropene (1-MCP) treatment effects on fruit physiological attributes and incidence and severity of storage disorders in ‘Royal Gala’ apples held in cold storage. In 2011, fruit segregated at harvest into two groups based on size (120 to 175, 250 to 350 g/fruit) were stored in air at 0.5 °C for 6 months and then at 20 °C for 7 days. In 2012, fruit were sorted into four groups (less than 200, 200 to 240, 241 to 280, and greater than 280 g/fruit), treated with 0 or 1 μL·L−1 1-MCP for 12 hours, and then stored in air at 0.5 °C for 3 or 6 months. Storage disorders were only detected at 6 months, regardless of 1-MCP treatment. In both control and 1-MCP-treated fruit, flesh breakdown incidence increased with fruit size, whereas severity was less associated with size. The progression of flesh breakdown developed in overall cortex tissue of control fruit but only detected in the stem-end tissue of 1-MCP-treated fruit. Internal ethylene concentration (IEC) decreased and CO2 production increased with increased fruit weight; however, 1-MCP-treated fruit had low IEC regardless of weight. Cortex tissue lightness (L*) increased with fruit size irrespective of tissue localization (stem end, equatorial, calyx end) at harvest. During 6 months’ storage, L* decreased with increased fruit size in controls but not 1-MCP-treated fruit. Fruit fresh weight loss increased with fruit size and storage duration, more so in controls when compared with 1-MCP-treated fruit. Furthermore, fruit circumference increased during storage with fruit size only for control fruit. These physical changes are associated with susceptibility of large fruit to flesh breakdown more so than small fruit. Reduced flesh breakdown incidence, progression of symptoms from the stem end into the cortex, and symptom severity in 1-MCP-treated fruit may indicate flesh breakdown is related to fruit ripening and senescence.

Pro-apoptotic effect of Persea americana var. Hass (avocado) on Jurkat lymphoblastic leukemia cells

Context: Therapy for leukemia has a limited efficacy. There is a need to search for alternative anti-leukemia therapies. Persea americana Mill var. Hass (Lauraceae) is a tropical fruit (avocado) that might be used against cancer.Objective: To investigate whether P. americana induces death in Jurkat lymphoblastic leukemia cells.Materials and methods: Four ethanol extracts (0.1, 0.5, 1, 2 and 5 mg/mL) from avocado fruit (endocarp, whole seed, seed and leaves) were analyzed against Jurkat cells. Hydrogen peroxide generation by oxidation of 2′,7′-dichlorodihydrofluorescein diacetate to the fluorescent compound 2′,7′-dichlorfluorescein assay, acridine orange/ethidium bromide staining, flow cytometry analysis of annexin-V/7-amino-actinomycin, mitochondrial membrane potential and immunocytochemistry detection of transcription factor p53, caspase-3 and apoptosis-inducing factor (AIF) were evaluated.Results: Endocarp, seed, whole seed, and leaf (0.1 mg/mL) extracts induced significant apoptosis in Jurkat cells (p < 0.001) in an oxidative stress-dependent fashion via mitochondrial membrane depolarization (52–87%), activation of transcription factor p53 (6.3–25.4%), protease caspase-3 (8.3–20%) and predominance of AIF reactivity (20.6–36%) in all extracts. Similar results were obtained with 0.5 mg/mL extracts. However, extract ≥1 mg/mL concentration induced necrosis (100%).Conclusions: P. americana extracts function as a pro-apoptotic compound. Leukemic cells are eliminated through an oxidative stress mechanism. This study contributes to the understanding of the molecular mechanism of the avocado and its therapeutic action on leukemia.

Threshold effects of photosynthetic efficiency parameters of wild jujube in response to soil moisture variation on shell beach ridges, Shandong, China

To investigate the threshold effects of photosynthetically active radiation (PAR) and soil mass water content (MWC) on photosynthetic efficiency parameters of Ziziphus jujuba Mill var. spinosa and to understand the adaptability of Z.jujuba to light and soil moisture variation, we determined optimal MWC and PAR for Z. jujuba which maintained higher net photosynthetic rate (PN) and water use efficiency (WUE). Using a Li-6400 portable photosynthesis system, we measured light response of PN, transpiration rate (E), WUE, and other gas-exchange parameters of 3-year-old Z. jujuba shrubs in a range of soil moisture conditions. The results showed that the leaf photosynthetic rate and WUE of Z. jujuba had a significant response to MWC and PAR. Given increases in the MWC (7.1–17.6%), the plant's light compensation point decreased and its light saturation point (LSP), apparent quantum yield, and maximum PN increased. When MWC was at 17.6%, the low and high light use efficiency of Z. jujuba was all maximal. PN obviously increased with increasing MWC (9.2–17.6%). However, PN decreased when MWC was too high or low. When PAR ranged from 800 to 1200 μmol m− 2 s− 1, PN and WUE were higher and the LSPs of PN and WUE ranged between 706 and 1209 μmol m− 2 s− 1. These data indicate that Z. jujuba possessed higher adaptability to light conditions. Based on photosynthetic efficiency parameters, the soil moisture availability and productivity of Z. jujuba were classified and evaluated. For Z. jujuba woodland, MWC < 9.2% and MWC>21.5% resulted in low productivity and medium WUE, 19.8–21.5% of MWC resulted in medium productivity and low WUE, 9.2–11.2% of MWC resulted in medium productivity and medium WUE, and 11.2–19.8% of MWC resulted in high productivity and high WUE. The optimum high productivity and high WUE of MWC were at 17.6%, and the corresponding optimum PAR was 1209 μmol m− 2 s− 1.

Effect of manure quality on nitrate leaching and groundwater pollution in wetland soil under field tomato (Lycopersicon esculentum, Mill var. Heinz) rape (Brassica napus, L var. Giant)

Recent decades have seen an increase in groundwater pollution thought to be a consequence of increasing intensity of land use, primarily through greater use of high N analysis materials as fertilizers. A two-season lysimeter experiment was carried out in a wetland in central Zimbabwe in order to determine the effect of cattle manure quality on (1) NO3–N concentration in leachate and nitrate leaching (2) dry matter accumulation and uptake of N by tomato and rape crops grown in wetland conditions. Two cattle manure quality types based on N content were used in the experiment. The manure collected from a kraal of the smallholder wetland community was classified as high quality manure (high N, 1.36 % N) while that collected from the adjacent commercial farming area was classified as low quality manure (low N, 0.51 % N). The two manure types were applied in rates of 0, 15, 30 Mg ha−1. The treatments were arranged in a randomized complete block design with four replicates. When 15 and 30 Mg high and low N manure ha−1 were applied, the concentration of NO3–N in leachate exceeded the recommended 10 mg L−1 concentration in portable water by 15–104 and 53–174 % respectively. The substitution of 15 and 30 Mg of high N manure with 15 and 30 Mg ha−1 of low N manure reduced total N lost through leaching by 10–43 and 22–69 % respectively. Ground water contamination by nitrate overload can be considerably reduced by application of low N manure to vegetable crops.

Fruit maturity, controlled atmosphere delays and storage temperature affect fruit quality and incidence of storage disorders of ‘Fuji’ apples

The effects of storage temperature, harvest maturity, controlled atmosphere (CA) storage regime, and CA strategies on fruit quality and the incidence of storage disorders during storage of ‘Fuji’ apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] were investigated. Flesh browning incidence was lower in fruit stored at 2°C than at 0°C, but fruit were also softer and had lower titratable acidity (TA) at the higher storage temperature. All subsequent studies were carried out at 0°C. High partial pressures of CO2 (pCO2) of 2.5kPa compared with <1kPa did not consistently affect flesh firmness, soluble solids concentration (SSC), and TA. The incidence of flesh browning was higher in more mature fruit and it was further aggravated by higher pCO2 in the storage atmosphere, irrespective of pO2, while watercore disappearance was more rapid at <1kPa CO2 than at 2.5kPa CO2. Flesh browning was also higher at 1.5kPa CO2 than at <1kPa CO2, although ethylene production was lowest at 1.5kPa pCO2. Stepwise delay of high CO2 or low O2 CA storage did not affect flesh firmness, TA, internal ethylene concentration, respiration rate, and ethylene production, but watercore disappearance was more rapid, compared with standard CA storage at 2 months. Flesh browning was not detected in the stepwise CO2 delayed CA treatment and low CO2 CA storage (<0.2kPa CO2), but a low (<4%) incidence of flesh browning was found in a delayed CA treatment and standard CA storage. These results indicate that ‘Fuji’ apples could be stored at 0°C in 1–2kPa O2/<1kPa CO2 if harvested at less than 190 days after full bloom. Stepwise CO2 delay CA or low CO2 CA storage regimes are recommended to retard the loss of fruit quality factors and reduce development of CA-related storage disorders.

Garden-waste-vermicompost leachate alleviates salinity stress in tomato seedlings by mobilizing salt tolerance mechanisms

The incidence of salinity-induced plant stress as a result of natural and anthropogenic factors in arid and semi-arid agricultural lands is great. In South Africa alone, 9 % of irrigated agricultural land is salt-affected. Commercial fertilizers used for improving soil nutrient levels are costly and affect the quality, lifespan and sustainability of soil and water resources. Organic farming practices are based on cost-effective and environmentally-aware management systems. Vermicompost leachate (VCL) is a vermicompost-derived liquid product that has become recognised as a suitable soil amendment product. Commercial tomato (Lycopersicon esculentum Mill var. Heinz-1370) seedlings were subjected to sodium chloride (NaCl) concentrations of 0, 25, 50 and 100 mM and were treated with 1:10 (v/v) WizzardWorms VCL prepared in Hoagland’s nutrient solution under greenhouse conditions. Morphological characters of VCL-treated tomato seedlings showed improved root growth and stimulated overall aboveground growth with significantly higher numbers of leaves, greater stem thickness and increased leaf area, even at a high NaCl-tested concentration (100 mM). The accumulation of compatible solutes such as proline and total soluble sugars indicate an induced salt tolerance or adaptive mechanism in VCL-treated tomato seedlings. The current investigation demonstrates the potential of an organic liquid to maximise tomato productivity by improving seedling growth performance under salt stress conditions.

Antioxidant metabolism of 1-methylcyclopropene (1-MCP) treated ‘Empire’ apples during controlled atmosphere storage

‘Empire’ apples [ Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] are susceptible to development of firm flesh browning during controlled atmosphere storage. The browning is thought to be a chilling injury and therefore fruit are typically stored at 2–3 °C to avoid fruit damage. However, flesh browning can be enhanced by 1-methylcyclopropene (1-MCP) treatment at these warmer temperatures. The objective of this work was to investigate the effect of 1-MCP on the antioxidant systems of ‘Empire’ apple fruit stored at 2 kPa O 2/2 kPa CO 2 at either 0.5 °C or 3.3 °C for up to 40 weeks. Lightness ( L*) and hue angle ( h°) changes of the flesh tissues were correlated with development of flesh browning. Nitroblue tetrazolium reducing activity was lower in 1-MCP treated fruit, but while changes in H 2O 2, MDA, ascorbic acid and dehydroascorbate, reduced and oxidized glutathione concentrations, and the activities of associated enzymes were affected by storage temperature and 1-MCP treatment, no consistent patterns of change were detected. Partial least squares regression analysis revealed that the activity of ascorbate peroxidase might be the candidate metabolite in flesh browning development at 3.3 °C, but overall, the results do not reveal a direct role of antioxidant metabolism during development of flesh browning in ‘Empire’ apples.

Molecular analysis of softening and ethylene synthesis and signaling pathways in a non-softening apple cultivar, ‘Honeycrisp’ and a rapidly softening cultivar, ‘McIntosh’

A feature of ‘Honeycrisp’ apples [ Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] is that they maintain flesh firmness over extended storage. The objective of this study was to elucidate molecular mechanisms that are responsible for slow softening of ‘Honeycrisp’ as compared with a rapidly softening cultivar, ‘McIntosh’. Fruit from both cultivars were picked during the normal harvest period and stored at 20 °C for 10 d. Internal ethylene concentrations (IECs) in ‘Honeycrisp’ fruit were lower than in ‘McIntosh’, but at climacteric levels of ethylene ‘Honeycrisp’ fruit maintained their firmness over this period, while ‘McIntosh’ softened rapidly. Concentrations of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) were higher in ‘Honeycrisp’ than in ‘McIntosh’ apples. qRT-PCR analysis was carried out for genes involved in ethylene biosynthesis, perception and signaling [ACC synthase ( MdACS); ACC oxidase ( MdACO); ethylene receptors ( MdETR and MdERS); constitutive triple response ( MdCTR); ethylene response factor ( MdERF)], as well as those involved in cell wall metabolism [polygalacturonase ( MdPG); xyloglucan endotransglucosylase ( MdXTH); expansin ( MdEXP); β-galactosidase ( Md β- GS); arabinofuranosidase ( MdAFase); pectate lyase ( MdPL)]. At comparable IECs, the expression of genes involved in ethylene synthesis, ethylene perception and signal transduction was generally much higher in ‘Honeycrisp’ than in ‘McIntosh’ fruit. However, the expression of MdAFase and MdEXP3 was generally lower in ‘Honeycrisp’ than in ‘McIntosh’, while that of MdPG and MdPL was extremely low in ‘Honeycrisp’. Expression of MdPG1 was very low, even though IECs were at climacteric levels. Absence of fruit softening in ‘Honeycrisp’ is probably associated with restricted cell wall enzyme activity. The lower maximum IECs found in ‘Honeycrisp’ compared with ‘McIntosh’ do not appear to be related to expression of genes involved in ethylene biosynthesis.

Development of a regeneration protocol through indirect organogenesis in prickly pear cactus ( Opuntia ficus-indica (L.) Mill)

An indirect organogenesis regeneration protocol for Opuntia ficus-indica (L.) Mill var “Blanco sin Espinas” is described. One centimeter square cladode explants sections from previously micropropagated prickly pear plants were cultured in Murashige and Skoog (MS) basal medium supplemented with 20 different combinations of 2,4-dichlorophenoxy acetic acid (2,4-D) and benzyladenine (BA). The best calli induction and regeneration response were observed when 2.26 μM 2,4-D and 2.21 μM BA combination was applied to the nopal explants. Regenerating calli was capable of forming new buds when transferred to MS basal medium supplemented with 0.5 μM BA (proliferation medium). Shoot elongation and rooting were achieved on MS medium without plant growth regulators. Excellent acclimatization to greenhouse conditions was observed for all transferred plantlets. By this procedure no morphological differences were observed between the regenerated and mother plants. This protocol may be also utilized to carry out plant regeneration after genetic transformation, in order to develop transformed plants without the presence of chimeric zones.

Involvement of ethylene in browning development of controlled atmosphere-stored ‘Empire’ apple fruit

‘Empire’ apples [ Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] are susceptible to development of chilling injury, expressed as firm flesh browning, during controlled atmosphere (CA) storage. Because of this susceptibility, fruit are typically stored at 2–4 °C, but the incidence of flesh browning can be increased by 1-methylcyclopropene (1-MCP) treatment at these temperatures. In this study, flesh browning development has been investigated in relationship to ethylene production, internal ethylene concentration (IEC), flesh firmness, total phenolic concentrations, and the activities of polyphenol oxidase (PPO) and peroxidase (POX) in the flesh tissues. Fruit were harvested from two orchards, either untreated or 1-MCP treated, and then stored under CA conditions at either 0.5 or 4 °C. Fruit were removed from storage at 1.5-month intervals for 10.5 months. 1-MCP treated apples were firmer than those of untreated apples, and had lower IECs, at all removals. Flesh browning incidence and severity developed earlier in 1-MCP-treated apples than untreated apples stored at either temperature. Total phenolic concentrations differed by orchard, but no major differences in concentrations were detected between untreated and 1-MCP treated apples. However, PPO activities were higher in the flesh of 1-MCP treated apples than untreated apples from both orchards and at both storage temperatures. POX activity was not consistently affected by 1-MCP treatment or storage temperature. Overall, our results suggest that inhibited ethylene production, either as a result of storage at 0.5 °C, or by treatment with 1-MCP at either temperature, may cause stress and damage to cells and result in higher PPO activity that leads to progressive flesh browning development during CA storage.

Nitrogen Fertigation Concentration and Timing of Application Affect Nitrogen Nutrition, Yield, Firmness, and Color of Apples Grown at High Density

A randomized complete block, split-plot experiment with six replicates was established and maintained for the first six fruiting seasons (1999 to 2004) in a high-density apple [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] orchard on M.9 rootstock planted in Apr. 1998. This report assesses responses to six main-plot fertigation treatments, each containing three tree subplots of five different cultivars (Ambrosia, Cameo, Fuji, Gala, and Silken). Fertigation treatments were a factorial combination of two nitrogen (N) rates and three N application timings. N was applied at low (28 mg N/L) or high (168 mg N/L) concentrations daily at 0 to 4, 4 to 8, or 8 to 12 weeks after full bloom (wafb). Under greater N inputs, all cultivars had increased midsummer leaf and harvested fruit N concentrations, decreased fruit firmness, and in heavy crop years, decreased percent red color. Annual yield of all cultivars was significantly increased by N rate in a single year, but their cumulative yields were not different between treatments as a result of rate or timing. Altering the timing of N application within 12 wafb only affected leaf and fruit tissue N concentration. Leaf N was higher after 4 weeks of fertigation any time, although concentrations declined over the growing season, reaching minimum values around harvest. Fruit N was increased by fertigation 4 to 12 wafb. Yield, fruit firmness, and color were unaffected by fertigation timing. Critical fruit quality issues for ‘Gala’ and ‘Silken’ were small fruit size, for Ambrosia low fruit numbers, and for ‘Cameo’ soft fruit. ‘Fuji’, which achieved high yield and leaf N concentration and firm fruit, had poor red color regardless of N treatments.

Effect of densities of planting on yield and essential oil components of Fennel (Foeniculum vulgare Mill Var. Soroksary)

In order to study the effect of different densities of planting on yield and essential oil components of Fennel(Foeniculum vulgare Mill Var. Soroksary), an experiment was carried out in college of agriculture Karaj at 2008.Experiment was conducted based on completely randomized block design with three replication and five plant densities.Five plants spaces were 10, 15, 20, 25 and 30cm on the row. The distance between rows in all treatments was 40cm.The essential oil extracted by water distilled method from seeds and essential oil was analyzed by gas chromatography(GC). The higher essential oil percentage (% 3.53) was obtained with the lowest densities of planting.The higherpercentage of anethole (%83.07), estragol (%3.47), fenchone (%8.04), p-cymene (%4.45), alpha-terpinene (%0.54),sabinene (%0.51), and alpha-Pinene (%0.48) were obtained with space between plants 25, 10, 20, 20, 15, 20, and 25cm,respectively.

Biochemical analysis of reactive oxygen species production and antioxidative responses in unripe avocado (Persea americana Mill var Hass) fruits in response to wounding

We analyzed the production of reactive oxygen species (ROS) and of detoxifying enzymes and enzymes of the ascorbate (ASC) acid cycle in avocado fruit (Pesea Americana Mill cv Hass) in response to wounding. The levels of superoxide anion (O(2-), hydroxyl radicals (OH.) and hydrogen peroxide (H(2)O(2)) increased at 15 min and 2 and 15 h post-wounding. Peroxidase (POD) activity had increased to high levels 24 h after wounding; in contrast, catalase and superoxide dismutase (SOD) levels hat decreased significantly at 24 h post-treatment. Basic POD was the major POD form induced, and the levels of at least three apoplastic POD isozymes -increased following wounding. Using specific inhibitors, we characterized one MnSOD and two CuZnSOD isozymes. CuZnSOD activities decreased notably 12 h after treatment. The activities of dehydroascorbate reductase and glutathione reductase increased dramatically following the wounding treatment, possibly as a means to compensate for the redox changes due to ROS production.

Antioxidant contents and activity of 1-methylcyclopropene (1-MCP)-treated ‘Empire’ apples in air and controlled atmosphere storage

The effect of 1-MCP on ripening and concentrations of total phenolics, flavonoids, anthocyanins and total antioxidant activity of ‘Empire’ apples ( Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.) was studied. Fruit were stored in air for up to 5 months, and in controlled atmosphere (CA) of 2 and 3 kPa O 2 (2 kPa CO 2) at 0.5 and 2.2 °C for 4.5 and 9 months. Ripening was delayed by 1-MCP treatment in both air and CA storage as indicated by lower internal ethylene concentrations and slower softening than in untreated fruit. Overall, total phenolic, flavonoid and anthocyanin concentrations as well as antioxidant activity were relatively stable during air and CA storage. In air-stored fruit, total phenolic concentrations were higher in the peel of 1-MCP treated fruit than in the control fruit, but slightly lower in the flesh of 1-MCP treated fruit. In CA-stored fruit, interactions between O 2 partial pressures, temperature and storage duration were detected but overall, few consistent trends were observed. However, flavonoid concentrations were higher in the flesh of 1-MCP treated than untreated fruit kept in 2 kPa O 2 while anthocyanin concentrations, only measured in the peel, were not affected by 1-MCP treatment. There were no correlations found between total phenolics and antioxidant activity. Ascorbic acid concentrations declined in both peel and flesh tissues of untreated and 1-MCP treated fruit stored in air, while changes of ascorbic acid concentrations in CA-stored fruit were inconsistent.