Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505
Performing Department
(N/A)
Non Technical Summary
Corn (a.k.a. maize) is an important, multi-use cereal crop in United States' agriculture production system; Major uses include animal feed, biofuel, and a multitude of food ingredients, starches, sweeteners, oil, etc. Fall armyworm has become an invasive and damaging pest of corn. Due to climate change, disease and insect pressures are increasing and thus there is an urgent need to develop new and effective tools and tactics to cope with these shifting stress trends. Usage of agrochemicals has become an integral part of today's crop protection strategies. To control insect pests, synthetic chemical deployment has led to a huge loss of healthy environments due to atmospheric, ground, and surface water pollution. An alternative is to reduce the use of these harmful pesticides by developing sustainable crop protection strategies.We have identified a group of plant botanicals that have immense potential in crop protection and health-promotors both for plants and animals. The goals of this project are to develop tactics and tools of using plant produced chemicals (bioactives/botanicals) in managing insect pests. The experimental approaches in this project will study the effectiveness of bioactive compounds as potential deterrents to insect pests. Cultivars of sorghum and corn have been developed that differentially synthesize these bioactives utilized in this study. Field and laboratory-based choice tests will be performed to understand the behavior of the adult insects for egg laying on different cultivars. The project will also analyze plant volatile compounds that can be used in a bio control strategy of fall armyworm management. Field based demonstrations and on-farm trials are planned to test the effectiveness of novel cultivars to manage insect pests. Arrangements have been made to reach out to farmers and stakeholders through the vast network of clientele of local corn seed industry and Penn State Extension specialists. The project will also provide training to students and researchers plant bioactives. Results from this project will allow development of novel push-pull plant defense strategies of IPM. Novel crop varieties of corn and sorghum from the project can be then integrated into sustainable production programs.
Animal Health Component
30%
Research Effort Categories
Basic
60%
Applied
30%
Developmental
10%
Goals / Objectives
This is a CPPM ARDP Applied Research-led single-function project addressing program area priorities of Plant Protection Tools and Tactics and b. Diversified IPM Systems. The Project will allow development of individual tools and tactics needed for pest management systems using maize and sorghum phytochemicals. Extension activities will include pilot field-scale demonstrations.This project will focus on agriculturally important maize crop which is highly vulnerable to insect damages especially fall armyworm (FAW) damage. In line with the CPPM program, the project will develop and implement sustainable IPM strategies of crop protection. To disseminate information of new tools and tactics, we have partnered with corn seed industry and extension specialists to interact with growers and stakeholders. Results will allow the development new host plant defense strategies with the use of plant bioactives and volatile organic compounds (VOC) for sustainable plant health. This project objectives are:1. Develop a novel targeted delivery of bioactives at the insect feeding sites of the plant.2. Identify VOC-mediated FAW behavioral changes to design crop defense strategies.3. Field screening to deploy direct and indirect defense strategies against fall armyworm.
Project Methods
Objective 1. Develop a novel targeted delivery of bioactives at the insect feeding sites of the plant. Dried leaf samples from sorghum plants will be used to obtain bioactives. Confirmation of compounds will be from HPLC profiles. Quantitative analysis will be done using calibration curves from targeted LC-MS to allow the quantitative comparison of desirable compounds. LC standards will be purchased from Alsachim (Strasbourg, France). We have been working with has done substantial troubleshooting and method development for the quantification of various bioactives. The identified bioactives will be tested against fall armyworm behavior. Delivery of bioactives will be designed using several methods that include but not limited to direct spraying on susceptible plants to make then resistant against FAW. Choice tests will be performed to assay caterpillars' choice to bite plants containing bioactives vs. controls. This task will allow us to test the olfactory behavior of FAW larvae as well as toxicity of bioactives in the laboratory assays. The results obtained from greenhouse grown plants will be then tested in the field conditions before deploying at a farms site.Objective 2. Identify volatile-mediated FAW behavioral changes that modulate defense strategies. Here, we will be characterizing FAW larval behavior and volatile organic compound (VOC) cues that dictate FAW adult oviposition and tri-trophic interaction studies involving plant-larva-parasitic wasp. We will observe FAW larval behavior in a choice arena with three plants from each genotype offered simultaneously. Plants will be placed in a guillotine arena. The guillotine arena is composed of a white box board platform with six, 5 cm holes cutout through which the six plant stems will be placed. Fifty neonate larvae will be released at the center of the arena and allowed to move toward and onto a plant (number of larvae may potentially change if necessary for better resolution of behavior). The number of individuals recovered from each plant will be recorded and compared every 15 min over a 3 hr period. Assay time period may be extended or reduced to improve insect response. The number of larvae recovered from the plants of each genotype treatment will be recorded and compared using an ANOVA.To verify that volatile cues are mediating host-plant choice by parasitic wasps, we will test their olfactory preference for the two maize genotypes using glass y-tube olfactometers. The olfactometer consists of a glass tube that branched into two arms with an internal diameter of 1.5 cm (Ali lab, Pennsylvania State University). Each arm of the olfactometer will be connected with Teflon tubing to a 35 cm tall × 15 cm wide glass chamber (Pennsylvania State University). Each chamber will contain one of the two genotypes in Assay 1, and one genotype either with or without pest damage. This allows for testing how the plants themselves compare in their constitutive attraction of the parasitoids and how inducibility of each genotype influences attraction. Scrubbed air will be pushed into the olfactometer from glass chambers containing the treatments using a filtered air pump. Wasps will be placed at the entrance of the olfactometer and given ten minutes to make their choice. We will perform field trials to test the effectiveness of high bioactives' content and attraction of parasitic wasps in response to emitted volatiles in field conditions. Results from two-choice assays will be recorded as binary responses and analyzed using the Chi-square tests.Objective 3.Field screening to deploy direct and indirect defense strategies against fall armyworm. Push-pull tactics are commonly deployed to understand and manipulate the behavior of insect pests and their natural enemies. These tactics make use of cues that push pests away from undesirable sources while pulling them towards a desirable source that appeal them. As a result, these tactics include direct insect behavior and influence of their distribution and abundance. Under this objective we will develop the tools and tactics for deterring FAW larvae using feeding behaviors and cues obtained from objectives 1 and 2. A nine-entry complete randomized block design with three replications will be planted in two independent blocks at PSU Agronomy farm. Each entry per replication will be grown as a 3-row, 17.5-foot-long plot. Out of 9 entries, 4 will be tolerant and 5 will be susceptible. Planting of resistant and susceptible entries in a RCBD will allow evaluation of the border row strategy. Block A will have one outermost all-around border row of high bioactive sorghum and one inner border row of maize cultivar high in VOC's. The Block B will be exactly the same as Block A except no border rows of sorghum and maize will be added. Using Davis scale, leaf damage of all entries in Block A and B will be evaluated at different plant stages.Data Analysis: The average concentrations of bioactives will be calculated on a per-plant basis from three plants/replication. Biochemical analysis for volatiles, sugars, and starch will be done on a row basis represented by bulked leaf samples per replication per genotype. The average leaf damage will be calculated on a per-plant basis from all 20 plants /replication from all entries as well as the two-border rows. Biochemical analysis for volatiles, will be done on a plant/row/entry basis. Statistical analysis will be performed using R. A one-way ANOVA test will be performed on each of the biochemical traits to measure genotype-wise differences and significant ANOVA results will be followed up with pairwise t-tests using Benjamini-Hochberg correction for multiple testing. A Pearson's correlation will be used to determine the pair-wise correlation of different traits.