| Popis: |
The quality of mature seed cones of Pinus caribaea var. hondurensis Barr. and Golf, collected across the planting range (Latitude 4°54′N to 10°37′N) in Nigeria, was evaluated and related to the topoclimatological conditions of the sites of collection. The sites were grouped on various bases to determine which grouping significantly affected seed-cone quality. Vegetation-zone and altitudinal groupings brought out more variation in cone characteristics than did latitudinal and age groupings. Seed cones ripened earlier in savanna areas having 4–5 months of dry season and an elevation of 393–600 m. Cone production was greatest at 393 m, cone size was largest at 1130 m and ovuliferous scales were more numerous at low elevations and in lowland rain-forest zones than at other sites. Cone length was positively correlated with the number of ovuliferous scales and number of seeds per cone in each location. The productive-cone percentage was 14–43 for the entire harvest and 50–83% when only the mature green cones were considered. This variable was insensitive to all the site attributes considered. The number of seeds per cone was very low for both mature green (1–12) and ripe (2–9) cones and was greatest at 1130 m altitude. The productive-cone percentage was positively correlated with latitude and altitude and negatively correlated with relative humidity, annual rainfall and minumum temperature. |
