The Key descriptors for forage grasses consist of an initial minimum set of characterization and evaluation descriptors for some species of the family Poaceae. This strategic set aims at facilitating access to and utilization of various tropical grass species and it does not exclude the addition of other descriptors later. Grasses are the most widely used feed resource for livestock in the tropics from natural grassland and planted pastures. Grasses can be directly grazed, cut and carried for stall feeding or cut and dried for hay to use during the dry season. Their stoloniferous, spreading and deep-rooted nature supports soil stabilization and prevents soil erosion. Grasses have wide economic importance in the tropics and are an important component of extensive grazing and silvopastoral systems in Latin America and intensive cut and carry systems in Sub-Saharan Africa and southeast Asia. Tropical turf grasses are widely used for amenity areas and public parks in both the tropics and subtropics. These general forage grass descriptors are limited to tropical species with specific examples from Andropogon gayanus, Bothriochloa pertusa, Cenchrus ciliaris, Cenchrus clandestinus, Cenchrus purpureus, Chloris gayana, Cynodon dactylon, Cynodon nlemfuensis, Digitaria eriantha, Megathrysus maximus, Melinis minutiflora, Panicum coloratum, Paspalum dilatatum, Paspalum plicatulum, Setaria sphacelata, Sorghum x almum, Tripsacum laxum, Urochloa brizantha, Urochloa decumbens and Urochloa ruziziensis. These are all grasses that are already being adopted by smallholder farmers worldwide. The key set of access and utilization descriptors was defined through an online survey, in which 35 experts from 19 different organizations and universities from 14 countries participated. Survey results were subsequently validated in consultation with a Core Advisory Group (see “Contributors”) led by Alice Muchugi and Jean Hanson from ILRI.
Muchugi, A., Hanson, J., González-Guzmán, J.J., Habte, E., Sime, Y., A., Alercia, A., Cerutti, A.L., Lopez, F. 2023. Key descriptors for forage grasses. International Livestock Research Institute, Addis Ababa, Ethiopia and FAO on behalf of the International Treaty on Plant Genetic Resources for Food and Agriculture, Rome, Italy. doi.org/10.4060/cc7516en.
Measured from ground to the top of the plant foliage at maturity. This may be expressed as short to tall compared to a mean measurement for the species planted on the same date in the same site and season.
Recorded at plant maturity.
| Code | Term | Description |
|---|---|---|
| 1 | Erect | |
| 2 | Decumbent | |
| 3 | Procumbent | |
| 99 | Other (e.g., semi-erect) |
Record the hairiness of the surface of a mature stem when first inflorescences are forming in the plot.
| Code | Term | Description |
|---|---|---|
| 0 | Glabrous | |
| 1 | Hairy | |
| 2 | Bristled | |
| 99 | Other |
Record the Presence or absence of stolon on 10 randomly selected plants and report as a mean.
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
Record the Presence or absence of Rhizome on 10 randomly selected plants and report as a mean
| Code | Term | Description |
|---|---|---|
| 0 | Absent | |
| 1 | Present |
Recorded at plant maturity.
Length of leaf from ligule to tip of a mature vegetative leaf measured when first inflorescences are forming in the plot.
Record width at the widest point of a mature vegetative leaf measured when first inflorescences are forming in the plot.
Record the predominant primary colour.
| Code | Term | Description |
|---|---|---|
| 1 | Grey | |
| 2 | Green | |
| 3 | Yellow | |
| 4 | Purple | |
| 5 | Red | |
| 6 | Blue | |
| 7 | Brown | |
| 99 | Other |
Record the hairiness when first inflorescences are forming in the plot on a mature leaf.
| Code | Term | Description |
|---|---|---|
| 0 | Glabrous | |
| 1 | Moderately hairy | |
| 2 | Hairy |
Record the predominant leaf margin of a mature leaf when first inflorescences are forming in the plot.
| Code | Term | Description |
|---|---|---|
| 1 | Entire | |
| 2 | Dentate | |
| 3 | Serrate | |
| 4 | Ciliate | |
| 99 | Other |
Recorded on a mature inflorescence.
| Code | Term | Description |
|---|---|---|
| 1 | Panicle | |
| 2 | Spike | |
| 3 | Raceme | |
| 4 | Umbel | |
| 99 | Other |
Recorded at 50% flowering.
| Code | Term | Description |
|---|---|---|
| 3 | Loose | |
| 5 | Medium | |
| 7 | Compact |
Record the length from the lowest spikelet to the tip of a mature inflorescence at 50% flowering.
Number of days from sowing/planting until first inflorescences are forming in the plot for first year after establishment and days from cutting until first inflorescences are forming in the plot for evaluation in subsequent years. Recorded for plants with the same planting/ cutting date at the same location in the same year.
Record the predominant primary colour.
| Code | Term | Description |
|---|---|---|
| 1 | White | |
| 2 | Grey | |
| 3 | Green | |
| 4 | Yellow | |
| 5 | Red | |
| 6 | Brown | |
| 7 | Blue | |
| 8 | Purple | |
| 9 | Black | |
| 99 | Other |
Record the weight of 100 randomly selected mature caryopses taking replicates to obtain a mean. This can be expressed as 100 or 1000 seed weight for smaller caryopses.
Record the dry matter weight of quadrats cut when first inflorescences are forming in the plot at 5-10 cm above ground (as relevant for the species) using representative samples that are dried and converted to kg dry matter/ha. Indicate season, plant age and physiological stage (e.g. vegetative/ flowering) at harvesting as results will change as the plant ages.
Percentage of spikelets remaining on the inflorescence at full maturity.
Legend:
Low
Medium
High
Recorded from representative samples taken from quadrats. Analytical assessment determined on a dried ground sub-sample of the whole plant. Indicate season, plant age and physiological stage (e.g., vegetative/ flowering) at harvesting as results will change as the plant ages.
Recorded from representative samples taken from quadrats. Analytical assessment determined on a dried ground sub-sample of the whole plant. Indicate plant age and physiological stage (e.g., vegetative/ flowering) at harvesting as results will change as the plant ages.
Recorded from representative samples taken from quadrats. Analytical assessment determined on a dried ground sub-sample of the whole plant. Indicate plant age and physiological stage (e.g., vegetative/ flowering) at harvesting as results will change as the plant ages.
Percentage of leaf on the entire plant, including all tillers, measured/ observed on a mature plant when first inflorescences are forming in the plot.
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Scored as percentage infection from a specific trial to induce disease or insect infestation, under conditions which are clearly specified. In each case, it is important to state the origin of the infestation or infection, i.e., natural, field inoculation, laboratory. Given the general nature of these descriptors covering a large number of grass species, an indicative list of common pathogens and insect pests are provided. Users should select those with economic impact or add additional ones relevant for the grass species being characterized and the production environment.
Legend:
Low
Intermediate
High
Record the percentage of plants showing drought symptoms under stress conditions.
Record the percentage of plants showing damage under low temperature. Record the temperature causing stress.
Record the percentage of plants showing symptoms of poor adaptation.
Record the percentage of plants showing symptoms of poor adaptation.
Record the percentage of plants showing symptoms of poor adaptation.
Record the percentage of plants showing symptoms of poor adaptation to grazing or defoliation by cutting.
Specify here any other additional information. Add any additional traits that are important to describe the diversity among accessions within this species.