Kabissa, Jeremiah Joe2026-08-292026-08-292016https://www.suaire.sua.ac.tz/handle/20.500.14820/7941Dissertationomplaints against the ineffectiveness of pesticides currently distributed by the Tanzania Cotton Board (TCB) and private dealers in the Western Cotton Growing Areas (WCGA) have persisted for nearly a decade which has rendered some famers abandoning the crop. Technically, the reasons for the low efficacy could be associated with insecticides or poor application techniques. A series of studies were conducted between September 2014 and September, 2015 in the WCGA to document the commonly used pesticides on cotton, examine their authenticity with reference to the registrar’s article and evaluate their effectiveness. Documentation of the commonly used insecticides, accessibility and perceived efficacy were studied through a survey conducted using structured questionnaires in five districts in Mwanza and Simiyu Regions. A total of 175 respondents were interviewed. Authenticity of the commonly used pesticides was examined through sampling among the commonly used pesticides, obtaining small volumes in screw-capped bottles, re-packaging and labelling by numbers to disguise the identity, after which they were sent to the Tropical Pesticide Research Institute (TPRI) laboratories for determination of active ingredients. The effectiveness of the commonly used pesticides was determined through a field experiment set at Ukiriguru Agricultural Research Institute. Cotton insect pests against which the pesticides were tested included; Helicoverpa armigera (Hubner), Aphis gossypii (Glover), Pectinophora gossypiella •(Sound), Dysdercus sp (Herrich- Schaeffer) and Earias sp (Walker/Boisduval). The results indicated that most of the approved and few of unapproved insecticides are used in controlling cotton pests in the WCGA. About 70% of insecticides used by farmers in all five Districts surveyed were supplied through CDTF and the remaining 30% were sourced from private agro-shops and open markets. About 40% of the insecticides sold in agro-shops and local market centres had expired but cotton farmers being unawareiii purchased them for use. About, 85% of agro-shop owners employed unskilled shopkeepers to sell pesticides. The confirmatory test at TPRI laboratories proved the collected insecticides to conform to the registrar’s records in terms of contents and active ingredients. The field tests showed that all insecticides were effective against target insect pests provided the proper dosage was applied at the right time and appropriate pests threshold. Pyrethyroids such as lambdacyhalothrin and cypermethrin when used in combination with organophosphates controlled both endocarpic and exocarpic boll worms and other insect pests very effectively but when lambdacyhalothrin was used singly, the effectiveness was compromised particularly on aphids. Likewise the endocarpic and exocarpic boll worms could not be effectively controlled using cypermethrin alone. The findings from this study resolved the long-standing doubt on efficacy of insecticides distributed to cotton growers through the CDTF. Ineffectiveness reported by farmers are mostly caused by use of inadequate amounts of insecticides (low dosages), mixing insecticides with poor quality waler (dirty water) and poor coverage of the crop canopy during spray. Wrong timing of the day to first spray and poor knowledge of pest threshold also contribute to the limited efficacy of the insecticides in small farmers’ setting. Therefore, the Tanzania cotton sector should take concrete steps to educate growers on proper use of insecticides and avoid the risks of insect pests developing resistance to the used insecticides particularly the Pyrethroids.enCotton Board (TCB)PesticidesWestern Cotton(WCGA)TanzaniaThesis