The preservation of Cucumeropsis mannii Naud-Holl (‘Egusi’ melon) seeds by manipulating the temperature, relative humidity and type of storage was carried out. Fungi were pathogenic on melon seeds stored at high relative humidities of 100% and 91%, but not at lower humidity between 0 and 55%. Disease manifested on the melon seeds at temperature of 20°C and 37°C whereas no disease incidence was observed at temperatures 5-10°C and 40°C. Disease incidence varied with storage condition. Seeds stored in the oven (40°C±2; R.H. 0%) had no fungal isolate after 12 months storage. Those seeds stored in the garden (27-33°C; R.H. 76-90%) and laboratory shelf (28°C-30°C; R.H. 80-87%) for the same period had fungal isolates which were absent in the beginning of storage. There was an increase in the percentage infectivity of the melon seeds as the storage period increased, for seeds stored in the garden and laboratory. Seeds stored in the oven were not infected at the end of 12 months storage period. Unshelled melon seeds were less infected with fungi when compared to shelled seeds.

Effects of pretreatment (preconditioning and cooling) and packaging on storage quality of non-astringent 'Fuyu' persimmons (Diospyros kaki L.) were investigated during storage at 2℃. After 3-month storage, occurrence of flesh browning was higher in fruits preconditioned without film packaging. As preconditioning temperature increased from 17 to 40℃, flesh browning and chilling injury increased, whereas black spot disease occurrence decreased.

Chapaties were prepared from rice flour so as to make this product available to patients suffering from gluten intolerance (celiac disease). The textural properties of the fresh and 24 h stored rice flour chapati were determined using a tensile deformation test. The extensibility and energy to rupture decreased whereas the peak force to rupture and tensile deformation modulus increased during storage. Different hydrocolloids like guar gum, xanthan, locust bean gum and hydroxypropylmethylcellulose were added to the rice flour at levels of 0.25% and 0.5% flour basis and it was observed that they improved the texture of chapati by keeping it more extensible during storage. Fungal α-amylase was also incorporated into the rice flour alone and in combination with the hydrocolloid and this resulted in further improvement in the texture. The retrogradation in the chapati after 24 h of storage was also studied using differential scanning calorimetry. Chapaties containing hydrocolloid and/or α-amylase showed lower retrogradation after storage. Rice flour chapaties can be made available to celiac disease patients and the undesirable textural changes, which take place in chapati as a result of starch retrogradation, can be delayed by the incorporation of hydrocolloids and α-amylase.

A new potato tuber disease has been observed in the Tulelake region, California, USA, since 1995, with tuber symptoms suggestive of silver scurf disease (Helminthosporium solani). In this work we isolated, identified and demonstrated the nature of the causal agent of this potato disease in California. In addition, the distribution of H. solani in potato fields and the inoculum potential at harvest time were investigated. Disease progress and H. solani spore populations were also characterised under commercial storage conditions. The main fungal genera associated with potato tubers in storage were Helminthosporium solani, Colletotrichum sp., Fusarium sp., and Rhizoctonia sp. The results of Koch's postulates indicated that H. solani is responsible for the outbreak of silver scurf in the Tulelake region. In a disease survey in three commercial potato fields naturally infested, H. solani infections occurred in all fields. However, the extension of the infections differed significantly between the fields. During potato storage, silver scurf usually increased over time. The percentage of the tuber surface covered by silver scurf varied from 3.5% up to 35.5% during the storage period. The number of H. solani lesions per tuber also progressively increased from 6% up to 35%, six months after storage. H. solani spore populations also increased over time in all studied potato stores; nevertheless, they followed no consistent pattern, exhibiting multiple and variable peaks of increase and reduction during the period of storage. | A partir de 1995, uma nova doença foi observada em tubérculos de batata provenientes da região de Tulelake, Califórnia, USA, com sintomas que sugeriam a doença conhecida como sarna prateada, causada por Helminthosporium solani. Assim, os objetivos deste trabalho foram: a) isolar, identificar a natureza do agente causal dessa doença de batata na Califórnia; b) investigar a distribuição de H. solani nos campos de batata de Tulelake e o seu potencial de inóculo no momento da colheita; c) caracterizar o progresso da doença e populações de esporos de H. solani em condições de armazenamentos comerciais. Em armazéns comerciais, os principais gêneros de fungos associados aos tubérculos doentes foram Helminthosporium solani, Colletotrichum sp., Fusarium sp. e Rhizoctonia sp. Os resultados dos postulados de Koch indicaram que H. solani é o responsável pelos ataques de sarna prateada na região de Tulelake. Em campos de batata naturalmente infestados, observou-se que infecções de H. solani ocorreram em todos os três campos estudados, entretanto, a extensão das infestações diferiram significativamente entre os campos. Durante o armazenamento, a incidência da sarna prateada aumentou progressivamente em todos os armazéns. A percentagem da superfície do tubérculo afetada por sarna prateada aumentou de 3,5% para 35,5% durante o período de armazenamento. O número de lesões de H. solani por tubérculo também aumentou de 6 para 35 lesões por tubérculo após 6 meses de armazenamento. As populações de esporos de H. solani também aumentaram significativamente ao longo do período de armazenamento em todos os armazéns estudados. Entretanto, esses aumentos não foram contínuos, ou seja, as populações apresentaram múltiplos picos de aumento e redução durante o período de armazenamento.

The use of UV-C irradiation treatment to control anthracnose caused by Colletotrichum gloeosporioides Penz. through induced resistance mechanism on mango fruits were determined in this study. Mango fruits exposed to UV-C (provided by a 15-watt UV lamp with 254 nm wavelength) for 20 minutes at distance of one meter from the source provided the lowest disease severity and incidence. UV-C fruits stored at 13 deg C exhibited greener peel color, better visual quality and lower disease severity than non-treated fruits up to two weeks of storage. Effects of UV treatment in conjunction with low temperature storage (13 deg C) led to better control of anthracnose on mango fruits than that of UV treatment followed with ambient storage. UV-C treatment did not adversely affected the total soluble solids, titratable acidity, pH and respiratory activity of the fruits. The treatment suppressed ethylene production thus, delaying ripening. It increased phenylala nine ammonia lyase activity which may account for the control of anthracnose through induced resistance mechanism. However, no significant difference in peroxidase activity was noted between treated and non-treated fruits.

Studies were carried out in 1997 and 1998 at Kuru, Jos Plateau, Nigeria to assess six storage methods for the storage of seed potato. The methods were: Storage in jute bags, perforated polythene bags, baskets, racks, crates and floor. Potato varieties used were Nicola (medium to long dormancy) and B7716-2 (short dormancy). The seed tubers were stored for six months during which daily maximum and minimum temperatures of the storage environment, and the relative humidity were recorded. Tuber weight loss, loss due to rots, sprout number and length per tuber at the end of the storage were also recorded. Results showed that only polythene bag reduced tuber weight loss, but resulted in highest tuber rots due to soft rot disease of potato. Poor light condition in jute bags encouraged the development of long and etiolated sprouts of seed potato. Sprout number per tuber was not affected by the storage methods. Varietal differences in tuber weight loss, sprout number and tuber rots were significant (P≤ 0.05). Due to dehydration, tuber weight loss increased by 37 percent during the six months storage. Based on the results obtained, storage is recommended in crates, racks and on floor of well-ventilated stores for short-term (4 months) storage, since these methods provided good ventilation of stored seed and tuber rots are low. [Niger Agric. J. 34 (2003): 91-96]

Plant disease epidemiology provides the key to both a better understanding of the nature of a disease and the most effective approach to disease control. Brown rot fungi (Monilinia spp.) cause mainly fruit rot, blossom blight and stem canker which results in considerable yield losses both in the field and in the storage place. In order to provide a better disease control strategy, all aspects of brown rot fungi epidemiology are discribed and discussed in the second part of this review. The general disease cycle of Monilinia fructigena„M. laxa, M. fructicola and Monilia polystroma is described. After such environmental and biological factors are presented which influence the development of hyphae, mycelium, conidia, stroma and apothecial formation. Factors affecting the ability of brown rot fungi to survive are also demonstrated. Then spatio-temporal dynamics of brown rot fungi are discussed. In the last two parts, the epidemiology of brown rot fungi was related to disease warning models and some aspects of disease management.

The effect of the fungal antagonist (Trichoderma F17c) to control root rot caused by Lasiodiplodia theobromae (Pat.) was verified through pot and field experiments. Tuber rotting was monitored at harvest and after two months of storage. A highly significant interaction in pot experiment was observed between 60 g Trichoderma F17c inoculum density (applied two and three months after planting) and infection based on percentage infected roots and disease control. There was no interaction between the inoculum level of Lasiodiplodia theobromae and Trichoderma F17c and time of application in the field. However, test of means revealed a significant difference between percent infected roots and percent disease control in both 50 and 100 g inoculum levels of L. theobromae. The higher the inoculum density of L. theobromae, the greater the percent infected roots, thus the lower the percent disease control. Regardless of inoculum densities of Trichoderma F17c (50, 75 and 100 g), root infection was reduced during storage when applied two and three months after planting than when applied during planting to one month. Reduced root infection was noticeable in 100 g followed by 75 and 50 g inoculum densities. Control provided by Trichoderma F17c was even better compared to the effect of Benlate. Benlate (fungicide) treatment was better in terms of net sales after harvest, however, when expenses were equated to the amount of roots left after deducting the percentage infection after storage, the Trichoderma F17c treatment had higher returns compared to Benlate. The results suggest that Trichoderma F17c grown in organic substrate can be used as an alternative to chemical control and effective for the management of postharvest rotting of sweet potato tubers caused by L. theobromae.

<p>Abstract</p> <p>Evidence suggests that a diet high in fruits and vegetables may decrease the risk of chronic diseases, such as cardiovascular disease and cancer, and phytochemicals including phenolics, flavonoids and carotenoids from fruits and vegetables may play a key role in reducing chronic disease risk. Apples are a widely consumed, rich source of phytochemicals, and epidemiological studies have linked the consumption of apples with reduced risk of some cancers, cardiovascular disease, asthma, and diabetes. In the laboratory, apples have been found to have very strong antioxidant activity, inhibit cancer cell proliferation, decrease lipid oxidation, and lower cholesterol. Apples contain a variety of phytochemicals, including quercetin, catechin, phloridzin and chlorogenic acid, all of which are strong antioxidants. The phytochemical composition of apples varies greatly between different varieties of apples, and there are also small changes in phytochemicals during the maturation and ripening of the fruit. Storage has little to no effect on apple phytochemicals, but processing can greatly affect apple phytochemicals. While extensive research exists, a literature review of the health benefits of apples and their phytochemicals has not been compiled to summarize this work. The purpose of this paper is to review the most recent literature regarding the health benefits of apples and their phytochemicals, phytochemical bioavailability and antioxidant behavior, and the effects of variety, ripening, storage and processing on apple phytochemicals.</p>

The objective of this study was to characterize the distribution of Mycobacterium paratuberculosis (Map) in the environment of infected and uninfected Minnesota dairy farms. Eighty herds known to be infected from Minnesota's Johne's Disease Control Program (JDCP) and 28 herds known to be uninfected from Minnesota Voluntary Johne's Disease Herd Status Program (VJDHSP) were sampled. Fecal samples from up to 100 cows in each herd were cultured in pools of 5 cows. Two environmental samples were obtained from each farm from various locations. All samples were tested using bacterial culture for Map. Eighty percent of the JDCP herds had at least one positive pool. Environmental samples were cultured positive in 78% of the JDCP herds. Two (7%) of the VJDHSP herds had one positive pool, and one herd had one positive environmental sample. Environmental samples were cultured positive in cow alleyways (77% of the herds), manure storage (68%), calving area (21%), sick cow pen (18%), water runoff (6%), and postweaned calves areas (3%). There was an association between maximum level of colonies per tube from cow alleyways and manure storage and fecal pool prevalence. Herds with both areas cultured negative were estimated to have 0.3 to 4% fecal pool prevalence. Herds with both areas having a heavy load of bacteria were estimated to have 53 to 73% fecal pool prevalence. The study results indicate that targeted sampling of cow alleyways and manure storage areas appears to be an alternative strategy for herd screening and Johne's infection status assessment and for estimating herd fecal prevalence.