Our results showed that castor-oil plant, hot pepper or crown
daisy intercropping with cucumber plants significantly reduced the
number of root-knot galls in cucumber plants. Castor-oil plant had
the greatest effect followed by crown daisy. However, other
screened plants aggravated the infection of M. incognita on
cucumber plants. In addition, castor-oil plant or hot pepper intercropping
with cucumber plants reduced the root growth of
cucumber but crown daisy intercropping with cucumber did not
markedly affect root growth of cucumber. The health of roots is
important for growth and yield of cash crops, beyond that crown
daisy itself is a popular vegetable and cash crop in China, so crown
daisy is the most appropriate intercrop with cucumber plants.
Actually, the consistent results based on our pot experiments from
2008 to 2010 provide evidence that crown daisy could reduce
nematode infection of intercropped cucumber, indicating it would
be a good partner in intercropping with a host plant in the field.