Research and Policy Memo #3

In January 2007 and June 2009, project and theme leaders working with the CGIAR Challenge Program on Water and Food (CPWF) were invited to tell stories about the ‘most significant change’ they had observed as a result of CPWF activity. 54 stories were collected in Round 1, and 15 in Round 2. A selection of 44 stories are presented here.<br/><br/>Many of the stories are grouped under 5 themes:-<br/><br/><ul> <li>Theme 1 Crop Water Productivity Improvement</li> <li>Theme 2 Water and People in Catchments</li> <li>Theme 3 Aquatic Ecosystem and Fisheries</li> <li>Theme 4 Integrated Basin Water Management System</li> <li>Theme 5: The Global and National Food and Water System</li> </ul><br/>The remaining stories are listed under Basin Focal Projects or the Small Grants Program.

This Workshop was jointly organized by the Tigray Agricultural Research Institute (Mekele, Ethiopia), The Tigray Bureau of Agriculture and Rural Development, Ethiopian Institute of Agricultural Research, Food and Agriculture Organization (FAO), FAO- ICARDA CACTUSNET, International Center for Agricultural research in the Dry Areas (ICARDA), Swiss Association for International Development (Helvetas-Ethiopia), and International Society for Horticultural Science (ISHS). The choice of East Africa and Ethiopia to host this workshop was not incidental. Indeed, (i) East Africa is facing food security and poverty issues challenges; (ii) FAO has been and still implementing fruitful projects in Tigray to promote cactus crop as food, feed and income diversification option; (iii) Tigray region and its research institutes and centers are obviously the most advanced in East Africa in the field of cactus pear crop development and uses (iv) the interest and support of the FAO Sub-Regional Office for Eastern Africa was a guarantee for the success of the workshop. The workshop coincides with the first shipment of cochineal to abroad to be processed to produce red carmin; this new initiative is most welcomed to diversify and increase poor farmers’ income.

Groups of 0+ Atlantic salmon (Salmo salar) smolts were transferred to duplicate seawater tanks, and subjected to five different ration levels, 0% (starved), 25%, 50%, 75% or 100% (full fed). Waste feed was collected after each meal. After six weeks all groups were re-fed in excess. During the trial period body weight and length increased significantly in the 50, 75 and 100% groups, while no significant changes in body weight were observed in the 0% and 25% groups. A significant decrease in SGR was observed in the 0 and 25% groups during the first month in sea water. After re-feeding, SGR increased in all groups. All groups, except the previously starved group, showed peak SGR between weeks 6-8 and 8-12. Food restriction at 0% and 25% of full ration for a period of six weeks resulted in significant osmotic disturbances. After six weeks in sea water, plasma Cl⁻ levels were higher in the 0% group than in the other groups. Branchial Na⁺,K⁺-ATPase activity increased in all groups following exposure to seawater. Re-feeding caused a transient increase in branchial Na⁺,K⁺-ATPase activity after two weeks in the previously starved group, with a concurrent reduction in plasma Cl⁻ levels. Previous exposure to different ration levels significantly influenced growth rate and mean body size. Compensatory growth and partial size compensation was seen in the 0, 25 and 50% feed deprivation groups, whereas full size compensation was found in the 75% group.

The inhibitory effect of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) mixture on fungal populations, Aspergillus section Flavi and aflatoxins accumulation in in-pod peanuts during storage in big bags was investigated. In-pod peanuts were previously conditioned at different water activities (0.94, 0.88, 0.84 and 0.76 aw) and treated with food-grade antioxidants. Both control and treated peanuts were stored for 6 months and sampled at monthly intervals. BHA-BHT mixture reduced the incidence of peanut fungal populations between 0.6-20.4% and between 1.2-33.1% during 1-3 and 4-5 storage months, respectively. Aspergillus section Flavi counts decreased with 36.5%, 46.3% and 77.4% in peanuts conditioned at 0.94, 0.84 and 0.76 aw levels and treated with antioxidants. At the above peanut aw conditions, the treatment applied reduced aflatoxin accumulation by 72.1%, while any effect on this metabolite production was observed at 0.88 aw. The antioxidant formulation used in this study has the potential to control aflatoxigenic populations in in-pod peanuts stored in half-permeable silos at ≤0.84 aw level.

Treatment of fresh fruits and vegetables with electrolyzed water (EW) has been shown to kill or reduce foodborne pathogens. We evaluated the efficacy of EW in killing Escherichia coli O157:H7 on iceberg lettuce, cabbage, lemons, and tomatoes by using washing and/or chilling treatments simulating those followed in some food service kitchens. Greatest reduction levels on lettuce were achieved by sequentially washing with 14-A (amperage) acidic EW (AcEW) for 15 or 30 s followed by chilling in 16-A AcEW for 15 min. This procedure reduced the pathogen by 2.8 and 3.0 log CFU per leaf, respectively, whereas washing and chilling with tap water reduced the pathogen by 1.9 and 2.4 log CFU per leaf. Washing cabbage leaves for 15 or 30 s with tap water or 14-A AcEW reduced the pathogen by 2.0 and 3.0 log CFU per leaf and 2.5 to 3.0 log CFU per leaf, respectively. The pathogen was reduced by 4.7 log CFU per lemon by washing with 14-A AcEW and 4.1 and 4.5 log CFU per lemon by washing with tap water for 15 or 30 s. A reduction of 5.3 log CFU per lemon was achieved by washing with 14-A alkaline EW for 15 s prior to washing with 14-A AcEW for 15 s. Washing tomatoes with tap water or 14-A AcEW for 15 s reduced the pathogen by 6.4 and 7.9 log CFU per tomato, respectively. Application of AcEW using procedures mimicking food service operations should help minimize cross-contamination and reduce the risk of E. coli O157:H7 being present on produce at the time of consumption.

An experiment were conducted to evaluate The effect of feeding frequencies and stocking size on growth and feed conversion ratio (FCR) of rainbow trout (O. mykiss) in brackish water for 102 days. Three stocking sizes (10, 25 and 40 g/fish) of rainbow trout and three feeding frequencies (feeding fish twice, three times and four times per day) were examined as the same time. Fish were fed at a restricted feeding program according to the rainbow trout standard table in the definite times during the light period. The results showed that in the group with 10 g initial weight increasing the feeding frequency, some growth factors like final weight, daily growth, and weight gain. But the other factors such as food conversion rate (FCR) and specific growth rate (SGR) decrease. It means in this group (10 g) two times feeding per day is not enough for an acceptable growth rate. In the two other groups with (initial weight 25 and 40 g) although by increasing the feeding frequency, some growth factors a little increase but these differences in 95% level (p،ـ0.05) are not significant. Therefore in rainbow trout culture with initial weight at least 25 g two times feeding per day was enough. The results of carcasses analysis of fish, showed that by increasing the feeding frequency there were no significantly difference at 95% level between the body compositions in all of treatments. With connivance of feeding frequencies, the best FCR was in the group with 10 g initial body weight and there was not any significant difference in SGR. So according to the results, it suggests that fish should be stocked with 10 g initial body weight.