The affix valac comes in the sense of matup after 1. rajas 2. kṛṣi 3. āsuti and 3. pariṣad,
As रजस्वला स्त्री, कृषीवलः कुटुम्बी, आसुतीवलः शौण्डिकः, परिषद्वलो राजा ॥ The lengthening of vowel in कृषि and आसुति takes place by 6.3.118. The affix वलच् comes only under certain senses and conditions, as shown in the above examples. Thus in रजोऽस्मिन् ग्रामे विद्यते, there is no affixing.
Vart:- The affix valach is seen after other words also. As भ्रातृवलः, पुत्रवलः, पितृवलः, उत्साहवलः ॥,