Seasonal diversity of entomofauna, their impact and management practices in tomato fields in Meru district, Tanzania

Seasonal diversity of entomofauna, their impact and management practices in tomato fields in Meru district, Tanzania

Author: 
Michael, Gabriel
Publisher: 
Rural Outreach Programme (ROP)
Date published: 
2021
Record type: 
Responsibility: 
Nyomora, AMS, jt. author
Mvungi, EF, jt. author
Sangu, EM, jt. author
Journal Title: 
African Journal of Food, Agriculture, Nutrition and Development
Source: 
African Journal of Food, Agriculture, Nutrition and Development, Vol 21, No. 4, May 2021, pp. 17952-17971
Abstract: 

Tomato is a highly cultivated vegetable in Tanzania. The intensive tomato cultivation and production in Tanzania has resulted in high pests and diseases build-up. A survey to identify and quantify entomofauna diversity in different seasons and pest management practices in Meru District was conducted. In addition, a laboratory experiment was done to assess the effectiveness of commonly used pesticides SnowBecco (Thiamethoxam)and Belt (Flubendiamide) against two dominating insect pests, white flies (Bemisia tabaci (Gennadius, 1889)) and leaf miner (Tuta absoluta (Meyrick, 1917)), respectively. The results obtained revealed that, tomato fields in Meru District had significantly higher entomofauna build up during dry season than the rainy season (U0.05 (df, 24)= 45, p = 0.0441). More than 70% of all collected entomofauna were dominated by the whiteflies (Bemisia tabaci) and tomato leaf miners (Tuta absoluta) belonging to orders Hemiptera and Lepidoptera, respectively. It was also observed that, the common pesticides management practices were the use of pesticidal cocktail, broad spectrum insecticides, use of botanical pesticides, frequent application of pesticide and insecticides over dosage. Moreover, yield reduction due to whiteflies and tomato leaf miners infestation were observed in terms of reduced fruits number per plant (38 and 18.4%), fruit size (22.4 and 14.2%), and fruits weight per plant by 43.6 and 26.2%, for Bemisia tabaci and Tuta absoluta, respectively. The study showed that the recommended doses in both tested insecticides caused significant pest mortality (F0.05 (df, 19) = 4.367, p = 0.0199) and (F0.05(df, 19) = 4.761, p = 0.0147) for B. tabaci and T. absoluta, respectively, within a specified period of time. The results suggest that high insect pest infestations could be caused by factors other than development of insecticidal tolerance including inappropriate identification of insect pests due to lack of training, and inappropriate selection and application of insecticides. Consequently, frequent application of broad spectra insecticides not only increases production expenses but also disrupts agroecosystem by killing beneficial entomofauna and disrupting soil organisms that are susceptible to insecticide toxicity.

Language: 
Country focus: 

CITATION: Michael, Gabriel. Seasonal diversity of entomofauna, their impact and management practices in tomato fields in Meru district, Tanzania . : Rural Outreach Programme (ROP) , 2021. African Journal of Food, Agriculture, Nutrition and Development, Vol 21, No. 4, May 2021, pp. 17952-17971 - Available at: http://library.au.int/seasonal-diversity-entomofauna-their-impact-and-management-practices-tomato-fields-meru-district