Impact of climate change and management cost of chromolaena odorata on maize production for smallholder farmers in Serengeti District, Tanzania

Abstract

Chromolaena odorata is a weed that has infested agricultural land in the Serengeti district and adversely reduced cropland and crop yield. This study evaluated the impact of climate change and the management cost of Chromolaena odorata on maize production in the Serengeti District. Firstly, the available roads were used as line transects for Chromolaena odorata observation. Global Position System coordinate collected was used to generate a distribution map of Chromolaena odorata in the Serengeti district. Climate change impact on maize production was assessed using maize production data from 2000-2018 from the Serengeti District office. Climate data were from the Grummet Game reserve. Correlation analysis was used and the results showed rainfall and maize production were positively correlated, (r = 0.08 and p = 0.73). Mean annual temperatures and maize yield were positively correlated, however, the correlation was not significant (r = 0.47 and p = 0.12). Therefore, the climate in Serengeti was not only the factor for the decline in maize yield. A field trial was performed in Serengeti to investigate the management cost and frequency of weeding on the growth and yield of maize, and to determine the best frequency of weeding to get an optimum yield. There were five treatments replicated four times. Treatments were; No weeding, weeding once, twice, thrice, and fourth. The highest yield was obtained in weeding four times treatment with 2403 kg/ha with significantly different (P<0.05, P=0.014). The lowest yield was obtained in no weeding treatment with 520 kg/ha. There was an addition of 1883 Kg. ha-1 of maize grain yield equivalent to a 70% increase Marginal return rate in weeding four times treatment. This study suggests that for better maize yield and profit farmers should perform weeding four times to control Chromolaena odorata on their cropland.