Rafael de Andrade Moral | National University of Ireland, Maynooth (original) (raw)

Papers by Rafael de Andrade Moral

Acta Scientiarum. Agronomy

The orange variety “x11”, which is a spontaneous mutant of the sweet orange, has a short juvenile... more The orange variety “x11”, which is a spontaneous mutant of the sweet orange, has a short juvenile period with early flowering. The data used in this paper are from a randomized design experiment that aimed to assess the plants' flowering characteristics when grafted onto two different varieties of lemon rootstock. The plants were pruned in each of the four seasons, and on each pruning occasion, the number of branches on each plant was counted and classified into four mutually exclusive flowering categories. The data presented large variability and many zeros. The statistical analysis included the use of generalized linear mixed models with a Bayesian approach. The results showed that flowering is not equal over the seasons, i.e., there are significant differences in the classification of the branches across the four seasons and the two varieties, with interactions between seasonal and branch effects.

Phytopathology®

Potato late blight remains the most significant disease threat of potato cultivation globally, of... more Potato late blight remains the most significant disease threat of potato cultivation globally, often requiring expensive, time-consuming and environmentally unfriendly approaches to disease management. The goal of this research was to evaluate whether an estimation of potato late blight risk based on environmental factors can be reliably used to adjust the standard potato late blight management practices and the role of cultivar resistance under growing conditions and contemporary Phytophthora infestans populations in the Republic of Ireland. Using the modified Irish Rules model, it was possible to reduce fungicide usage by 58.7% on average, compared to current standard practices used by growers and without adversely compromising disease control and yield, with similar results achieved by the half dose programme. Host resistance levels were found to be correlated with a delay in the initiation of the epidemics, final foliar disease levels and reduction of fungicide usage. Disease le...

Frontiers in Sustainable Food Systems

Since its recent establishment in Hawaii, the coffee berry borer (CBB), Hypothenemus hampei (Cole... more Since its recent establishment in Hawaii, the coffee berry borer (CBB), Hypothenemus hampei (Coleoptera: Curculionidae), threatens yields, quality, and price of coffee production. A limited number of insecticides (primarily Beauveria bassiana) are used to control CBB with minimal disruption in this agroecosystem. We evaluated two insecticide spray strategies across eight coffee farms in the Kona and Ka'u districts of Hawaii Island. Coffee growers sprayed insecticides approximately monthly (calendar basis) or else in response to CBB field monitoring data (threshold based). Overall, farms adopting spray thresholds performed more insecticide applications early in the season (May to July), but significantly fewer overall, when compared with calendar-based strategies (i.e., 4-5 vs. 7-11 seasonal sprays, respectively). Generalized linear models assessing the variability in CBB infestation rates, berry penetration, and infection by B. bassiana indicated that threshold-based sprays provided equivalent CBB control compared with calendar ones. When corrected for yield, there were economic savings for threshold-vs. calendar-based spray programs (i.e., cost 5.4 vs. 11.8% of gross yield). Total defects in processed coffee after harvest were statistically similar between the two spray regimes, i.e., 8.5 ± 1.0% and 10.4 ± 1.7%, respectively. We hypothesize that B. bassiana applied early in the season is more effective, since the fungus targets initial CBB infestations when the prolonged location of founder females in the outer berry endosperm favors its infection. Our study suggests that spray timing for CBB based on field monitoring data can reduce costs; however, additional measures, such as field and post-harvest sanitation, are necessary to achieve sustainable CBB control in the Islands.

EntomoBrasilis

Resumo. O presente estudo teve como objetivos avaliar a resposta funcional dos instares larvais e... more Resumo. O presente estudo teve como objetivos avaliar a resposta funcional dos instares larvais e adultos de três espécies de coccinelídeos predadores [Harmonia axyridis (Pallas), Cycloneda sanguinea (Linnaeus) e Hippodamia convergens Guerin Meneville] em diferentes densidades de Brevicoryne brassicae (Linnaeus), comparando o desempenho da espécie invasora com as espécies locais. Observou-se que H. axyridis consumiu mais insetos que as outras espécies; o número de pulgões predados pelas três espécies de coccinelídeos aumentou com a troca do instares larvais e, que as fêmeas tenderam a predar mais pulgões que os machos. A voracidade das larvas de 4º instar é similar a dos adultos, às vezes até maior, como no caso da C. sanguinea. Exceto no 1º instar larval, todos os outros estágios de vida mostraram aumento do consumo de pulgões à medida que a oferta de presas aumenta. Os resultados mostraram que a resposta funcional do tipo III foi indicada apenas pelas larvas de 3º instar de H. axy...

Water, Air, & Soil Pollution

Scientific Reports

The use of Metarhizium against sugarcane spittlebugs in Brazil is one of the most successful and ... more The use of Metarhizium against sugarcane spittlebugs in Brazil is one of the most successful and long lasting biological control programs using entomopathogenic fungus in the world. However, studies to monitor the fate of this fungus on the sugarcane agroecosystem are rare, especially with respect to its persistence, efficacy in pest control and impact on the local populations of Metarhizium. The present study aimed at documenting the efficacy and persistence of M. anisopliae strain ESALQ1604 in a sugarcane field by using microsatellite molecular markers. The species diversity of Metarhizium was characterized in insects, soil and sugarcane roots in a sprayed and an unsprayed plot. Although the infection rates were not very high (≤ 50%), the applied strain was recovered from spittlebugs after 7, 30 and 60 days' post-application, but accounted for only 50%, 50% and 70.5% of all insects killed by M. anisopliae, respectively. All haplotypes from spittlebug were associated with a single subclade of M. anisopliae. The highest haplotype diversity was found in soil (h = 0.989) and in the smallest in spittlebug (h = 0.779). Metarhizium robertsii, M. anisopliae, M. brunneum; one taxonomically unassigned lineage was found in soil and only M. brunneum and M. anisopliae were isolated from roots. This study revealed the great diversity of Metarhizium spp. in the sugarcane agroecosystem and the importance of the local population of M. anisopliae on spittlebugs management.

Biocontrol Science and Technology

Arthropod-Plant Interactions

Ciência Rural

ABSTRACT: This study investigated the influence of cage sizes on the survival and reproductive po... more ABSTRACT: This study investigated the influence of cage sizes on the survival and reproductive potential of Chrysoperla externa (Hagen). Size of breeding cages significantly affected the reproductive potential of C. externa . Our results indicated that in cages smaller (7.5cm of diameter) than those usually recommended for the rearing of this insect (10cm diameter), females showed higher rates of oviposition. Reduction of space for rearing natural enemies in the laboratory is very important for developing biological control programs.

Basic and Applied Ecology

In agroecosystems, parasitoids and predators may exert top-down regulation and predators for diff... more In agroecosystems, parasitoids and predators may exert top-down regulation and predators for different reasons may avoid or give preference to parasitised prey, i.e., become an intraguild predator. The success of pest suppression with multiple natural enemies depends essentially on predator-prey dynamics and how this is affected by the interplay between predation and parasitism. We conducted a simple laboratory experiment to test whether predators distinguished parasitised prey from nonparasitised prey and to study how parasitism influenced predation. We used a host-parasitoid system, Spodoptera frugiperda and one of its generalist parasitoids, Campoletis flavicincta, and included two predators, the stinkbug Podisus nigrispinus and the earwig Euborellia annulipes. In the experiment, predators were offered a choice between non-parasitised and parasitised larvae. We observed how long it took for the predator to attack a larva, which prey was attacked first, and whether predators opted to consume the other prey after their initial attack. Our results suggest that, in general, female predators are less selective than males and predators are more likely to consume non-parasitised prey with this likelihood being directly proportional to the time taken until the first prey attack. We used statistical models to show that males opted to consume the other prey with a significantly higher probability if they attacked a parasitised larva first, while females did so with the same probability irrespective of which one they attacked first. These results highlight the importance of studies on predator-parasitoid interactions, as well as on coexistence mechanisms in agroecosystems. When parasitism mediates predator choice so that intraguild predation is avoided, natural enemy populations may be larger, thus increasing the probability of more successful biological control.

Acta Physiologiae Plantarum

Drought stress promotes biochemical and physiological alterations in plant metabolism that limit ... more Drought stress promotes biochemical and physiological alterations in plant metabolism that limit growth and yield. This study investigated the accumulation of caminobutyric acid (GABA) in plant tissue, the stomatal conductance (gs) and changes in leaf anatomy in Eucalyptus following drought stress situation. In this study, eight Eucalyptus clones were evaluated under normal water supply (control) and drought stress conditions (stress). For the control treatment, plants were irrigated every day with an automated system until the soil was saturated, and for the stress treatment, drought stress was imposed by non-irrigation of plants, and pots were covered using plastic sheeting to avoid rainfall and humidity. This study has shown that:

Agriculture, Ecosystems & Environment, 2016

A B S T R A C T Establishment, persistence and local dispersal of the entomopathogenic fungi Meta... more A B S T R A C T Establishment, persistence and local dispersal of the entomopathogenic fungi Metarhizium anisopliae (ESALQ1037) and M. robertsii (ESALQ1426) (Ascomycota: Hypocreales) were investigated in the soil and rhizosphere following soil drench application in strawberries between 2012 and 2013 at a single location in Inconfidentes, Minas Gerais, Brazil. Metarhizium spp. isolates (n = 108) were collected using selective agar media and insect bait methods, and characterized by sequence analyses of the 5'-end of the translation elongation factor 1-a and the MzFG543igs intergenic region and by multilocus simple sequence repeat analysis. Both applied fungal isolates were frequently recovered from bulk soil and rhizosphere samples of the treated plots, suggesting that they were able to establish and disperse within the soil. Persistence within the soil and strawberry rhizosphere for both fungal isolates was observed up to 12 months after application with frequencies of 25% of haplotypes similar to isolate ESALQ1037 and 87.5% of haplotypes similar to isolate ESALQ1426, respectively. Overall, M. robertsii was the most abundant species in the agroecosystem studied representing 77.8% of the isolates recovered across all sample dates.

Revista Da Estatistica Da Universidade Federal De Ouro Preto, 2014

Fungal Ecology, 2016

We report an endemic entomopathogenic fungus, known in Brazil as the 'salmão' fungus and identifi... more We report an endemic entomopathogenic fungus, known in Brazil as the 'salmão' fungus and identified here as Colletotrichum nymphaeae (Sordariomycetes: Glomerellales), infecting populations of citrus orthezia scale, Praelongorthezia praelonga. The seasonal prevalence of this pathogen in P. praelonga populations was investigated in three commercial citrus groves maintained under different pesticide regimes. Two citrus groves included inundative releases of another insect pathogenic fungus, Lecanicillium longisporum. Natural epizootics were consistently observed, with up to 84% infection rates being recorded during the warm rainy season. Temporal progression of C. nymphaeae-induced disease varied among the three pesticide regimes. Low infection levels from C. nymphaeae were associated with intensive application of broad spectrum pesticides. However, the prevalence of C. nymphaeae followed a density-dependent pattern with insect host abundance, irrespective of the pesticide regime. High proportions of Lecanicillium-infected insects were observed following infection peaks of C. nymphaeae and both fungi together contributed to 95% overall mortality of citrus orthezia during the wet season. Hence, the combined effect of both fungi considerably improves the biological control of citrus orthezia. We also surmise that the host abundance, environmental conditions, and application frequency of chemical pesticides in citrus groves exert a great influence in the seasonal prevalence of C. nymphaeae-induced disease. Altogether, these results suggest that C. nymphaeae is an important pathogen of P. praelonga and indicate that frequent use of synthetic pesticides may delay or reduce fungal epizootics.

BioControl, 2016

Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the vector of the causal agent of Huanglongbin... more Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the vector of the causal agent of Huanglongbing disease, and Toxoptera citricida Kirkaldy (Hemiptera: Aphididae) is the vector of the citrus tristeza virus. D. citri and T. citricida share the same habitat and both are susceptible to Beauveria bassiana and Isaria fumosorosea. Therefore, the aim of this study was to evaluate the horizontal transmission of B. bassiana ESALQ-PL63 and I. fumosorosea ESALQ-1296 between D. citri cadavers and uninfected D. citri adults, as well as between T. citricida cadavers and uninfected D. citri adults under laboratory and semifield conditions. In the laboratory, the presence of one to ten D. citri cadavers infected with B. bassiana and I. fumosorosea in citrus plants resulted in mortality rates of D. citri adults ranging from 51.2 to 81.9 % and 36.2 to 68 %, respectively. When T. citricida cadavers were used, the mortality rates of uninfected D. citri adults ranged from 35.4 to 87.7 % with B. bassiana and from 41.7 to 80.4 % with I. fumosorosea. The horizontal transmission was also confirmed under semi-field conditions. The results indicate that the control of D. citri using I. fumosorosea and B. bassiana can be promoted through conidial cycling in T. citricida, by generating new infection cycles, which may contribute to the overall performance of microbial control in citrus.