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Crystals may modify the food quality, reduce a plant palatability, and choice to insects, or defend against pests. Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) is considered one of the most damaging pests in field crops in the world, and is usually associated with several hosts. We examined relations between the choices of whitefly with calcium oxalate crystals (COC) presence in weeds. The treatments were weed species Amaranthus viridis L., Amaranthus viridis L., Bidens pilosa L., Chenopodium album L., Nicandra physalodes L., and Solanum americanum Mill., and, as control, Brassica oleraceae var. capitata L. B. tabaci infestation was evaluated at 7, 14, 21, and 28 days after infestation (DAI), the height and shoot dry mass at 28 DAI, and leaf blades were prepared from all treatments. B. oleraceae var. capitata, S. americanum, and B. pilosa showed greater B. tabaci infestation in this order, respectively. In the presence of COC, the reverse occurred, since in these plants there was a lower presence of COC. It is concluded that the presence of COC influences B. tabaci preference in the choice of its hosts.

Sustainable weed management strategies are important for reducing chemical inputs and development of weed resistance. This study aimed to evaluate the effect of extracts from winter cover crops (ce...

Solanum americanum Mill. is a weed that occurs with a number of crops, and it is known for its high seed production and its staggered germination. The objective of this work was to evaluate the germination behavior of S. americanum seeds under the influence of chemical and environmental factors. In the laboratory, we tested the effect on germination of (i) constant and alternating temperatures, (ii) seed washing, (iii) exposure time and concentration of chemical treatments and (iv) seeding depth and soil covered with plant residue on seedling emergence. The variables analyzed were germination percentage, germination rate index, seedling emergence and length of the seedlings. The results indicated that alternating temperatures are the main way to promote germination of S. americanum; however, chemical treatments can help to increase the germination percentage and rate index. There was no increase in germination with seed washing, with the exception of KNO₃ application. A GA₃ concentration of 0.84 g L⁻¹ and an exposure time of 21.22 h in 0.2% of KNO₃ promoted the highest germination of S. americanum. Germination occurs when seeds remain on the soil surface and are not covered by crop residue.

Ralstonia solanacearum causes bacterial wilt disease in many plant species. Type III-secreted effectors (T3Es) play crucial roles in bacterial pathogenesis. However, some T3Es are recognized by corresponding disease resistance proteins and activate plant immunity. In this study, we identified the R. solanacearum T3E protein RipAZ1 (Ralstonia injected protein AZ1) as an avirulence determinant in the black nightshade species Solanum americanum. Based on the S. americanum accession-specific avirulence phenotype of R. solanacearum strain Pe_26, 12 candidate avirulence T3Es were selected for further analysis. Among these candidates, only RipAZ1 induced a cell death response when transiently expressed in a bacterial wilt-resistant S. americanum accession. Furthermore, loss of ripAZ1 in the avirulent R. solanacearum strain Pe_26 resulted in acquired virulence. Our analysis of the natural sequence and functional variation of RipAZ1 demonstrated that the naturally occurring C-terminal truncation results in loss of RipAZ1-triggered cell death. We also show that the 213 amino acid central region of RipAZ1 is sufficient to induce cell death in S. americanum. Finally, we show that RipAZ1 may activate defence in host cell cytoplasm. Taken together, our data indicate that the nucleocytoplasmic T3E RipAZ1 confers R. solanacearum avirulence in S. americanum. Few avirulence genes are known in vascular bacterial phytopathogens and ripAZ1 is the first one in R. solanacearum that is recognized in black nightshades. This work thus opens the way for the identification of disease resistance genes responsible for the specific recognition of RipAZ1, which can be a source of resistance against the devastating bacterial wilt disease., This work was supported by a grant from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center no. PJ01317501), the Rural Development Administration and National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT) (NRF-2019R1A2C2084705 & 2018R1A5A1023599 (SRC)), Republic of Korea. C.S. was supported by the Creative-Pioneering Researchers Program through Seoul National University. M.V.’s research was funded by the research grants (PID2019-108595RB-I00 and SEV/2015/0533) from the Spanish Government and the CERCA Program from the Catalan Government (Generalitat de Catalunya).

BACKGROUND: Drosophila suzukii (Matsumura) is a major fruit pest in temperate regions worldwide, but in subtropical Florida, winter‐grown strawberries have not been severely affected. Zaprionus indianus Gupta is another invasive drosophilid species and a pest of some tropical fruits. To improve monitoring, trapping systems for D. suzukii and Z. indianus were tested. Morphology, ovarian status and the suitability and availability of non‐crop hosts as possible D. suzukii population‐limiting factors were assessed. RESULTS: Traps with commercial attractants captured more D. suzukii but fewer Z. indianus than those with a homemade mixture. In central and northern Florida, < 10% and 30‐80% of D. suzukii, respectively, exhibited darker, winter morph coloration, and 55‐75% of females from central Florida were carrying mature and/or immature eggs. Adult D. suzukii were reared from fruits of two of 28 potential hosts: elderberry (Sambucus nigra) and nightshade (Solanum americanum). Nightshade, but not elderberry, was common on field perimeters (21 and six of 36 fields, respectively). Traps placed in wooded or partially wooded field edges yielded the most D. suzukii. CONCLUSION: Florida strawberry is at risk of D. suzukii infestation, as flies were captured throughout the growing season. However, fly captures remained relatively low, peaking at 1.5 flies per trap per day. In central Florida, the low availability and suitability of non‐crop hosts likely limit population growth. The finding of few flies in northern Florida may additionally be attributable to a greater proportion of flies displaying winter morph coloration than in central Florida. © 2018 Society of Chemical Industry

Plants of Nicandra physaloides, Solanum americanum and Euphorbia heterophylla with leaf lesions have been found naturally grown among tomato plants in commercial fields in Brazil. Tomato bacterial spot was occurring in these fields. Xanthomonad-like isolates were obtained from affected weed leaf samples. These isolates were species identified using BOX-PCR and specific primers. Isolates from N. physaloides and S. americanum were identified as Xanthomonas perforans and that of E. heterophylla were identified as X. gardneri. Each of them was able to artificially infect and cause symptoms on the three weed species and tomato plants.

The tomato red spider mite, Tetranychus evansi Baker and Pritchard, is one of the most serious pests of solanaceous crops in Africa. Field experiments were conducted to investigate its effects on the growth and leaf yield of five African nightshade species viz. Solanum americanum, S. sarrachoides, S. scabrum, S. tarderemotum and S. villosum during the 2008 and 2009 growing seasons. Plants were infested with 2–4 day-old female spider mites which were allowed to multiply. The number of mite motiles increased throughout the growing season in unsprayed plots and this number varied significantly between the African nightshade species. Except for S. sarrachoides, leaf damage was high on the other four Solanum species irrespective of the spraying regime during both seasons. However, S. scabrum had a significantly greater leaf area ratio (ratio of leaf area to total plant weight) and specific leaf area (ratio of leaf area to total leaf dry weight) during both seasons. Overall yields were 1.5 times more in S. scabrum and S. sarrachoides compared to S. americanum, S. tarderemotum and S. villosum. Our results show that T. evansi infestation affects the leaf area ratio and specific leaf area of African nightshade species differentially which eventually determines the plant's overall leaf yield. These findings present an opportunity for evaluation and selection of African nightshade species that can withstand spider mite infestation in small holder farms for increased vegetable production in Africa.

Aphis craccivora Koch (Hemiptera: Aphididae) é um afídeo-praga que ocorre em diferentes cultivos e causa danos relacionados ao hábito da sucção de seiva. No Brasil, são raros os registros de plantas daninhas hospedeiras dessa espécie, particularmente no Estado do Rio Grande do Sul (RS). Plantas daninhas infestadas com afídeos foram encontradas em área experimental localizada no campus da Universidade Federal de Santa Maria (UFSM), RS, em duas datas, 22/02/2010 e 25/03/2010. No segundo registro (25/03/2010), cada planta daninha foi medida e avaliada quanto ao número de afídeos. A espécie foi identificada como Aphis craccivora e as plantas daninhas hospedeiras, como Amaranthus hybridus Linnaeus, 1753 (Amaranthaceae), caruru-roxo, e Solanum americanum Mill, 1768 (Solanaceae), maria-pretinha. Este trabalho faz o primeiro registro de A. hybridus e S. americanum hospedando A. craccivora em Santa Maria, no Rio Grande do Sul.

Three field studies were conducted to determine the selectivity on leeks ( Allium porrum L.) of early post-transplant herbicides and their efficacy on weed populations and crop yields. Herbicide treatments were cinmethylin, metolachlor, oxyfluorfen, prodiamine, and pendimethalin. Both a non-treated and a weed-free control were added. The most common species were the broadleaved weeds Eclipta alba (L.) Hassk. , Rorippa teres (Michx.) Stuckey, Geranium carolinianum L., Amaranthus viridus L., and Solanum americanum P. Mill., while Paspalum distichum L. was the most predominant grass species. The herbicides providing the most consistent season-long weed control were metolachlor, oxyfluorfen, prodiamine, and pendimethalin. Plots treated with metolachlor, prodiamine, and pendimethalin had the highest yields and plant vigor and were comparable to those for the weed-free control plots.

Abstract A total of 327 root samples collected from horticultural and agronomic crops, and weeds associated with these crops in Florida crop production regions, were examined. Isozyme phenotypes, esterase (EST) and malate dehydrogenase (MDH) phenotypes were used to characterise and identify the species of Meloidogyne present in these samples. At least 26 females from each sample were examined using polyacrylamide gel electrophoresis. Sixteen major bands of EST activity were found, corresponding to 12 phenotypes. A species-specific EST phenotype was consistently associated with each of the Meloidogyne spp. identified: Meloidogyne arenaria, M. floridensis, M. graminicola, M. hapla, M. incognita, M. javanica, M. mayaguensis and M. partityla. Two unique EST phenotypes, which have not been described, were found associated with three unidentified nematode populations. Five bands of MDH activity and four phenotypes were also found among the populations. During this study, new host records were determined for M. floridensis and M. mayaguensis, two recently reported Meloidogyne spp. in Florida. Plant species found as new hosts of M. floridensis were Cucumis sativus, Phaseolus sp., Solanum melongena and one weed species, Emilia sonchifolia, and the M. incognita-resistant peach rootstock ‘Flordaguard’. New hosts for M. mayaguensis were Carica papaya, Capsicum annuum var. Longum, and six weed plants, including Eclipta prostrata, Fatoua villosa, Panicum sp., Poinsettia cyathophora, Solanum americanum and also one unidentified weed species belonging to the family Acanthaceae. To our knowledge, Florida is the only geographic area of North America where M. floridensis and M. mayaguensis have been detected.

The pepper weevil, Anthonomus eugenii Cano, is an important pest of Capsicum spp. pepper in Florida, Puerto Rico, and Central America. Catolaccus hunteri Crawford is the most abundant parasitoid attacking pepper weevil larvae in Florida. Weekly releases of C. hunteri at a rate of 1600 adults per 0.2-ha plot in organically-grown bell pepper, C. annuum L., beginning at first bloom resulted in fewer weevil infested fruit compared to 0.2-ha plots where no parasitoids were released. Weekly releases of C. hunteri adults on nightshade, Solanum americanum Mill, during the fall/winter off-season followed by weekly releases of the same parasitoid in adjacent bell pepper during the spring in-season resulted in fewer infested pepper fruit compared to off-season nightshade and in-season pepper where no parasitoids were released. The results of these experiments demonstrate the potential of augmentative releases of C. hunteri for suppressing infestations of pepper fruit by pepper weevil larvae.

Species from the Solanum nigrum complex are not as popular as potatoes and peppers but are economically important fruit or leafy vegetables in some parts of the world. The aim of this study was to look at the hybridization potential of genotypes from the Solanum nigrum complex, and two cocktail tomato cultivars, to facilitate a future breeding program. Solanum americanum Mill., S. burbankii Bitter, S. chenopodioides Lam., S. retroflexum Dun. and S. scabrum L. are some of the species found in Southern Africa. Crosses, including reciprocals, were made between these five species and two cocktail tomato cultivars. Fifty percent of the crosses made, resulted in fruit set, but only 22.5% of the produced seeds germinated to yield progeny. Cytological analyses of the chromosome numbers showed no variation from the normal euploid series. The occurrence of polyploidy between the species is probably the most efficient barrier to natural hybridization between the species.

The susceptibility of leaves and berries of five night-shade species to infection by the potato late blight pathogenPhytophthora infestans was tested. American black nightshade (Solanum americanum) and eastern black nightshade (Solanum ptycanthum) were resistant to infection. However, two accessions (entire-edged and dentate-edged leaf) of hairy nightshade (Solanum sarrachoides), cutleaf nightshade (Solanum triflorum), and bitter or climbing nightshade (Solanum dulcamara) were susceptible. Survival of the pathogen in susceptible species was tested under different environmental conditions. The pathogen survived for at least 2 wk in both hairy nightshade accessions when plant material was kept in soil at a temperature of 20 C. However,P. infestans survived 48 h at −15 C only in the entire-leaf hairy nightshade accession. In the laboratory, oospores of the pathogen were formed in inoculated plants of the two hairy nightshade accessions, cutleaf nightshade, and ‘Russet Burbank’ potato, but not in American black nightshade, bitter nightshade, or eastern black nightshade.

Weeds were sampled in commercial vegetable fields in Palm Beach County, FL in August 2001, December 2001, and March 2002 for the presence of Phytophthora capsici. Fields sampled had a recent history of this plant pathogen. P. capsici was successfully isolated from the roots of six of 42 Carolina geranium (Geranium carolinianum) plants, four of 28 American black nightshade (Solanum americanum) plants, and two of 130 common purslane (Portulaca oleracea) plants. All but one of the 12 isolates were of the A1 mating type. All 12 isolates were resistant to mefenoxam, although at different levels. All but one isolate were strongly pathogenic on pepper seedlings. When two or three isolates recovered from each weed were inoculated onto the roots of their weed host of origin, P. capsici was recovered from the roots. Isolates of P. capsici were tested on four other solanaceous weeds of importance or potential importance to agricultural fields in Florida: Solanum nigrum, S. ptycanthum, S. carolinense, and S. capsicoides. Recovery of P. capsici from roots varied with weed species and isolate tested. P. capsici caused disease mortality on S. nigrum, and no reisolation of P. capsici was possible with S. capsicoides. This is the first report of S. americanum and G. carolinianum being alternative hosts for P. capsici under field conditions. This study also validated P. oleracea as an alternative host. In Florida, and perhaps elsewhere, weeds may contribute to pathogen survival in the absence of a host crop or when propagules may not readily survive in soil or plant debris.

Although proteinase inhibitor proteins are known to confer insect resistance in transgenic plants, their endogenous roles remain undefined. Here, we describe the expression of a proteinase inhibitor II (PIN2) protein from Solanum americanum in phloem of stems, roots and leaves suggesting a novel endogenous role for PIN2 in phloem. The phloem consists of parenchyma cells, sieve elements (SE), and companion cells (CC) which are in close association with SE. We isolated two cDNAs encoding PIN2, SaPIN2a and SaPIN2b, from a S. americanum cDNA library using a tomato PIN2 cDNA as hybridization probe. SaPIN2a shows 73.6% identity to SaPIN2b. Southern blot analysis confirmed that two genes occur in S. americanum. Northern blot analysis showed that both are wound-inducible and are expressed in flowers. Unlike SaPIN2b and other previously characterized plant PIN2 proteins, SaPIN2a is abundantly expressed in stems. In situ hybridization studies on stem sections showed that SaPIN2a mRNA is expressed in CC and some SE, likely the immature developing SE, of external and internal phloem. Western blot analysis using SaPIN2a-specific antibodies showed SaPIN2a accumulation in stems, leaf midribs and fruits. Immunohistochemical localization, using these antibodies, revealed SaPIN2a expression in external and internal phloem of stem. Immunoelectron microscopy of stem, root and leaf sections further localized SaPIN2a to the CC and predominantly to the SE, particularly the parietal cytoplasm adjacent to the cell wall, the lumen and the sieve-area pores. These results suggest that, other than a possible role in plant defense, SaPIN2a could be involved in regulating proteolysis in the SE.

Electron transport in a paraquat-resistant (R) biotype of Solanum americanum Mill. (American black nightshade), when measured as the photoreduction of ferricyanide by thylakoid membranes, was significantly lower than that of a sensitive (S) biotype. The discrepancy in the rate of photosynthesis was confirmed by measuring carbon dioxide fixation at the whole plant level. Dry matter accumulation by the R biotype was exceeded by the S biotype. Superoxide production by nontreated, illuminated thylakoid membranes was also lower in the R biotype, and the increase in oxidative stress that resulted from paraquat treatment was greater in the S biotype. Paraquat-treated thylakoids of the R biotype and nontreated thylakoids of the S biotype had similar rates of O − 2 production. The low rates of electron transport and correspondingly low levels of oxidative stress in nontreated thylakoids of the R biotype imply that paraquat resistance in S. americanum is due to reduced photosynthetic electron flow.

Studies were conducted to probe the nature of paraquat resistance in Solanum americanum (American black nightshade). This initial characterization was focused on the comparative examination of paraquat uptake, translocation, and compartmentalization of a paraquat-resistant (R) biotype and a paraquat-sensitive (S) biotype. Uptake of paraquat by whole plants of both biotypes was equivalent. No paraquat was translocated out of the treated leaf of the S biotype. However, the R biotype translocated paraquat both acropetally and basipetally. As for whole plants, paraquat uptake by leaf discs did not differ with biotype. Paraquat efflux from leaf discs of both biotypes was biphasic with the rapid phase occurring during the first 10 min. Paraquat efflux occurred more rapidly in the S biotype. A compartmentalization study showed that 37 and 22% of the absorbed paraquat was located in an unbound state in the apoplast of the S and R biotypes, respectively. Although the R biotype adsorbed 15% of the paraquat compared with 12% in the S biotype, rapid sequestration of paraquat by apoplastic adsorption is not a plausible explanation of resistance in S. americanum since there was no biotypic difference in the percentage of paraquat found in the cytoplasm. Paraquat stimulated greater ethane production in the S biotype. These results support a primary mechanism of paraquat resistance in S. americanum that is located within the protoplast.

The tobacco aphid, Myzus nicotianae Blackman, is a major pest of tobacco in the United States. It was separated from the green peach aphid, M. persicae (Sulzer), and described as a new species in 1987. Information on its host range is limited because the two species are so similar. Therefore, the performance of the tobacco aphid was studied on 28 potential host plants in six families. Numbers of offspring, age at first reproduction, longevity, weight, and percentage reproducing were compared. Tests were conducted on excised leaves or leaf disks maintained in Petri dishes in an environmentally-controlled chamber. Myzus nicotianae reproduced on hosts in the families Asteraceae, Convolvulaceae, Cruciferae, Malvaceae, and Solanaceae, but not on Spinacia in Chenopodiaceae. Myzus nicotianae generally reproduced most quickly, was heaviest, and produced the most nymphs on tobacco, Nicotiana tabacum L., and American black nightshade, Solanum americanum (Solanaceae). Performance also was good on Capsicum and S. dulcamara L. (Solanaceae). Aphids exhibited fair-to-good performance on three species of Ipomoea (Convolvulaceae), Datura, and Physalis (Solanaceae); Raphanus and two species of Brassica (Cruciferae); and Abelmmoschus (Malvaceae). Performance was fair on two species of Ipomoea, three species of Solanum, Lactuca (Asteraceae), and several Brassica. Longevity was short, and very few offspring were produced on Gossypium (Malvaceae) and Lycopersicon (Solanaceae). This study indicates that M. nicotianae does well on several species in five plant families that contain important crop and weed species.

Sensitivity of 49 tomato cultivars and four weeds to DPX-E9636 was determined in greenhouse experiments. Cultivar tolerance varied from completely tolerant to intolerant. The most efficacious application method in greenhouse experiments was early POST for the weeds tested (yellow nutsedge, prostrate eclipta, and paraquat-resistant and -sensitive American black nightshade). Paraquat-resistant American black nightshade was 123 times more sensitive to DPX-E9636 than the paraquat-sensitive biotype. Under field conditions and at 0, 36, or 72 g ai/ha applied one week after transplanting, tomato cultivars showed no response to DPX-E9636 in visual vigor ratings 3 wk treatment, or in shoot fresh or dry weight 4 wk after treatment.

Potato yellow mosaic virus (PYMV) is one of the most important tomato begomoviruses in the Caribbean basin (Morales et al ., 2006). In Venezuela, a recent survey showed that PYMV is the most widespread and prevalent begomovirus in tomato…

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:51:57Z No. of bitstreams: 1 S0100-83582010000200008.pdf: 622239 bytes, checksum: b68fcb198e7a070900f8f9e28872f6a6 (MD5) Made available in DSpace on 2013-08-22T18:51:57Z (GMT). No. of bitstreams: 1 S0100-83582010000200008.pdf: 622239 bytes, checksum: b68fcb198e7a070900f8f9e28872f6a6 (MD5) Previous issue date: 2010-06-01 Made available in DSpace on 2013-09-30T17:50:14Z (GMT). No. of bitstreams: 2 S0100-83582010000200008.pdf: 622239 bytes, checksum: b68fcb198e7a070900f8f9e28872f6a6 (MD5) S0100-83582010000200008.pdf.txt: 26462 bytes, checksum: d1f9395e885febe5ab7a4818f4c3fb2a (MD5) Previous issue date: 2010-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:13:26Z No. of bitstreams: 2 S0100-83582010000200008.pdf: 622239 bytes, checksum: b68fcb198e7a070900f8f9e28872f6a6 (MD5) S0100-83582010000200008.pdf.txt: 26462 bytes, checksum: d1f9395e885febe5ab7a4818f4c3fb2a (MD5) Made available in DSpace on 2014-05-20T13:13:26Z (GMT). No. of bitstreams: 2 S0100-83582010000200008.pdf: 622239 bytes, checksum: b68fcb198e7a070900f8f9e28872f6a6 (MD5) S0100-83582010000200008.pdf.txt: 26462 bytes, checksum: d1f9395e885febe5ab7a4818f4c3fb2a (MD5) Previous issue date: 2010-06-01 Um experimento em casa de vegetação foi conduzido entre novembro de 1995 e abril de 1996 na FCAV/UNESP, Brasil, objetivando estudar a produção de matéria seca, a distribuição e o acúmulo de macronutrientes por Solanum americanum - uma importante planta infestante de culturas anuais e perenes no Brasil. As plantas foram cultivadas em vasos de 7 L com substrato de areia, os quais foram irrigados diariamente com solução nutritiva de Hoagland & Arnon. O delineamento experimental foi inteiramente casualizado, com quatro repetições. Os tratamentos corresponderam às épocas de avaliação, em intervalos de 14 dias, iniciando-se 21 dias após a emergência (DAE). em cada avaliação, as plantas de quatro vasos foram analisadas quanto à produção de matéria seca e ao conteúdo de macronutrientes. S. americanum apresentou pequeno acúmulo de matéria seca e de macronutrientes no início da fase experimental. Esses acúmulos intensificaram-se após 77 DAE, atingindo o máximo valor teórico aos 142, 142, 164, 149, 140, 149 e 152 DAE, para matéria seca, N, P, K, Ca, Mg e S, respectivamente. K e N foram os macronutrientes acumulados em maior quantidade por plantas de S. americanum. A greenhouse trial was carried out from November 1995 to April 1996 at FCAV/UNESP, Brazil, aiming to study the dry matter production and the accumulation and distribution of macronutrients in Solanum americanum, an important weed for annual and perennial crops in Brazil. The plants were grown in seven liter pots with sand substrate, irrigated daily with Hoagland & Arnon nutrient solution. The experimental design was completely randomized with four replicates. The treatments corresponded to evaluation times at 14 day intervals, beginning 21 days after emergence (DAE). In each evaluation, the plants of four pots were analyzed for dry matter production and macronutrient content. S. americanum had a small dry matter and macronutrient accumulation at the beginning of the experimental stage, increasing after 77 DAE and reaching the maximum theoretical value at 142, 142, 164, 149, 140, 149 and 152 DAE, for dry matter, N, P, K, Ca, Mg, and S, respectively. K and N were the most accumulated macronutrients for S. americanum plants. Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Dep. de Biologia Aplicada à Agropecuária UNESP FCAV Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Dep. de Biologia Aplicada à Agropecuária UNESP FCAV

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:51:56Z No. of bitstreams: 1 S0100-83582010000100006.pdf: 202973 bytes, checksum: ffb786814bed008000982867f95d0358 (MD5) Made available in DSpace on 2013-08-22T18:51:56Z (GMT). No. of bitstreams: 1 S0100-83582010000100006.pdf: 202973 bytes, checksum: ffb786814bed008000982867f95d0358 (MD5) Previous issue date: 2010-01-01 Made available in DSpace on 2013-09-30T17:49:45Z (GMT). No. of bitstreams: 2 S0100-83582010000100006.pdf: 202973 bytes, checksum: ffb786814bed008000982867f95d0358 (MD5) S0100-83582010000100006.pdf.txt: 25881 bytes, checksum: d239e1fd2721d69cb4e9c9fa1c28f16b (MD5) Previous issue date: 2010-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:13:20Z No. of bitstreams: 2 S0100-83582010000100006.pdf: 202973 bytes, checksum: ffb786814bed008000982867f95d0358 (MD5) S0100-83582010000100006.pdf.txt: 25881 bytes, checksum: d239e1fd2721d69cb4e9c9fa1c28f16b (MD5) Made available in DSpace on 2014-05-20T13:13:20Z (GMT). No. of bitstreams: 2 S0100-83582010000100006.pdf: 202973 bytes, checksum: ffb786814bed008000982867f95d0358 (MD5) S0100-83582010000100006.pdf.txt: 25881 bytes, checksum: d239e1fd2721d69cb4e9c9fa1c28f16b (MD5) Previous issue date: 2010-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) O tomateiro (Lycopersicum esculentum) é uma das mais importantes hortaliças produzidas no mundo, porém sua produtividade pode ser reduzida em função da convivência com Solanum americanum (maria-pretinha). O objetivo desta pesquisa foi avaliar o efeito da adubação na relação de interferência intra e interespecífica entre plantas de tomateiro e S. americanum. Duas plantas em condições de convivência intra e interespecífica, por espécie, foram plantadas em vasos e adubadas com 13, 18 e 24 g de 4-14-8 por vaso, sendo avaliadas características de crescimento de ambas as espécies aos 90 dias após o transplante das plantas. A adubação com 4-14-8 estimulou o desenvolvimento da área foliar e da massa seca de caules, folhas e frutos de S. americanum, além da área foliar e da massa seca de folhas e frutos do tomateiro. A convivência interespecífica proporcionou maior altura de plantas de S. americanum, bem como menor altura e massa seca de folhas e frutos do tomateiro. Houve interação dos fatores adubação e convivência somente para o tomateiro, sendo a altura e a massa seca de folhas da cultura influenciadas negativamente quando submetidas às maiores doses de adubo e à competição com S. americanum. Tomato (Lycopersicum esculentum) is one of the leading vegetable crops grown worldwide, but its productivity may be reduced due to coexistence with Solanum americanum (black nightshade). This work aimed to evaluate the effect of fertilization on intra- and inter-specific interference between tomato and S. americanum plants. Two plants in intra- and inter-specific coexistence conditions of both species were planted in pots and fertilized with 13, 18 and 24 g of 4-14-8 per pot to evaluate the growth characteristics of both species at 90 days after transplanting. The 4-14-8 fertilization stimulated the development of the leaf area and dry mass of stems, leaves and fruit of S. americanum, consequently and equally influencing the leaf area and leaf and fruit dry mass of tomato. The inter-specific coexistence allowed a greater height of S. americanum plants, promoting a lower height and dry mass of leaves and fruit of the tomato plants. There was interaction between the factors fertilization and coexistence only for the tomato plant. Crop height and leaf dry mass were affected negatively by S. americanum competition and application of higher fertilizer rates. Universidade Estadual de São Paulo Faculdade de Ciências Agrárias e Veterinárias Dep. de Biologia Aplicada à Agronomia UNESP FCAV Dep. de Biologia Aplicada à Agropecuária UNESP FCAV Dep. de Biologia Aplicada à Agropecuária

O trabalho teve como objetivo o estudo fitossociológico e a determinação dos períodos críticos de interferência da comunidade infestante na cultura da beterraba transplantada. Os tratamentos consistiram em períodos semanais crescentes de convivência e de controle da comunidade infestante, a partir da segunda semana após o transplante das mudas. A comunidade infestante foi avaliada por meio do número de indivíduos e da massa seca acumulada correspondente, para cada população de planta daninha e período avaliado. A cultura foi colhida 91 dias após o transplante das mudas, quando se avaliou o diâmetro transversal e a produtividade comercial das raízes. As principais plantas daninhas encontradas foram Amaranthus viridis, Coronopus didymus, Galinsoga parviflora, Nicandra physaloides e Solanum americanum. As populações encontradas apresentaram alta similaridade entre si. O período anterior à interferência e o período total de prevenção à interferência foram 51 e 35 dias após o transplante das mudas, respectivamente. A produção da beterraba mantida no limpo foi 44,92 t ha-1, e a redução devido à interferência das plantas daninhas por todo o ciclo foi mais de 70%. The objective of this research was to study the phytosociological and critical interference periods of weed communities on transplanted beets. The treatments consisted of increasing weekly weedy/weed-free periods, starting at the second week after seedling transplanting. The weed community was evaluated based on the number of individuals and their corresponding accumulated dry mass, for each weed population and evaluated period. The beets were harvested 91 days after transplanting, followed by evaluation of the cross-sectional diameter and marketable yield. The weed communities were composed mainly of Amaranthus viridis, Coronopus didymus, Galinsoga parviflora, Nicandra physaloides and Solanum americanum, and the populations were very similar. The period before weed interference and the total period of weed interference prevention were 51 and 35 days after transplanting, respectively. The beet yield in the weed-free treatment was 44.92 t ha-1 and the reduction from weed interference was more than 70%.

O objetivo deste trabalho foi estudar a anatomia das folhas das espécies de plantas daninhas Nicandra physaloides (joá-de-capote), Solanum viarum (joá-bravo), Solanum americanum (maria-pretinha) e Raphanus raphanistrum (nabiça), visando obter melhor entendimento sobre as barreiras que cada espécie impõe à penetração dos herbicidas. Folhas completamente expandidas do terceiro ao quinto nó foram coletadas de plantas de ocorrência espontânea no campo. Das folhas de cada espécie foram obtidas três amostras da região central mediana, com aproximadamente 1 cm2, as quais foram utilizadas em estudos da estrutura, clarificação e nas observações em microscópio eletrônico de varredura (MEV). Todas as espécies avaliadas são anfiestomáticas. O principal obstáculo foliar à penetração de herbicidas constatado em N. physaloides foi a alta densidade tricomática. Já em relação a S. viarum, baixa densidade estomática na face adaxial, alta densidade tricomática, presença de placas de cera epicuticular e grande espessura das cutículas foram as principais barreiras detectadas. S. americanum apresentou como principais obstáculos foliares à penetração de herbicidas a baixa densidade estomática na face adaxial e a grande espessura da cutícula da face adaxial, sendo esta última a única barreira constatada nas folhas de R. raphanistrum. This research aimed to study the leaf anatomy of the weed species Nicandra physaloides, Solanum viarum, Solanum americanum and Raphanus raphanistrum to acquire a better understanding of the barriers each species imposes upon herbicide penetration. Completely expanded leaves from the third to the fifth node were collected from plants spontaneously occurring in field. Three samples, with approximately 1 cm2, were taken at the central portion of the leaves in each species. These samples were used in structural studies, clarification and observation using a scanning-electron microscope (SEM). All species are amphistomatic. The main leaf barrier against herbicide penetration in N. physaloides was high trichomic density, whereas in S. viarum, the main barriers were low stomatic density in the adaxial side, high trichomic density, high content of epicuticular wax and high cuticle thickness. S. americanum's main leaf barriers were low stomatic density and high cuticle thickness in the adaxial side. High cuticle thickness in the adaxial side was the only barrier observed in leaves of R. raphanistrum.

In October 2005 and September 2006, two outbreaks of bacterial wilt occurred in the south and north (90 and 95 m above sea level, respectively) of Mauritius, respectively, on different potato cultivars in seed potato fields. Symptoms were reported at harvest when profuse creamy exudates were observed oozing from the eyes of tubers. The brown appearance of the vascular rings, which was accompanied by extensive maceration, suggested potato brown rot. Severe symptoms with complete rotting of vascular tissues and oozing from heel ends of tubers were commonly observed. Ralstonia solanacearum has been regularly encountered for decades around the island, but before October 2005, all isolates belonged to Race 1 biovar 3. The pathogen was isolated from samples collected from the two outbreaks by plating on Kelman's medium amended with 100 ppm of polymixin B sulfate. Thirty-three isolates were obtained from stems and tubers of potato cvs. Spunta, Delaware, Atlantic, and Belle Isle, from soil samples, and weed hosts Solanum americanum, Lycopersicon pimpinellifolium, and Oxalis latifolia. These weeds, however, did not show symptoms of wilting or vascular browning, although oozing was observed when the stems were cut and placed in water. When reinoculated in tomato bioassays, 17 tested isolates caused wilting and were successfully reisolated, confirming Koch's postulates. All colonies were positive for Ralstonia by the Spot√Check LF test (Adgen, Ayr, UK) and by indirect plate-trapped antigen-ELISA (Agden) using monoclonal antibodies raised against Race 3 strains. Isolate biovar was determined by performing standard biochemical tests (1). All 33 isolates metabolized maltose, lactose, and cellobiose but not trehalose and the hexose alcohols dulcitol, mannitol, and sorbitol, thereby showing that they all belong to biovar 2 of Andean phenotype 2A. The final identification was performed by a PCR test using Race 1 specific primers PSIF and PSIR (4) and Race 3 specific primers 630 and 631 (3). The Race 3 specific band was amplified from all isolates while the Race 1 specific band was not. Assignment to biovar 2 was independently confirmed by CABI Identification Service, UK. R. solanacearum R3bv2 is distributed worldwide, occurring in temperate regions, subtropical areas, and at higher altitudes in the tropics, reportedly because of its lower temperature optimum. Brown rot is often disseminated by seed potato tubers that are latently infected by the pathogen (2). Seed potato fields typically undergo a 7-year crop rotation with sugar cane in Mauritius, so it is unlikely that the pathogen was present in these fields for a long time. The infection of weeds in these same fields was probably due to the movement of water contaminated by tuber exudates. Epidemiological results suggest that R. solanacearum R3bv 2A was recently introduced into Mauritius, although its origin is not known. Generally, R3bv2 strains around the world appear to be clonal and seem to be spreading rapidly into previously uninfested areas such as Mauritius. Stronger standards for seed potato testing may be needed to prevent a wide dissemination of R3bv2. References: (1) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (2) A. C. Hayward et al. Page 420 in: Bacterial Wilt Disease: Molecular and Ecological Aspects. P. Prior et al., eds. Springer, Berlin, 1998. (3) M. Fegan et al. Page 19 in: Bacterial Wilt Disease: Molecular and Ecological Aspects. P. Prior et al., eds. Springer, Berlin, 1998. (4) Y.-A. Lee et al. Appl. Environ. Microbiol. 67:3943, 2001.

The absorption and metabolism of C14-metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H) one] was studied in barnyard grass (Echinochloa crusgalli (L.) Beauv.) grown in soil or aqueous solution and in American nightshade (Solanum americanum L.) grown in aqueous solution containing radioactive metribuzin. Barnyard grass (BG) plants did not lose any radioactive CO2 in respiration and the total dry weight per plant was not affected by metribuzin. A major portion of the radioactivity recovered from BG plants was found in a compound which had approximately the same chromatographic properties as standard metribuzin. A negative correlation was obtained between the total radioactivity of metribuzin per gram of dry matter and age of both BG and American nightshade (AN) plants, but the degradation of metribuzin was significantly higher in AN than BG. Both plant species gained tolerance to metribuzin with age.

Eight accessions of weedy nightshades representing five species were evaluated for response to four herbicides applied preemergence in growth chamber studies and four herbicides applied postemergence in greenhouse studies. Species differed in susceptibility to all herbicides evaluated. The largest differences were found with postemergence appli- cations of chlorsulfuron {2 -chloro-N- ( ((4-methoxy-6-meth- yl -1, 3,5 -triazin- 2-yl)amino) carbonyll benzenesulfonamide}; hairy nightshade (Solanum sarrachoides Sendt. #3 SOLSA) was relatively susceptible, but eastern black nightshade (S. ptycanthum Dun.) was very tolerant. S. ptycanthum, how- ever, was one of the more susceptible species. It was always more susceptible than black nightshade (S. nigrum L. # SOLNI) to all other herbicides evaluated. Additional index words. Acifluorfen, alachlor, bentazon, chIoramben, chlorsulfuron, PPG-884, metolachlor, RH- 8817, Solanum ptycantbum, Solanum americanum, Solanum sarrachoides, Solanum interius, SOLNI, SOLSA.

Information from taxonomic treatments and comparisons of accessions from numerous locations grown in the field and greenhouse were combined and summarized to produce a key and descriptions of common agricultural nightshades in North America (Solanum americanumMill.,S. nigrumL.,S. ptycanthumDun., andS. sarrachoidesSendt.). Quantitative and qualitative descriptions of key characters and photographs of important morphological structures are provided to facilitate field identification. Problems with nomenclature among these species are discussed, and a system of common names that would standardize usage is proposed.

Two forms of Solanum nigrum subsp. nigrum, two forms of S. nigrum subsp. schultesii, S. americanum, S. chenopodioides, S. sarrachoides, S. scabrum, S. villosum subsp. villosum and S. villosum subsp. puniceum were grown in pots for over 4 months to measure their effect on numbers of potato cyst–nematodes, Globodera rostochiensis and G. pallida, in the soil. No Solanum tested significantly reduced numbers of G. rostochiensis or G. pallida. Solanum americanum, S. sarrachoides and S. villosum puniceum increased numbers of G. pallida slightly.