The above mentioned affixes after the word bhāra preceded by the word vaṃśa etc., have the sense of 'who carries away, or conveys or brings that'.,
The case in construction here is accusative (तद्). Thus, वंशभारं हरति, वहति आवहति वा = वांशभारिकः, कौटजभारिकः, बाल्वजभारिकः ॥
Why do we say \after भार\? Observe वंशं हरति, no affixing. Why do we say \preceded by वंश &c\. Observe व्रीहिभारं हरति, no affixing.
According to another explanation, the phrase भाराद् वंशादिभ्यः is explained as भारभूतेभ्यो वंशादिभ्यः. Then the sutra will mean \the above named affixes come after वंश &c. when they denote a load\. Thus भारभूतान् वंशान् हरति = वांशिकः; कौटजिकः, बाल्वजिकः ॥ Why do we say \when denoting a load भार\? Observe वंशं हरति ॥ Why do we say after वंश &c.? Observe भारभूतान् व्रीहीन् वहति ॥ Both these explanations are valid and traditional.
The word हरति means to carry to another place or to steal; वहति means to carry on ones back or head, आवहति means to produce or bring.
1 वंश, 2 कुटज, 3 बल्वज, 4 मूल, 5 स्थुणा, (स्थुण), 6 अक्ष, 7 अश्मन्, 8 अश्व, 9 लक्षण, 10 इक्षु, 11 खट्वा ॥,