Comparative Effects of Natural and Synthetic Fungicides on the Pink Root Disease of Onion (<i>Allium cepa </i>L.), in Nursery

Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.

Characterizations of Drinking Water Quality for Populations of Hann Bel-Air (Dakar, Senegal)

Populations of Hann Bel-Air municipality are supplied with drinking water from taps water of “Sénégalaise Des Eaux” (SDE) and Jambar pumps which capturie directly the groundwater. This municipality is characterized by a strong environmental pollution which can affect the quality of drinking water. To determine actual quality of that water, 10 samples were taken and analyzed. Physico-chemical results have shown that tap water is more suitable for domestic consumption than Jambar pump water. The results show that physical parameters such as electrical conductivity (maximum value of 2671 μS/cm) exceed World Health Organization standard. The pH of the water from Jambar pumps is between 6.04 and 6.09, which demonstrates the aggressive character of that water. For tap water, pH values of 7.03 to 7.09 demonstrate their alkalinity. For chemical analyses, bicarbonates and sulphates concentrations respectively meet World Health Organization standards. Tap water meets World Health Organization standard for nitrates. With respect to chloride, the threshold of 250 mg/L is exceeded at all levels, but we note that high chloride concentrations are part of the exemptions granted to SDE. Tap water and water from water table have concentrations of calcium, potassium, iron and magnesium irreproachable. For sodium, EP3, EP4 and P5 samples from the web exceed World Health Organization standard with a peak of 310.27 mg/L. Tap water is more drinkable than groundwater but its quality needs to be improved and especially controlled for the well-being and sustainable health of consumers.

Farmers’ Perception and Impact of Rice Yellow Mottle Disease on Rice Yields in Burkina Faso

Rice improvement for disease resistance has scarcely involved farmers’ knowledge in Sub-Saharan Africa. A participatory rural appraisal was conducted in two main rice cultivation areas in Burkina Faso to assess farmers’ awareness of rice production constraints with emphasis on rice yellow mottle disease (RYMD) and its management. Farmers’ preference for rice varieties to be used in the breeding program was also assessed. Major concerns for rice cultivation as perceived by farmers were water shortage and RYMD. However, relative importance of each constraint depended on the survey areas, RYMD being prominent at Banzon while water shortage predominated at Mogtedo. Mogtedo farmers preferred rice variety FKR19 because of its tolerance to drought. At Banzon, farmers’ first criterion was taste which was reflected in the choice of variety FKR18. Yield was also a major criterion in both areas, positioning NERICA varieties FKR56N, FKR62N, and FKR60N among the top preferred varieties. Farmers mentioned RYMD as the most important rice disease. Most farmers used varietal shifts or pesticide treatments for RYMD management. RYMD incidence reached 28% in average at Banzon over the 2012-2013 main growing seasons. In rice varieties FKR56N, FKR62N and TS2, diseased plants yielded 79.3% less than the healthy ones. Accordingly, based on disease incidence, overall yield loss in the study area was estimated at 22.3%. Altogether, rice production can be significantly increased by taking RYMD into account in a participatory rice breeding strategy.