-A reduction in herbicide use is one of modern agriculture's main interests and several alternatives are being investigated with this objective, including intercropping. Gliricídia (Gliricidia sepium) mulch has no allelopathic effect on corn or beans but significantly decreased the population of some weed species. The objective of this study was to evaluate green ear and grain yield in corn cultivars as a response to weed control achieved via intercropping with gliricidia. A completely randomized block design with five replicates and split-plots was used. Cultivars AG 1051, AG 2060, BRS 2020, and PL 6880 (assigned to plots) were submitted to the following treatments: no hoeing, hoeing (performed at 20 and 40 days after sowing the corn), and corn intercropped with gliricidia. Gliricidia was grown in a transplanting system to ensure uniform germination and fast establishment in the field. Seeding was made in 200-cell trays with one seed per cell (35 mL volume). The plants emerged two to three days after sowing and were transplanted to a permanent site two to three days after emergence. Corn was sown on the same day gliricidia was transplanted. Sixteen weed species occurred at different frequencies, with uneven distribution in the experimental area. Cultivars AG 1051 and AG 2060 were the best with reference to most characteristics employed to evaluate green corn yield. Cultivar AG 1051 provided the highest grain yield. The highest green ear yield and grain yield values were obtained with hoeing. However, the fact that intercropped plots showed intermediate yield between the values obtained for hoed and non-hoed plots indicates that gliricidia was beneficial to corn, and exerted a certain level of weed control.Keywords: Zea mays, Gliricidia sepium, cultivars, green corn, grain yield.RESUMO -Um dos principais interesses da agricultura moderna é a redução no uso de herbicidas; para isso, diversas alternativas estão sendo investigadas, inclusive a consorciação. A cobertura do solo com ramos de gliricídia (Gliricidia sepium) não tem efeito alelopático sobre o milho ou feijão, mas diminui significativamente a população de algumas espécies de plantas daninhas. O objetivo deste estudo foi avaliar os rendimentos de espigas verdes e de grãos de cultivares de milho, em resposta ao controle de plantas daninhas, por meio da consorciação com gliricídia. Utilizou-se o delineamento de blocos ao acaso com parcelas subdivididas e cinco repetições. Os cultivares 1051, AG 2060, BRS 2020 e PL 6880 (atribuídos às parcelas) foram submetidos aos seguintes tratamentos: sem capina, duas capinas (realizadas aos 20 e 40 dias após a semeadura) e consorciação com gliricídia. Esta planta foi cultivada em um sistema de transplantio, para garantir germinação uniforme e rápido estabelecimento no campo. A semeadura foi feita em bandejas de 200 células, com uma semente por célula (volume de 35 mL). As plantas emergiram dois a três dias após a semeadura e foram transplantadas para o local definitivo dois a três dias após a emergência. O milho...
ResumoEste trabalho teve por objetivo a elaboração de um índice que permita a seleção acurada de cultivares de milho com aptidão tanto para a produção de minimilho quanto para de milho verde. Os experimentos foram realizados no ano agrícola de 2002/2003 com dez cultivares comerciais de milho em dois experimentos. O primeiro quanto ao rendimento de minimilho e o segundo quanto ao de milho verde, delineados em blocos ao acaso com três repetições. A importância relativa dos caracteres estudados foi estimada por meio do método dos componentes principais e o agrupamento destes foi realizado pela análise de fatores. O seguinte índice foi obtido: I = 0,031 NEM + 0,013 MEM + 0,207 NEV + 0,243 MEV -0,16 AP -0,058 MFP, em que, NEM, MEM, NEV, MEV, AP e MFP são o número e a massa de espigas empalhadas de minimilho e de milho verde, altura de planta e massa de pendão fresca respectivamente. Esse índice indicou que híbridos triplos DKB 350, AG 8080 e AG 6690 e o duplo DKB 747 revelaram os melhores desempenhos para as produções de minimilho e de milho verde.Palavras-chave: componentes principais, análise de fatores, Zea mays L. Selection index of maize cultivars with twice fitness: baby corn and green corn AbstractThis study aimed to propose an index for allowing accurate selection of corn hybrids for producing both baby corn and green corn. The experiments were carried out during the 2002/2003 growing season and ten commercial corn cultivars were evaluated in two experiments, the first for evaluating the yield of baby corn and the second for the yield of green corn. Both experiments were designed in randomized blocks, with three replications. The relative importance of traits was estimated by the principal components method and the cluster analysis was carried out. The following index was obtained: I = 0.031 NEM + 0.013 MEM + 0.207 NEV + 0.243 MEV -0.16 AP -0.058 MFP, being considered the variables: number and mass of husked ears for baby corn (NEM and MEM) and green corn (NEV and MEV), plant height (AP) and the fresh mass of tassel (MFP). This index indicated that the three-way cross hybrids DKB 350, AG 8080 and AG 6690 and the double-cross hybrids DKB 747 have the best performances for the production of baby corn and green corn.
-In Mata Fresca, an area located on the border of the states of Rio Grande do Norte and Ceará, in Brazil, small farmers have a source of income from the production of cassava roots, using planting densities of around 5,000 plants ha -1 . This procedure might be helping to limit higher yields of the roots, since some studies have shown that it is possible to obtain higher yields of cassava using higher densities. The objective of this study was to evaluate the root yield and other characteristics of the cassava, as a response to planting density. The Vermelhinha cultivar was submitted to planting densities of from 5,000 to 21,000 plants ha -1 , at intervals of 2,000 plants ha -1 , in an experiment under irrigation. A completely randomized block design with four replications was used. The ideal planting densities in order to maximise leaf green matter, stems and branches, total roots, total marketable roots, number of marketable roots, marketable-root dry matter and stem dry matter, were 17,800; 17,077; 14,416; 13,594; 16,436; 12,361; and 18,149 plants ha -1 respectively. When adopting the planting density used by the farmers, a yield for marketable roots of 15,837 kg ha -1 was obtained. By using the optimal density as found in this work (13,594 plants ha -1 ), the yield was more than double that of the farmers. Increasing planting density reduced both the length of the marketable roots and the harvest index (the ratio of marketable-root dry matter to total plant dry matter).Key words: Manihot esculenta. Spacing. Plant populations.RESUMO -Na Mata Fresca, área situada na divisa dos Estados do Rio Grande do Norte e Ceará, pequenos agricultores têm como fonte de renda a obtida com a produção de raízes de mandioca, usando densidades de plantio em torno de 5.000 plantas ha -1 . Esse procedimento pode estar limitando a obtenção de maiores rendimentos de raízes, pois alguns trabalhos demonstraram que é possível a obtenção de rendimentos maiores da mandioca, com maiores densidades. O objetivo do trabalho foi avaliar o rendimento de raízes e outras características da mandioca em resposta à densidade de plantio. A cultivar Vermelhinha foi submetida às densidades de plantio de 5.000 a 21.000 plantas ha -1 , com intervalos de 2.000 plantas ha -1 , em experimento irrigado. Utilizou-se o delineamento de blocos completos casualizados com quatro repetições. As densidades de plantios ideais para maximizar a obtenção de matérias frescas de folhas, caule + ramos, total de raízes, de raízes comercializáveis, número de raízes comercializáveis, e de matérias secas de raízes comercializáveis e da parte aérea foram de 17.800; 17.077; 14.416; 13.594; 16.436; 12.361 ), o rendimento foi mais do dobro do rendimento do agricultor. O aumento da densidade de plantio reduziu o comprimento das raízes comercializáveis e o índice de colheita (relação entre a matéria seca das raízes comercializáveis e a matéria seca total da planta). Palavras-chave:Manihot esculenta. Plantas-populações. Plantas-espaçamento.
Resumo -O objetivo deste trabalho foi avaliar o crescimento do pimentão cv. Atlantis sob diferentes arranjos espaciais. Foram avaliados três arranjos de espaçamentos entre fileiras duplas e fileiras simples de plantio (1,5x0,5, 1,6x0,4 e 1,7x0,3 m), e quatro espaçamentos entre plantas nas fileiras (0,2, 0,3, 0,4 e 0,5 m), combinados em esquema fatorial. Utilizou-se o delineamento de blocos ao acaso, com três repetições e parcelas subdivididas no tempo. A avaliação de crescimento foi realizada em nove épocas espaçadas em 14 dias, com a primeira avaliação realizada 14 dias após o transplantio (DAT). Até os 126 DAT, foram avaliados: área foliar (AF); índice de área foliar (IAF); massas secas de folhas (MSF), do caule (MSC), de frutos (MSFr) e do total da parte aérea (MST); taxa de crescimento absoluto (TCA), assimilatória líquida (TAL) e de crescimento relativo (TCR); e as razões de área foliar (RAF) e de massa foliar (RMF). As alterações em AF, TCR, RMF e RAF foram independentes do espaçamento entre fileiras que, no entanto, influenciou MSF, MSC, MSFr e MST, IAF e TCA. O aumento do espaçamento entre plantas reduz o IAF e a RAF e aumenta a AF, MSF, MSC, MSFr, MST, TCA e TAL, mas não influencia a TCR e RMF.Termos para indexação: Capsicum annuum, acúmulo de massa seca, análise de crescimento, densidade de plantio. Growth of green pepper in different spatial arrangementsAbstract -The objective of this work was to evaluate the growth of green pepper cv. Atlantis under different spatial arrangements. Three spacing arrangements between double and simple planting rows (1.5x0.5 m, 1.6x0.4 m and 1.7x0.3 m) and four spacing distances between plants in the rows (0.2, 0.3, 0.4 and 0.5 m) combined in factorial scheme were evaluated. A randomized block design in split-plots divided in time with three replicates was used. The growth assessment was done in nine occasions, 14 days apart, and the first one was performed 14 days after transplanting (DAT). Leaf area (LA), leaf area index (LAI), dry masses of leaves (LDM), stem (SDM), fruit (FrDM) and total shoot (TDM); absolute growth rate (AGR), rates of net assimilation (NAR) and relative growth (RGR); and leaf area (LAR) and leaf mass (LWR) ratios were evaluated until 126 DAT. The changes in LA, RGR, LWR and LAR did not depend on row spacing, but spacing influenced LDM, SDM, FrDM and TDM, LAI and AGR. The increase in spacing reduces LAI and LAR, and increases LA, LDM, SDM, FrDM, TDM, AGR and NAR, but does not influence RGR and LWR.Index terms: Capsicum annuum, accumulation of dry mass, growth analysis, planting density. IntroduçãoA densidade de plantio é um dos principais fatores que influenciam o rendimento das culturas (López-Bellido et al., 2005), inclusive a do pimentão (Jolliffe & Gaye, 1995). A densidade de plantio está associada à competição intraespecífica por luz, água e nutrientes. Outro aspecto associado à densidade de plantio é o arranjo das plantas no campo, isto é, a distribuição espacial das plantas na área de plantio. Estudos relacionados à densidade de plantio com ...
RESUMO -O objetivo foi avaliar algumas características qualitativas e estimar o teor de sólidos solúveis (TSS) nas porções basal (ligada ao pedúnculo), mediana e apical do fruto da pinheira. Para a estimação desse teor, três pinhas de cada uma de dez árvores, de pomares localizados em Mossoró-RN e Aracati-CE, com idade entre seis e oito anos, foram utilizadas. As árvores foram consideradas repetições (blocos), os frutos foram considerados parcelas e as porções dos frutos, subparcelas. Três frutos de cada árvore foram descascados e divididos em três porções aproximadamente iguais, da base para o ápice. O material foi triturado e filtrado. No suco obtido, foram feitas três leituras em um refratômetro. A média destas três leituras representou o valor de cada subparcela. A análise de variância conjunta indicou efeitos de locais, blocos em locais, porções e da interação locais x frutos x porções. O peso do fruto variou de 226 a 418 g e o rendimento de polpa, de 45 a 54 %. O TSS na porção basal (26,49 %) foi inferior aos teores das porções mediana (28,02 %) e apical (27,53 %), mas não diferiu significativamente daquele da porção apical.Termos de indexação: pinha, ata, brix, frutos tropicais, fruta-do-conde. DETERMINATION OF THE QUALITY AND SOLUBLE SOLIDS CONTENT AT DIFFERENT PARTS OF CUSTARD APPLE (Annona squamosa L.) FRUITABSTRACT -The objective of this research was evaluate some qualitative traits and estimate the soluble solids content (SSC) in basal (linked to peduncle), median and apical fractions of the custard apple. Three fruits of each one of the ten trees, from 6-8 years old, orchards growing at Mossoró-RN and Aracati-CE, Brazil were utilized. The trees were considered replications (blocks), the fruits were the plots and the fruit fractions were the subplot. Three fruits of each tree were peeled and fractioned in the mentioned portions. The material was homogenized in a blender and filtered in nylon. In the juice obtained, three readings in a digital refractometer were made. The average of these values represented the value for each splitplot. The joint analysis of variance showed effects of sites, blocks whitin sites, fractions and sites x fruits x fractions interaction . The fruit weight varied 226 to 418 g and the pulp yield (pulp weight/fruit weight) varied of 45 to 54 %. The SSC in basal fraction (26.49 %) was lower than in the median (28.02 %) and in the apical (27.53 %) portions contents, but did not differ significantly from that to the apical fraction.
2RESUMO -Na experimentação agrícola, a utilização do tamanho e da forma adequada de parcela são técnicas experimentais importantes para aumentar a precisão do experimento. Assim, objetivou-se nesse trabalho determinar o tamanho e forma adequada de parcela para experimentação em campo com girassol. Para isso, o experimento foi conduzido em blocos completos casualizados com 14 cultivares de girassol em 10 repetições. As parcelas foram constituídas de quatro fileiras de seis metros de comprimento, espaçadas de 0,7 m e 0,3 m entre plantas. A área útil da parcela (7,56 m 2 ), composta das duas fileiras centrais, foi dividida em 12 unidades básicas, cada uma constituída por três plantas na fileira (0,63 m 2 ), obtendo-se o rendimento de grãos de girassol. O tamanho conveniente da parcela experimental foi estimado pelo método de Hatheway e a sua forma adequada foi determinada pelo método da informação relativa. O método de Hatheway permitiu estimar diversos tamanhos convenientes de parcelas, muitos de tamanhos aplicáveis para experimentos de avaliação de cultivares de girassol. Parcela no formato retangular 1 x 6 (fileira com dezoito plantas e 3,78 m 2 de área útil), foi considerada a forma adequada para avaliação do rendimento de grãos de cultivares de girassol e, também, foi menor que o tamanho geralmente indicado nas pesquisas com a cultura do girassol. Palavras-chave: Helianthus annuus L.. Método de Hatheway. Método da informação relativa.ABSTRACT -In agricultural experimentation, the use of the appropriate size and shape for the plot is an important experimental technique for increasing the accuracy of the experiment. The aim of this work therefore was to determine a suitable plot size and shape for field experimentation on the sunflower. To do this, the experiment was carried out in a randomised design of complete blocks, with 14 sunflower cultivars in 10 replications. The plots consisted of four rows, each of six metres in length, at a spacing of 0.7 m, with 0.3 m between plants. The working area of the plot (7.56 m 2 ) comprising the two central rows, was divided into 12 basic units, each consisting of three plants per row (0.63 m 2 ), to obtain seed yield in the sunflower. A suitable plot size was estimated using Hatheway's method, with an appropriate shape being determined by the method of relative information. Hatheway's method made it possible to estimate several convenient plot sizes, many of them suitable for experiments to evaluate sunflower cultivars. A 1 x 6 rectangular plot (a row with 18 plants and a working area of 3.78 m 2 ) was considered the appropriate shape for evaluating grain yield in sunflower cultivars, and was also smaller than the size usually found in research into the sunflower crop.
-Cowpea (Vigna unguiculata (L.) Walp.) is widely cultivated in northeast Brazil for production of both green grains and dry grains. Green grains are cowpea grains with a 60 to 70% moisture content that are very appreciated by the local people. The cultivation of cowpea in northeast Brazil is performed mostly using landraces and the low yields achieved in some areas of that region are generally attributed to the cultivation of less productive landraces. The objectives of this research were to identify the best landraces in terms of green bean yield and the characters that hold the most positive direct effects on this yield via path analysis. Twelve landraces of undetermined growth were evaluated in two experiments conducted in Mossoró, Brazil. The first experiment (E1) was sprinkler-irrigated and the second (E2) was conducted under rainfed conditions, but was irrigated whenever necessary. Pod yield and dimensions and green grains were evaluated, in addition to the main grain yield components. A randomized block design with five replications was used. The data presented here identified eight landraces with the highest yields. In addition, cowpea yield was higher in the dry season (E1) than in the rainy season (E2). The number of pods per plant had the largest direct positive effect on green grain yield.Keywords: Vigna unguiculata. Green grain. Landraces. RENDIMENTO DE GRÃOS VERDES E ANÁLISE DE TRILHA EM VARIEDADES TRADICIONAIS DE FEIJÃO-CAUPI
-Apparently, there are no custard apple cultivars defined for the northeastern region of Brazil. The establishment of breeding programs aimed at the selection of types from productive locations for later cloning is desirable. This work's objective was to evaluate the yield (during the first three crops) and quality (first crop) of fruits from 20 half-sibling custard apple tree progenies, selected from home orchards. An additional objective was to estimate genetic parameters for the traits evaluated. A micro sprinkling-irrigated experiment was conducted in Mossoró-RN, Brazil, as random blocks with five replications. In characteristics evaluated for periods longer than a year (diameter, height and mean weight of fruits, number of fruits ha -1 and fruit yield (kg ha -1 ), and a split-plot design was adopted, with progenies considered as plots and annual cropping seasons as subplots. The best progenies in terms of fruit yield (A3 and A4) are not necessarily the best for fruit dimensions and fruit mean weight (A2, FE4, JG1, JG2, SM1, SM7, and SM8). These progenies show great potential to be used in future studies on crosses or on vegetative propagation. In this regard, progeny JG2 should be highlighted as promising in terms of yield and fruit size. The progenies are not different with regard to percentages (in relation to mean fruit mass) of pericarp, endocarp, seeds, and receptacle, in the fruit, and fruit volume, number of seeds/fruit, and total soluble solids content in the fruit pulp, but progeny FE4 presents higher total titratable acidity in the fruit pulp. Narrow-sense heritability estimates were relatively high for all characteristics in which there was variability between progenies, with higher values for number of fruits ha -1 (80 %) and fruit yield (78 %). Relatively high coefficients of genotypic variation (around 20%) were observed for number of fruits ha -1 and fruit yield, with lower values for the other characteristics. There were positive genotypic and phenotypic correlations between fruit diameter (FD) and fruit height, FD and mean fruit weight, and number of fruits ha -1 and fruit yield. Index Terms: Annona squamosa L., bullock's heart, sweetsop, heritability, genotypic correlation ESTIMATIVAS DE PARÂMETROS GENÉTICOS DO RENDIMENTO E DA QUALIDADE DO FRUTO DE PROGÊNIES DA PINHEIRARESUMO -Aparentemente não existem cultivares de pinheira definidas para o Nordeste brasileiro. É desejável o estabelecimento de programas de melhoramento, visando à seleção de tipos de locais produtivos para posterior clonagem. O objetivo do presente trabalho foi avaliar o rendimento (nas três primeiras safras) e a qualidade (na primeira safra) dos frutos de 20 progênies de meias-irmãs de pinheiras, selecionadas em pomares caseiros. Um objetivo adicional foi a estimação de parâmetros genéticos para as características avaliadas. O experimento, irrigado por microaspersão, foi realizado em Mossoró-RN, em blocos ao acaso, com cinco repetições. Nas características avaliadas em três safras (diâmetro, altura e peso médio d...
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