Author
|
Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/13/2004 Publication Date: 3/31/2005 Citation: Smith, J.R., Goenaga, R.J. 2005. Field performance of two snap bean cultivars at varying levels of exchangeable aluminum. Journal of Plant Nutrition. 28:237-246. Interpretive Summary: High levels of soluble soil aluminum can be toxic to many species of plants, including snap bean. Aluminum toxicity can be a major production problem for snap bean farmers in many parts of the world. Some snap bean varieties appear to be more tolerant to aluminum toxicity than others. Hence, plants breeders are attempting to improve snap bean tolerance to aluminum toxicity. Using seedling and vegetative tests in laboratories and greenhouses to determine snap bean tolerance is quicker and cheaper than using field tests with mature plants. The results of some research has suggested that testing snap beans for aluminum tolerance as seedlings may be a good way to determine if they are tolerant as mature plants. However, no one has confirmed that snap beans that show tolerance as seedlings or vegetative plants in a greenhouse or laboratory will also show tolerance as mature plants in the field. The purpose of this research was to determine if snap bean cultivars Dade and Tendercrop, previously shown to respond differently for aluminum tolerance in vegetative tests, are different for aluminum tolerance as mature plants in the field. Thirty side-by-side plots of Dade and Tendercrop were grown in a field with varying levels of aluminum in Corozal, Puerto Rico in 1999 and 2000. Grain weight was used to determine the response of each cultivar to soil aluminum. The results indicated that both varieties were negatively and similarly affected by aluminum toxicity. Hence, this study does not support the assumption that seedling tests for aluminum tolerance can identify mature snap bean plants with tolerance to aluminum. Technical Abstract: Aluminum (Al) toxicity can be a major problem to common bean (Phaseolus vulgaris L.) production in many parts of the world. Seedling/vegetative assays have demonstrated genotypic differences among bean genotypes for tolerance to Al toxicity, but insufficient information is available to determine if results are indicative of tolerance measured in the field on mature plants. A two-year field study was conducted to determine if snap bean cultivars Dade and Tendercrop, previously shown to respond differently for Al tolerance in early vegetative assays, also exhibited differential Al tolerance as mature plants in field assays. Exchangeable Al varied from 0 to 10.67 centimoles of charge per kilogram. In 1999, grain weights of Dade and Tendercrop were negatively associated with exchangeable Al, but did not differ from each other in their association with exchangeable Al. In 2000, the grain weight of Dade was lower than in 1999, but still negatively associated with exchangeable Al. For Tendercrop, 2000-year effects also reduced grain weight, but so much so that no association between grain weight and exchangeable Al was evident. Dade and tendercrop differed in grain weight in the absence of Al in 2000, but their Al responses were not different. This study demonstrates the complexity of genotypic response to acid soils with Al toxicity, but does not support the assumption that early vegetative assays can identify Al tolerance in mature snap bean plants. |
