Humic Fertilizer and Vermicompost Applied to the Soil Can Positively Affect Population Growth Parameters of Trichogramma brassicae (Hymenoptera: Trichogrammatidae) on Eggs of Tuta absoluta (Lepidoptera: Gelechiidae)

Abstract

The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r ), finite rate of increase (λ), net reproductive rate (R), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r , λ, and R were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.

From Lab to Field: Role of Humic Substances Under Open-Field and Greenhouse Conditions as Biostimulant and Biocontrol Agent

“…Joshi et al (2014) present the list of pathogens and pests controlled through vermicompost application, highlighting that the main chemical components of the vermicompost belong to HS. There are four approaches by which HS can contribute to the plant defense mechanisms under field and greenhouse conditions: (1) enhancing the soil microbial activities that play as biological control agents, such as Trichoderma (McLean et al, 2012;Motta and Santana, 2013;Mohamadi et al, 2017); (2) direct interaction with plant pathogen (e.g., Nematodes, Late blight) (Zaller, 2006;Seenivasan and Senthilnathan, 2018;D'Addabbo et al, 2019;Liu et al, 2019);…”

Bottom-up effects of irrigation, fertilization and plant resistance on Tuta absoluta: implications for Integrated Pest Management

“…Large-scale long-term experiments should be interesting to investigate if the slow-growth-highmortality hypothesis (Benrey & Denno 1997) applies in this scenario. In another experiment, humic fertilizer and vermicompost applied to the soil enhanced population growth parameters of a Trichogramma parasitoid species on eggs of T. absoluta (Mohamadi et al 2017). This is puzzling as it is unlikely that the quality of T. absoluta eggs be affected by tomato fertilization, and we may suggest that such experiment should be repeated while checking fertilization effects on tomato VOC emission and their effects on parasitoids.…”

Vermicompost and bactericide application minimized common bacterial blight development and enhanced nodulation and agronomic performances of bean varieties in Southern Ethiopia

“…There are various research reports suggesting that VC applications alone and in integration with organic or inorganic fertilizers enhance soil fertility, nutrient uptake, mineralization, N‐fixation, plant growth and productivity, soil physical conditions (aeration, drainage, facilitation of actions of N, P, and K exchange) and moisture retention capacity, soil microbial population and activity, and nutrient cycling (Bark & Gulati, 2009; Manivannan et al., 2009; Roy et al., 2010; Saha et al., 2008; Sharma et al., 2018) and suppress plant pests through different mechanisms (Basco et al., 2017; Baum et al., 2015; Doan et al., 2015; Edwards et al., 2004; Koul, 2008; Mohamadi et al., 2017; Nadana et al., 2020). Chemical seed treatment and foliar applications have also been considered promising options to manage the CBB of common bean across the world (Ararsa et al., 2018, 2019; Girma, 2023; Hailu & Tontosha, 2021; Harveson, 2009; Schwartz, 2004).…”