Expected LER values for each species were 0.5, 0.33, 0.25 and
0.2 for mixed plots with two, three, four, and five species,
respectively. Values above or below these expected ratios indicate
up- or down-regulation. In 2011, watermelon grew vigorously and,
therefore, contributed more to plot LERs than the expected values.
Watermelon yield was up-regulated in all intercropping combinations
indicating the beneficial effect of mixed cropping on
watermelon production. All other component crops were downregulated
compared to their expected values in 2011. However, in
2012, with the altered planting dates, watermelon was outcompeted by okra and as a result, okra yield was greater than
expected in all intercropping combinations where it was included.
Peanut production was also greater than expected in all
combinations except for Spw and watermelon production was
lower than expected in all combinations except Spw. Just as in 2011,
cowpea and pepper had lower yields than expected in intercropping
treatments. Since all plots were planted at the same density,
per plant production values follow the same statistical pattern as
LER. Per plant production data are therefore presented in Table A1.