The study investigated the effects of seed size on germination and early growth of Anacardium occidentale. The study was carried out at the screen house of the Federal College of Forestry, Ibadan. Seeds of A. occidentale were categorized into three size classes length, breadth and weight as small (2.0 – 2.5 cm, 1.0 – 1.5 cm and 2.5 – 5.0 g), medium (2.6 – 3.0 cm, 1.6 – 2.0 cm and 5.1 – 7.5 g) and large (3.1 – 3.5 cm, 2.1 – 2.5 cm and 7.6 – 10.0 g). Seeds were sown for each class into the germination baskets filled with sterilized river sand. The seeds were watered daily and monitored for germination with daily record of new sprouts. The seedlings were transplanted into polythene pots filled with topsoil. The experiment was laid in Completely Randomized Design (CRD) with three treatments and ten replicates. The parameters assessed include seedling height (cm), collar diameter (mm), leaf production and leaf area (cm2). The data collected were subjected to Analysis of Variance and means were separated by Least Significant Difference at 5% level of probability. Germination results showed cumulative percentages of 60.43%, 73.78% and 77.33%. The result from growth parameters showed a direct association with the sizes of the seeds. The large, medium and small-sized seeds had 26.17 cm, 22.55 cm and 17.93 cm in seedling height with 7.14 mm, 6.59 mm and 6.26 mm in collar diameter respectively. Large seeds of A. occidentale should be adopted for quick germination and fast growth to establish its orchard.
Key Words: Anacardium occidentale, seed size, growth, germination