Gaps in knowledge – the projected programmes include:
AFurther studies on proper site preparation; introduction of nitrogen-fixing treesOption A
BAnd multipurpose trees; arid and semi-arid zone afforestation; growing of trees in conjunction with agriculture; environment degradation assessmentOption B
CUse of saline water for raising tree crops; forest genetics; setting up of seed orchardsOption C
It has been possible to raise the yield of resin from chir pine from the existing 1.5 kg per tree to 3.5 kg on the average per tree by using the American Bark Hack method in conjunction with ______ sulfuric acid: