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Postharvest biology and technology of litchi fruit 全文
2003
Jiang, Yueming (author) | Yao, Lihu (author) | Lichter, Amon (author) | Li, Jianrong (author)
The mature litchi fruit is round to oval in shape and bright red in colour. It has a thin, leathery and indehiscent pericarp surrounding a succulent, edible white aril. The aril contains a relatively large dark brown seed. Litchi fruit is non-climacteric with little change in soluble solids concentration or titratable acidity after harvest. The fruits deteriorate rapidly unless proper handling techniques are employed. The major factors reducing the storage life and marketability of litchi fruit are microbial decay and pericarp browning. Low temperature storage at 1-5°C is used to reduce pathological decay, but has a only limited role in reducing pericarp browning. Moreover, the fruits deteriorate rapidly when removed from cold storage. Under refrigeration, litchi fruit has a storage life of approximately 30 days. Pulp quality and disease development are generally stable during cold storage until such time as fruit become visually unacceptable based on the evaluation of pericarp browning. Sulfur dioxide fumigation has been the most effective postharvest treatment for control of pericarp browning in litchi fruit, and is used extensively in commercial situations. However, there is increasing consumer and regulatory resistance to the use of this chemical. Insect disinfestation has become increasingly important with the expanding export market. Irradiation and heat treatments for insect disinfestation of litchi fruit have been found to be alternatives to treatment with insecticides. Recent research has focused on reducing these major postharvest problems in order to produce light-coloured, chemical-free fruit without disease or insect infestation.
显示更多 [+] 显示较少 [-]Isolation and identification of Phoma exigua var. foveata (Foister) Boerema - the causative agent of potato gangrene | Izolacija in identifikacija glive Phoma exigua var. foveata (Foister) Boerema, povzrociteljice gangrene krompirjevih gomoljev 全文
2003
Munda, A., Agricultural Inst. of Slovenia, Ljubljana (Slovenia)
Gangrene is an important storage disease of potato tubers. It causes significant losses due to the internal decay of the tissue. Gangrene has been reported from many European countries, being of the greatest economic importance in northern temperate countries. The disease is primarily caused by Phoma exigua var. foveata, although it can be caused by either of the two varieties of Phoma exigua Desm
显示更多 [+] 显示较少 [-]Use of sodium bicarbonate and Candida oleophila to control anthracnose in papaya during storage 全文
2003
Gamagae, S.U. | Sivakumar, D. | Wijeratnam, R.S Wilson | Wijesundera, R.L.C.
The potential of using the biocontrol agent Candida oleophila and sodium bicarbonate solution alone or in combination to reduce anthracnose caused by Colletotrichum gloeosporioides on papaya (Carica papaya L.) in storage was investigated. Treatment with 2% sodium bicarbonate did not significantly affect the growth of the biocontrol agent The efficacy of sodium bicarbonate at 2% for control of anthracnose increased when combined with C. oleophila strain (1-182) resulting in significant reduction of disease incidence at 13.5°C and 95% RH for 14 days and afterwards by 2 days at simulated marketing conditions (25°C, 75%). The growth of C. gloeosporioides was reduced significantly in the presence of C. oleophila in both inoculated and naturally infected fruits. Thus, use of sodium bicarbonate at 2% with the antagonist C. oleophila is a promising alternative to chemicals to control anthracnose, a major postharvest disease on papaya during storage.
显示更多 [+] 显示较少 [-]Efficacy of chlorine dioxide for disease control on stored potatoes 全文
2003
Olsen, Nora L. | Kleinkopf, Gale E. | Woodell, Lynn K.
The post-harvest application of chlorine dioxide (CIO2) was evaluated as a disease suppressant for stored potatoes. Chlorine dioxide was prepared by acidifying a buffered sodium chlorite solution with a food grade acid. In vitro studies verified the effectiveness of CIO2 at low concentrations (ED50 = 2 to 122 ppm) against Erwinia carotovora (soft rot), Fusarium spp. (dry rot) and Helminthosporium solani (silver scurf). Evaluations of tubers inoculated with Phytophthora infestans (late blight) and Fusarium spp. or infected with H. solani and then treated with CIO2 either going into storage or through the humidification system resulted in a lack of disease suppression. Inconsistent performance of CIO2 in storage appeared to be a result of several contributing factors. Chlorine dioxide concentrations varied greatly (up to six-fold), depending upon the method of activating and diluting sodium chlorite solutions. Chlorine dioxide is a gas soluble in water and, therefore, is easily released from solution (25%-75% loss) into the air when applied as an aqueous spray. Chlorine dioxide reacts quickly with the tuber and associated organic matter, thereby reducing the effectiveness. Applying higher than currently registered rates may be necessary to achieve measurable disease suppression.
显示更多 [+] 显示较少 [-]A study of some biochemical and histopathological responses of wet-stored recalcitrant seeds of Avicennia marina infected by Fusarium moniliforme 全文
2003
Anguelova-Merhar, V.S. | Calistru, C. | Berjak, P.
Although fungi cause a recognized problem during storage of recalcitrant seeds of many tropical species, there are no data to date on defence strategies of these seeds against fungal attack. To ascertain whether recalcitrant seeds of Avicennia marina elaborate compounds that might suppress fungal proliferation during hydrated storage, the production and efficacy of β-1,3-glucanase (EC 3.2.1.39) and chitinase (EC 3.2.1.14) were studied in relation to histopathological changes. Freshly harvested seeds had low β-1,3-glucanase and chitinase activities and fluorescence microscopy revealed progressive deterioration of the internal tissues of these seeds associated with fungal infection during hydrated storage. In seeds treated to minimize associated fungi (clean seeds), β-1,3-glucanase and chitinase activities increased significantly during 10 d of hydrated storage. Similar high levels of activity were observed when these seeds were experimentally infected with Fusarium moniliforme and subjected to further storage. The histopathological observations indicated delayed disease development in the 10-d clean-storage period, although the hypersensitive response was not observed. The results suggest that, although the recalcitrant seeds of A. marina elaborate some antifungal enzymes, there is a lack of effective defence strategies that might lead to successful responses against fungal infections.
显示更多 [+] 显示较少 [-]Genetic mapping of GBE1 and its association with glycogen storage disease IV in American Quarter horses. 全文
2003
WARD, T.L. | Valberg, S.J. | Lear, T.L. | Guérin, Gérard | Milenkovic, Dragan | Swinburne, J.E. | Binns, M.M. | Raudsepp, T. | Skow, L. | CHOWDHARY, B.P. | Mickelson, J.R.
Effect of GA3, 2,4-D and coating solution on storage life of lime under modified atmosphere condition
2003
Sirichai Kanlayanarat(King Mongkut's University of Technology Thonburi, Bangkok (Thailand). School of Bioresources and Technology) | Apiradee Uthairatanakig(King Mongkut's University of Technology Thonburi, Bangkok (Thailand). School of Bioresources and Technology) | Chalermchai Wongs-aree(King Mongkut's University of Technology Thonburi, Bangkok (Thailand). School of Bioresources and Technology)
Results showed that the fruit coated with Sta-fresh no.360 mixed with GA3 or 2,4-D could delay color change, weight loss, titratable acidity and soluble solid and vitamin C losses as well as reduce the disease and physiological disorder better than uncoated fruits mixed with GA3 or 2,4-D. GA3 application at 100 and 500 ppm with or without Sta-fresh no.360 effectively delayed color change and weight loss as well as reduced the disease and physiological disorder better than that at 0 and 20 ppm, respectively. The fruit treated with 2,4-D showed that the concentration at 500 ppm with or without Sta-fresh no.360 was the most effective in delaying color change and reducing the disease. For the modified atmosphere condition at 5 and 10 percent CO2 could delay color change and reduce the disease better than that at 0.03 and 1 percent CO2, respectively. However, the fruit stored at 10 percent CO2 showed the physiological disorder symptom, i.e. the skin being turned brown. This physiological disorder symptom increased in coated fruit stored at 10 percent CO2, which limited the storage life of limes to just 45 days, the same as the control. Meanwhile, uncoated limes treated with GA3 at 100 and 500 ppm and coated limes treated with GA3 at 0, 20, 100 and 500 ppm, stored at 0.03, 1 and 5 percent CO2 could maintain their storage life up to 60 days.
显示更多 [+] 显示较少 [-]ADVANTAGES OF ARTIFICIAL REPRODUCTION TECHNIQUES FOR WHITE-CLAWED CRAYFISH (AUSTROPOTAMOBIUS PALLIPES LEREBOULLET) 全文
2003
CARRAL J. M. | SÁEZ-ROYUELA M. | CELADA J. D. | PÉREZ J. R. | MELENDRE P. M. | AGUILERA A.
With the aim of preserving and increasing endangered stocks of white-clawed crayfish, research on juvenile production has been carried out. Advantages in application of newly developed techniques of egg storage, transport and artificial incubation techniques are discussed. Eggs can be removed from maternal pleopods during the early stages of embryonic development and placed in artificial incubation devices. This practice avoids egg losses caused by aggressive contacts, female disease or death and the production of stage-2 juveniles in different batches by means of temperature manipulation. Furthermore transmission of pathogens from broodstocks to offspring can be minimised. Egg storage and transport have some advantages in the artificial reproduction of crayfish. Firstly, embryonic development continues under storage conditions and thus water and human effort can be saved during this period. Temperature plays an important role on both efficiency rates and duration of embryogenesis. Secondly, egg transport could facilitate restocking programs, as there is no need to move berried females to other habitats. To sum up, the combined use of artificial incubation and storage/transport techniques could have important applications to the development of astacid crayfish culture.
显示更多 [+] 显示较少 [-]Study on the effect of Rhizoctonia root and crown rot on the quality and quantity of sugar beet
2003
Mahmoudo, Seyyed Bagher | Soltani, Jamshid | Rahnamaeyan, Mehrdad | Babae, Babak | Tavangar Ranjbar, Bahman | Banisadr, Fereydon | Arjmand, Mohammad Naser
Three type of sugar beet root rot symptoms including brown root and crown rot, dry rot canker and violet root rot was observed in the vicinity of Lorestan and Chenaran sugar factories. About 25% of samples showed root and crown rot symptoms and 30% of them had dry rot cankers. Violet root rot was endemic and 3.3% of the samples showed the symptom. Rhizoctonia solaniAG-2 and Rhizoctonia solani AG-4 were isolated from brown root and crown rot symptoms and Rhizoctonia crocorum also isolated from violet root rot symptoms. Using seedling traps bioassay of infected soils could not trapped any Rhizoctonia isolate. Infected fields vicinity Lorestan sugar factory was estimated 32%, while for Chenaran factory 45% was estimated. Sugar content of diseased roots with disease severity of 3-4 (0-7 scale) was measured half of their healthy plants. The amount of Na and K and aminonitrogen was measured in diseased roots (with moderate and sever disease severity) 2-3 times of their healthy plants. Considering these findings and due to develop the disease in storage periods, using roots with disease severity above 3 is not recommended.
显示更多 [+] 显示较少 [-]Effects of ethylene and 1-MCP on the quality and storage life of strawberries 全文
2003
Bower, J.H. | Biasi, W.V. | Mitcham, E.J.
Strawberry quality declines rapidly after harvest. Deterioration may be accelerated by ethylene and is potentially increased, decreased or unaffected by the ethylene inhibitor 1-MCP (1-methylcyclopropene). We have examined the effects of 0.01, 0.05, 0.1 and 1 μl l−1 of ethylene and 0.01, 0.1, and 1.0 μl l−1 1-MCP on the quality attributes and respiration rates of strawberries stored at 0 or 5 °C. Ethylene did not affect the rate of rot development. However, calyx quality was significantly reduced by exposure to 0.1 or 1.0 μl l−1 ethylene. Treatment with 1 μl l−1 1-MCP protected the calyx tissue from these effects. Exposure of strawberries to 0.01, 0.1 or 1.0 μl l−1 1-MCP did not affect overall fruit acceptability but did slightly increase the rate of rot development. 1-MCP treatment reduced ethylene production by the fruit. Increased production of CO2 by 1-MCP treated fruit was associated with the earlier onset of rots. Although the results suggest that blocking ethylene perception interferes with disease resistance in strawberries, there was only a small effect on total storage life. It was concluded that neither the removal of low levels of ethylene from the storage environment nor the treatment with 1-MCP are likely to be cost effective methods of extending strawberry storage life. It was concluded that neither removing low levels of ethylene from the storage environment nor treating with 1-MCP are likely to be cost-effective methods of extending storage life.
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