A. Further studies on proper site preparation; introduction of nitrogen-fixing trees
B. And multipurpose trees; arid and semi-arid zone afforestation; growing of trees in conjunction with agriculture; environment degradation assessment
C. Use of saline water for raising tree crops; forest genetics; setting up of seed orchards
D. All of the above
The correct answer to the question: "Gaps in knowledge – the projected programmes include:" is "All of the above".