Establishment of optimum plant densities for dry season sorghum grown on Vertisols in the semiarid zones of Cameroon
Dry season transplanted sorghum is grown on Vertisols in the Lake Chad Basin at approximately 10,000 plants ha-1. Increasing plant density was hypothesised to be one way of increasing yields in this cropping system. To test this hypothesis, a trial was conducted in four environments near Maroua in n...
| Autores principales: | , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés Francés |
| Publicado: |
African Journals Online
2002
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| Acceso en línea: | https://hdl.handle.net/10568/92752 |
| Sumario: | Dry season transplanted sorghum is grown on Vertisols in the Lake Chad Basin at approximately 10,000 plants ha-1. Increasing plant density was hypothesised to be one way of increasing yields in this cropping system. To test this hypothesis, a trial was conducted in four environments near Maroua in northern Cameroon (one year at Yoldeo and three years at Salak) examining densities ranging from 10,000 to 50,000 plants ha-1. Grain yields were not significantly increased by increasing planting density in any of the environments because of reduced panicle size. For example, as planting density was doubled from 10,000 to 20,000 ha-1, the mean density of panicles harvested was increased by 85% but mean grain weight per panicle was decreased by 45%. Thus, in all environments, mean grain yields increased by 100 kg ha-1 (9%) at the transplant density of 20,000 ha-1 and 150 kg ha-1 at 26,667 plants ha-1. A comparison of results from three years at Salak suggests that the fraction of plants bearing panicles is influenced by the annual rainfall and, especially, the amount of rain during August and September. However, even after a season of adequate rainfall, panicle grain weight decreased with increasing panicle density, suggesting that there is little scope for increasing dry season sorghum transplant density without supplemental irrigation. Considering increases in labour input for nursery establishment, transplanting and harvest, the increased revenue from increasing planting density does not compensate for increased costs. The economic optimum is around 10,000 ha-1, which is similar to the current farmers' practice. |
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