Onion (Allium cepa L.) plant growth response to varying levels of leaf and root damages – a preliminary study

Abstract

A biotic and biotic stresses can cause severe damages to leaves and/or roots of plants leading to reduction in productivity and plant death. A greenhouse pot-experiment was performed to determine the interactive effects of leaf and root damages on onion (Allium cepa L. ‘Braddock’) plant growth and productivity. The treatments were: 1) leaf damage (LD: 0, 25, 50, 75 and 100%); and 2) root damage (RD: 0, 50 and 100%) at transplanting. Onion plants with LD 75% or 100% under severeRD100% exhibited the least plant growth rate, and reduced bulbing ratio and bulb fresh weight compared to control intact plants. Moderate leaf damage i.e., LD 25%combined with severe root damage RD 100% had the highest plant growth rate and bulbing ratio compared to the other treatments suggesting that plants with severe root damage, but moderate leaf damage promoted onion plant growth. In conclusion, this preliminary study showed that combined leaf and root damage or root damage alone significantly (P<0.05) reduced onion plant growth and productivity. However, leaf damage alone did not significantly (P>0.05) reduce onion plant growth and productivity. Future work will investigate plant morpho-physiological response.