Neco Model Questions Vol1 2018 Agricultural Science Question 1

A field trial was set up to investigate the effect of intercropping maize (Zea mays) with cowpea (Vigna unguiculata) on the population of the stem borer pest (Chilo partellus). The experiment consisted of three treatments, each replicated three times (randomised complete block design). The treatments were: T1 – Sole maize T2 – Sole cowpea T3 – Maize + cowpea intercropped (1 m spacing between rows of each crop). At 45 days after planting, the number of stem borer larvae per plant was counted in each plot. The data obtained are shown in the table below: | Plot | Treatment | Larvae per plant | |------|-----------|------------------| | 1 | T1 | 12 | | 2 | T1 | 15 | | 3 | T1 | 13 | | 4 | T2 | 4 | | 5 | T2 | 5 | | 6 | T2 | 3 | | 7 | T3 | 6 | | 8 | T3 | 5 | | 9 | T3 | 7 | Using the data above, answer the following: a) Determine the mean number of larvae per plant for each treatment. b) Calculate the percentage reduction in mean larvae count of the intercropped treatment (T3) relative to the sole maize treatment (T1). c) Discuss two ecological reasons why intercropping may have reduced the stem borer population. d) Suggest one management practice that could be combined with intercropping to further suppress stem borer attacks.