Journal of Agricultural Research | 2021
Compensatory growth mechanisms in lettuce plants after partial defoliation
Abstract
Leaf area loss is a frequent problem in crops, and it can be caused by biotic or abiotic factors. Reduced leaf area can produce \nalterations in plants, affecting their metabolism, growth, and yield. The leaf area in lettuce plants (Lactuca sativa L.) is often \naffected by herbivores such as slugs. The effects of partial defoliation on the growth of lettuce plants were evaluated under \ngreenhouse conditions in Tunja, Colombia. Some plants had half of their leaves removed, while others were left intact \nas a control. The variables normally used in the basic analysis of plant growth were evaluated. There was nonsignificant \ndifference between the two treatments; however, lettuce plants showed a remarkable ability to reduce the negative effect \ncaused by partial defoliation, and they managed to maintain a balance in the root to shoot ratio, leaf area ratio, specific \nleaf area, leaf weight ratio, DM partitioning, and harvestable DM. Partial defoliation decreased the absolute growth rate \nby 17.8% and the relative growth rate by 13.8%. Additionally, the chlorophyll content index and the number of leaves \nincreased by 16.0% and 15.4%, respectively, in plants subjected to partial defoliation compared with the control plants. \nThese results indicate the regeneration capacity of the plants after partial defoliation.