Utilização do cloreto de clorocolina no controle do bicudo-do-algodoeiro

The objective of the present work was to evaluate the effect of the growth regulator chlorocholine chloride (CCC) in the control of the boll weevil (Anthonomus grandis Boheman) on cotton (Gossypium hirsutum L.). The experiment was conducted at the Experimental Farm of the Faculdade de Ciências Agrárias e Veterinárias (UNESP), Jaboticabal Campus, State of São Paulo, Brazil, during the 1988/1989 growing season. The experimental design used was the latin square. The chlorocholine chloride was sprayed on the cv IAC-19 cotton plants 70 days after emergence in the doses of 0, 25, 50, and 100 g/ha in a single application as well as 25 g/ha + 25 g/ha in two applications. The second application was 15 days after the first. There was no significant differences on cotton yield. Although the split application as well as the single application of 25 g/ha increased yield in 11.6% and 11.5%, respectively.These same treatments also increased earliness. After the last hand harvest the number of immature cotton bolls left in the field was 64.5% lower in the plots treated with chlorocholine chloride. Despite the higher earliness and the reduction of the number of immature cotton bolls, the chlorocholine chloride treatments were not sufficient to induce an effective aid in the boll weevil control but indicates a possibility of using growth regulators in the cotton crop as an auxilary strategy in integrate pest management programs.O presente trabalho foi desenvolvido com o objetivo de avaliar o efeito do regulador de crescimento cloreto de clorocolina (CCC), no controle do bicudo-do-algodoeiro (Gossypium hirsutum L. r. latifolium Hutch ). O experimento foi conduzido na Fazenda Experimental da Faculdade de Ciências Agrárias e Veterinárias - Campus de Jaboticabal da UNESP, SP, no ano agrícola de 1988/1989. O delineamento experimental utilizado foi o quadrado latino. O produto foi aplicado em pulverização, aos 70 dias da emergência das plântulas do algodoeiro, cultivar IAC-19, nas doses de 0; 25; 50 e 100 g/ha de cloreto de clorocolina, em aplicação única e 25 g/ha + 25 g/ha, parceladas, sendo a segunda aplicação 15 dias após a primeira. Não houve diferença significativa na produção de algodão em caroço. Entretanto, a dose parcelada de 25 g/ha + 25 g/ha e a de 25 g/ha, em aplicação única, promoveram aumentos de 11,6% e 11,5% no rendimento, respectivamente. Esses mesmos tratamentos conferiram maior precocidade à produção. O número de maçãs restantes, após a última colheita, foi significativamente menor nos tratamentos com cloreto de clorocolina, que apresentaram 64,5% menos de maçãs imaturas. Apesar da maior precocidade e da redução do número de maçãs imaturas, os tratamentos não foram suficientes para provocar um efetivo controle do bicudo; mas a análise dos resultados indica a possibilidade de utilização de reguladores de crescimento em algodoeiro como estratégia auxiliar em programas de manejo integrado de pragas

Identification of promising wheat genotypes for crossing

The objective of this study was to identify promising wheat genotypes from the IAPAR breeding program for crossesby multivariate techniques. Measures of dissimilarity between genotypes were obtained from multicategoric variables. To identifyclusters, Tocher optimization and UPGMA were used. The genotypes were divided into five diverging groups, indicating a widegenetic base of the wheat breeding program of the Agricultural Research Institute of Paraná (IAPAR). As indicated by the geneticdistance, crosses involving the cultivars IPR 85 and IPR 118 seem to be the most promising to increase genetic gains in both grainand flour quality as well as for agronomic parameters

Photoperiodism and genetic control of the long juvenile period in soybean: a review.

Soybean (Glycine max (L.) Merrill)is a short day plant that flowers when days are shorter than the maximum critical value, and this period is specific for each genotype. Soybean sensitivity to photoperiodism determines the limits of the sowing period for a latitude and hinders adaptation to wider ranges of latitude. The long juvenile period (LJP), which delays flowering under short day condictions, has been identified in soybean cultivars. The introduction of the LJP characteristic in soybean has made its cultivation possible in regions with latitudes lower than 15 o . Knowledge of the controlling genetic mechanisms of this characteristic can help in the development of soybean genotypes for lower latitudes with greater adaptation to sowing periods within the same latitude. Some conclusions about the genetic LJP control in soybean were reached from the present review: a) plants with LJP have a lower development rate for flowering, resulting in the lengthening of the vegetative period; b) the LJP characteristic has a direct influence on plant photoreceptivity and flowering induction; c) the genetic control of flowering time in short days is determined by a different and independent genetic system from that which determines long day flowering time; d) late flowering under short day conditions is a quantitative characteristic controlled by recessive genes, and it is believed that one to five main genes control flowering. Genotypes with a single pair of recessive alleles did not have LJP

Inheritance of spread hilum in soybean

O objetivo deste trabalho foi estudar a herança da expressão da característica hilo esparramado nos genótipos T48, Bragg e BR 16. Foi encontrado um gene recessivo que condiciona o fenótipo hilo esparramado no genótipo T48. A expressão do caráter hilo esparramado é dependente do locus T_ que controla cor de pubescência, pois somente ocorre em genótipos com pubescência marrom (T_), o que caracteriza efeito pleiotrópico deste locus sobre a característica hilo esparramado. Não houve influência de efeito maternal na expressão desta característica.The objective of this work was to study the inheritance of the expression spread hilum in the genotypes T48, Bragg and BR 16. One recessive gene conditioning the phenotype spread hilum in the T48 genotype was found. The expression of the spread hilum is dependent of locus T_, which controls pubescence color; therefore it occurs only in genotypes with brown pubescence (T_), which characterizes pleiotropic effect of this locus on the trait spread hilum. No maternal effect was found in the expression of spread hilum

Genotype x environment interaction in soybean: evaluation through three methodologies

Soybean is cultivated in the wide range of environments of Paraná State. Selection for genotypes of high andpredictable yields with wide adaptability are main targets of the breeding programs for this region. The adaptability andstability of 30 soybean cultivars of three different maturity groups (early, semi-early and medium maturity) with a focus ongrain yield were evaluated in the crop seasons 1999/2000, 2000/2001 and 2001/2002 through three different methodologies,in 30 different environments of the state of Paraná. The experiment had the design of random blocks with 3 replications. Thegenotypes performed differently regarding yield adaptability and stability. Cultivars CD 202 (early), M SOY 7202 and CD 206(semi-early), and M SOY 7602 (medium) attained the highest level of adaptability and stability of the 30 evaluated environments

Adaptabilidade e estabilidade de populações de milho-pipoca

The identification of higher stable cultivars makes the cultivar recommendation process safer. The objective of this work was to evaluate the adaptability and stability of eight popcorn populations for grain yield and popping expansion in two environments of the north area of the state of Paraná. The populations and the control (ZÉLIA) were evaluated in Londrina and Faxinal in two agricultural years using randomized block experimental design with three replications. For the variance analysis the parameters of grain yield and popping expansion were taken into account and the adaptability and stability were estimated based on the model proposed by Eberhart and Russel. The hibrid ZÉLIA and the populations UEL PAPA, UE PASHA, UEL PO, UEL PAMPGA, UEL PAPCB and UEL PAPYY performed the best grain yield results, 3,203.50, 3,733.41, 3,512.08, 3,176.25, 2,847.49, 2,764.75 and 2,421.66 kg ha-1 and popping expansion 27.68, 25.05, 27.41, 27.17, 27.64, 28.60 and 27.36, respectively, presenting previsible behavior for the cultivation with low risks in the studied area.A identificação de cultivares com maior estabilidade torna o processo de recomendação de cultivares mais seguro. O objetivo deste trabalho foi avaliar a adaptabilidade e estabilidade de oito populações de milho-pipoca quanto a produtividade e capacidade de expansão em dois locais no norte do Estado do Paraná. As populações e a testemunha (ZÉLIA) foram avaliadas em Londrina e Faxinal em dois anos agrícolas, utilizando delineamento experimental de blocos ao acaso com três repetições. Na análise de variância, consideraram-se os parâmetros de produtividade e capacidade de expansão e a adaptabilidade e estabilidade foram estimadas com base no modelo proposto por Eberhart e Russell. O híbrido ZÉLIA e as populações UEL PAPA, UE PASHA, UEL PO, UEL PAMPGA, UEL PAPCB e UEL PAPYY apresentaram os melhores resultados de produtividade, 3.203,50, 3.733,41, 3.512,08, 3.176,25, 2.847,49, 2.764,75 e 2.421,66 kg ha-1 e capacidade de expansão 27,68, 25,05, 27,41, 27,17, 27,64, 28,60 e 27,36, respectivamente, apresentando comportamento previsível para o cultivo com baixos riscos na região

Assessment of genetic diversity in maize inbred lines using RAPD markers

RAPD molecular markers were used to analyze genetic diversity between 16 corn lines. Twenty-two primerswere used resulting in the amplification of 265 fragments, of which 237 (84.44%) were polymorphic. Using the UPGMAmethod the genetic associations obtained showed 5 distinct heterotic groups. A principal coordinates analysis also showed anassociation of lines in 5 groups, in agreement with the results observed in the dendrogram. A bootstrap procedure wasapplied to verify whether the amount of markers used was sufficient to ensure reliability of the results, the procedure showeda coefficient of variation of 8.3%, suggesting that the markers were sufficient to assess genetic diversity between the analyzedlines. The high rate of polymorphism between lines revealed by RAPD markers indicated that the method is efficient to analyzegenetic diversity in corn lines and that the genetic divergence can be used to establish consistent heterotic groups between cornlines

Análise combinatória de populações de milho pipoca em topcrosses

The objective of this work was to evaluate the heterotic potential of 14 popcorn populations through topcrosses. In the 1997/1998 crop year, topcrosses hybrids were obtained as a result of crosses between the populations and the tester, which was composed of an equal mixture of seeds from all 14 populations. The populations and the hybrids were evaluated in field, in a randomized block design, with three replications. The estimates for genetic parameters and the topcrosses variance analyses were made. Based on the results of yield and popping expansion of the experiments, the following populations were selected for the syntheses of composite: UEL SI, UEL PAP, UEL ZP, UEL PP, CMS 43 and RS 20. This broad composite is the most promising for use as base populations in breeding programs.O objetivo deste estudo foi avaliar, por meio de topcrosses, o potencial heterótico de 14 populações de milho pipoca. No ano agrícola 1997/1998, foram obtidos os híbridos topcrosses resultantes dos cruzamentos das populações com o testador, que se constituiu da mistura eqüitativa de sementes de todas as 14 populações. No ano agrícola 1999/2000, as populações e os híbridos foram avaliados em dois experimentos, em delineamento de blocos ao acaso, com três repetições. Foram estimados os parâmetros genéticos, e realizadas as análises de variância dos topcrosses e das populações. Com base nos resultados da capacidade geral de combinação das populações avaliadas nos topcrosses, para os caracteres produtividade e capacidade de expansão, foram selecionadas, para formar o composto amplo, as populações genitoras UEL SI, UEL PAP, UEL ZP, UEL PP, CMS 43 e RS 20. Esse composto apresenta maior potencial para uso como população base no melhoramento

Factor analysis and environmental stratification in the assessment of soybean adaptability and stability

O objetivo deste trabalho foi avaliar a eficiência de diferentes métodos de estratificação ambiental, a representatividade dos locais de avaliação, e a adaptabilidade e estabilidade de genótipos de soja, por meio de ensaios de produtividade de grãos, nos estados do Paraná e Santa Catarina, nos anos agrícolas de 2000 a 2003, em um total de 15 ambientes. Foram utilizados, para estratificação ambiental, o método tradicional de Lin e a análise de fatores aliada ao porcentual de parte simples (PS%) da interação genótipo vs. ambiente (GxA). Na determinação da adaptabilidade e estabilidade dos genótipos, foram utilizados modelos baseados em regressão linear única e bissegmentada. Foram testados 21 genótipos de soja em delineamento de blocos ao acaso com três repetições, na avaliação da produtividade de grãos. O genótipo RB 605 apresenta ampla faixa de adaptação com elevada produtividade média de grãos. De acordo com ambos os métodos, as localidades de Palotina e Brasilândia do Sul podem ser reduzidas a somente um local de ensaio.A análise de fatores associada ao PS% da interação GxA é mais seletiva para estratificação ambiental, em relação ao método tradicional de Lin.The objective of this work was to assess the efficiency of different methods of environmental stratification, the representation level of the evaluation places, and the adaptability and stability of soybean genotypes, through yield trials in the Paraná and Santa Catarina States, Brazil, in the agricultural years of 2000 to 2003, totaling 15 environments. For environmental stratification, the Lin's traditional method and factor analysis, allied to percentage of the simple portion (SP%) of genotype vs. environment interaction (GxE), were utilized. Adaptability and stability of the genotypes were determined by linear and bisegmented regression models. Twenty one soybean genotypes were evaluated on randomized complete blocks design, comprising three replications, and the analyzed variable was grain yield. RB 605 genotype is highly adapted and presents high yield. According to both methods, Palotina and Brasilândia do Sul localities can be reduced to one trial location. The factor analysis allied to SP% of GxE interaction is more selective to environmental stratification in relation to the Lin's traditional method