Competitividade do feijoeiro-comum com o capim-marmelada [Brachiaria plantaginea (link) hitch.]

Methodologies of competitive interaction quantification between weeds and crops are not widely elucidated and compared in the literature. The competitive ability of common-bean (Phaseolus vulgaris) relative to alexandergrass (Brachiaria plantaginea) was assessed and two approaches of replacement series experiment analysis were compared. The response of the species to the presence of each other at different densities and proportion was evaluated. Replacement series at total densities of 625, 816 and 1,111 plants m-2 were performed at the proportions of common-bean:alexandergrass of 100:0 (pure stand of common-bean), 75:25, 50:50, 25:75 and 0:100% (pure stand of alexandergrass), at four replicates in a randomized block design. Data analyses were performed by the qualitative compared to the quantitative approach. The quantitative approach provided larger number of information than did the qualitative approach, and indicated that there was intraspecific competition among common-bean plants, and a minimum of interspecific competition from alexandergrass. There was no intraspecific competition among alexandergrass plants, being the crop effect on the weed larger than the effect among alexandergrass plants. The ecological niche differentiation was partial, since the crop intraspecific competition was larger than the interspecific, and the last one was negligible, at the same time that the weed interspecific competition was larger than the intraspecific. Common-bean, as a competitor species, is superior to alexandergrass.As metodologias de quantificação das interações competitivas entre plantas cultivadas e daninhas não estão amplamente elucidadas e comparadas na literatura. A competitividade da cultura de feijão-comum (Phaseolus vulgaris) em relação ao capim-marmelada (Brachiaria plantaginea) foi avaliada pela comparação entre o método qualitativo e um método quantitativo de análise de resultados. A resposta de cada espécie à presença da outra foi obtida em três séries substitutivas nas densidades totais de 625, 816 e 1.111 plantas m-2. Em cada série, as proporções entre plantas de feijão-comum e de capim-marmelada foram de 100:0 (estande puro de feijão-comum), 75:25, 50:50, 25:75 e 0:100% (estande puro de capim-marmelada). Os tratamentos foram dispostos em delineamento experimental de blocos ao acaso, com quatro repetições. O método quantitativo proporcionou maior número de informações que o qualitativo e evidenciou que para o feijão-comum houve competição intra-específica e mínima competição interespecífica do capim-marmelada. Não houve competição entre as plantas de capim-marmelada, sendo que, o efeito da cultura sobre a planta daninha foi maior que o efeito competitivo entre as plantas de capim-marmelada. A diferenciação de nicho ecológico foi parcial uma vez que a competição intra-específica da cultura foi maior que a interespecífica, sendo a última desprezível, ao mesmo tempo que a competição interespecífica sobre a planta daninha foi maior que a intra-específica. O feijão-comum, como espécie competidora, é superior ao capim-marmelada

Harmonic analysis applied to monthly mean temperatures date of Campinas, SP

O presente trabalho tem como objetivo estudar as temperaturas médias mensais de Campinas, SP, através de seus componentes harmônicos e sintetizar aqueles componentes que se mostrarem significativos. Aos dados de temperaturas médias mensais aplicou-se a análise harmônica para cada ano e para o conjunto total dos anos, ajustados a um ano médio referentes ao Município de Campinas, SP, num período de 91 anos (1890 a 1980). Como os dados originais de temperaturas médias não apresentaram as pressuposições da análise de variância, estudou-se uma transformação conveniente aos dados e verificou-se que Y = X1,84216 satisfaz estas condiçoes. A estabilidade dos componentes harmônicos das temperaturas médias mensais foi testada pelo método da análise de variância, revelando-se significativas as ondas com período anual, semestral e trimestral. A equação de regressão obtida pelos resultados da análise harmônica do total dos 91 anos foi ajustada a um ano médio e é apresentada por: Ŷt = 257,5209 + 67,3803 sen (30° t + 93,1827° + + 16,0434 sen (60° t + 331,5798°) + + 2,4962 sen (120° t + 209,0092°). A equação ora determinada explica 99,8% das variações devidas a meses. Somente a onda anual explicou praticamente 94,5%. Estimou-se um máximo durante o mês de fevereiro (Ŷ1 = 321,03) equivalente à temperatura de Ŷ1 = 22,94° e um mínimo durante o mês de julho (Ŷ6 = 181,40), equivalente à temperatura de Ŷ6 = 16,83°.The purpose of the present paper was to study the monthly mean temperatures of Campinas Municipality (SP) through their harmonic components and to synthesize those components which showed significance. It was applied the harmonic analysis to the monthly mean temperatures of each year and to the total of 91 years adjusted to one average studied (1890 to 1980). As the original data of mean temperatures didnt showed the presuppositions of the analyses of variance, a convenient transformation was calculated and it was found that Ŷ = X1.84216 satisfied these conditions. The stability of the harmonic components of the monthly mean temperatures was tested through the method of analysis of variance showing significant those waves with periods of three, six and twelve months. The regression equation obtained by the results of the harmonic analysis from the total of 91 years studied was adjusted to one year average and is presented: Ŷt = 257.5209 + 67.3803 sen (30° t + 93.1827°) + + 16.0434 sen (60° t + 331,5798°) + + 2.4962 sem (120° t + 209.0092°). The model here determinate explains 99.8% of the monthly variations. The one year period wave explained itself 94.5% of those variations. During february it was estimated a maximum of Ŷ1 = 321 .03 equivalent to the temperature Ŷ1 = 22,94° and during july a minimum of Ŷ6 = 181.40, equivalent to the temperature Ŷ6 = 16.83°

Emergência do capim-marmelada em duas regiões do Estado do Paraná

The objective of this experiment was to determine the periodicity and intensity of emergence as well as the survival of Brachiaria plantaginea (Link) Hitch. seeds in two regions of Paraná State, Brazil. A randomized complete block in factorial design 2 x 3 x 2, with three replications was used. The factors studied were: seed survival in the soil; seed burial depth, and soil management. Ceramic cylinders were installed in a wheat/soybean rotation under field conditions. The cylinders were filled with sterilized soil up to the limits established for the depth of seed distribution. A plastic net was placed into the cylinders to separate the treated soil from the untreated soil used to fill the cylinders. Three hundred seeds of B. plantaginea were mixed to the untreated soil. The weed seedlings were counted every 14 days and pulled out of the cylinders. The highest peak of B. plantaginea emergence occurred in the summer, coincidently with the period of highest temperature and rainfall. There was more emergence in tilled than in no-tilled soil. The highest emergences occurred in the smallest depth. The germination percentage of the seeds removed from the cylinders was higher in one year than two-year buried seeds.O objetivo do trabalho foi determinar a periodicidade e intensidade da emergência, bem como a sobrevivência de sementes de capim-marmelada (Brachiaria plantaginea (Link) Hitch.) em duas regiões do Estado do Paraná. O delineamento experimental foi o de blocos ao acaso, no esquema fatorial 2 x 3 x 2, com três repetições. Os fatores estudados foram: tempo de permanência e profundidade de distribuição das sementes no solo, e manejo do solo. Foram utilizados cilindros de cerâmica instalados em condições de campo, numa rotação trigo/soja. Os cilindros receberam solo esterilizado, até os limites estabelecidos para a profundidade de distribuição das sementes. Nessas profundidades foram colocadas telas de plástico, sobre as quais foram acrescentados volumes complementares de solo contendo 300 sementes de B. plantaginea. A cada 14 dias, a partir da instalação do experimento, foram feitas contagens e arrancadas as plântulas emergidas nos cilindros. As sementes recuperadas dos cilindros foram submetidas a testes de germinação em laboratório. Os maiores picos de emergência ocorreram no verão, coincidindo com as elevações da temperatura e precipitação pluvial. Houve maior emergência no tratamento com revolvimento do solo. As maiores emergências ocorreram quando as sementes estavam em profundidades menores. A germinação das sementes que permaneceram no solo por um ano foi mais intensa do que a das que permaneceram por dois anos

Performance of 'Okitsu' Satsuma Mandarin on nine rootstocks

Mandarins have become increasingly valued as citrus fruits for the fresh market due to the easy peeling, attractive flavor, and health and nutritional properties. Plant growth and yield, and characteristics of fruits of 'Okitsu' Satsuma mandarin (Citrus unshiu Marc.) trees grafted on nine rootstocks were evaluated in Londrina, northern Paraná, Brazil. The rootstocks were: 'Rangpur' lime (Citrus limonia Osb.); 'Cleopatra' (Citrus reshni hort. ex Tanaka) and 'Sunki' mandarins (Citrus sunki hort. ex Tanaka); 'C-13' [Citrus sinensis × Poncirus trifoliata (L.) Raf.] and 'Carrizo' citranges [C. sinensis × P. trifoliata (L.) Raf.]; 'Volkamer' lemon (Citrus volkameriana V. Ten. & Pasq.); trifoliate orange [P. trifoliata (L.) Raf.; 'Caipira DAC' sweet orange [C. sinensis (L.) Osb.] and 'Swingle' citrumelo [Citrus paradisi Macfad. cv. Duncan × P. trifoliata (L.) Raf.]. The highest plant growth was for the trees on 'Cleopatra' mandarin and 'Caipira DAC' sweet orange. In contrast, the smallest size was for the trees on 'Volkamer' lemon and trifoliate orange. The largest difference between the trunk diameter below and above the grafting point was induced by 'Swingle' citrumelo. Trees of 'Okitsu' Satsuma mandarin on 'Swingle' citrumelo presented the highest yield, while 'C-13', 'Carrizo', 'Sunki', and 'Swingle' induced the largest fruit masses. With regard to fruit characteristics, 'Carrizo' and trifoliate orange induced the best ratio and juice content. Based on theoretical values, 'Rangpur' lime and 'Volkamer' lemon induced the lowest yield

Trifoliate Orange-Related Rootstocks Enhance the Horticultural Performance of ‘Shamouti’ Sweet Orange under Humid Subtropical Condition

The narrow genetic pool for both scions and rootstocks used in the Brazilian orchards makes the citrus industry vulnerable to biotic and abiotic threats. Orchard diversification by using different scion–rootstock combinations is an efficient measure to promote citrus protection, through increasing the level of genetic diversity. In this paper, we report the horticultural performance of the mid-season ‘Shamouti’ sweet orange grafted on five different rootstocks (‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘C-13′ citrange, and ‘Cleopatra’ and ‘Sunki’ mandarins) in a long-term experiment (2007–2017) under the Brazilian humid subtropical condition. ‘Shamouti’ trees were assessed for vegetative growth, yield, and fruit quality. Additionally, a study was performed to estimate tree density and yield for new plantings. Trees grafted on ‘Swingle’ and ‘C-13′ rootstocks were less vigorous and more productive, with cumulative yields of >480 kg per tree, allowing high-density plantings (363–337 trees·ha−1). Trees on ‘Cleopatra’, ‘Sunki’, and ‘Rangpur’ were the most vigorous among the tested rootstocks, with tree heights > 4.20 m. However, they took longer to establish in the field, evidenced by their growth progress. These combinations also displayed the lowest tree density estimation (≤311 trees·ha−1). Trees on ‘Cleopatra’ exhibited the lowest cumulative yield (255 kg per tree). Although some significant differences were found for fruit quality, all rootstock combinations produced fruit of suitable quality, attending the commercial grading. Our findings evidence the potential of the trifoliate orange-related rootstocks ‘C-13′ and ‘Swingle’ to be used as promising rootstocks for ‘Shamouti’ cultivation in the humid subtropics, promoting genetic diversification and enhancing yield and tree density in new orchards

Citrus tristeza disease severity and agronomiC performanCe of 'pÊra' sweet orange CuLtivars and seLeCtions in the north and northwest regions of the state of paraná, BraziL 1

aBstraCt -'Pêra' sweet orange is the most important citrus cultivar in Brazil, but it is highly susceptible to Citrus tristeza virus (CTV), the causal agent of citrus tristeza disease. In this study, we evaluated the severity of citrus tristeza disease and its relation with the agronomic performance of seven cultivars and six selections of 'Pêra' sweet orange under field conditions in the North and Northwest regions of the State of Paraná, Brazil. The citrus tristeza disease severity was determined based on symptoms of stem pitting. The vegetative growth assessed in trees of all four locations for the 2012 season, and in two field plots for the 2011, 2012 and 2013 harvests, respectively. The cultivar 'IPR 153' (Bianchi) had the best performance concerning stem pitting severity, while Selection 27 was among the ones with the highest rate of vegetative growth. Further, Selections 27 and 12, and the cultivar 'Vimusa' had the largest fruit yields. Based on correlation analysis, stem pitting symptoms severity was negatively correlated with vegetative growth and fruit yield. Furthermore, environmental conditions may have played an important role in the severity of citrus tristeza disease and consequently on the agronomic performance of the cultivars and selections of 'Pêra' sweet orange in the North an