Category Archives: Annals of Applied Biology

Lethality of pesticides on immature and adult stages of Ceratitis capitata (Diptera: Tephritidae)

Posted on 10 December 2023 by

This manuscript provides information Using sub-doses of the insecticides to simulate the degradation of the active ingredients at levels below the 100% concentration. We showed that Deltamethrin (pyrethroid) showed little efficiency for the control of C. capitata when compared to Malathion (organophosphate) and Spinetoram (spinosyn). The article also provides information on the effect of these pesticides on different life stages of the insect (egg, larva, pupa, and adults).

Abstract

The species Ceratitis capitata (Weidemann, 1824), known as Mediterranean fruit fly, is an important pest for fruit trees worldwide. The control of this pest is carried out mainly by the chemical method, using organophosphorus, pyrethroid, and spinosyn pesticides. The lethality of doses of malathion, deltamethrin, and spinetoram on immature and adult stages of C. capitata was evaluated under laboratory conditions. The egg, larval, pupal, and adult stages were exposed to doses of pesticides through contact and ingestion. The doses were obtained by decreasing the recommended doses (malathion: 200 mL L⁻¹, deltamethrin: 50 mL L⁻¹, and spinetoram: 120 g ha⁻¹) with intervals of 20%, this being the minimum dose used. The variables evaluated were: viability of eggs and pupae and mortality of larvae and adults. Application of spinetoram and malathion through contact caused high mortality of adults, with LD₉₀ at the sub-doses of 43.74% (52.48 g c.p. ha⁻¹) and 68.81% (137.62 mL c.p. 100 L⁻¹), respectively. The mortality of adults by ingestion of deltamethrin and malathion allowed us to estimate only the LD₅₀. Only the pesticide deltamethrin presented LD₅₀ for the egg stage. The larval and pupal stages the effect of the pesticides on larvae treated through contact resulted in 52% mortality with spinetoram and 62% with malathion. The mortality of larvae and pupae treated through ingestion was below 20% for the three pesticides. Sub-doses of spinetoram (43.74%; 52.48 g c.p. ha⁻¹) and malathion (68.81%; 137.62 mL c.p. 100 L⁻¹) can be used since they present a 90% efficiency on C. capitata adult when applied by contact under laboratory conditions.

Phenological description and thermal time requirements for the seedling phase of three Brazilian native forest species

Posted on 9 October 2023 by

Morphology of the germination process (epigeal) and seedlings development stages of Libidibia ferrea (co: cotyledon; e1-e2: first pair of eophylls; in: embryo; ep: epicotyl; fr: fruit; hp: hypocotyl; me: metaphyll; pr: primary root; se: seed). Drawings made by Bruna Oliveira Borges.

Abstract

Understanding the phenological stages and thermal requirements of the seedling phase of forest species is crucial for sustainable nursery management. This study proposed an adaptation of a phenological scale based on the basic Biologische Bundesanstalt, Bundessortenamt, and Chemical industry, associated with the thermal requirement to describe the phenological stages during the seedling phase of three forest species: Cybistax antisyphilitica, Libidibia ferrea, and Platycyamus regnellii. The phenological scale of C. antisyphilitica and L. ferrea was defined and described through 22 seedling development stages ranging from dry seed to 20th visible leaf emitted on the main stem (from 00 to 120) and P. regnellii for 12 leaf development stages, from dry seed to 10th visible leaf emitted on the main stem (from 00 to 110). In addition, the duration (days) and thermal time (°C day) were determined for each seedling development stage. C. antisyphilitica needs to accumulate more energy (and days) to finish the seedling phase (1551.9°C day or 261 days) compared to L. ferrea (1127°C day or 175 days) and P. regnellii (1109.7°C day or 193 days). However, the three forest species exhibit similar energy demands throughout most stages of seedling development, except code 09–12 for C. antisyphilitica. This study provides important information for optimizing silvicultural techniques, evaluating the response of temperature on phenological stages, and assessing the impacts of global warming on forest seedling development.

Interview with Prof. Evgenios Agathokleous, School of Applied Meteorology, Nanjing University of Information Science and Technology (NUIST), China

Posted on 4 October 2023 by nRicardo A. Azevedon

Annals of Applied Biology, EarlyView.

Modification of anthracnose severity in açaí seedlings by the endophytic fungus Hypoxylon anthochroum strain 2.4996

Posted on 4 October 2023 by

The endophytic fungus Hypoxylon anthochroum 2.4996, which was identified through morphological, cultural, and molecular characteristics, was able to change anthracnose severity in açaí palm (Euterpe precatoria), enhancing the necrotic areas of the leaflets.

Abstract

The cultivation of açai palm, which yields tasteful and nutritional fruits, has been stimulated by the high commercial values of açai pulps; however, the occurrence of anthracnose (a disease caused by the fungus Colletotrichum gloeosporioides) on açaí nursery and orchards has been a challenge for the shift from açaí extractivism to its cultivation. The interaction among endophytic fungi and host can change the plant disease severity, facilitating infection by phytopathogens and increasing its damage to plants. Therefore, this study aimed to investigate the antagonistic activity of five endophytic fungi against C. gloeosporioides, as well as to evaluate the anthracnose severity in açaí seedlings in response to the inoculation of the most promising of the tested endophytic fungus. First, in vitro evaluation showed that most of the fungi were able to grow over C. gloeosporioides mycelia. The endophytic fungi Graphium sp. 2.4765 and Hypoxylon anthochroum 2.4996 recorded the highest rates of growth inhibition, 79.3% and 77.0%, respectively. Because H. anthochroum 2.4996 presented better in vitro growth and spore production, it was chosen for subsequent evaluations. Second, in planta evaluation showed that the inoculation of H. anthochroum 2.4996 in diseased plants enhanced both the necrotic area in leaflets and disease symptoms. Third, comparative analyses based on the cultural, micromorphological and molecular characteristics have shown that such strain is related to H. anthochroum. Overall, this study highlights the complexity of the plant–microbe interactions.

Canopy architecture and diurnal CO2 uptake in male and female clones of yerba‐mate cultivated in monoculture and agroforestry

Posted on 4 October 2023 by

Two cultivation systems caused differential responses of secondary sexual dimorphism—leaf photosynthesis on area basis showed gender segregation in agroforestry, while metamer length and specific leaf area showed gender segregation in monoculture. Intriguingly, light-response curves of photosynthesis do not differ between monoculture and agroforestry, indicating strong adaptation of yerba-mate to shade and high-light.

Abstract

Secondary sexual dimorphism (SSD) in flowering plants is expressed by sexual differences of characters that are not directly related to gamete production. The leaf C/N ratio, photosynthetic traits or clonal responses have never been studied in relation to SSD in yerba-mate. It was hypothesized that leaf and plant photosynthesis are higher in female than in male individuals because females must supply photoassimilates to compensate for the additional reproductive investments of SSD in biomass. Here, we investigated how two contrasting light environments (monoculture—MO and agroforestry—AFS) and plant genders change leaf and plant photosynthesis, plant architecture, leaf and branch biomass production and C and N investments of two male and two female clones. To model the 3D yerba-mate structure, virtual trees were constructed using measurements of plant morphology using VPlant modelling software. The light-response curves of leaf CO₂ assimilation were used to model instantaneous leaf and daily plant photosynthesis. Photosynthetic traits derived from light-response curves did not differ between MO and AFS. Some architectural traits were segregated sexually only in MO, while some physiological ones only in AFS. Leaf photosynthesis was higher in females than in males in AFS over a large part of the diurnal cycle, but SSD was not expressed in carbon gains at plant or daily scales. Leaf C/N ratio was higher in MO than in AFS, indicating MO as an ecosystem with higher degree of environmental degradation. Female clones had leaves with lower C/N ratio than males in both systems, relating to higher leaf photosynthesis on an area basis in females. SSD expressed in leaf photosynthesis over a large part of the diurnal cycle in AFS was not observed in carbon gains at plant or daily scales, indicating that the integration of physiology and architecture equalized the gender specificities. The insensitivity of photosynthetic traits derived from light-response curves indicated acclimation of yerba-mate leaves to a wide range of incoming light.

Critical stage and key natural mortality factors of Hypothenemus hampei in commercial coffee plantations

Posted on 2 October 2023 by

Predators ants, parasitoids, entomopathogenic fungi, and malformations during the Hyphothenemus hampei life cycle caused 75.34% of the mortalities seen within their populations. Adult mortality is the principal factor that regulates the size of populations of this insect. Predatory ants were the key mortality factor for H. hampei.

Abstract

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), is one of the most important coffee pests, and is present in almost all countries producing this crop, causing annual losses of US$350 million. Natural factors regulate H. hampei populations in coffee crops. Ecological life table analysis is a robust tool that allows the estimation of the mortality caused by these factors. Therefore, the main objective of this study was to determine the critical stage and the key mortality factors affecting H. hampei in the field. Data for constructing life tables were collected over 2 years in six coffee plantations in the regions of Paula Cândido and Viçosa, Minas Gerais State, Brazil. The average mortality of H. hampei was 75.34% ± 5.85%. The mortality at each developmental stage was 24.32% ± 2.83% (eggs), 7.29% ± 1.01% (first instar), 11.58% ± 1.46% (second instar), 9.68% ± 1.10% (third instar), 7.45% ± 1.01% (pupa), and 15.02% ± 1.29% (adult; n = 124). The mortality factors observed and quantified in this study were parasitism by Prorops nasuta (Hymenoptera: Bethylidae), predation by ants (Crematogaster spp., Pheidole spp. and Solenopsis spp.), physiological disorders and fungal infection by Beauveria bassiana and Metarhizium anisopliae. The critical mortality stage of H. hampei was the adult stage. The key factors for mortality of H. hampei adults were predatory ants, followed by B. bassiana and malformations (these insects had deformities in the head, wings, legs, or abdomen). This information is essential to conserve the activities of natural enemies and, thus maintain H. hampei natural mortality factors in coffee plantations, reducing damage to the crops and the need for excessive insecticide interventions.

Source‐sink patterns on coffee trees related to annual climate variability: An approach through stable isotopes analysis

Posted on 2 October 2023 by

This study highlights the importance of using stable isotope analysis as a reference point for long-term coffee ecophysiological studies. We have provided evidence to support the hypothesis that variations in the δ¹³C and δ¹⁵N values for the dry matter of bulk material from leaves, heterotrophic organs, and the cellulose in the growth tree rings of coffee trees have temporal and spatial patterns that suggest the differential use of substrates and signals the influence of the climate on the growth and phenology of the trees.

Abstract

Stable isotopic determination constitutes a useful tool to identify the processes that control the dynamics of the carbon and nitrogen flow in plants, unravelling the mechanisms of their differential investment under different environments. This work aimed to evaluate the spatiotemporal variation of source-sink patterns of coffee trees under field conditions in response to climatic conditions through the assessment of stable isotopes. For this purpose, stems, leaves, and fruit samples from coffee trees were collected following a temporal pattern based on the region's climatic characteristics and the plant's phenology and a spatial pattern considering different parts of the canopy. The carbon and nitrogen percentage content, the C/N ratio, and the carbon and nitrogen isotopic compositions (δ¹³C and δ¹⁵N) were determined for all samples. The basal portion of the orthotropic branch was also considered for the isotopic analysis of the tree's growth rings. The results obtained were correlated with the climatic variables of the region through a Pearson correlation analysis (p < .05). Coffee plants showed traditional δ¹³C values of C3 plants. Temporal δ¹³C variation was associated with the different growth rates between phenological stages and the use of substrates produced at different times under different environmental conditions leading to differences in photosynthetic discrimination. Spatial δ¹³C variation was observed with heterotrophic tissues isotopically heavier than leaves, with a significant decrease trend in δ¹³C values from the top (upper third) to the bottom (lower third), associated with ecophysiological differences between the canopy, isotopic fractionation processes downstream of photosynthetic carbon discrimination, and the fixation of C from other pools. Temporal δ¹⁵N variation was associated with the precipitation rates in the region and the fertilization distribution across the tree, while the spatial variation was with the plant's nitrogen assimilation and translocation patterns. The tree growth rings isotopic analyses showed isotopic differences between growth rings of the same plant addressed by the climatic conditions, with precipitation being the primary climatic determinant influencing the fixation and discrimination against ¹³C. Our results highlight the importance of using stable isotope analysis as a reference point for coffee ecophysiological studies to characterize how the temporal and spatial patterns of δ¹³C and δ¹⁵N emerge and signal the influence of climate on the source-sink relationship of coffee trees under field conditions.

Manipulating table beet growth using exogeneous gibberellic acid 3 in New York, USA

Posted on 1 October 2023 by nSarah J. Pethybridge, nSean Murphy, nEric Branch, nPratibha Sharma, nJulie R. Kikkertn

Table beets are grown in New York, USA for processing into cans and jars (left) for which their suitability is dictated by quality and root shoulder diameter.

Abstract

Table beet (Beta vulgaris ssp. vulgaris) root suitability for processing into cans and jars is dictated by quality and shoulder diameter (crown width). For shoulder diameter, roots are sorted into six classes and those in the small (19.1–44.5 mm) and small/medium (44.6–40.8 mm) classes are considered suitable. Smaller (≤19 mm) roots are usually lost in harvesting while larger (≥40.9 mm) roots are typically discarded. Exogenous (foliar-applied) gibberellic acid 3 (GA₃) may alter source-sink carbohydrate partitioning with potential advantages for processing table beet producers. Small plot replicated trials were conducted in each of 3 years (2020, 2021 and 2022) to evaluate the effect and optimal timing of exogenous GA₃ on table beet yield components in New York, USA. GA₃ was applied as ProGibb at 30 ppm in all trials and as ProGibb at 30 ppm and FalGro 2X LV at 67 ppm (label rates) in 2022. GA₃ as ProGibb resulted in significant increases in foliar health attributes (leaf blade length and width, petiole diameter, normalized difference vegetative index and dry weight of foliage). GA₃ as ProGibb significantly reduced average root shoulder diameter and affected the percentage of roots in various size categories. The percentage of tiny roots (<19 mm) was significantly decreased while the percentage of small roots was increased. The percentage of small/medium roots were unaffected. In 2022, the percentage of small roots was significantly increased compared to nontreated plots but was not significantly different between GA₃ as either ProGibb or FalGro applied at 42 or 62 Days after Planting (DAP). Exogenous GA₃ had no consistent, significant effect on the severity of the foliar disease, Cercospora leaf spot. The significant increase in foliar health attributes from GA₃ is beneficial for harvest that relies upon top pulling machinery. Increases in the percentage of small roots and reductions in tiny roots can reduce wasted crop input investments. The optimal number of GA₃ applications was seasonally dependent, ranging from a single application at 40 or 62 DAP in 2 years, to two applications in 2021. GA₃ applications late (>80 DAP) in the cropping season had no significant effect on foliar health attributes or root yield components. The implications of these results on the New York table beet processing industry are discussed.

Deroceras laeve as a potential agricultural pest in Darjeeling Himalayas, India: Palatability and preference of economically important plants

Posted on 30 September 2023 by nNeha Kumari Gupta, nPranesh Paul, nGautam Adityan

The plant food preference and palatability of the slug Deroceras laeve, reported from Darjeeling Himalayas, India, was assessed. The pumpkin leaf was consumed maximally by D. laeve while mint leaf was least consumed, though the fecundity was higher in lettuce and cabbage diet. Apart from being positively linked with body mass, the consumption rate of D. laeve was considerably higher than the controphic slug, Meghimatium bilineatum.

Abstract

The invasion of the terrestrial ecosystem by gastropods has immense negative impacts on ecosystem functions, health, and agricultural plants. The non-native slug, Deroceras laeve (O. F. Müller, 1774), a recognised agricultural pest in native and invaded regions, was recently reported from the Darjeeling Himalayas, India. We assessed the plant palatability and preference of D. laeve using selected plants being farmed in Darjeeling Himalayas (basil, cabbage, coriander, lettuce, mint, pumpkin leaf, and spinach) by laboratory-based choice and non-choice experiments. Moreover, we evaluated the correlation between different chemical features of the plants with the consumption rate of D. laeve and observed the fecundity of D. laeve reared on different plant diets. The highest consumption rate of D. laeve was observed for pumpkin (12.99 ± 1.33 mg dry mass) and the lowest for mint (1.63 ± 0.13 mg dry mass), with a significant positive correlation between consumption rate and D. laeve body mass (for lettuce: R = .47, p = .0009 and other plant species: R = .52, p = .00004) was observed through the non-choice experiment. Moreover, the consumption rate of the non-native slug, D. laeve, was considerably higher than a controphic slug, Meghimatium bilineatum. In the choice experiment, D. laeve preferred lettuce, followed by pumpkin, cabbage, and coriander, even in the presence of detritus and significantly avoided spinach, mint, and basil. The consumption rate of D. laeve had a significant negative correlation with calcium (R = −.49, p = .003) and potassium (R = −.37, p = .03), and a positive correlation was observed for magnesium (R = .37, p = .03). However, no correlation was observed for zinc, silica, total carbohydrate, protein, and phenol content of the leaves. The highest fecundity of D. laeve was observed in the lettuce and cabbage diet, while no eggs were laid on the mint diet. Hence, the consumption of different leaves, irrespective of physical and chemical features (hairiness, amount of silicon, protein, carbohydrate, and phenol), suitable life history traits, and suitable habitats, may facilitate D. laeve as a potential agricultural pest in the Darjeeling Himalayas, India.

The detection of Bursaphelenchus xylophilus via accelerated strand exchange amplification: An ultra‐rapid and accurate method

Posted on 29 September 2023 by

In this work, an approach for the ultra-fast and accurate detection of B. xylophilus in pinewood called accelerated strand exchange amplification (ASEA) was established for the first time, which only needs one Bst DNA polymerase and a set of primers.

Abstract

One of the most damaging pathogens of pinewood is the pinewood nematode, Bursaphelenchus xylophilus, which could cause an adverse effect on the ecosystems of forests and the commerce of timber. Therefore, it is crucial to realize rapid and accurate B. xylophilus detection. In this work, an accelerated strand exchange amplification method (ASEA) was established to detect B. xylophilus for the first time. By integrating with fast nucleic acid extraction, the whole detection procedure could be finished within 30 min, dramatically shortened the detection time. The ASEA method exhibited high specificity towards B. xylophilus and the detection limit for B. xylophilus plasmid DNA was as low as 1.0 × 10⁰ copies/μL. Furthermore, the ASEA approach also exhibited accurate detection for B. xylophilus when applied to actual pinewood samples, meeting the demand of B. xylophilus detection in realistic scenario. We believe the ASEA method has significant potential for B. xylophilus detection, and it will be helpful for controlling forest pest and quarantine regulations.