DOI: 10.36347/sajb.2015.v03i02.011

Pages: 173-177

Seed production is the first stage of plant restoration. A study was conducted to investigate the influence of stand age and dbh class on seed production of Pinus kesiya, with much emphasis on number of cones, seed weight, seed quantity, and seed viability. Cones were collected from Pinus kesiya stands of 20, 25, 30 and 39 years old in Chongoni Forest Plantation, Malawi. The results shows that stand age and dbh class significantly (p<0.001) affected seed production. Number of cones, seed weight and quantity increased as the stand age increases and reached the maximum at 25 years (maturity age) up to 30 years of age (rotational age) then gradually decreased. The differences may be attributed to metabolic processes which are highly intensified at maturity age and rotational age. On the other hand, number of cones, seed weight and quantity increased with an increase of dbh class. Neither stand age nor dbh class (p>0.05) influenced seed viability. This imply that as long as mature seeds are collected they will germinate irrespective of stand age or dbh class. Stand age and dbh class had strong polynomial (r>0.99, p=0.05) and linear (r>0.97, p=0.05) relationship with number of cones, seed weight and quantity per tree respectively. This entails that stand age and dbh class could be used as parameters for predicting seed production. However, there were weak relationship between both stand age (r=0.259, p=0.966) and dbh class (r=0.059, p=0.941) on seed viability. Furthermore, the results shows that at individual tree level, dbh class was a better predictor of seed production than stand age, while stand age was a better predictor than dbh class of seed production at stand level. It is therefore, recommended that seeds of Pinus kesiya should be collected from the stands of 25 to 30 years old in Malawi and the surrounding countries in order to maximize seed production. However, if seed collection is to be done on individual mother trees, then it is recommended to collect from