Test Bench for the Mechanical Distribution of Predators to Control Insect Pests

In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle （CPB） succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops.

Effects of Mechanical Aeration on the Compaction and Hydraulic Conductivity of a Grassy Sward

In a golf course located at El Kantaoui, Sousse, Tunisia, this study was carried out over a sandy soil grassy sward to investigate the effects of mechanical aeration （perforation of the sward with an aerators machine called ＂Vertidrain＂） on its compaction and hydraulic conductivity. For this purpose, many soil cores were extracted using a 1.6 e.g. m effective width Verti-Drain aerator equipped with hollow spades spaced 65 e.g. mm apart. Aeration was performed at a rate of 350 holes/m2. Soil resistance to penetration and permeability were determined at the initial state before aeration as well as 10, 20, and 30 days after aeration. Compared to the initial state, the results showed that mechanical aeration greatly affects the grassy sward ground by reducing its resistance to penetration as 35% and 43% decrease in penetration resistance were noticed at 5 e.g. cm depth 10 and 20 days after aeration, respectively. Also, resistance to penetration decreased by 41% and 48% at 15 e.g. cm depth during the same two periods of time with a relatively constant moisture content. However, soil resistance to penetration at 5 and 15 e.g. cm depths only decreased by 21% and 26%, respectively. Regarding the soil hydraulic conductivity measured after aeration, a significant improvement at the 1% level with the method of variance analysis, was observed compared to that at the initial state （4.9 e.g. cm hl）. Indeed, the hydraulic conductivity was 12.5, 13, and 14.1 e.g. cm h-1 10, 20, and 30 days after aeration, respectively.

Production of Ryazhenka,a traditional Ukrainian fermented baked milk,by using electro-activated whey as supplementing ingredient and source of lactulose

In this work,electro-activated whey(EAW)was used as ingredient in the preparation of Ryazhenka,a fermented baked milk,at a supplementation level of 3 and 9%.Fermentation kinetics,viscosity,color,antioxidant capacity,and protein profiles of the final product were studied.Moreover,effect of electro-activation onβ-lactoglobulin allergenicity was evaluated by a specific ELISA test.The results showed that addition of electro-activated whey as supplementing ingredient is technologically feasible in the process of Ryazhenka production.The fermentation kinetics showed that this process was in the technologically accepted interval even if the addition of EAW delayed the fermentation phase.The viscosity study showed that addition of EAW permitted to obtain a final product with good followability corresponding to good consistency of drinkable dairy beverages.Moreover,addition of EAW prevented syneresis during the refrigerated storage at 4℃ and enriched the product with lactulose which is a recognized prebiotic.The chromatic evaluation of the final product showed a compatibility of EAW with Ryazhenka which is known for its specific yellowish-brownish color.Addition or EAW significantly improved the antioxidant capacity of the Ryazhenka with values of IC_(50)DPPH=2.54±0.02 and IC_(50)PFRAP=244.03±28.83 for the Ryazhenka produced by adding 9%EAW to the milk after the baking process and prior to fermentation.Moreover,by using aβ-lactoglobulin specific ELISA test,this study showed a significant decrease of whey and pureβ-lactoglobulin allergenicity by 95%.This decrease was also observed in Ryazhenka supplemented with 9%EAW but at lower level.Thus,it can be concluded that electro-activated whey can be considered as a promising functional ingredient containing a prebiotic lactulose as functional ingredient in the dairy industry.