1 Gita Sloka Every Day - Chapter 18 - Moksha Sanyasa Yoga - Sloka 44

The entire content of this mail is from Shri V N Gopala Desikan's  Srimad Bhagavad Gita, published by Vishishtadvaita Research Centre, Chennai and The Bhagavad Gita by Swami Chidbhavananda published by Ramakrishna Mission

The distinctiveness of each varna as evinced by its svadharma is delineated as follows:

1 Gita Sloka  Every Day - Chapter 18 - Moksha Sanyasa Yoga - Sloka 44

Krishi gaurakshya vanijyam vaishya karma sva bhavajam I

Paricharya atmakam karma sudrasya api sva bhavajam II sloka 44

कृषि गौरक्ष्य वाणिज्यं वैश्य कर्म स्व भावजं I 

परिचर्या आत्मकां कर्म शूद्रस्य अपि स्व भावजं II श्लोक 44

Agriculture, cattle reasring and trade are the duties of the vaishyas, born of their own nature; and action consisting of service is teh duty of teh sudras born of their own nature.

The duties of the vaishya are as follows : farming, cattle breeding, trade, which consists of buying and selling, and earning wealth. The duty of the sudra is to be of service. 

Besides the above, the rituals prescribed in the vedas like the yagnas should be done, according to ones caste and ashrama. Yagnas and such other works are common to the three castes of brahmins, kshatriyas and  vaishyas. Controlling the indriyas, etc. is to be done by those, among the three castes, who seek moksha.

A brahmin leads his life, by participating in the yagnas, teaching the vedas and accepting gifts. A kshatriya administers the kingdom and protects the people. A vaishya does farming etc and a sudra is of service top others.