خيارات البحث
النتائج 1 - 10 من 58
[Helminthosporium solani infection: a storage disease in potatoes]
2002
Nielsen, S.L. | Kohistani, R. | Moeller, L.
Studies on the development of storage scab in apple and its management النص الكامل
2002
J.L. KAUL1, J.N. SHARMA and
Fruits of Royal and Golden Delicious apple cultivars were harvested, wrapped and stored in ambient conditions at Kotkhai in Himachal Pradesh, India. Storage scab, caused by Venturia inaequalis, appeared after 45 days in both the cultivars. With Golden Delicious apples, disease incidence was 10 and 20% after 45 and 90 days, respectively. Royal Delicious apples showed comparatively less disease. On average, 3-5 scab lesions developed per fruit. Scab infected apples were unfit for storage due to pronounced shrinkage and rotting caused by other fungi. Pre-harvest sprays of captan (0.2%) exhibited maximum reduction in storage scab, percentage disease control being 85, 80 and 74% at 45, 60 and 90 days, respectively, followed by bitertanol (0.075%) and carbendazim (0.05%). Pre-harvest sprays of carbendazim and captan were 100% effective in controlling postharvest fruit decay for 60 days. Postharvest dip treatment of apple fruits in bitertanol (0.075%) gave maximum control of storage scab up to 90 days, followed by carbendazim and captan. Carbendazim dip treatment, however, completely controlled the fruit rotting in common storage for 3 months.
اظهر المزيد [+] اقل [-]Etiology and management of storage rot of ginger in Himachal Pradesh النص الكامل
2002
DOHROO, N.P.
Pythium ultimum, Fusarium oxysporum and Verticillium chlamydosporium were found associated with storage rot of ginger. The disease was noticed in storage pits from January, which reached its maximum intensity in April at IS.SoC temperature and 67.S per cent relative humidity. Studies on the effect of pre-storage treatments on storage rot of ginger revealed that the pre-storage treatment with Topsin-M and Bavistin each at 0.2 per cent concentration for 60 minutes reduced incidence of storage rot, loss in rhizome weight, surface shriveUing sprouting of ginger and increased the recovery of the rhizomes.
اظهر المزيد [+] اقل [-]Postharvest disease control in lychee النص الكامل
2002
Johnson, G. I. | Cooke, A.W. | Sardsud, U.
Lychee (Litchi chinensis Sonn.) is a highly perishable commodity. Internationally, sulphur dioxide fumigation, modified atmosphere packaging, fungicide and hot water dips, and cool storage are used to reduce disease losses. This paper summarizes results of screening work with these treatments and comments on their current utility. Hot benomyl was equally effective at 50 and 52°C in controlling postharvest disease lesions (caused by Alternaria alternata, Phomopsis sp. and other fungi) on lychee cv. Bengal during storage at 5°C for up to 30 days. Since this work has been completed, benomyl has been withdrawn as a postharvest fungicide but thiabendazole has been an effective replacement. Hot benomyl appeared less effective on cv. Kwai Mai Pink, where heat damage of the pericarp interacted with disease expression. Prochloraz also provided good disease control but unfortunately caused tainting. Sulphur dioxide slow release pads provided good disease control, but caused bleaching of the pericarp. Colour gradually returned after removal of the sulphur dioxide pads. Penicillium spp. infected fruit that were not completely fumigated. Cool storage (5°C) per se delayed disease expression on cv. Bengal for up to 16 days. A. alternata, Colletotrichum gloeosporioides, Colletotrichum acutatum and Pestalotiopsis sp. were recorded as pathogens of lychee fruit.
اظهر المزيد [+] اقل [-]Evaluation of storage losses of onion sets depending on the storage temperature
2002
Krawiec, M. (University of Agriculture, Lublin (Poland). Dept. of Seed Production and Nurseries)
Two temperature ranges were applied: 0-1 and 18-20 deg C, which, according to the research of many authors prevent vernalization of onion sets. The experiment was carried out in the years 1996-99. For storage, two cultivars of onion were selected, divided into 4 size class. Determined were the extent of the weight losses, the total storage losses, and occurrence of disease symptoms. It was found that storage in a temperature of 18-21 deg C had a significant effect on the increase in total storage losses in comparison with storage in a temperature of 0-1 deg C. The smaller the onion sets stored, the more bulbs completly dried up and the fewer were sprouting into leaves
اظهر المزيد [+] اقل [-]Survival of conidia of Clonostachys rosea on stored barley seeds and their biocontrol efficacy against seed-borne Bipolaris sorokiniana النص الكامل
2002
Jensen, Borge | Knudsen, I.M.B. | Jensen, D.F.
Survival and biocontrol activity of Clonostachys rosea (isolate IK726) conidia during storage on barley seeds were investigated. The initial density of colony forming conidia on seed was 4 x 10(3) to 9 x 10(4) colony forming units (cfu)/seed After 5 months storage at 4 degrees C, the density decreased by less than one order of magnitude and the biocontrol efficacy against seedling blight caused by seed-borne Bipolaris sorokiniana was maintained at a significantly high level (> 80% disease reduction) for > 5 months. Conidial survival on seeds stored at 20 degrees C declined more rapidly than at 4 degrees C, and biocontrol efficacy was significantly reduced after 3-5 months. However, conidia produced on solid media over 20 days survived better than conidia produced in liquid culture and conidia from solid media produced over 12 days. In contrast, when seeds treated with conidia were packed with silica gel and stored at 20 degrees C, the cfu density decreased by less than one order of magnitude after 5 months and the biocontrol efficacy was still high after 6 months. A dose-response curve revealed that 10(3) cfu/seed were needed for 80% control of seedling blight. Similar control was obtained in storage experiments when approximately 10(3) cfu/seed were recovered from seed, indicating that conidia which survived also retained a high ability to control disease.
اظهر المزيد [+] اقل [-]Prolonged storage of ‘Karuthacolomban’ mango by modified atmosphere packaging at low temperature النص الكامل
2002
Mature ‘Karuthacolomban’ mangoes were sealed in low-density polyethylene (LDPE) bags to create modified atmosphere (MA) conditions and stored at 13°C and 94% r.h. The effect of potassium permanganate impregnated bricks as ethylene scavengers and activated granular charcoal as carbon dioxide scavengers on extending the storage life of mango was examined. The in-package concentrations of oxygen, carbon dioxide and ethylene, and changes in physico-chemical properties during storage were determined. Storage was terminated at different intervals, and the fruits were allowed to ripen naturally under ambient conditions. The optimum storage period was determined based on the visual quality rating (VQR) and disease index (DI) of the ripened fruits. The physico-chemical and sensory properties of the ripened fruits subjected to MA storage were determined and compared with the fruits packaged in perforated LDPE bags. In-package oxygen, carbon dioxide and ethylene concentrations were 2.3%, 6.2% and 0.24 mg kg–¹, respectively, in packages containing the scavengers on day 21 in storage. These corresponding concentrations in the packages were 7.5%, 11.7% and 0.8 mg kg–¹, respectively, in the absence of scavengers on day 21 in storage. The fruits packaged with scavengers had lower percent weight loss and minimum changes in physico-chemical properties compared with the fruits packaged without scavengers. The modified atmosphere created in LDPE was effective in delaying ripening of ‘Karuthacolomban’ mangoes up to 16 d; ripening was further delayed up to 21 d in the presence of scavengers. Physico-chemical and sensory properties, VQR and DI of MA stored mango after ripening were similar to those packaged in perforated LDPE bags. Therefore, packaging of ‘Karuthacolomban’ mango in 0.05 mm LDPE bags of 1:1 surface area to weight ratio (cm²g–¹) with 50 ml of saturated potassium permanganate absorbed onto suitable porous matrices and 2 g of activated granular charcoal could be recommended to increase storage life at 13°C.
اظهر المزيد [+] اقل [-]Effect of hot water and chitosan on postharvest quality and shelf life of mango cv. Mahajanaka
2002
Wittawas Sasananun(Chiang Mai University, Chiang Mai (Thailand). Postharvest Technology Institute) | Vicha Sardsud(Chiang Mai University, Chiang Mai (Thailand). Faculty of Agriculture. Department of Plant Pathology) | Uraporn Sardsud(Chiang Mai University, Chiang Mai (Thailand). Faculty of Science. Department of Biology)
Study of chitosan effected to Colletotrichum gloeosporioides on PDA showed that all concentrations of chitosan could not inhibiting spore germination. A study of chitosan effected on symptom development of anthracnose disease on mango fruits, was conducted by infecting the mango fruits with the fungus. It was found that the mango fruits coated with 1.00 percent chitosan had the lowest disease occurance. Effect of chitosan on quality and shelf life of mango fruits were determined. It was found that the mango fruits coated with chitosan at 0.50, 0.75 and 1.00 percent had less weight loss than the fruits uncoated and coated with 0.25 percent. But, the peel of mango fruits coated with 0.75 and 1.00 percent chitosan had abnormally changed in colour and gave 5 days of storage life, while the mango fruits which uncoated and coated with 0.25 and 0.50 percent chitosan could last for 9 days. The fruits coated with chitosan after dipping in hot water at 52 and 55 deg C for 10 minute were stored at room temperature (25 deg C). The results showed that fruits dipped in hot water at 52 deg C for 10 minute and 55 deg C for 5 minute, and then coated with 0.50 percent chitosan gave the best result on decreasing anthracnose disease occurance. Temperatures and times of dipping did not effect on weight loss, firmness, total soluble solids (TSS) and titratable acidity (TA). However, fruits dipped in high temperature water and for a long period of time prolong colur change in peel and flesh. The storage life of all treatments in hot water were 9 days.
اظهر المزيد [+] اقل [-]Effects of nutrition on desiccation tolerance and virulence of Colletotrichum truncatum and alternaria alternata conidia النص الكامل
2002
Montazeri, M. | Greaves, M.P.
The promising mycoherbicides Colletotrichum truncatum and Alternaria alternata were grown respectively in liquid and solid semi-defined media. C. truncatum conidia produced in a medium with a C:N ratio of 5:1 showed higher desiccation tolerance (survival during storage) at 15% relative humidity and 25 degrees C, greater germination on the host leaf and greater disease expression on Sesbania exaltata than those produced in media with C:N ratios of 15:1 or 40:1. Similar results were obtained with conidia of A. alternata produced on a medium with a C:N ratio of 15:1. Conidia washed with 0.9% (w/v) NaCl produced higher tolerance to desiccation, and greater disease incitement, than unwashed conidia of C. truncatum or conidia washed with water. In contrast, washing had no positive effect on desiccation tolerance in A. alternata.
اظهر المزيد [+] اقل [-]Effect of cold treatment on survival and development of codling moth (Lepidoptera: Tortricidae) in cherry النص الكامل
2002
Hansen, J.D.
'Bing' cherries, Prunus avium L., were obtained from an organic orchard and a conventional commercial orchard. The two groups were examined separately in replicated tests infested with each fruit initially infested with a first-instar codling moth, Cydia pomonella (L.). To simulate commercial postharvest holding conditions, the treatments were 0 (control), 1, 2, 4, 7, 10, and 14 d cold storage at 3.3 degrees C. The fruits were examined three or more times to determine larval survival, life stage, fruit condition, and fungal disease. Survival of first instars was affected only by cold storage durations of greater than or equal to 7 d. When infested with codling moth larvae, both organic and conventionally grown cherries quickly deteriorated from fungal diseases. The rate of moth development was estimated from the surviving larvae and was significantly different between organic and conventionally grown cherries for all instars except the second.
اظهر المزيد [+] اقل [-]