Answer
The quark combination $ssu$ can not produce $\Sigma^+$
Work Step by Step
The $\Sigma^+$ has strangeness $-1$
The up quark $u$ has strangeness $0$
The strange quark $s$ has strangeness $-1$
The net strangeness of $ssu$ is $-2$
Therefore, the quark combination $ssu$ can not produce $\Sigma^+$
