Abstract

  Aphids (Brevicoryne brassicae) pose a threat to production of most vegetables including rape by sap sucking and transmitting viral diseases. A trial was carried out at the Jichidza High School, Masvingo Zimbabwe (2019) to evaluate the repellent properties of Mexican marigold (Tagetes minuta) aqueous extracts on aphid population in rape (Brassica napus). The experiment was laid out as a randomised complete block design (RCBD) with four treatments (0%, 2%, 4% and 6%) concentration of Mexican marigold extracts on rape replicated five times. Application of these concentrations was done at fortnight interval from week one after planting to week six of age. Data on growth rate, aphid counts, and cumulative leaf weight was collected from week three to week six after planting. The results showed that, the effects of Mexican marigold on growth rate, aphid population and cumulative leaf weight were significantly different (p < 0.05). Using 6% concentration of Mexican marigold aqueous extracts recorded the highest growth rate, lowest aphid population and highest leaf weight as compared to all other treatments. However, results from using 2% concentration of Mexican marigold aqueous extracts were not significantly different (p > 0.05) from the use of 4% concentration of Mexican marigold aqueous extracts in rape. From the results, it can be concluded that the use of 6% concentration of Mexican marigold in rape is an effective control method for aphids. From this study, it is recommended that poor smallholder farmers can utilise the repellent properties of Mexican marigold to reduce aphid yield losses in rape.

Keywords: Repellent; Brassica napus; Tagetes minuta; Aqueous; Brevicoryne brassicae

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Citation

Citation: Nyasha Sakadzo., et al. “Evaluating the Repellent Properties of Mexican Marigold (Tagetes minuta) Aqueous Extracts on Aphid Population in Rape (Brassica napus)". Acta Scientific Microbiology 3.4 (2020): 65-70.

Copyright

Copyright: © 2020 Nyasha Sakadzo., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.