Uninjured Fruit Research Articles

Reduction of Citrus Fruit Fungal Rot Disease using the Commercial Bio-Agent Bacillus subtilis

The results of the laboratory experiment on PDA media showed that B. subtilis at all concentrations (0.1ml, 0.5ml, 1ml/plate) led to a significant reduction in the fungal growth of the two pathogenic fungi, P. polonicum and G. candidum, with an inhibition rate that increased with increasing concentration. The effect of B. subtilis on the growth of P. polonicum was higher than that of G. candidum. In the experiment of storing fruits under natural conditions, the results showed the significant effect of B. subtilis in reducing the severity of infection in injured (artificially wounded) citrus fruits (orange, lemon, sour orange) when treated with the spore suspension of G.candidum and P. polonicum, compared to the significantly higher infection severity in the absence of the biological agent B. subtilis. The percentage of spoilage (reduction of the final fruit weight) increased in the fruits due to infection after 7 days of storage in the spore suspension treatments of G. candidum in oranges, especially in the wounded fruits compared to the normal, uninjured fruits. The same is the case with lemon and orange, as it was observed, in general, that the percentage of weight reduction in wounded fruits increased even in the control treatments than in the normal (uninjured) fruits, while the presence of bacteria B. subtilis reduced the spoilage to normal limits that did not differ from the final fruit weight in the control treatment.

IN VITRO EVALUATION OF DIFFERENT LOCALLY AVAILABLE PRESERVATIVES AGAINST THE FUNGUS CAUSING TOMATO FRUIT ROT DISEASE

The post-harvest tomato fruit rot caused by Alternaria solani is a major threat to the tomato fruits. Our main objective of this study was to assess the locally available plant based preservatives against post-harvest tomato fruit rot. The in-vitro antifungal effect of 09 different treatments (07 plants based = black pepper, red pepper, turmeric, clove, garlic, onion and papaya seed and 02 chemical preservatives = Potassium metabi-sulphate, PMS and Sodium benzoate, SB) showed significant (P < 0.05 = 0.0000) variation among the treatment groups. Black pepper followed by red pepper and turmeric remained the best antifungal and preservative after 05, 10 and 15 days after treatment (DAT) in B-group (inoculated and uninjured fruits). However, in A-group (inoculated and injured fruits), lowest infection percent was recorded for black pepper followed by red pepper and turmeric after 05, 10 and 15 DAT. The response of all treatments was obvious after 15 DAT. No infection of test fungus was recorded when black pepper and red pepper were applied. Whereas, with the application of turmeric (8.33%) and garlic (9.33%) lowest infection percent was observed with no significant difference. The response of onion (4.33%), papaya seed (6%), clove (7.66%) and SB (15%) appeared moderate with no significant difference. After 30 days, the lowest number of spoilt fruits were recorded with the treatment of black pepper (01) and red pepper (01) followed by turmeric (02), clove (02), onion (02) and SB (02) in B-group. Based on best physical structure, maximum numbers of tomato fruits were observed in clove (04) followed by black pepper (03) and SB (03) when treated without any injury (B group). While in case of A group, almost all fruits in all treatments become spoilt after 30 days of treatment. It has been proved that locally available plant based preservatives have an excellent antifungal and preservative potential against post-harvest tomato fruit rot disease caused by Alternaria solani. These plant based preservatives increase the shelf-life of tomatoes without any health hazards. To the best of our knowledge, this is the first time conducted study, where antifungal and preservative potential of locally available plant products against post-harvest tomato fruit rot caused by Alternaria solani have been explored.

Frugivory by Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) Alters Blueberry Fruit Chemistry and Preference by Conspecifics.

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive pest from Asia that feeds on many agricultural crops in the United States, including blueberries. Yet, the effects of H. halys feeding on fruit chemistry and induced resistance to insects remain unknown. Here we hypothesized that frugivory by H. halys changes fruit chemical composition, which in turn affects insect feeding behavior. In field experiments, blueberry fruit was either mechanically injured or injured by 0 (control), 2, 5, or 10 H. halys Total soluble solids (°Brix) and anthocyanin and phenolic content in injured and uninjured fruits, as well as their effects on feeding behavior by conspecifics, were measured subsequently in the laboratory. Results showed lower °Brix values in injured fruit as compared with uninjured fruit. Fruit injured by 2 and 5 H. halys also had 32 and 20% higher total phenolics, respectively, than the uninjured controls. The proportions of the anthocyanins derived from delphinidin, cyanidin, and petunidin increased, whereas those from malvidin decreased, in fruit after mechanical wounding and frugivory by H. halys In dual-choice tests, H. halys fed more often on uninjured fruit than those previously injured by conspecifics. These results show that frugivory by H. halys reduces the amounts of soluble solids, alters anthocyanin ratios, and increases levels of phenolics, and, as a result, injured fruits were a less preferred food source for conspecifics. To our knowledge, this is the first study to investigate the effects of frugivory on fruit chemistry and induced fruit resistance against a fruit-eating herbivore.

On the inability of ants to protect their plant partners and the effect of herbivores on different stages of plant reproduction

Ants co-occur with herbivorous thrips in several tropical plants, but their interactions are largely unexplored. Should thrips be deterred by ants, a positive effect of ants on plant fitness might be expected. Here, by using an experimental study design with ant-present and ant-excluded treatments, we investigated the influence of Camponotus blandus on Pseudophilothrips obscuricornis abundance and herbivory in three extrafloral nectaried species: Banisteriopsis malifolia, B. laevifolia and B. stellaris. In addition, we examined the effect of thrips herbivory on flower set and fruit development and dispersion. Thrips abundance and herbivory were higher on ant-present stems of B. malifolia and B. laevifolia, where thrips managed to escape from ants by hiding in between clusters of flower buds (thygmotaxis behaviour). In B. stellaris the results were the opposite, as flower bud clusters did not offer hiding places, so thrips were unable to hide from ants; thus both thrips abundance and herbivory were lower on ant-present stems. Thrips herbivory had no significant effect on flower and fruit set, but samaras (V-shaped winged fruits of Malpighiaceae) attacked by thrips presented severe distortions and asymmetries. This caused damaged fruits to be dispersed closer to the mother plant, whereas uninjured fruits were dispersed further away. This study is evidence that ant–plant–herbivore systems have variable outcomes depending on the species involved, their behaviour and the plant structure under consideration. Unlike other herbivores, thrips negatively influence the very last stage of plant reproduction. The minute and furtive herbivorous thrips have long been ignored in natural systems, but because of their wide host range, they may be important herbivores even in extrafloral nectaried plants, which are usually fiercely protected by ants.

Improving the Performance of the Granulosis Virus of Codling Moth (Lepidoptera: Tortricidae) by Adding the Yeast Saccharomyces cerevisiae with Sugar

Studies were conducted with the codling moth granulosis virus (CpGV) to evaluate whether adding the yeast Saccharomyces cerevisiae Meyen ex E. C. Hansen with brown cane sugar could improve larval control of Cydia pomonella (L.). Larval mortalities in dipped-apple bioassays with S. cerevisiae or sugar alone were not significantly different from the water control. The addition of S. cerevisiae but not sugar with CpGV significantly increased larval mortality compared with CpGV alone. The combination of S. cerevisiae and sugar with CpGV significantly increased larval mortality compared with CpGV plus either additive alone. The addition of S. cerevisiae improved the efficacy of CpGV similarly to the use of the yeast Metschnikowia pulcherrima (isolated from field-collected larvae). The proportion of uninjured fruit in field trials was significantly increased with the addition of S. cerevisiae and sugar to CpGV compared with CpGV alone only in year 1, and from the controls in both years. In comparison, larval mortality was significantly increased in both years with the addition of S. cerevisiae and sugar with CpGV compared with CpGV alone or from the controls. The numbers of overwintering larvae on trees was significantly reduced from the control following a seasonal program of CpGV plus S. cerevisiae and sugar. The addition of a microencapsulated formulation of pear ester did not improve the performance of CpGV or CpGV plus S. cerevisiae and sugar. These data suggest that yeasts can enhance the effectiveness of the biological control agent CpGV, in managing and maintaining codling moth at low densities.

The incidence of storage rots after postharvest apple washing

The effect of four postharvest apple washing treatments and two unwashed treatments on fruit surface microflora and the development of storage rots in punctured and uninjured fruit were assessed A significantly higher incidence of storage rot was observed in punctured apples (1635) than in uninjured apples (13) after washing in water with high fungal populations (P

Factors Affecting the Differential Capture of Male and Female Codling Moth (Lepidoptera: Tortricidae) in Traps Baited with Ethyl (E,Z)-2,4-Decadienoate

Studies were conducted in apple to evaluate factors that differentially affect the catch of male and female codling moth, Cydia pomonella L., in traps baited with ethyl (E, Z)-2,4-decadienoate (pear ester). We examined the time of moth capture in the diel cycle and the recapture rates of marked moths in sex pheromone mating disruption (MD) and untreated orchards. The attractiveness of pear ester–baited traps was compared among five apple cultivars. Experiments also assessed the influence of trap height, the distance of the trap from sex pheromone dispensers, proximity of foliage surrounding the trap, trap size, and proximity of adjacent clean and codling moth–injured fruit on moth captures. The responses of male and female moths significantly differed in response to many of these factors. For example, the time of peak female capture occurred earlier than for males. A higher proportion of recaptured, marked moths were females in MD versus untreated orchard plots. Significantly more male but not female moths were caught in traps placed high versus low in the tree canopy. Traps placed on the perimeter of the canopy caught significantly more female moths than traps placed within the canopy and surrounded by foliage. Smaller trap surfaces caught significantly more males than females. Traps placed adjacent to uninjured fruit caught significantly more females than traps placed away from fruit. No differences occurred between sexes in response to other factors: significantly higher counts of both sexes occurred in blocks of ‘Granny Smith’ versus four other apple cultivars; recapture rates of marked moths were not different at release points ranging from 10 to 50 m for either sex; and trap placement relative to MD dispensers or injured versus uninjured fruits was not a significant factor affecting moth catches or their sex ratio. Effective monitoring for either or both sexes of codling moth should consider standardizing these factors. Lure and kill strategies should include factors that optimize the captures of female moths.

Factors Affecting the Differential Capture of Male and Female Codling Moth (Lepidoptera: Tortricidae) in Traps Baited with Ethyl (<I>E</I>, <I>Z</I>)-2,4-Decadienoate

Studies were conducted in apple to evaluate factors that differentially affect the catch of male and female codling moth, Cydia pomonella L., in traps baited with ethyl (E, Z)-2,4-decadi- enoate (pear ester). We examined the time of moth capture in the diel cycle and the recapture rates of marked moths in sex pheromone mating disruption (MD) and untreated orchards. The attrac- tiveness of pear esterÐ baited traps was compared among Þve apple cultivars. Experiments also assessed the insuence of trap height, the distance of the trap from sex pheromone dispensers, proximity of foliage surrounding the trap, trap size, and proximity of adjacent clean and codling mothÐinjured fruit on moth captures. The responses of male and female moths signiÞcantly differed in response to many of these factors. For example, the time of peak female capture occurred earlier than for males. A higher proportion of recaptured, marked moths were females in MD versus untreated orchard plots. Sig- niÞcantly more male but not female moths were caught in traps placed high versus low in the tree canopy. Traps placed on the perimeter of the canopy caught signiÞcantly more female moths than traps placed within the canopy and surrounded by foliage. Smaller trap surfaces caught signiÞcantly more males than females. Traps placed adjacent to uninjured fruit caught signiÞcantly more females than traps placed away from fruit. No differences occurred between sexes in response to other factors: signiÞcantly higher counts of both sexes occurred in blocks of OGranny SmithO versus four other apple cultivars; recapture rates of marked moths were not different at release points ranging from 10 to 50 m for either sex; and trap placement relative to MD dispensers or injured versus uninjured fruits was not a signiÞcant factor affecting moth catches or their sex ratio. Effective monitoring for either or both sexes of codling moth should consider standardizing these factors. Lure and kill strategies should include factors that optimize the captures of female moths.

Tebufenozide Targeted Against Codling Moth (Lepidoptera: Tortricidae) Adults, Eggs, and Larvae

The effectiveness of tebufenozide applied against the adult, egg, and larvae of codling moth, Cydia pomonella (L.), was evaluated. Significant reductions in fecundity and egg hatch occurred after 1-h and 24-h exposures of females and 24-h exposures of males-only to residues in plastic plates. A significant reduction in egg hatch was also found after a 1-h exposure of males. The ovicidal effects of tebufenozide in field trials did not significantly differ for eggs laid on residues or treated topically. Corrected egg mortality exceeded 95% for cohorts laid <130 degree-days after sprays were applied. Fecundity and egg hatch were measured after either a 24-h exposure of moths or a 10-d exposure of moths and eggs on apple trees. Significant reductions in both fecundity and fertility occurred compared with an untreated control up to 7 d in the 24-h assays and accounted for 60-70% fewer larvae produced per mated female. The mean numbers of larvae produced per mated female after the 10-d exposure were reduced 100-75% in assays started on day 0-21 after the spray application compared with the untreated control. Fecundity was significantly reduced for 7 d and egg hatch was reduced for the entire 21-d test period in these trials. Residues had a 14-d half-life on apple foliage. Residues applied to foliage or to foliage and fruit did not significantly increase the proportion of uninjured fruit compared with the untreated control in bioassays where neonates were placed on foliage 10 cm from fruit. However, the proportion of injured fruits with shallow stings versus deep entries was higher on the treated versus the untreated plants. Field applications of tebufenozide reduced fruit injury >90% when applied early during emergence. Plots treated after the beginning of egg hatch had a larger proportion of injured fruits with shallow larval feeding.

Effect of environmental conditions and inoculum density on infection of guava fruits by Colletotrichum glososporioides.

The influence of environmental factors (temperature and humidity), inoculum density on infection by Colletotrichum glososporioides and development of anthracnose lesions were determined on uninjured, sand-injured and punctured fruits. The optical temperature for severe infection was 30 degrees C, whereas the disease incidence was less at 20 and 35 degrees C. Inoculated guavas that received 1-60 h of continuous free moisture developed lesions, but the disease was minimal (0-7%) after 1-6 h free moisture. Infection rates of uninjured, sand-injured and punctured fruits receiving 60 h of free moisture were 34, 70 and 100%, respectively. Disease incidence increased as inoculum density increased from 101 to 106 conidia/ml. In field conditions, the development of anthracnose lesions was greater on punctured guavas than on uninjured or sand-injured ones, in both rainy and winter seasons. In general, the number of lesions was highest in sand-injured fruits, followed by punctured and uninjured fruits. In rainy season the number of lesions on injured and uninjured fruits was greater than similarly treated guavas in winter.

Evaluation of two screening methods for resistance of apricot, plum and peach toMonilinia laxa

Monilinia laxa causes important pre- and post-harvest losses in stonefruit. In order to initiate a breeding programme for increased resistance toM. laxa, two screening tests were used. In the “uninjured fruit inoculation” test, 30 mature fruits of each variety were inoculated on their surface by depositing 20 μl of conidial suspension. In the “artificially injured fruit inoculation” test, 10 mature fruits were inoculated on both sides by injecting 20 μl of conidial suspension. Genotypic differences were found in both tests, within the three species studied. Marked differences were observed in the uninjured fruit inoculation test. Differences between genotypes were slighter in the artificially injured fruit inoculation test. Within each species, the rankings of the genotypes according to the two tests were not correlated. Both testing procedures would be usefully applied in a breeding programme to obtain genotypes with combined resistance toMonilinia laxa.

Transmission of Mucor piriformis to Fruit of Prunus persica by Carpophilus spp. and Drosophila melanogaster

Vinegar flies and nitidulid beetles acquired propagules of M. piriformis and transferred them to 75-100% of injured peach fruit. In general, C. hemipterus transmitted M. p. to wounded fruit more efficiently than C. freemani. Propagules of M. p. persisted for at least 15 days on D. melanogaster and 11 days on C. hemipterus. Only the nitidulid beetles transmitted the fungus to uninjured peach fruit, causing fruit rot on 42-75% of uninjured fruit

Effects of Tufted Apple Budmoth (Lepidoptera: Tortricidae) Injury on Quality and Storageahility of Processing Apples

A study was done to determine the impact of tufted apple budmoth (TABM), Platynota idaeusalis (Walker), feeding injury on the quality and storageability of ‘Yorking’ apples destined for processing markets. Apples were evaluated according to USDA standards for processing. Quality measurements such as soluble solids, firmness, weight loss, and decay were determined at harvest and at various intervals during regular and controlled atmosphere storage. Most TABM-injured fruit remained as a U.S. #1, thus not impacting the grower’s financial return. At harvest, soluble solids in uninjured and injured U.S. #1 fruit did not differ, but soluble solids were significantly lower in uninjured fruit than in U.S. #2 (cider or cull apples). Weight loss was significantly higher for injured apples compared with uninjured apples at all regular storage periods. Percentage of decayed fruit among TABM injured apples was significantly higher than among uninjured fruit in regular storage after 6 mo and in controlled atmosphere storage after 9 mo. In general, TABM injury tended to accelerate fruit maturity and decrease fruit quality during storage.

Freeze fracture evidence for lateral phase separations in the plasmalemma of chilling-injured avocado fruit

Unripe avocado fruit (Persea americana Mill. cv Hass) were held at 6 °C either in air or in an atmosphere with 100 PPM ethylene and were assessed for chilling injury after one and two weeks. Injury did not occur in any fruit after one week. After two weeks, the fruit in air were still uninjured, but the fruit subjected to ethylene exhibited chilling injury. When the uninjured fruit (both air-treated for one and two weeks and ethylene-treated for one week) were allowed to warm to room temperature before freezing for freeze fracture electron microscopy, replicas revealed membranes with a randomly dispersed pattern of intramembranous particles (IMPs). However, when these uninjured fruit were frozen for freeze fracture without warming, particle-free domains were visible in the plasmalemma. The membranes of the ethylene-treated, chilling-injured (2 weeks) fruit, on the other hand, contained particle-depleted regions in the plasmalemma of fruit frozen not only from 6 °C but also in those allowed to warm to room temperature before freezing for freeze fracture. These particle depleted microdomains were not seen in fruit kept continuously at room temperature (20 °C), even in the presence of high levels of endogenous ethylene which is produced during normal ripening. We suggest these particle-depleted microdomains formed in the fruit frozen for freeze fracture from low temperatures and in the chilling-injured fruit to be due to lateral phase separations of the membrane components, possibly due to an increase in the viscosity of some membrane lipids, leading to the formation of microdomains of gel phase lipid in the plane of the membrane. These phase separations appear to be initially reversible by raising the temperature, however, this reversibility is apparently lost after injury has occurred. With regard to the cause of chilling injury in avocados, we suggest that some secondary effect is involved due to the long term presence of gel phase lipids in the membrane.

A LOW-SPRAY APPLE-PEST-MANAGEMENT PROGRAM FOR SMALL ORCHARDS

AbstractFrom 1981 to 1984, a low-spray management program was employed against injurious arthropods on the 40 disease-resistant apple trees in my experimental orchard in Massachusetts. The program consisted of an annual early-season application of petroleum oil followed by 2 applications of phosmet (1 at petal fall and another 10–14 days later). Visual traps were used to suppress Rhagoletis pomonella flies. For all years combined, a mean of 89.7% of fruit sampled at harvest in this orchard was free of insect injury compared with 0% uninjured fruit on neighboring unsprayed trees. Populations of foliar-feeding pests never reached injurious levels.

Periderm morphology of mature ‘Golden Delicious’ apple with special reference to russeting

Periderm morphology of ‘Golden Delicious’ in relation to russet development revealed that injury occurring at anthesis persisted at fruit maturation. Uninjured fruit had uniformity in cuticle, epidermal and cortical cell development in contrast to injured fruit which had a broken disrupted cuticle with extensive phellem development. Sloughing of phellem continued until outer hypodermal tissues were exposed.

The effect of mechanical injury on exudation from immature and mature peanut fruits under axenic conditions

Sugars and amino-N compounds exuded from axenically-grown peanut fruits following mechanical injury, were measured by gas-liquid and thin-layer chromatography. Injury of the peanut fruit surface resulted in a 10–20 fold increase in sugar exudation and an increase in the amount of amino N exuded. Analysis of leachates of the weblite (an exploded shale soil substitute) in which axenic fruits developed showed that exudation of sugars had occurred from uninjured fruits in situ. These results support the hypothesis that exudates in the geocarposphere are an important ecological factor affecting microbes in the soil and the colonization of peanut fruits by Aspergillus flarus.

Volatiles from Injured and Uninjured Valencia Oranges at Different Temperatures

SUMMARY— Volatiles emanating from injured and uninjured Valencia oranges increased in number and amount with increasing temperature. The amount of emanated volatiles increased about 20‐fold from uninjured fruit and about 50‐fold from injured fruit between holding temperatures of 2 and 38°C. The average amount of volatiles emanating from injured oranges was nearly 75 times as great as that from uninjured fruit; the number of components did not increase. These results demonstrate the need for caution in interpretation of aroma patterns from oranges and for strict standardization of experimental conditions.

Keltamuumiotaudin tarttuvaisuudesta sekä sen ehkäisemisestä Paration-valmisteilla

The significance of fruit lesions of different kinds in brown-rot infection has been investigated. M. fructigena conidia were rubbed with a paint brush on the surface of apples uninjured and injured in different ways. All the uninjured fruits remained healthy. Slight injury done by copperlime 0.5 % (Cuprosan 3) and smallish spots, without cracking of the fruit, due to apple scab (Venturia inaequalis) were also unfavorable to the penetration of the brown-rot fungus. Infection in the former case was 0 %, in the later 7.1 % of apples inoculated. The inoculation of apples with severe corking and cracking resulted in 20.0 % infection and the inoculation of fruits injured by the codling moth (Carpocapsa pomonella) in 75.0 % respectively. All the fruits were infected when conidia were placed in a wound made with a knife-blade. It is thought that the susceptibility of lesions of different kinds to the brown-rot fungus is chiefly due to the moisture of the substrate and the air in the immediate proximity of the growing hypha. Spraying with the usual fungicides appears to be successful in controlling the brown-rot disease only if every fresh wound is covered (12). The control of apple scab and codling moth is also of importance, to avoid lesions made by these. It was thought that a compound penetrating the fruit tissues might be effective in controlling the disease through inhibiting the growth of mycelium in the tissues. One such chemical penetrating the plant tissues is diethylnitrophenylthiophosphate (E 606) (6). Parathion is found to inhibit the growth of Sclerotinia fructigena conidia (1). The fungistatic action on the brown-rot fungus of Parathion and some other chemicals penetrating the fruit tissues was investigated in the laboratory by dipping apples of the variety Charlottenthal or soaking them for 24 and 48 hours in the liquids. Every treatment consisted of 6 apples. Table 2. shows the daily growth of the brown-rot spot on apples treated in different ways and inoculated. The growth rate is shown in figure 2. Dipping, which corresponds in effect to one spraying (6), in 0.1 % mercuric chloride and in 0.1 % Cheminova-Parathion retarded the growth of the fungus. Soaking for 24 hours in Parathion reduced the growth greatly, soaking for 48 hours made the growth poor. Soaking in 0.05 % copper sulphate, 0.5 % tannin, 1 % ferrous sulphate and 0.1 % hydroquinone, too, retarded the growth of the fungus. The observations indicate that Parathion possesses an obvious fungistatic action on the brown-rot fungus and is possibly efficient in controlling it. For this reason a preliminary spraying experiment was carried out in 1950. The results indicate that Parathion was the preparation most successful in controlling the disease. This is due to the fungistatic action of Parathion and also to its insecticidal properties. Further investigations are needed into the significance of Parathion compounds in the control of the brown-rot disease.

Bacterial Plant Diseases in Japan

The bacterial spot of tomato was found causing a considerable loss in the districts devoted to production of tomato in Chosen. Its symptoms were found to be identical with the description given by E. M. DOIDGE, M. W. GARDNER, and J. B. KENDRICK, however, with a greater damage on the pedicels and peduncles. On about April when the plants are still in the seedling stage, this disease first becomes apparent, causing its greatest spread in the months of June and July, especially after rain which follows the sunny days. Greatest loss occured on the soil of relatively low water holding capacity and low in organic matter.The writer has found the causal organism to be practically same as the one described by the above mentioned investigators and B. B. HIGGINS, as Bacterium vesicatorium.The infection is effected through the stomatal openings and the injured tissues, and rarely uninjured fruits. The organism overwinters in the soil and in the infected leaves, stalks and seeds. Effective control of the disease is obtained by the seed disinfection with 1: 1000 to 1: 3000 solution of mercuric chloride, followed by spraying two or three times with 3-2-75 or 3-2-90 Bordeaux mixture prior to the appearance of the disease.