Page 1 of 8
European Journal of Applied Sciences – Vol. 12, No. 5
Publication Date: October 25, 2024
DOI:10.14738/aivp.125.17599.
Martin, W. O., James, O. K., Kirongo, B. B., & Gichora, M. (2024). Growth and Productivity of 11-Year-Old Pine Hybrids in Turbo- Kenya. European Journal of Applied Sciences, Vol - 12(5). 161-168.
Services for Science and Education – United Kingdom
Growth and Productivity of 11-Year-Old Pine Hybrids in Turbo- Kenya
Welimo O. Martin
Kenya Forestry Research Institute
James Ole Kiyiapi
University of Eldoret,
Department of Forestry and Wood science
Balozi B. Kirongo
University of Eldoret,
Department of Forestry and Wood science
Mercy Gichora
Kenya Forestry Research Institute
ABSTRACT
Exotic Plantation species, especially of the Pinus genus are very popular in many
countries. In the Tropics, and Kenya in particular, Pinus radiata and Pinus patula
are the most widely planted. But exotic species have many challenges and attacks
by diseases and pests are common. Research has therefore to keep abreast with
establishment effort to thwart massive disease attacks and losses. Species and
provenance trials are conducted with this in mind. A Pine hybrids trial was
conducted in Turbo, Kenya with the aim of testing the suitability of 11 hybrids
against the locally grown Pinus patula. The experiment was established in a
Randomized Complete Block Design (RCBD). Height, Diameter (Dbh) and survival
were assessed and results at age 11 years were analyzed and are reported in this
paper. Results showed that there were statistically significant differences (p
<0.001) in height and Dbh between the hybrids. The control (Pinus patula)
performed poorly compared to some of the hybrids. Mean Dbh at 11 years ranged
from 12.9cm to 25.68cm for the hybrids against 18.8cm of Pinus patula while mean
height range was 11.6m to 23.18m against 20m of Pinus patula. Hybrids volume
(D2*H) performance ranged between 328m3 per Ha to 1,894m3 per Ha compared to
1,006.9m3 per Ha for P. patula. The highest volume was found for PatxOoc (patula- by-oocarpa hybrid) with 1,894m3 per Ha. Hybrids PatxTecL and PatxOoc had
superior performance for both growth variables (Dbh and Height) throughout the
experiment period. These results embrace the view that hybrids are better
performing than pure races and that there is value in doing more research in
hybrids in the tropics to diversify genetic base and improve growth and
productivity.
Keywords: Pines, hybrids, growth, productivity.
Page 2 of 8
Services for Science and Education – United Kingdom 162
European Journal of Applied Sciences (EJAS) Vol. 12, Issue 5, October-2024
INTRODUCTION
Globally, there are more than 120 species of pines (Myers, 2022) making pines to be one of the
most preferred commercial forestry species. This is due to their fast growth and high timber
quality as compared to many other softwood species. Pines are an important industrial
plantation genus representing 15% to 20% of industrial wood produced in Southern United
States (Cubbage et al., 2005) and form 25% in Kenya and 54% in South Africa (Maxwell, 2022).
Currently, the main largescale plantation pine in Kenya is Pinus patula, whose growth and
productivity are much lower than Pinus radiata. The establishment of Pinus radiata in Kenyan
forest plantations was abandoned due to attack by Dothistroma needle blight. Alternative fast- growing species were therefore sought to ensure that there is diversity of plantation species.
Research on pine hybrids has proved to be a breakthrough in offering opportunities for
improvement of wood properties as well as coming up with alternatives better adapted to
different environmental conditions and variable climatic conditions (Mitchell, R.G; et al, 2013;
Camcore, 2013). Hybrids have the potential to combine superior desirable traits from both
parents and they have successfully been used in other tree species (Dungey, 2001). Considering
their local and global importance, their development is viewed as an opportunity for the future
(Hagreaves et al., 2008; Hagreaves et al., 2017). Their success is relied upon to inform their
inclusion in to largescale plantations for purposes of improved growth and reduced risks
associated with climate change and pests and disease threats in order to address wood supply
deficit in Kenya, which is currently estimated at 15 million m3 and is projected to increase to
30 million m3 by 2030. Pine species and hybrids diversification is one the options towards
achieving better performance in terms of fast growth, better wood quality, resistance to
diseases and pests and better performance across wide agro-ecological ranges.
This pine hybrids trial was established in Turbo in 2011 with joint support from the
International Program for Tree Improvement and Conservation through Central American and
Mexico Coniferous Resources Cooperative (CAMCORE) and Kenya Forestry Research Institute
(KEFRI). The objective of the research was to determine the growth and productivity of pine
hybrids in Turbo, Kenya.
MATERIALS AND METHODS
Study Area
This study was conducted in Turbo, which is one of Kenya Forestry Research Institute sub- centres, with main research activities on plantation forestry. This Centre lies at 035°3' 45.62''E
and 0°38' 2.265''N, at an altitude 1,859m above sea level, with 18.3°C mean annual
temperatures. The site receives approximately 1,500mm mean annual rainfall, mainly between
May and September. Soils in the site are dark brown, clay loams with moderate drainage.
Study Material
11 pine hybrids seed used to establish this experiment were acquired from CAMCORE, with
general collection of P. patula included as a control. All the seed were pre-treated by soaking in
water at room temperature (20 ±2°C) for 24 hours then separately sown and covered with
loose river sand with each hybrid clearly labeled. After germination, they were pricked out in
pots filled with soil from pine plantations. Pots of individual hybrids were well labeled to keep
seed source identity. Normal nursery tending operations were applied uniformly until the