In the present work, the mass transfer characteristics, namely moisture diffusivity and moisture transfer coefficient of “Violet de Galmi” variety of onions were evaluated using the analytical model. Onions were dri...In the present work, the mass transfer characteristics, namely moisture diffusivity and moisture transfer coefficient of “Violet de Galmi” variety of onions were evaluated using the analytical model. Onions were dried in a single layer at different temperatures (40℃, 50℃, 60℃, and 70℃) and for a relative humidity of drying air of 20%. The results showed a reasonably good agreement between the values predicted by the correlation and the experimental observations. This model computed the Biot number, effective moisture diffusivity, and mass transfer coefficient. Effective diffusion coefficient values are obtained between 0.2578 × 10<sup>-9</sup> m<sup>2</sup>·s<sup>-1</sup> and 0.5460 × 10<sup>-9</sup> m<sup>2</sup>·s<sup>-1</sup>. Mass transfer coefficients of “Violet de Galmi” onion drying vary between 3.37 × 10<sup>-7</sup> m·s<sup>-1</sup> and 13.38 × 10<sup>-7</sup> m·s<sup>-1</sup>. Numbers of mass transfer Biot are found between 0.9797 and 2.9397. The activation energy E<sub>a</sub> is 31.73 kJ·mol<sup>-1</sup>.展开更多
Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and...Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and post-harvest losses. To date, knowledge of major diseases of the crop is limited, limiting the development of effective control strategies. The objective of this study was to test the pathogenicity of some species of Fusarium. To this end, 33 fungal isolates collected from onion plants in 17 localities and belonging to five Fusarium species were used to inoculate onion seeds and bulbs to determine the pathogenic species responsible for damping-off on seedlings and basal bulb rot in Burkina Faso. The virulence of pathogenic isolates was determined according to the percentages of seedling damping-off evaluated 28 Days After Sowing, and the extent of rot in millimetres on inoculated bulbs. The evaluation of isolates on seedlings revealed that the most pathogenic isolates belong to the species F. proliferatum (I29, I21, I37, I33, I31), F. thapsinum (I35) and F. solani (I38) which resulted in 58.33% - 70.83% of seedling damping-off. The most pathogenic isolates on bulbs belong to the species F. proliferatum (I4, I29, I32) and F. oxysporum (I52, I50, I16) which caused 21.67 to 25 mm of rot on bulbs. Isolate I29 was very virulent on both seedlings and bulbs. The isolates of F. fujikuroi species were all low pathogenic on seedlings but one of them, (I27), expressed average pathogenicity on bulbs.展开更多
文摘In the present work, the mass transfer characteristics, namely moisture diffusivity and moisture transfer coefficient of “Violet de Galmi” variety of onions were evaluated using the analytical model. Onions were dried in a single layer at different temperatures (40℃, 50℃, 60℃, and 70℃) and for a relative humidity of drying air of 20%. The results showed a reasonably good agreement between the values predicted by the correlation and the experimental observations. This model computed the Biot number, effective moisture diffusivity, and mass transfer coefficient. Effective diffusion coefficient values are obtained between 0.2578 × 10<sup>-9</sup> m<sup>2</sup>·s<sup>-1</sup> and 0.5460 × 10<sup>-9</sup> m<sup>2</sup>·s<sup>-1</sup>. Mass transfer coefficients of “Violet de Galmi” onion drying vary between 3.37 × 10<sup>-7</sup> m·s<sup>-1</sup> and 13.38 × 10<sup>-7</sup> m·s<sup>-1</sup>. Numbers of mass transfer Biot are found between 0.9797 and 2.9397. The activation energy E<sub>a</sub> is 31.73 kJ·mol<sup>-1</sup>.
基金the Congregation of the Sisters of the Immaculate Conception of Ouagadougou(S.I.C.O)and the Institute of Environment and Agricultural Research(INERA)for their financial support for this work.
文摘Onion (Allium cepa L.) is the second most important vegetable crop in Burkina Faso and provides an important source of income for those involved in the sector. However, producers are facing significant pre-harvest and post-harvest losses. To date, knowledge of major diseases of the crop is limited, limiting the development of effective control strategies. The objective of this study was to test the pathogenicity of some species of Fusarium. To this end, 33 fungal isolates collected from onion plants in 17 localities and belonging to five Fusarium species were used to inoculate onion seeds and bulbs to determine the pathogenic species responsible for damping-off on seedlings and basal bulb rot in Burkina Faso. The virulence of pathogenic isolates was determined according to the percentages of seedling damping-off evaluated 28 Days After Sowing, and the extent of rot in millimetres on inoculated bulbs. The evaluation of isolates on seedlings revealed that the most pathogenic isolates belong to the species F. proliferatum (I29, I21, I37, I33, I31), F. thapsinum (I35) and F. solani (I38) which resulted in 58.33% - 70.83% of seedling damping-off. The most pathogenic isolates on bulbs belong to the species F. proliferatum (I4, I29, I32) and F. oxysporum (I52, I50, I16) which caused 21.67 to 25 mm of rot on bulbs. Isolate I29 was very virulent on both seedlings and bulbs. The isolates of F. fujikuroi species were all low pathogenic on seedlings but one of them, (I27), expressed average pathogenicity on bulbs.
