This Descriptor list consists of an initial minimum set of characterization and evaluation descriptors for Sclerocarya birrea. Sclerocarya birrea, commonly known as marula is an important multipurpose fruit tree of the semi-arid and sub-humid zones of sub-Saharan Africa. It belongs to the family Anacardiaceae.
This is not intended to be an exhaustive descriptor list, but rather a key list of descriptors and traits that are relevant to describing, categorizing, and especially utilizing germplasm of indigenous fruit trees.
Chege J., Muchugi A., Nyoka B.I., Kang’ethe S., Jamnadass R., Cognetti de Martiis S., Cerutti A.L., Alercia A. 2021. Key descriptors for Sclerocarya birrea (marula). World Agroforestry, Nairobi, Kenya and the Food and Agriculture Organization of the United Nations, Rome, Italy. ISBN: 978-9966-108-48-7
Measure from ground level to the top of the tree.
Indicate the age of the tree in years
Distance from the ground level to the point of emergence of first branch. If grafted, also record height of graft union and rootstock name.
Diameter record at breast height.
Measured as the mean diameter using two directions [East-West, South-North].
Record the predominant shape of 10 leaflets randomly selected
| Code | Term | Description |
|---|---|---|
| 1 | Round | |
| 2 | Oblong | |
| 3 | Lanceolate | |
| 4 | Elliptic | |
| 5 | Obovate | |
| 99 | Other (specify in the Notes descriptor) |
| Code | Term | Description |
|---|---|---|
| 1 | Female | |
| 2 | Male | |
| 3 | Hermaphrodite |
Record the predominant shape of 25 fruits randomly selected
| Code | Term | Description |
|---|---|---|
| 1 | Roundish or Sub globose | |
| 2 | Obovoid | |
| 99 | Other (specify in the Notes descriptor) |
Record the average fresh weight of 25 mature fruits randomly selected.
Record the average length of 25 mature fruits randomly selected at the longest point.
Record the average diameter of 25 mature fruits randomly selected at the widest point.
Record the average weight of pulp from 25 mature fruits randomly selected.
| Code | Term | Description |
|---|---|---|
| 1 | Sour | |
| 2 | Sweet |
| Code | Term | Description |
|---|---|---|
| 3 | Low | |
| 5 | Intermediate | |
| 7 | High |
Record the average length of 25 stones [nuts] randomly selected measured at the longest point
Record the average width of 25 stones randomly selected measured at the widest point.
Average number of kernels per stone from 25 randomly selected stones.
Record the average weight of 100 kernels randomly selected.
Record the average length of 25 kernels randomly selected measured at the longest point.
Record the average width of 25 kernels randomly selected measured at the widest point.
| Code | Term | Description |
|---|---|---|
| 1 | Early | |
| 2 | Late |
| Code | Term | Description |
|---|---|---|
| 1 | Early | |
| 2 | Intermediate | |
| 3 | Late |
Record the total number of mature fruits on tree.
Record the total weight of all mature fruits on tree.
Biotic stress susceptibility
Biotic stress susceptibility
Biotic stress susceptibility
Biotic stress susceptibility