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Recorded in Brazil since 2004, Huanglongbing (HLB), or simply Greening, is the most impacting disease in citrus production worldwide. It induces qualitative and quantitative losses in production, but also can be lethal to the infected citrus plant. The disease is caused by phloem-limited bacteria with three identified species, Candidatus Liberibacter asiaticus (CLas), Ca. L. africanus (CLaf), and Ca. L. americanus (CLam). CLas and CLam are reported in Brazil, being vectored by the Asian citrus psyllid Diaphorina citri. HLB-infected citrus exhibit blotchy mottling with green islands on leaves, and small and lopsided fruits. As the infection progresses, excessive fruit drop and dead branches are frequently observed, shortening the trees' lifespan and reducing fruit yield and quality. HLB occurrence is restricted to the States of São Paulo, Minas Gerais, Mato Grosso do Sul and Paraná, which corresponds to more than 85% of citrus production in Brazil. Although citrus production is concentrated in these states, commercial citrus groves are present in 85% of the microregions of Brazil, reinforcing the economic and social importance of citrus for the country. Thus, in addition to the economic damage already caused to the national citrus industry, the spread of HLB to other regions of Brazil represents a great risk to the economic and food security of these non-affected regions. For this reason, the management of HLB is supported by legislative force, both at the federal and state levels. In 2008, based on scientific knowledge at the time, the Brazilian Ministry of Agriculture published a Normative Instruction 53 (IN53) which established criteria related to HLB surveillance and control, imposing the obligation to carry out periodic phytosanitary inspections, eradication of symptomatic hosts and planting HLB-free nursery trees. The implementation of IN53 has already resulted in the eradication of 55.5 million HLB-infected citrus plants in the State of São Paulo alone in the period from 2007 to 2019. In May 2021, IN53 was revoked and Portaria 317 was published. This new policy establishes the National Programme for HLB Prevention and Control. It addresses the problem according to the HLB status in each State, with or without the disease, and sets the general guidelines for local control actions. In view of the economic importance and complexity of this pathosystem, the disease has required concerted mobilization of the research community and inter-institutional cooperation, which has been working intensively to understand all the components directly and indirectly involved with the pathosystem. Also, a major cooperation effort is needed to gather all the information to develop and/or improve technologies and cultural practices to fight the disease better and reduce its impacts as much as possible. Here we present some of these efforts which are being carried out to develop short, medium and long term solutions for HLB control and management in areas of occurrence, as well as for surveillance and risk mitigation in non-affected areas.

Brazil is the world?s largest sweet orange producer, but production in the state of Acre is small and does not meet the local demand, despite having climatic conditions that are adequate for its cultivation. The objective of this study was to evaluate the behavior of the ?Pera? orange using different rootstocks under the edaphoclimatic conditions of Rio Branco, Acre, Brazil. We grafted the scion of the ?Pera? orange onto nine citrus rootstocks: ?Cleopatra? mandarin, TSKFL x CTTR ? 013, LVK x LCR ? 038, TSKC x CTQT 1439 ? 004, LVK x LVA ? 009, ?Indio?citrandarin, ?Santa Cruz Rangpur? lime, TSKFL x CTC - 25 ? 002, and TSKC x CTSW ? 038. The experiment was organized in a random block design with three replicates and two plants per parcel. The following characteristics were evaluated: compatibility between scion and rootstocks, tolerance to drought, production and fruit quality. There was an effect of the rootstocks on the behavior of the ?Pera? variety. The ?Santa Cruz Rangpur? lime, ?Indio? citrandarin, and the hybrid LVK x LCR - 038 rootstocks presented the best performance of the ?Pera? orange. Therefore, they constitute an alternative to the ?Rangpur? lime and may be incorporated into the current ?Pera? orange production system of the region. O Brasil é o maior produtor mundial de laranja-doce, mas no Estado do Acre a produção é pequena e não atende à demanda local, apesar de possuir condições climáticas adequadas ao seu cultivo. O objetivo do trabalho foi avaliar o comportamento de laranjeira ?Pera? sobre diferentes porta-enxertos nas condições edafoclimáticas de Rio Branco, Acre. A copa de laranjeira ?Pera? foi enxertada em nove porta-enxertos de citros: ?Cleópatra?, TSKFL x CTTR ? 013, LVK x LCR ? 038, TSKC x CTQT 1439 ? 004, LVK x LVA ? 009, Citrandarin ?Indio?, ?Santa Cruz Rangpur? lime, TSKFL x CTC - 25 ? 002 e TSKC x CTSW ? 038. Empregou-se um delineamento em blocos ao acaso com três repetições e duas plantas na parcela. Foram avaliadas características vegetativas, compatibilidade entre copa e porta-enxertos, tolerância à seca, produção e qualidade dos frutos. Houve efeito dos porta-enxertos sobre o comportamento da variedade copa. Os porta-enxertos limoeiro ?Cravo Santa Cruz?, citrandarin ?Indio? e o híbrido LVK x LCR ? 038 refletiram em melhor desempenho da laranjeira ?Pera?. Sendo assim, constituem como alternativas ao limoeiro ?Cravo? e podem ser incorporados ao atual sistema de produção de laranjeira da região. Made available in DSpace on 2019-12-03T18:12:20Z (GMT). No. of bitstreams: 1 26917.pdf: 3671431 bytes, checksum: 5da5017c9cd04544f4dbf67bb1433d71 (MD5) Previous issue date: 2019

Made available in DSpace on 2021-06-25T11:24:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundo de Defesa da Citricultura-Fundecitrus Embrapa Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Huanglongbing (HLB), the most important citrus disease worldwide, is associated with bacteria transmitted by the Asian citrus psyllid (ACP) preferably through new shoots present in the canopy. In a commercial citrus plant, the vegetative growth of the scion is influenced by the rootstock variety in which it is grafted. Although all commercial citrus varieties planted in recent years are susceptible to HLB, the dynamics of the rootstock in grafted plant could influence the progress of HLB, whether at the plant or grove scale. In this work, HLB incidence in 'Valencia' sweet orange grafted onto 16 rootstocks and its relationship to the tree canopy volume and flushing dynamics were evaluated in a field trial under ACP control. The experiment was conducted under rainfed conditions in Bebedouro, state of Sao Paulo, Brazil, from 2011 to 2019. 'Flying Dragon' trifoliate orange known for its dwarfing characteristics was used as the rootstock. A reduction in canopy volume by 77% at 8 years of age were observed compared to the most vigorous rootstocks. The frequency of flush shoots of 'Valencia' sweet orange was not influenced by the rootstock, but the abundance of flush shoots was lower on three semi-dwarfing rootstocks and as well as 'Flying Dragon'. Although HLB incidence on 'Flying Dragon' was lower than on 'Rangpur' lime and other three semi-standard rootstocks (trees with canopy volume between 51 and 75% of the 'Rangpur' lime canopy volume), all other combinations had similar HLB disease progress regardless of the canopy volume and flushing dynamics. Moreover, under field conditions, variations on the cumulative HLB incidence greater than 26% were necessary to significantly separate rootstocks. Therefore, the results suggest that true dwarfing rootstocks have potential to integrate the management program for HLB and that mechanisms in addition to tree vigor appear to be involved in the host-vector relationship. Univ Estadual Paulista, Fac Ciencias Agr & Vet, BR-14884900 Jaboticabal, SP, Brazil Embrapa Mandioca & Fruticultura, BR-44380000 Cruz Das Almas, BA, Brazil Fundecitrus, BR-14807040 Araraquara, SP, Brazil Univ Estadual Paulista, Fac Ciencias Agr & Vet, BR-14884900 Jaboticabal, SP, Brazil FAPESP: 2014/26758-0 Embrapa: MP 02.13.03.003.00.01 Embrapa: 22.16.04.030.00.00

The serotoninergic system plays an important role in the ontogeny of the mammalian central nervous system, and changes in serotonin production during development may lead to permanent changes in brain cytoarchitecture and function. The present study investigated the programming effects of neonatal serotonin depletion on behavior and molecular components of the serotoninergic system in adult male and female rats. Subcutaneous para-chlorophenylalanine (pCPA) administration (100 mg kg−1) was performed daily on postnatal days 8–16 to deplete brain serotonin content. During adulthood, elevated plus-maze, open field, social interaction, forced swimming, and food, saline, and sucrose intake tests were performed. Relative expression of serotonin neurotransmission components in several brain areas was determined by qPCR. Additionally, serotonin immunofluorescence and neuropeptide mRNA expression were assessed in dorsal raphe (DRN) and paraventricular (PVN) nuclei, respectively. Rat performance in behavioral tests demonstrated a general increase in locomotor activity and active escape behavior as well as decreased anxiety-like behavior after neonatal brain serotonin depletion. The behavioral programming effects due to neonatal serotonin depletion were more pronounced in females than males. At the gene expression level, the mRNA of Tph1 and Tph2 were lower in DRN while Htr2c was higher in the amygdala of pCPA-treated males, while Htr1a, Htr2c, Oxt, Avp, Crh, and Trh were not different in any treatments or sex in PVN. The results indicate that neonatal serotonin depletion has long-term consequences on locomotion and anxiety-like behavior associated with long-lasting molecular changes in the brain serotoninergic system in adult rats.

Early life stress is considered a risk factor for the development of long-term psychiatric disorders. Maternal deprivation (MD) is a useful paradigm to understand the neurobiological underpinnings of early stress-induced changes in neurodevelopment trajectory. The goal of the present study was to examine the effects of a chronic treatment with escitalopram (ESC) on the hippocampal levels of BDNF and neuropeptide Y (NPY), expression of serotonin type 1A receptor (5-HT1A), plasma corticosterone levels and emotional behaviours in male and female adolescent rats submitted to MD at 9 days of life (group DEP9) and challenged with a brief and mild stress (saline injection (SAL)) at the end of MD. Whole litters were kept with mothers (CTL) or submitted to MD (DEP9). Within each group, pups were stress-challenged (CTL-SAL and DEP9-SAL) or not (CTL-NSAL and DEP9-NSAL). ESC or vehicle treatments began at weaning and lasted 24 days, when animals were sacrificed for determination of neurobiological variables or submitted to a battery of tests for evaluation of emotional behaviours. The results showed that BDNF levels were higher in SAL-challenged males and in DEP9-SAL females, whereas 5-HT1A receptor expression was reduced in DEP9 males and in SAL-challenged females. There were no changes in NPY or corticosterone levels. In the forced swim test, SAL-challenged males and DEP9 females displayed less immobility and ESC only increased social motivation in males. The results indicated that neonatal stress led to sex-dependent changes in neurobiology and behaviour and that chronic ESC treatment had minor effects on these parameters.

Citrus relatives are a relevant source of valuable traits for use in citrus breeding, including resistance to diseases such as Huanglongbing (HLB). Resistant rootstocks may impact tree responses to HLB. This requires graft compatibility, which has been poorly investigated within the Aurantioideae. In this study, the biometric characteristics and the anatomy of the graft union of 86 scion/rootstock combinations were assessed. This comprised 18 genotypes/species and 8 genera from Citrinae, Balsamocitrinae, and Clauseninae subtribes sensu Swingle and Reece. Most graft combinations were found to be noncompatible. Phylogenetic proximity did not ensure successful grafting as, for example, Orange jasmine autografts failed, whereas some intergeneric grafts were successful (>60% of graft-take). Plant scion height was directly related to graft-take, but the correlation between the scion and rootstock stem diameters was not a reliable indicator of graft compatibility. Rangpur/Tabog, Tabog/Rangpur, Wampee/Rangpur, Wampee/Pomeroy, Wampee/Swingle, Pomeroy/Wampee, and Swingle/Wampee were the most compatible intergeneric graft combinations. Graft-take success for this was at similar levels to those of sweet orange grafted on common citrus rootstocks. The position as a scion or rootstock in the combination affected the performance and was specific to the genotypes tested. The lack of differentiation between xylem-derived calli and the accumulation of phenolic compounds at the graft union were clear anatomical and biochemical markers, respec-tively, of incompatibility for most Aurantioideae combinations. In the field, within a set of the ten most promising combinations, Hamlin/Rangpur (control) was the only one that became infected by ‘Candidatus Liberibacter asiaticus’. This was first observed 12 months after planting. Overall, the assessment of biometric traits and anatomy of the graft union allowed Aurantioideae genotypes to be divided into four clusters, with respect to their graft compatibility, as follows: fully compatible with high graft-take and plant growth; potentially compatible with high graft-take but lower plant growth; partially incompatible with lower graft-take and poor plant growth; and fully incompatible with a complete absence of graft-take.

The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more intensive cultivation, the performance of Valencia sweet orange was evaluated over nine years on four rootstocks, which induced contrasting vigor, at 513, 696 and 1000 treesha􀀀1. Agronomic Institute of Campinas (IAC) 1697 and IAC 1710 citrandarins, and diploid and allotetraploid (4) Swingle citrumelos were classified as semidwarfing, super-standard, standard, and dwarfing rootstocks, respectively. The fruit yield per tree was decreased at higher tree densities, notably for more vigorous rootstocks. Conversely, the cumulative productivity was increased over the evaluation period by 27% at 1000 treesha􀀀1, irrespective of the rootstock, and the most vigorous rootstock resulted in 2.5 times higher production than the dwarfing one on average. Most fruit quality parameters were seldom influenced by the tree density, while the rootstock was a decisive factor in improving the quality and the soluble solids content. Dwarfing rootstocks allowed for harvesting 17% more fruit per minute by manual pickers. Because the tree row volume per area is lower with such rootstocks, even at higher tree density, spray volume can be reduced, although appropriate equipment should be developed for better spray coverage on smaller trees. Nine years after planting under strict vector control, the cumulative incidence of huanglongbing-symptomatic trees on IAC 1710 was double that on Swingle 4. Taken together, the results suggested that the land use efficiency in the citrus industry can be further improved by planting vigorous rootstocks at moderate to high tree densities. Nevertheless, obtaining highly productive semi-dwarfing and dwarfing rootstocks is the sine qua non for making high-density pedestrian sweet orange orchards more profitable

Brazil is the largest producer of sweet orange and its juice in the world. Extensive cultivated area is located under an Aw climate in the North–Northwest of the state of São Paulo and the Triângulo of Minas Gerais state, being subjected to severe drought events. Although 56% of the orchards are irrigated in these regions, there is a need for drought tolerant rootstocks as an alternative to traditional genotypes such as Rangpur lime and Volkamer lemon, which are susceptible to the endemic citrus sudden death disease (CSD). In this sense, the tree size and production of Valencia sweet orange grafted onto 23 rootstock genotypes were evaluated over a ten-year period in rainfed cultivation at 7.0 m × 3.0 m spacing. Most evaluated types resulted from the cross of Poncirus trifoliata with Citrus, but two interspecific hybrids of Citrus (Sunki mandarin × Rangpur lime hybrids), the Barnes trifoliate orange and a tetraploid selection of Swingle citrumelo were also tested. Tropical Sunki mandarin was used as the reference control. Those hybrids coming from the cross of Sunki × Flying Dragon induced large tree sizes to Valencia sweet orange as well as the other citrandarins, Tropical Sunki mandarin and the Sunki mandarin × Rangpur lime hybrids, whereas only the tetraploid Swingle citrumelo behaved as a dwarfing rootstock, decreasing the canopy volume by 77% compared to that induced by the most vigorous citrandarin 535. The citrandarins 543 and 602 and the citrange C38 induced the highest mean fruit production, 67.2 kg·tree−1, but they also caused pronounced alternate bearing and only the hybrid 543 led to a high production efficiency consistently. Graft incompatibility symptoms were not observed over the evaluation period, and the canopy shape of Valencia sweet orange was also influenced by the rootstocks tested. Two citrandarins and one citrange were selected as the most promising alternative rootstocks for Valencia sweet orange grown under an Aw climate, even though productivity would likely benefit from supplementary irrigation.

The objective of this work was to determine the influence of eight rootstocks on the yield, fruit quality, and survival of 'Pêra CNPMF D6' sweet orange (Citrus sinensis) trees grown under rainfed conditions in a cohesive soil of the Brazilian Northeast. In 2014-2018, the yield, fruits, and survival of trees planted in 1997 were evaluated in a randomized complete block design. Yield was assessed using annual fruit production, yield efficiency, and the alternate bearing index. Tree survival was considered the percentage of plants that remained alive until 2018. Fruit quality was evaluated by physicochemical attributes. 'Cravo' confirmed its good yield performance. Despite the lower number of trees, the 'Mazoe' rough lemon rootstock induced the highest fruit yield. The 'Cravo' x 'Cleópatra' hybrid and 'Volkameriano' lemon favored the highest trees survival, whereas 'Indio' citrandarin and 'Cravo' lime resulted in intermediate levels. The 'San Diego' and 'Riverside' citrandarins induced shorter tree with a high yield efficiency and a higher alternate bearing index, respectively. Fruits with less juice and mass were induced, respectively, by 'Riverside' citrandarin and 'Volkameriano' lemon. It can be concluded that the 'Mazoe' rootstock induces a higher fruit yield and 'Cravo' x 'Cleópatra' and 'Volkameriano', a greater survival. In addition, all rootstocks, except 'Riverside' and 'Volkameriano', induce fruit that meet the minimum quality requirements. Resumo: O objetivo deste trabalho foi determinar a influência de oito porta-enxertos no rendimento, na qualidade do fruto e na sobrevivência de laranjeiras (Citrus sinensis) 'Pêra CNPMF D6' cultivadas, em regime de sequeiro, em solo coeso do Nordeste brasileiro. Em 2014-2018, foram avaliados, no delineamento de blocos ao acaso, o rendimento, os frutos e a sobrevivência de árvores plantadas em 1997. O rendimento foi avaliado a partir da produção anual de frutos, da eficiência produtiva e do índice de alternância produtiva. A sobrevivência das árvores foi considerada a percentagem de plantas que permaneceram vivas até 2018. A qualidade dos frutos foi avaliada por meio de atributos físico-químicos. 'Cravo' confirmou seu bom desempenho produtivo. Apesar do menor número de árvores, o porta-enxerto limoeiro rugoso 'Mazoe' induziu a maior produtividade de frutos. O híbrido 'Cravo' x 'Cleópatra' e o limoeiro 'Volkameriano' favoreceram a maior sobrevivência das árvores, enquanto o citrandarin 'Indio' e o limoeiro 'Cravo' resultaram em níveis intermediários. Os citrandarins 'San Diego' e 'Riverside' induziram, respectivamente, árvores menores, com alta eficiência de produção e maior índice de alternância produtiva, respectivamente. Frutos com menos suco e massa foram induzidos, respectivamente, pelo citrandarin 'Riverside' e o limoeiro 'Volkameriano'. Conclui-se que o porta-enxerto 'Mazoe' induz maior rendimento de frutos e 'Cravo' x 'Cleópatra' e 'Volkameriano' maior sobrevivência. Além disso, todos os porta-enxertos, exceto 'Riverside' e 'Volkameriano', induzem frutos que atendem os requerimentos mínimos de qualidade.

The objective of this work was to evaluate the effect of nine rootstocks on 'Jaffa' sweet orange (Citrus sinensis) for its vegetative, productive, and qualitative traits, and for its susceptibility to three pest mites (Eutetranychus banksi, Tetranychus mexicanus and Phyllocoptruta oleivora). The following parameters were evaluated: vegetative growth, yield, physiochemical characteristics of fruit, and density of pest mites. 'Sunki Tropical' mandarin conferred high cumulative yields whereas 'Orlando' tangelo and 'Rugoso Vermelho' lemon imparted bigger fruit with low brix, and less acidity to 'Jaffa'. Indio and 'Riverside' citrandarins induced more acid fruit of smaller sizes, as well as low-cumulated yields and canopy volumes. Also, the 'Cravo Santa Cruz' lime, 'San Diego' citrandarin, and the hybrids HTR-051 and LVK x LCR-010 conferred lower-cumulated yields to 'Jaffa'. The rootstocks did not influence the population levels of the evaluated mites. 'Sunki Tropical' mandarin, 'Cravo Santa Cruz' lime and 'Rugoso Vermelho' lemon stand up as excellent rootstock options for 'Jaffa' sweet orange in the Northeastern Brazil.

Neonatal adversity can impact neurodevelopmental trajectories. This study examined the long-term effects of maternal deprivation on day 9 (DEP9), associated or not to a stressor (saline injection [SAL]), on contextual fear conditioning (Experiment 1) and emotional behaviors (Experiment 2) in Wistar rats. Whole litters were either assigned to DEP9 or control groups, and on day 10, half of the litters in each group received an SAL or not (NSAL). DEP9-SAL male adolescents showed the longest freezing time and DEP9 adult males froze more than females. Females exhibited less anxiety-like behavior than males; DEP9-SAL females spent more time in the open arms and DEP9 males visited less the extremity of the open arm in the elevated plus maze. Early life stress increased conditioned and innate fear in males, but not in females, indicating a clear sexual dimorphism in the response to potentially threatening stimuli.

In Brazil, diseases caused by soil-borne pathogens such as Fusarium oxysporum f. sp. passiflorae are major constraints to the yellow passion fruit crop. We report the use of the survival analysis technique to assess the resistance of Passiflora spp. to Fusarium wilt in field conditions in a coastal tableland region of Brazil. Fifty genotypes were evaluated comprising the species Passiflora edulis, P. alata, P. gibertii, P. nitida, P. setacea, P. cincinnata, and backcross [(P. edulis x P. cincinnata) x P. edulis] and three graft combinations of P. edulis onto P. nitida, P. gibertii or P. alata. Plant growth and Fusarium wilt incidence were evaluated using 30 plants of each genotype in a completely randomized design. The highest growth speed indexes (GSI) were observed in P. cincinnata (BGP077) and P. edulis (BRS-GA) grafted onto P. gibertii (BGP008) with 12.04 and 11.96, respectively. Conversely, P. nitida (BGP390) had the lowest growth rate (4.10). Plants of P. gibertii, P. nitida and P. setacea did not present Fusarium wilt symptoms until 15 months after planting and presented the same median survival time with 466 days. Among P. edulis genotypes, Fusarium wilt incidence varied within three reaction groups, with the highest median survival time of 286 days. P. alata and P. cincinnata plants had high Fusarium wilt incidence (median survival time 250 and 252, respectively), similar to P. edulis, with 80% of symptomatic plants at 15 months after planting and median survival time of 240 days. Interspecific backcross hybrids differed from genotypes and intraspecific hybrids of P. edulis despite the similar median survival time among all of them (239–252 days). Grafting P. edulis onto wild species did not decrease Fusarium wilt incidence in relation to the most resistant group of P. edulis genotypes.

Citrus Huanglongbing (HLB) management relies on adoption of preventive measures including the use of healthy nursery trees, area-wide control of the vector Diaphorina citri, and eradication of symptomatic trees. Cultural practices including tree density could contribute to HLB management. We investigated the role of tree density on the incidence of HLB using a historical dataset from commercial orchards in Sao Paulo State, Brazil. The HLB incidence from 2013 to 2015 was compared through 495 blocks of different tree ages (3 to 13 years old), tree localization within the farm (edge or non-edge), and tree densities (from 220 to 714 trees·ha−1) according to the tree spacing used. Diaphorina citri was controlled rigorously in all commercial blocks using drench applications of systemic insecticides and foliar sprays of contact insecticides. The results indicated that cumulative HLB incidence was predominantly lower at higher tree densities. In addition to vector control and removal of HLB-symptomatic trees, planting of trees in high densities may reduce the proportions of HLB-infected trees, thereby contributing to improved profitability for farmers in HLB-endemic sites. In particular, this management practice should be applied at the edges of farms.

Naturally occurring subsoil horizon restricting root development and a narrow genetic base of scion-rootstock combinations make the citriculture in Brazilian Northeast prone to biotic and abiotic stresses. The diversification of citrus orchards through the introduction of new scion-rootstocks combinations is an important strategy to reduce the risks associated with these constraints. Three experiments aiming at identifying appropriate scion-rootstock combinations for enhancing genetic diversification in citrus orchards under rainfed conditions in tropical hardsetting soils were established in Sergipe state in 2008. In each one, a different sweet orange (‘Sincora’, ‘Valencia Tuxpan’ and ‘Pineapple’) was grafted on six rootstocks (‘Santa Cruz’ Rangpur lime, ‘Red Rough’ lemon, ‘Orlando’ tangelo, ‘Sunki Tropical’ mandarin, HTR–051 and VKLxRPL–010 hybrids). After eight years the experiments were evaluated for plant development, yield performance and fruit quality. In general, all sweet oranges grafted on ‘Red Rough’ lemon showed great development and cumulative yield as does with ‘Santa Cruz’ Rangpur lime, with the later showing better fruit quality as an advantage. Inversely, HTR-051 hybrid displayed low yields despite high yield efficiency, for this rootstock induces dwarfism. ‘Sunki Tropical’ mandarin brought high yields of medium quality fruits, while the VKLxRPL-010 hybrid induced productive precocity, especially for ‘Sincora’ sweet oranges. Based upon these results, all tested scions grafted on ‘Red Rough’ lemon and ‘Santa Cruz’ Rangpur lime, followed by ‘Sunki Tropical’ mandarin are indicated for genetic diversification of groves, when planted at conventional density. On the other hand, the hybrid HTR-051 seems to have great potential for high density orchards, since it shows high yield efficiency and good quality of fruit.

Fusarium wilt is considered the main fungal disease of yellow passion fruit plants in Brazil. There is ample anecdotal evidence of greater intensity of Fusarium wilt after water shortage in field conditions, but this association needs scientific confirmation. There is also a need to increase the efficiency of inoculation with Fop (Fusarium oxysporum f. sp. passiflorae) under controlled conditions for research purposes. Therefore, in this study we evaluated the effect of propagation method (from cuttings or seedlings) associated with controlled water deficit on the incidence of Fusarium wilt in yellow passion fruit plants. The artificial inoculation with Fop involved application of a spore suspension of 106 conidia mL−1 and infestation of the potting media with Fop grown in sand and cornmeal substrate. For anatomical analysis, root segments were used from inoculated and non-inoculated plants (control). Seedlings that were submitted to water deficit presented the highest incidence of Fusarium wilt, 75.0%, while in the irrigated control the incidence was below 40.0%. The mortality associated with Fop in cutting-propagated plants did not differ from non-inoculated plants. The plants subjected to water stress had greater presence of hyphae and chlamydospores and reduced starch concentration in the root cortex region. Propagation by seeds associated with controlled water stress can be used to screen accessions of P. edulis for resistance to Fusarium wilt.

Forest residues are frequently used as energy sources by Brazilian forest companies. The removal of such residues is known to reduce wood productivity, especially when fertilizer application rate is low. This study aimed to evaluate after two forest rotations the effects of forest residue management on wood productivity when fertilizer is applied at a high rate; and the effect of timber harvest intensity on soil organic matter and microbial activity. We assessed tree growth, soil microbial biomass and activity, and we fractionated soil organic matter (SOM) via its oxidation resistance. These assessments were performed after conducting a field trial comparing harvest residue management over two successive rotations in the same plots. We found no significant effect of treatments on wood productivity when the residues were removed for the first time; however, wood productivity reduced by 15% during the second rotation with residue removal even with high rates of fertilizer application. Further, 40% reduction in microbial biomass and soil respiration was noted with forest residue removal. At the reestablishment time, the SOM in the top soil (0–0.05 m layer) was 25% lower at the site where the forest residues were removed, and this difference increased to 50% at 300 days after the reestablishment. This reduction was found mainly in the SOM labile fraction.

As in several fruit crops, citrus trees with decreased size allow for a higher planting density, which may lead to higher productivity and facilitate operations such as harvesting and spraying. The use of dwarfing rootstocks is one of the most feasible methods for tree size control, but few commercial varieties are available to date. In this work, the long-term performance of Valencia sweet orange grafted onto 51 hybrid citrus rootstocks was evaluated in rainfed cultivation at 6.0 m × 2.5 m tree spacing in Northern São Paulo State, Brazil. About a third of the evaluated hybrids were classified as dwarfing and semi-dwarfing rootstocks, that is, respectively inducing a relative canopy volume of &lt, 40% and 40–60% compared withthe standard rootstock, the Rangpur limeSanta Cruz selection. The production efficiency and soluble solids concentration were conversely related to the canopy volume. Three citrandarins of Sunki mandarin (TSKC) × Flying Dragon trifoliate orange (TRFD) were grouped within the most productive dwarfing rootstocks. Other hybrids that expressively decreased tree size were mainly sensitive to drought, therefore, the mean fruit yield was low, indicating the need for irrigation, albeit fruit quality was high. Estimated productivity on the selected TSKC × TRFD rootstocks would double to an average of 40 t·ha−1·year−1 if tree spacing wasadjusted to the smaller tree size. Although the HTR-208 citrandarin and the LCR × CTSW-009 citrumelimonia were as vigorous as the Santa Cruz Rangpur lime, they induced an outstanding fruit yield due to their highertolerance to drought and, hence, can be considered for rainfed cultivation at wider tree spacing.

The genetic improvement of sour passion fruit has the main objective of obtaining genotypes with high fruit yield and quality. The determination of the ideal early selection is extremely relevant to reduce costs and time in the selection of promising genotypes for use in genetic improvement programs. In this context, this work aimed to determine the ideal selection phase through estimates of genetic parameters, phenotypic, genotypic correlations and analysis of repeatability. A total of 14 yellow passion fruit hybrids in Lençóis (Bahia State, Brazil) were evaluated in a randomized block design with five replications and nine agronomic traits from three harvests with five fruits evaluated per repetition. Genetic parameters, repeatability coefficient and phenotypic and genotypic correlations were estimated for each evaluation cycle. For most parameters, the traits changed according to the evaluation cycle. Most of the genetic parameters showed favorable genetic conditions for the selection in the first harvest. The correlations between the traits fruit weight, peel and seedless pulp weight, fruit length and diameter were more stable in the different harvests. Through the repeatability analysis based on the principal components of covariance and correlation, it was possible to estimate a sample of 13 fruits per hybrid for prediction with accuracy of 90% for the physical traits of sour passion fruit.

Made available in DSpace on 2021-06-25T10:19:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 ‘Candidatus Liberibacter asiaticus’ (Las) is an unculturable, phloem-limited, insect-transmitted bacterium associated with the Asiatic form of huanglongbing (HLB), the most destructive citrus disease. In Asia and the Americas, it is transmitted by the Asian citrus psyllid (Diaphorina citri Kuwavama). Despite considerable research, little is known about the processes involved in plant infection and colonization by Las. This study was conducted to determine whether the basal portion (below girdling) of the plant is an important route for Las to move laterally from a point of inoculation on a branch to pathogen-free branches elsewhere in the canopy, and to quantify the influence of actively growing tissues on vertical upward (acropetally) or downward (basipetally) movement of Las. Nongirdled and fully or partially girdled stems of potted plants of ‘Pera’ sweet orange, graft-inoculated above or below girdling, were sampled in distinct regions and assessed by qPCR, 6 months postinoculation. Las invaded all regions of partially and nongirdled plants but remained restricted to the inoculated regions of fully girdled plants, evidence that in planta bacterium movement is limited to the phloem. In fully girdled plants, starch accumulated above the girdling site, probably because of changes in flow of phloem sap. To study the influence of actively growing tissues, inoculated ‘Valencia’ sweet orange plants were kept intact or were top- or root-pruned to force production of new tissues, and sampled at 15-day intervals. Las migrated rapidly and most predominantly toward newly developing root and leaf tissues. The rapid and predominant movement of Las to newly developed shoots and roots would explain failures of canopy heat treatments and pruning to cure HLB-affected trees, and reinforces the need to protect rapidly growing new shoots from feeding by D. citri in order to minimize transmission and spread of the pathogen by the vector within and between orchards. Fundo de Defesa da Citricultura (Fundecitrus) Universidade Estadual Paulista (UNESP) Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Universidade Estadual Paulista (UNESP)

The water deficit is one of the main limiting factors to the yield of sweet oranges. The present study aimed to determine alternative rootstocks to ‘Rangpur’ lime for ‘Pera’ sweet oranges grown on tropical hardsetting soils with greater potential tolerance to water deficit. Six citrus scion/rootstock combinations were grown during eight years in an orchard established in Sergipe, Brazil. The tree height, number of fruits per plant, cumulated fruit yield, leaf proline content and survival rate of trees were evaluated between 6th and 8th year after planting. Greater rate of tree loss occurred among the sweet orange onto ‘Orlando’ tangelo, which also induced the lowest cumulative fruit yield. After prolonged water deficit, moderate to high proline content was found in trees grafted on Sunki of Florida mandarin × C13 citrange – 012° (TSKFL × CTC13-012), ‘Orlando’ tangelo, ‘Indio’ and ‘Riverside’ citrandarin. Conversely, after a short water deficit during the wet season, trees on ‘San Diego’ citrandarin and Rangpur lime clone of Centro Nacional de Pesquisa Mandioca e Fruticultura – CNPMF 03 ‘Rangpur’ lime showed higher proline content. Trees onto TSKFL × CTC13-012 and ‘Indio’ also induced the greatest accumulated fruit yield at the 8th year after planting. It is assumed that ‘San Diego’ and CNPMF 03 ‘Rangpur’ induce response more quickly to water deficit, whereas TSKFL × CTC13-012 and ‘Indio’ are less susceptible to prolonged deficit. Therefore, trees on ‘San Diego’ and Indio citrandarin, CNPMF-03 ‘Rangpur’ lime, TSKFL × CTC13-012 hybrid present greater potential to tolerate water deficit and produce more fruits on the hardsetting soils of the coastal tablelands of the Brazilian Northeast.

The search for alternative rootstocks to the ‘Rangpur’ lime tree is a challenge to the sustainability of citrus in the Tabuleiros Costeiros (Coastal Tablelands) of Northeastern Brazil. New varieties should meet high drought tolerance with water deficit, cohesive soils, resistance to citrus diseases and inducing high production of fruit. In this work, the performance of ‘Pera’ sweet orange was evaluated on ‘Tropical Sunki’ mandarin and 27 hybrid citrus rootstocks in Umbauba, Sergipe. A local selection of the ‘Rangpur’ lime was the control. Planting was in 2013 at tree spacing of 6.0 × 3.0 m, without irrigation. Tree size, fruit yield and quality, tree survival rate and graft-compatibility were assessed until 2019. Experimental design was completely randomized blocks with 29 treatments, three replicates and four plants in the plot. Two selection indices were applied to the data to assist in decision making. The ‘Tropical Sunki’ mandarin induced similar cumulative fruit yield in relation to the ‘Rangpur’ lime, suggesting a good drought tolerance of the former rootstock. The TSKC × (LCR × TR) - 073 induced slightly lower productivity, compensated by higher productive efficiency and higher concentration of soluble solids, whereas LCR × TR - 001 and HTR - 166 were highly efficient dwarfing rootstocks. The multiplicative and the rank sum indices showed high correlation, both classifying ‘Tropical Sunki’ mandarin, ‘Santa Cruz Rangpur’ lime, LVK × LCR - 010 and - 038, HTR - 127, in addition to the three aforementioned hybrids, as superior to the local selection of ‘Rangpur’ lime.

Soil cover with plastic film is a practice used to optimize the agronomic performance of different crops, but its behavior in the citrus growing conditions of Brazil remains unknown. Five experiments in commercial orchards located in the state of São Paulo, in rainfed or irrigated systems, were carried out to evaluate the effect of soil cover with plastic film (white/black or silver/black color) on the vegetative growth and initial production of sweet orange trees up to 3.5 years after planting. In each location and experiment, completely randomized design was used, with four to ten replicates and five to twelve useful trees per plot. Considering the set of results, soil cover with plastic film increased the average canopy volume by 27% and the average production per tree by 33% compared to control trees without plastic cover. The positive effect of plastic cover was observed until the third year of its application, gradually decreasing with its degradation. In general, greater relative increases were observed in variables evaluated with the use of plastic cover in rainfed experiments than irrigated ones, while the effect of white/black either silver/black films was similar. Resumo A cobertura do solo com filme plástico é uma prática utilizada para otimizar o desempenho agronômico de diferentes culturas, mas não se conhece seu comportamento nas condições de cultivo de citros no Brasil. Cinco experimentos em pomares comerciais localizados no Estado de São Paulo, em sequeiro ou irrigados, foram realizados para avaliar o efeito da cobertura de solo com filme plástico (cor branca/preta ou prata/preta) no crescimento vegetativo e na produção inicial de laranjeiras-doces até 3,5 anos após o plantio. Em cada localidade e experimento, utilizou-se delineamento inteiramente casualizado, com quatro a dez repetições e de cinco a doze plantas úteis por parcela. Considerando-se o conjunto de resultados, a cobertura de solo com filme plástico aumentou, em média, 27% o volume de copa e 33% a produção média por planta em relação à testemunha sem cobertura. O efeito positivo da cobertura foi observado até o terceiro ano de sua aplicação, reduzindo-se gradativamente com sua degradação. Em geral, observaram-se maiores incrementos relativos nas variáveis avaliadas com o uso da cobertura nos experimentos de sequeiro em relação aos irrigados, enquanto o efeito de filmes nas cores branca/preta e prata/preta foi similar.

The production of mandarins is incipient in Northeastern Brazil in spite of the large regional market. Few studies have reported the performance of mandarins under the tropical conditions in Brazil, considering that, in general, the quality and yield of these fruits are more expressive in regions of subtropical and Mediterranean climates. In this work, tree size, fruit production and quality of four mandarin hybrids (‘Piemonte’ mandarin-tangor, ‘Murcott’ tangor and ‘Page’ and ‘Nova’ tangelo-mandarin) grafted on ‘Rangpur’ lime rootstock in Umbaúba, State of Sergipe, Brazil, were evaluated. The experimental design was randomized blocks with three replicates and three trees per plot. Planting was carried out in 2008 at tree spacing of 6.0 x 3.0 m in rainfed cultivation system. ‘Piemonte’ mandarin-tangor was more productive than ‘Murcott’ tangor and ‘Nova’ and ‘Page’ tangelo-mandarin, under the conditions evaluated in Umbaúba up to the eleventh year after planting. Regarding fruit quality, ‘Piemonte’ mandarin-tangor and ‘Page’ tangelo-mandarin can be indicated both for fresh consumption and for processing due to their higher total soluble solids, ratio and vitamin C content in relation to ‘Murcott’ tangor. Resumo A produção de tangerinas é incipiente na região Nordeste, embora o mercado consumidor regional seja expressivo. Há poucos estudos sobre o desempenho de tangerineiras nas condições tropicais do Brasil, considerando-se que, em geral, a qualidade e o rendimento de frutos dessas frutíferas sejam mais expressivos em regiões de clima subtropical e mediterrâneo. Neste trabalho, avaliaram-se crescimento de plantas, produção e qualidade de frutos de quatro híbridos de tangerineira (tangerineira-tangor ‘Piemonte’, tangor ‘Murcott’ e tangerineira-tangelos ‘Page’ e ‘Nova’ ) enxertados em limoeiro ‘Cravo’, em Umbaúba-SE. O delineamento experimental foi em blocos casualizados, com três repetições e três plantas por parcela. O plantio foi realizado em 2008, no espaçamento de 6,0 m x 3,0 m, em cultivo de sequeiro. A tangerineira-tangor ‘Piemonte’ foi mais produtiva que o tangor ‘Murcott’ e os tangerineira-tangelos ‘Page’ e ‘Nova’ , nas condições avaliadas em Umbaúba-SE, até ao décimo primeiro ano de plantio. Para a qualidade dos frutos, a tangerineira-tangor ‘Piemonte’ e o Tangerineira-tangelo ‘Page’ podem ser indicados tanto para o consumo in natura quanto para processamento, pois apresentaram resultados superiores para sólidos solúveis totais, ratio, rendimento industrial e vitamina C em relação ao tangor ‘Murcott’.

Apresentação A partir da composição de um comitê encabeçado pelo pós-doutorando Mateus de Almeida Prado Sampaio, tendo a colaboração dos professores Eduardo Paulon Girardi, Rosa Ester Rossini e Eve-Anne Bühler, trabalhamos ao longo de mais de um ano para elaborar este dossiê temático que ora apresentamos. O tema proposto, “Expansão do Agronegócio no Brasil: características, contradições e conflitos”, justificou-se pelo fato do país se destacar mundialmente como player central em diversas cade...

Apresentacao A partir da composicao de um comite encabecado pelo pos-doutorando Mateus de Almeida Prado Sampaio, tendo a colaboracao dos professores Eduardo Paulon Girardi, Rosa Ester Rossini e Eve-Anne Buhler, trabalhamos ao longo de mais de um ano para elaborar este dossie tematico que ora apresentamos. O tema proposto, “Expansao do Agronegocio no Brasil: caracteristicas, contradicoes e conflitos”, justificou-se pelo fato do pais se destacar mundialmente como player central em diversas cade...

Memories of adverse events can be maladaptive when they lead to exaggerated fear, as observed in post-traumatic stress disorder (PTSD). Fear conditioning and fear sensitization are learning processes thought to play a role in fear-related disorders, and only few animal studies have evaluated the relationship between the associative and non-associative fear memory components on the development and maintenance of PTSD-like behavioral changes. Here we assessed the effects of a single dose of propranolol (10 mg/kg) or saline after fear memory retrieval on the long-term behavioral responses induced by severe stress in male rats. Animals were submitted to contextual fear conditioning (delayed shock group) or not (non-shock group) and underwent fear memory retrieval followed by propranolol or saline administration two weeks later. Rats were then evaluated in different behavioral tests to assess the expression of the conditioned fear response, anxiety-like and exploratory behaviors, and fear response after the presentation of unknown acoustic stimulus. Post-retrieval propranolol did not disrupt the subsequent expression of neither conditioned fear response nor the exploratory deficit and fear sensitization response, indicating that propranolol failed to mitigate long-term behavioral changes induced by severe stress in rats.

The objective of this work was to evaluate five nonparametric selection indices for the selection of hybrid citrus rootstocks grafted with 'Valência' sweet orange, using horticultural traits relevant for the juice processing industry. Forty-six rootstocks were evaluated in a randomized complete block design, with three replicates and five trees in the plot, in the period from 2009-2015, in a rainfed cultivation. The means of the variables plant height, accumulated fruit yield, fruit yield efficiency, total soluble solids concentration, juice yield, and drought-tolerance were used to calculate the following indices: multiplicative index (IEi), sum of classification (IMMi), genotype-ideotype distance (DiI), and ranking indices (IRKi, based on simple means; and IRKii, based on linear normalization). The indices were efficient to classify the hybrids in relation to general performance. Spearman’s correlation showed a high similarity between most nonparametric indices, notably between IRKi and IRKii. The ranking indices, mainly IRKii, provide a more coherent classification of the hybrids, which allows of the selection of more productive and drought-tolerant rootstocks to produce high-quality fruit for processing. Resumo: O objetivo deste trabalho foi avaliar cinco índices de seleção não paramétricos para a seleção de citros híbridos como porta-enxertos, enxertados com laranjeira 'Valência', com base em atributos horticulturais relevantes para a indústria de processamento de suco. Avaliaram-se 46 porta-enxertos em delineamento de blocos ao acaso, com três repetições e cinco plantas na parcela, no período de 2009-2015, em cultivo de sequeiro. As médias das variáveis altura de planta, produção acumulada de frutos, eficiência produtiva de frutos, concentração de sólidos solúveis totais, rendimento de suco e tolerância à seca foram utilizadas para calcular os seguintes índices: multiplicativo (IEi), soma de classificação (IMMi), distância genótipo-ideótipo (DiI) e ranqueamento (IRKi, baseado em médias simples; e IRKii, baseado em normalização linear). Os índices foram eficientes em classificar os híbridos em relação ao desempenho geral. A correlação de Spearman mostrou alta similaridade entre a maioria dos índices não paramétricos, notadamente entre IRKi e IRKii. Os índices de ranqueamento, principalmente o IRKii, fornecem uma classificação mais coerente dos híbridos, o que permite a seleção de porta-enxertos mais produtivos e tolerantes à seca, para a produção de frutas de alta qualidade para processamento.

The objective of this work was to evaluate types of cuttings, indole-3-butyric acid (IBA) concentrations, and potting media on the rooting of passion fruit (Passiflora edulis) cultivars, and to compare the initial performance of flowering-competent cuttings cultivated in a trellising system or in a nonstaking method on ground covered with plastic mulch. The passion fruit cultivars evaluated were BRS Gigante Amarelo, Isla Redondo Amarelo, and FB 200 Yellow Master were evaluated. The assessed treatments were: softwood or semi-hardwood cuttings; five concentrations of IBA (0, 500, 1,000, 2,000, and 4,000 mg L-1); and the pine bark or phenolic foam potting media. Initial growth, fruit yield, and bacteriosis severity were evaluated in the field in flowering-competent cuttings and seedlings, both in the trellising system and in the nonstaking method on mulched ground. For the evaluated cultivars, a high rooting rate (>90%) was observed for both softwood and semi-hardwood cuttings grown in phenolic foam or decomposed pine bark for potting media, regardless of the IBA concentration. In the espalier system, 14 months after transplanting, fruit yield was 45% higher for cuttings than for seedlings. Unstaked plants had a low number of flowers and fruit set, and a great damage by bacteriosis according to the used cultivar. The evaluated cultivars can be propagated either by softwood or semi-hardwood cuttings, in phenolic foam or decomposed pine bark, without IBA application. Flowering-competent cuttings have the potential to anticipate the production in the trellised cultivation of yellow passion fruit. Resumo: O objetivo deste trabalho foi avaliar tipos de estacas, concentrações de ácido indolbutírico (AIB) e substratos de cultivo, no enraizamento de cultivares de maracujá (Passiflora edulis), e comparar o desempenho inicial de estacas floríferas conduzidas em sistema de espaldeira ou no método de cultivo rasteiro em solo protegido com cobertura de plástico. Avaliaram-se as cultivares de maracujá BRS Gigante Amarelo, Isla Redondo Amarelo e FB 200 Yellow Master. Os tratamentos avaliados foram: estacas herbácea ou lenhosa, cinco concentrações de AIB (0, 500, 1.000, 2.000 e 4.000 mg L-1); e os substratos de cultivo casca de pinheiro ou espuma fenólica. Em campo, o crescimento inicial, a produção de frutos e a severidade da bacteriose foram avaliados em plantas de estacas competentes para florescer e em mudas, tanto no sistema em espaldeira como no método rasteiro em solo com cobertura de plástico. Para as cultivares avaliadas, observou-se alta taxa de enraizamento (>90%) tanto para as estacas herbáceas como para as semilenhosas, em substrato de espuma fenólica ou casca decomposta de pinheiro, independentemente da concentração de AIB. No sistema de espaldeira, após 14 meses de cultivo, a produção foi 45% maior para plantas obtidas de estacas que para mudas. As plantas rasteiras apresentaram baixo número de flores e frutos e grande severidade de bacteriose conforme a cultivar utilizada. As cultivares avaliadas podem ser propagadas por estaquia herbácea ou semilenhosa, em espuma fenólica ou em casca de pinheiro decomposta, sem aplicação de AIB. As estacas floríferas apresentam potencial para antecipar a produção em cultivo de maracujá-amarelo em espaldeira.

A morte súbita dos citros (MSC) é uma doença biótica de origem desconhecida, transmitida por vetores aéreos e borbulhas, que afeta cultivares de laranjas doces e tangerinas enxertadas nos limoeiros Cravo, Volkameriano e Rugoso. As mesmas cultivares enxertadas nas tangerinas Cleópatra e Sunki, trifoliata e citrumelo Swingle são assintomáticas. O objetivo deste trabalho foi avaliar nove seleções de citrumelo quanto à tolerância à MSC e seus efeitos no desenvolvimento de laranjeiras Valência cultivadas sem irrigação. Utilizou-se o delineamento inteiramente casualizado com nove tratamentos (citrumelos) e cinco repetições sendo cada parcela representada por uma planta. Após 16 anos no campo, nenhuma planta apresentou sintomas de MSC ou anel de goma (bud union ring) entre a copa e o porta-enxerto. Dados de 14 colheitas controladas revelam que as laranjeiras Valência enxertadas nos citrumelos Swingle, W-2, F80-7 e F80-8 apresentaram as maiores produções sendo que W-2 e F80-7 induziram produção precoce e não motivaram alternância de produção. Os citrumelos W-2, Swingle e F80-7 formaram as plantas mais altas e os citrumelos F80-5, F80-3 e F81-18 induziram as árvores mais baixas. Embora não proporcionarem elevada produção de frutos por planta, estes três porta-enxertos apresentaram maior eficiência produtiva, e o F80-5 motivou também produção precoce e menor diâmetro de copa, possibilitando maior densidade de plantio.