Translator Disclaimer
25 November 2019 Fertilizing Corn With Manure Decreases Caterpillar Performance but Increases Slug Damage
Elizabeth Rowen, John F. Tooker
Author Affiliations +
Abstract

Many farmers use manure as an alternative to inorganic fertilizer. Previous research has shown that manure can decrease plant susceptibility to herbivores, but the mechanisms remain unclear. To determine how manure affects herbivore performance in a greenhouse setting, we fertilized corn with stacked cow manure or an equivalent amount of NPK fertilizer and measured caterpillar development, plant nutritional content, and defenses. After 4 wk of growth, we allowed fall armyworm (Spodoptera frugiperda) or black cutworm (Agrotis ipsilon) caterpillars to feed on these plants for 6 d. Compared to inorganic fertilizer, manure reduced mass-gain of black cutworm caterpillars and smaller fall armyworms. We paired this greenhouse experiment with a 3-yr field experiment, which incorporated a wheat cover-crop treatment crossed with the two fertilizer treatments in a 2 × 2 factorial design. We measured plant damage early in the season from naturally occurring herbivores and measured neonate fall armyworm performance on field-collected leaf tissue. In 2017, corn in manure-fertilized plots sustained more herbivore damage, primarily driven by a higher incidence of slug damage. Fall armyworm performance, however, was lower on leaves collected from manure-fertilized plants. In contrast to previous studies, we did not find increased micronutrients or enhanced defenses in manure treated plants. While manure can offer resistance to some herbivores, our results suggest that this resistance can be overshadowed by habitat conditions.

© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Elizabeth Rowen and John F. Tooker "Fertilizing Corn With Manure Decreases Caterpillar Performance but Increases Slug Damage," Environmental Entomology 49(1), 141-150, (25 November 2019). https://doi.org/10.1093/ee/nvz145
Received: 6 August 2019; Accepted: 11 November 2019; Published: 25 November 2019
JOURNAL ARTICLE
10 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

Share
SHARE
KEYWORDS
herbivory
manure
micronutrient
plant defense
soil fertility
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top