Foliar and soil treatments of Brassica napus that elicit antibioses in Brevicoryne brassicae

Authors: JAVED, MUHAMMAD - University Of Agriculture - Pakistan; UL HASAN, MANSOOR - University Of Agriculture - Pakistan; SAGHEER, MUHAMMAD - University Of Agriculture - Pakistan; SAHI, SHAHBAZ - University Of Agriculture - Pakistan; Mankin, Richard

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2022
Publication Date: 4/5/2022
Citation: Javed, M., Ul Hasan, M., Sagheer, M., Sahi, S., Mankin, R.W. 2022. Foliar and soil treatments of Brassica napus that elicit antibioses in Brevicoryne brassicae. Agronomy Journal. 12(4):882. https://doi.org/10.390/agronomy12040882.
DOI: https://doi.org/10.3390/agronomy12040882

Interpretive Summary: Aphids are important pests of canola and other oilseed crops worldwide. Widespread use of pesticides has resulted in the build-up of resistance, and alternatives to manage this and other pests are under investigation by researchers. Researchers in Pakistan and at ARS CMAVE in Gainesville, FL considered the effects on aphids of adding foliar applications of salicylic acid, citric acid and other naturally produced chemicals that induce resistance mechanisms in canola, and soil applications of silicon and ammonium sulfate nutrients to potted plants in greenhouses. The goal was to increase plant health without pesticide use, while making it more difficult for the aphids to feed on the plants and reproduce. Several of the combined foliar and soil treatments produced significant reductions in aphid growth and reproduction and such treatments will be considered further in attempts to develop ecofriendly aphid management methods.

Technical Abstract: Applications of induced-resistance (IR), nutrient-deterrence (ND), and soil amendment (SAM) treatments to Brassica napus L. significantly reduced the fitness of a major aphid pest, Brevicoryne brassicae L. Effects of different combinations and doses of IR, ND, and SAM on aphids were compared with labeled dosages of Carbosulfan and a control. Statistically significant, dose dependent differences between treatments and control were found for several measures of aphid fitness, including Kaplan-Meir functions, reproduction time, effective fecundity (Md), intrinsic rates of natural increase (rm), relative growth rate (RGR), and generation time. For progeny, development/pre-reproductive period and percent progeny nymph survival also were significantly different from control. Carbosulfan was the most rapidly acting treatment; however, 1 mM salicylic acid (SA) produced statistically significant reductions in aphid fitness compared to control, followed by 1 mM citric acid (CA), 0.5 mM SA, and 0.5 mM CA. Silicon (Si) at 50 kg/ha was the most effective ND treatment. Ammonium sulfate (AS) decreased fitness only at 25 kg/ha. Several SAM combinations of both elemental sulfur (ES) and bio-sulfur (BS) treatments with compost (Cp) also yielded statistically significant reductions in aphid fitness. These results provide context for future exploration of IR, ND, and SAM treatments to improve canola yield and reduce aphid damage.