Determination of damaged leaf area and physiological responses of melon plants submitted to different infestation levels of Liriomyza sativae

Ewerton M Costa,Rômulo Magno O Freitas,Elton Lucio Araujo,Paolo Augustus F Silva

doi:10.1590/s0102-053620170415

Ewerton M Costa, Rômulo Magno O Freitas + Show 2 more

Open Access

https://doi.org/10.1590/s0102-053620170415

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Abstract

ABSTRACT The leafminer Liriomyza sativae (Diptera: Agromyzidae) is one of the main pests of melon crop (Cucumis melo) in the Brazilian semiarid. The aims of this study were to determine the damaged leaf area and assess the physiological responses of melon plants submitted to different levels of infestation per larvae of L. sativae. The study was carried out in a greenhouse, using plants of melon of the cultivar Iracema (yellow melon). The design utilized was completely randomized, with five treatments {control (no infestation in the leaves) and four infestation levels (1; 10; 20 and 30 larvae per leaf)} and 10 replications (melon plants). Initially we evaluated the physiological aspects: photosynthetic rate (µmol CO2/m2/s), stomatal conductance (mol H2O/m2/s) internal CO2 concentration (µmol CO2/m2) and leaf transpiration (mmol H2O/m2/s). After the measurements of physiological aspects, the evaluated leaves of each plant were cut close to the petiole and scanned individually with a measuring scale on the side, being the determination of the damaged leaf area performed with the aid of software for processing and analysis of images. The averages of damaged leaf area observed were of 1.2; 6.3; 19.6 and 40.8 cm2 for infestations of 1; 10; 20 and 30 larvae/leaf respectively. In relation to the physiological aspects, the rate of photosynthesis, stomatal conductance and transpiration significantly decreased with the increase of leafminer larvae per leaf. The internal CO2 concentration increased with the increase in the number of larvae per leaf.

Highlights

Determinação da área foliar danificada e de respostas fisiológicas do meloeiro frente à infestação de Liriomyza sativae
Researches related to determination of physiological responses of the plants according to attack by insects may help, with other factors, as costs of phytosanitary treatment and production value, in order to determine the level of economic damage, and, the level of pest control, increasing integrated management system (Neves et al, 2006), since, the level of control is based on the number of insects per leaf, Hortic. bras., Brasília, v.35, n.4, October-December 2017 as it is in melon crop (Braga Sobrinho et al, 2007)
Due to the importance of species of the genus Liriomyza such as pests in ornamental and agricultural plant grown worldwide (Parrela, 1987; Murphy & Lasalle, 1999), researches aiming to evaluate damaged leaf area and physiological aspects, especially photosynthetic rate, of plants infested with leafminer larvae had already been carried out in tomato (Solanum lycopersicum) (Johnson et al, 1983), celery (Apium graveolens) (Trumble et al, 1985), chrysanthemum (Chrysanthemum morifolium) (Parrela et al, 1985), lima bean (Phaseolus lunatus) (Martens & Trumble, 1987), cherry tomato (Lycopersicon esculentum) (Lee et al, 2004), cucumber (Cucumis sativus) (Al-Khateeb & Al-Jabr, 2006), potato (Solanum tuberosum) (Bueno et al, 2007) and beans (Phaseolus vulgaris) (Yildirim et al, 2010)

Summary

Introduction

Determinação da área foliar danificada e de respostas fisiológicas do meloeiro frente à infestação de Liriomyza sativae. Os objetivos do trabalho foram determinar a área foliar danificada e avaliar as respostas fisiológicas de plantas de meloeiro frente a diferentes níveis de infestação por larvas de L. sativae. Leafminer Liriomyza sativae (Diptera: Agromyzidae) is one of the main pests of melon crop (Cucumis melo) in the Brazilian semiarid (Araujo et al, 2013). The larvae of this insect consumes the leaf mesophyll, decreasing photosynthetic capacity of the plants, which promotes a reduction of accumulation of total soluble solids of the plants, decreasing the quality and affecting the market (Araujo et al, 2007; Guimarães et al, 2009). Due to the importance of species of the genus Liriomyza such as pests in ornamental and agricultural plant grown worldwide (Parrela, 1987; Murphy & Lasalle, 1999), researches aiming to evaluate damaged leaf area and physiological aspects, especially photosynthetic rate, of plants infested with leafminer larvae had already been carried out in tomato (Solanum lycopersicum) (Johnson et al, 1983), celery (Apium graveolens) (Trumble et al, 1985), chrysanthemum (Chrysanthemum morifolium) (Parrela et al, 1985), lima bean (Phaseolus lunatus) (Martens & Trumble, 1987), cherry tomato (Lycopersicon esculentum) (Lee et al, 2004), cucumber (Cucumis sativus) (Al-Khateeb & Al-Jabr, 2006), potato (Solanum tuberosum) (Bueno et al, 2007) and beans (Phaseolus vulgaris) (Yildirim et al, 2010)

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