Morphometrics of Pinus patula crown and its effect on cone characteristics and seed yield in Kenya

Pinus species and other conifers have cones as an essential unit for seed production. Cone production in pines is not uniform and often varies among compartments and sectors within the crown. Many countries experience challenges in seed production from orchards due to poor practices. The present study aimed to evaluate within-crown cone production patterns, cone characteristics, and seed yield in a Pinus patula clonal seed orchard in Londiani, Kenya. Crown height was divided into three equal portions and a further subdivision done for each of the parts into two sections. There were differences in cone characteristics within the crown, between the sections and compartments. The majority (67.1%) of the cones in the present study were curved. The study also showed that cone shape had no significant influence on seed yield. The present study observed cones collected from the top portion of the crown yielded the highest amount of seed (33.3±4.91 seeds) (p<0.05) while the bottom part had the lowest (14.4±2.76) (p<0.05). The study recommends the collection of P. patula seeds from the upper part of the crown in unmanaged stands. Further, it suggests that management through pollarding needs to be done regularly to minimize within-crown differences. Key words: Pinus patula, crown, cone characteristics, seed yield, clonal seed orchard.