Seed Production Area (SPA) is defined as a phenotypically superior stand made up of vigorously growing healthy trees, upgraded by thinning to remove poorer phenotypes and treated and managed to cause abundant seed production. Tree improvement is a stepwise process involving exploration, collection, evaluation, breeding, multiplication, distribution and conservation of genetic resources. Developing seed production areas is one of the first steps in tree improvement programme that can be used to obtain genetically improved seed for immediate planting.

                Good plantations of Dalbergia sissoo (Roxb.) planted in the state of Rajasthan  were surveyed and good seed stands planted from 1966-82 were intercompared with each other for desired traits. After inter-comparision, a 20 ha. area at 40-55RD of Navrang Dehsar Branch, Hanumangarh was converted into seed production area.  Out of 1052 trees, 562 plants have been culled and 490 trees were retained after scoring each tree in the stand and ranking them in descending order. After culling, the average height, clear bole, and girth/diameter have been shifted towards higher side by 0.44m, 0.58m, and 0.54cm, respectively. Seeds collected after establishment of SPA showed improvement in seed weight and germination percentile.

Dalbergia sissoo (Roxb.), seed production area, culling