Can overcompensation increase crop production?

Abstract

The two most pressing challenges to agriculture worldwide are feeding a rapidly growing human population and developing more sustainable agricultural practices that do not threaten human and ecosystem health. We address these challenges through research in plant-herbivore interactions, specifically overcompensatory responses in potato to herbivore damage. While herbivory is usually detrimental to most crops, some potato cultivars can overcompensate and increase crop productivity up to two-fold in response to herbivore damage. However, biotic and abiotic factors are known to influence compensatory responses. Here we tested if compensatory plant responses to herbivory increase productivity of potatoes under field conditions along gradients of altitude and landscape simplification in 15 different farms. Our results suggest that compensatory plant responses could double the mean productivity of a potato farm in relation to the productivity of undamaged plants. The compensatory response is best predicted by pest pressure on a farm with potato plants having the maximum productivity when 10% of the tubers are damaged and decreasing in productivity as pest pressure increases. To a lesser extent an interaction between altitude and landscape simplification did affect the compensatory response, suggesting that abiotic factors play an important role in compensation. Our results suggest that overcompensation-based management practices could be used to maximize yields on working potato farms. Further research is required to determine action thresholds (i.e. the damage levels at which pest control needs to be enacted to maximize yields and minimize insecticide use) to develop more sustainable ways of increasing yields in the future.

Tecia solanivora infestation increases tuber starch accumulation in Pastusa Suprema potatoes

“…Consistent with the documented overcompensation responses in Pastusa Suprema (Poveda et al ; Poveda et al ; Poveda ), we observed changes in both gene expression and primary metabolism in systemic tubers resulting from T. solanivora infestation. The 80% reduction in sucrose content in the systemic tubers, which occurred within 1 d of larval infestation (Figure B), could be due to either reduced transport of sucrose to these tubers or increased conversion of sucrose into starch.…”

“…Perhaps more surprising than tolerance is the observation that, in some cases, tissue removal through herbivory can ultimately result in a higher biomass or seed production, compared to uninfested plants (Belsky ; Paige and Whitham ; Lennartsson et al ; Strauss and Agrawal ), an effect that is commonly referred to as overcompensation. Some potato cultivars, notably Pastusa Suprema, a commercially grown Colombian potato variety, show significant increases in total tuber dry mass in response to infestation with T. solanivora larvae (Poveda et al ; Poveda ). On 10 different farms, plants that had 1% to 10% of their tubers damaged by T. solanivora larvae produced approximately 2.5‐fold more marketable (undamaged) yield than potato plants that were completely undamaged.…”

Overcompensation: a 30‐year perspective

“…, Poveda et al. , this Special Feature). As an example, the indirect positive effects of herbivores on plant performance are mediated by improved soil nutrient pools or by the removal of competitors (de Mazancourt et al.…”

“…Poveda and her colleagues have previously shown that low level herbivory by the Guatemalan tuber moth can lead to a doubling in yield of a Columbian potato variety (e.g., Poveda et al. ). Because compensatory responses appear to be context‐dependent, in this Special Feature, Poveda et al.…”

Overcompensation for insect herbivory: a review and meta‐analysis of the evidence

“…Our goal is to increase awareness of overcompensation for insect herbivory and to aid in answering several unresolved questions about the ecological and evolutionary consequences of overcompensation (Whitham et al 1991, Agrawal 2000. For example, how prevalent is overcompensation for insect herbivory in agricultural systems (Bardner and Fletcher 1974), and how can we use knowledge of overcompensatory mechanisms to increase crop yield (Poveda et al 2018)? Do latitudinal climate differences affect plant compensatory responses (Anstett et al 2016)?…”