Archived
This content is available here strictly for research, reference, and/or recordkeeping and as such it may not be fully accessible. If you work or study at University of Kentucky and would like to request an accessible version, please use the SensusAccess Document Converter.
Publication Date
1981
Description
In 1978 an evaluation program was initiated to select legumes that (1) grow and produce seed on acid soils under aluminum and water stress, (2) persist under grazing, and (3) tolerate pests and diseases. The work is being conducted at the Cerrados Agricultural Research Center, near Brasilia, at lat 15°S and altitude 1,000 to 1, 100 m . Annual rainfall is 1,500 mm, mostly distributed in a 6-month wet season, and mean annual temperature is 21°C. Nine hundred legume accessions from thirteen genera have now been established as spaced plants on the 2 major soil types of the region. The pH of the soils is 4.6, with aluminum saturation in excess of 70 %. Known nutrient deficiencies were corrected. Results are reported for 352 of the accessions over a 2-year period. The most promising genus is Stylosanthes. Seventeen accessions of S. guianensis (Aubl.) Sw. , S. capitata Vog. , S. scabra Vog. , and S. uiscosa Sw. have combined good adaptation to acid soil conditions and good tolerance to pests and diseases. All S. guianensis accessions belong to a distinctive group of fine-stemmed, highly viscous ecotypes currently referred to as the "tardio" group. Their outstanding attribute is tolerance to anthracnose, the major limiting factor to the use of the genus in the region. Seed of the selected accessions is being multiplied for evaluation under grazing. The number of accessions of Stylosanthes has been increased further within the program. None of the other genera have shown tbe potential of the genus Sylosanthes. New Calopogonium Desv. and Galactia P. Br. accessions were no more productive than commercial control cultivars. Aescl!)lnomene L. accessions were highly susceptible to anthracnose, while those of Pueraria DC ., Teramnus P. Br. , Vigna Savi, and Centrosema (DC.) Benth. species grew relatively poorly. Zornia J.F. Gmel. accessions were very vigorous, but all plants were very susceptible to an insect/virus/fungus complex. Tolerance has been found in new ecotypes of Z. brasiliensis V og. Most Desmodium Desv. species showed poor vigor and were affected by the disease little-leaf mycoplasma. Observations are continuing with these other genera, but introductions are being made on a more limited scale.
Citation
Thomas, D and De Andrade, R P., "Preliminary Evaluation of Legume Germ Plasm in the Cerrados of Brazil" (1981). IGC Proceedings (1981-2023). 3.
(URL: https://uknowledge.uky.edu/igc/1981/section1/3)
Archival?
Archival
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Preliminary Evaluation of Legume Germ Plasm in the Cerrados of Brazil
In 1978 an evaluation program was initiated to select legumes that (1) grow and produce seed on acid soils under aluminum and water stress, (2) persist under grazing, and (3) tolerate pests and diseases. The work is being conducted at the Cerrados Agricultural Research Center, near Brasilia, at lat 15°S and altitude 1,000 to 1, 100 m . Annual rainfall is 1,500 mm, mostly distributed in a 6-month wet season, and mean annual temperature is 21°C. Nine hundred legume accessions from thirteen genera have now been established as spaced plants on the 2 major soil types of the region. The pH of the soils is 4.6, with aluminum saturation in excess of 70 %. Known nutrient deficiencies were corrected. Results are reported for 352 of the accessions over a 2-year period. The most promising genus is Stylosanthes. Seventeen accessions of S. guianensis (Aubl.) Sw. , S. capitata Vog. , S. scabra Vog. , and S. uiscosa Sw. have combined good adaptation to acid soil conditions and good tolerance to pests and diseases. All S. guianensis accessions belong to a distinctive group of fine-stemmed, highly viscous ecotypes currently referred to as the "tardio" group. Their outstanding attribute is tolerance to anthracnose, the major limiting factor to the use of the genus in the region. Seed of the selected accessions is being multiplied for evaluation under grazing. The number of accessions of Stylosanthes has been increased further within the program. None of the other genera have shown tbe potential of the genus Sylosanthes. New Calopogonium Desv. and Galactia P. Br. accessions were no more productive than commercial control cultivars. Aescl!)lnomene L. accessions were highly susceptible to anthracnose, while those of Pueraria DC ., Teramnus P. Br. , Vigna Savi, and Centrosema (DC.) Benth. species grew relatively poorly. Zornia J.F. Gmel. accessions were very vigorous, but all plants were very susceptible to an insect/virus/fungus complex. Tolerance has been found in new ecotypes of Z. brasiliensis V og. Most Desmodium Desv. species showed poor vigor and were affected by the disease little-leaf mycoplasma. Observations are continuing with these other genera, but introductions are being made on a more limited scale.
