Shegaw, Ahmed (PhD)Assefa, Taye2020-02-082023-11-102020-02-082023-11-102019-06http://etd.aau.edu.et/handle/12345678/20566The intensive use of synthetic pesticide has undeniably resulted in adverse and sometimes irreparable effects on the environment including human health. Therefore, alternative pest management strategies are desired. Natural pesticides have proven potential for pest management and they are being used throughout the world. To this effect, this thesis investigated the production and characterization of locally available custard apple seed extract for its possible application as natural pesticide using ethanol (97%) as a solvent. The raw seed moisture content, fat content, ash and organic matter content were determined properly. The extraction parameters were extraction time, temperature and ethanol to custard apple seed ratio. A maximum of 12.63 % total extraction yield of pesticide was achieved at the optimal conditions of 4h, 50 and 7:1 v/w of extraction time, temperature and ethanol to CAS ratio respectively. The individual and interaction effect of these parameters on the yield of oil was studied and optimum conditions were established by using RSM of Box-Behnken method of Design Expert 7.0.0 software. The characteristics of CAS extract were then evaluated using different analytical methods. Specific gravity, flash point, water solubility, pH value and TVOCs were analyzed with respective methods. The FT-IR analysis indicates presence of C=O group of the unsaturated lactone group. The GC-MS result shows that the presence of uvaricin, annonacin and squamocin. From the statistical analysis method, all the three factors had an impact on the yield directly and extraction time with temperature, extraction time with ethanol to CAS ratio, temperature with ethanol to CAS ratio had also a significant effect on the yield. Using model optimization of the factors were found the optimum points of extraction time (3.99hr), temperature (49.92 ) and ethanol to CAS ratio (7.04:1 v/w) with 12.63 % yield of product. Generally, the results found in this study showed that CAS extract seems to be a viable alternative option for the production of the natural pesticide.en-USNatural pesticidesCustard apple seedUvaricinAnnonacinquamocinRSMThesis