The Grafton Primary Industries Institute (830 ha) is located at Trenayr, approximately 10 kilometres north of Grafton. The Institute is unique in NSW by providing operational and research functions for agriculture, aquaculture and forestry from the one location.

Cattle grazing, cropping, sugar cane, timber and fisheries research are presently the mainstay research activities of the Grafton district. These diverse coastal industries are reflected in the wide range of programs at the Institute.

The Institute has been involved in the evaluation of many enterprises over the years. Many types of crops, from fruit trees (mangoes, lychees, citrus) to crops such as tobacco and pineapples, have been evaluated on the property. More recently the main crops have been maize, sugar cane, soybeans and winter cereals. With the North Coast of NSW being the major Australian soybean production area, the soybean research program at Grafton is of particular importance.

Livestock enterprises have included beef and dairy cattle, pigs, poultry and aquaculture. Grafton was the research centre that demonstrated the benefits to the beef industry in crossbreeding Bos indicus and Bos taurus cattle.

Research and advisory work at the Institute is presently directed at the control and eradication of various terrestrial and aquatic weeds by chemical, biological and mechanical means. These weeds include salvinia, cabomba and lantana.

Institute staff have played an important role in the welfare of pets and livestock affected by local floods and by partaking in the eradication programs that were effective against exotic animal diseases such as equine influenza and avian influenza.

The Institute also houses the Grafton Aquaculture Centre that has pioneered aquaculture of fresh water species such as Silver Perch. Grafton Aquaculture Centre also has a number of programs monitoring the wild freshwater fish community of the Clarence River. This  includes operating and maintaining the largest freshwater acoustic listening array in Australia which tracks the movement of some 200 tagged fish over an area in excess of  600 linear kilometres.

A wide range of programs supporting the timber industry are also located at the Institute. These include northern plantation management, the Tree Improvement Centre and the plantation nursery.