ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 70 Number 4
Research Notes
Use of bicarbonate nutrient solution to study carambola rootstock tolerance to calcareous conditions
Thomas E. Marler
Chlorosi responses of 'Maha' carambola (Averrhoa carambola L.) scions grafted on seedling root tocks of 'Maha,' 'Golden Star,' and M-18960 were studied under greenhouse conditions to determine rootstock effects and to evaluate the feasibility of using a bicarbonate nutrient solution system to assay for iron chlorosis. A nutrient solution with 5 mM HCO3- increased chlorosis symptoms in plants immediately after transferring them from a bicarbonate-tree solution. There was a linear increase in severity of chlorosis in these plants with time up to 83 days after transfer when the study was terminated. There was no consistent difference in the degree of chlorosis among the 'Maha' scions grafted on the three rootstock groups. These results suggest that this method may be useful for studying carambola germplasm responses to calcareous conditions. The preliminary information in this study on the influence of rootstock on bicarbonateinduced chlorosis suggests that scion genotype may be more important in carambola than rootstock genotype when considering tolerance to calcareous edaphic conditions.
Keywords: Averrhoa carambola; Iron deficiency chlorosis