Orientador: Regiane Cristina O. de Bueno / Coorientador: Marcelo de Almeida Silva / Banca: Carlos Gilberto Raetano / Banca: Denise Tourino Rezende de Cerqueira / Resumo: A arquitetura das plantas pode ser modificada pelas práticas de condução da cultura influenciando assim aspectos fitossanitários e a produtividade. Diante disso, este trabalho teve como objetivo verificar a influência de diferentes arranjos de plantio na população de pragas e nas características morfofisiológicas na cultura da soja. O experimento foi composto por oito tratamentos, sendo quatro sistemas de plantio com diferentes espaçamentos entre linhas e duas cultivares de soja, uma de hábito de crescimento determinado e outra indeterminado e quatro repetições com parcelas de 12 x 07 m. Foram avaliados utilizando a população de insetos-praga, os danos de percevejos, os parâmetros morfofisiológicos, e ao final do ciclo as variáveis agronômicas e produtividade. Em relação à população de insetos-praga os sistemas de plantio convencional e fileira dupla foram os que tiveram maior ocorrência de lagartas desfolhadoras. Quanto à população de percevejos e inimigos naturais não houve diferença entre os tratamentos. No teste de tetrazólio houve maior quantidade de danos nos grãos no sistema de fileira dupla. A condição fisiológica das plantas de soja se manteve melhor nos sistemas de plantio convencional e fileira dupla, porém para os parâmetros de razão da área foliar (RAF) e área foliar específica (AFE) não houve diferença. O sistema de plantio reduzido apresentou maior quantidade de ramificações e consequentemente maior quantidade de vagens e grãos, entretanto este incremento não refletiu na produção, pois os tratamentos não diferiram entre si quanto à produtividade. / Abstract: The architecture of the plants can be modified by the driving practices of culture influencing plant health and productivity. Thus, this study aimed to investigate the influence of different planting arrangements in the pest population and the morphophysiological traits in soybean. The experiment consisted of eight treatments, four tillage systems with different row spacings and two soybean cultivars, one of determinate growth habit and other indeterminate and four replications with plots of 12 x 07 m. Were evaluated using the population of insect pests, stink bug damage, the morphophysiological parameters , and at the end of the cycle variables agronomic and productivity. In relation to the population of insect pests conventional tillage systems and double row were those who had a higher incidence of defoliating caterpillars. As the population of bed bugs and natural enemies there was no difference between treatments. In tetrazolium test a higher amount of damage to grain in double row system. The physiological condition of the soybean plants kept in the best of conventional and double row planting systems, but for the parameters of leaf area ratio (RAF) and specific leaf area (AFE) there was no difference. The system of reduced tillage had greater amount of branching and hence larger amount of beans and grains, however this increase was not reflected in production because the treatments did not differ in terms of productivity. / Mestre

Thesis (M.Sc. Agriculture (Agronomy)) -- University of Limpopo, 2015 / Low yields in dry bean are often reported to be associated with lack of inoculation of seeds prior to planting. This also results in little fixed nitrogen contributed by the crop. Soil phosphorus (P) is another important yield limiting factor in most of the dry bean producing regions. Two field experiments were conducted to investigate the response of dry bean cultivars to inoculation and phosphorus application under dryland farming conditions during 2011/2012 and 2012/2013 growing seasons at the Syferkuil farm of University of Limpopo. The experiments were carried out as a split split-plot arrangement in randomized complete block design with four replications. Main plot factor comprised two dry bean cultivars viz, red speckled bean and small white haricot. Rhizobium phaseoli inoculation levels (inoculated and uninoculated) were assigned in the sub-plot whilst the sub-sub plot was applied with three phosphorus rates at 0, 45 and 90 kg P kg/ha. Growth parameters, phenological characteristics and yield data were collected during the course of the experiments. The results of the two experiments showed that there was no interactive effect of treatments on growth and yield parameters. However, there was a significant interactive effect of cultivar and inoculation on phenological characteristics in both growing seasons. Main effects of cultivar and inoculation significantly affected most of the parameters measured. Inoculated red speckled bean produced tallest plants which reached 50% flowering and maturity earlier than the small white haricot variety. In both growing seasons grain yield was significantly different between the two cultivars (P ≤ 0.01). The red speckled bean produced higher grain yield of 1657 kg ha-1 and 2547 kg ha-1 in 2011/2012 and 2012/2013, respectively. In contrast, the small white haricot bean achieved grain yield of 1396 kg/ha and 1797 kg/ha in the respective seasons. Grain yield was significantly increased by approximately 16.15% and 27.50% with Rhizobium inoculation in the respective seasons. Phosphorus application at varying rates did not have a significant influence on all parameters measured the experiment in both 2011/2012 and 2012/2013 seasons.

Includes bibliographical references (leaves 241-25). Aims to evaluate sampling procedures; assess the extent and magnitude of yield loss caused by Pratylenchus neglectus; assess the population dynamics of Pratylenchus neglectus in cereals; determine whether resistance occurs in field crops; and, assess whether variation occurs between geographically isolated species of Pratylenchus neglectus

Includes bibliographical references (leaves 241-25). / xiv, 259 leaves, [10] leaves of plates : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Aims to evaluate sampling procedures; assess the extent and magnitude of yield loss caused by Pratylenchus neglectus; assess the population dynamics of Pratylenchus neglectus in cereals; determine whether resistance occurs in field crops; and, assess whether variation occurs between geographically isolated species of Pratylenchus neglectus / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied and Molecular Ecology, 2001

Crop development models are commonly used in research. However, their use as crop management tools for growers is rare. Decision support systems (DSS), which combine crop models with expert systems, are being developed to provide management assistance to growers. Researchers at Oregon State University are in the process of developing a DSS. Research was conducted to develop a computer program to provide current and generated weather data for use by the DSS. The objectives of this research were to obtain a weather station, develop a set of quality control procedures to check data from the station, obtain a weather generator program, and create a weather data manager program to implement the above objectives. A weather station was obtained and was placed near two existing weather stations for ten months. Data from the weather station was compared with the other two stations for values of monthly average maximum temperature, minimum temperature, and daily total solar radiation and monthly total precipitation. The weather station performed well. Only measurements of total daily solar radiation were consistently different from the other stations. Based on a comparison of the weather station with an Eppley pyranometer, a factor was calculated to correct the solar radiation readings. The quality control procedures used on the weather data were adapted from automated procedures given in the literature. When tested, the procedures performed as desired. When used on actual data from the weather station, values that failed the procedures were apparently legitimate values. Options were added to the data manager program that allow the user to quickly decide what to do with failed values. For a weather data generator, WGEN was chosen from the generators presented in the literature. An input parameter file was created for the Corvallis, Oregon area and thirty years of data were generated. Monthly means from this data were compared with thirty-year historical monthly means for Corvallis. Precipitation data from WGEN compared well with the historical data. The generated data for maximum and minimum temperature and daily total solar radiation had great differences from the historical data. It is believed that the input parameters for the Corvallis area suggested by the authors of WGEN are not appropriate. The weather data manager program was written in the C programming language, and occupies approximately 98 kilobytes of disk space, not including the eleven files created directly and indirectly by the program. The main functions of the program are: 1) retrieving data from the weather station and performing quality control procedures on the data (allowing the user to decide what to do with values that failed QC); 2) viewing and editing of files by the user; 3) weather data generation (creating a file of only generated data or appending generated data to the file of current data from the weather station to create a file containing a full year of weather data); and 4) miscellaneous functions (monitoring the weather station, setting the calendar in the station's datalogger, and changing information used by the data manager program). It is hoped that this program will be a significant contribution towards the development of a decision support system. / Graduation date: 1992

No description available.

The effects of cytokinin-like Thidiazuron growth regulator on the regeneration responses of callus cultures of Turkish bread Triticum aestivum L. cv. (BaSak 95, Gerek 79, and Bezostaja 1) and durum Triticum durum Desf. cv. (Kunduru, &Ccedil / akmak 79, and Kirmizi 5132) wheat varieties have been investigated in this study. High callus induction frequencies are found to be independent of bread and durum wheat varieties ( &rsaquo / 96%) whereas the callus weight is found to be variety-dependent. For bread wheat, BaSak 95 and for the durum wheat Kunduru is found to be the best performers. TDZ treatments are found to be negatively affecting the regeneration capacity of all the tested bread wheat varieties whereas for the durum wheat variety of Kunduru positive effect is observed. Since the culture efficiency is a derivation from the regeneration capacity, this parameter yielded very similar results as in the case of regeneration capacity for both bread and durum wheat varieties. In bread wheat varieties, the TDZ treatments increased the number of regenerated plants more than 2-fold when compared with the control and likewise very similar results were obtained from durum wheat varieties. Unfortunately, following their transfer to soil, plants that were treated with various concentrations of TDZ displayed reduced vigor probably due to underdeveloped roots. In addition, majority of these plants did not sufficiently develop above the ground parts when compared with the control plants. The simplicity and rapid development of shoots using mature embryos could potentially be used for regenerating superior plants following gene transfer studies in the future.

No description available.

The South Burnett region of Queensland is Australia's most important rainfed peanut (Arachis hypogea L.) production area. It also produces a considerable amount of cereal and grain legume crops. The cropping soils of the region are red, acid to neutral, clay loams that are classified as Ferrosols (Australian Soil Classification). Over 50 years of cropping on these soils has resulted in severe depletion of nutrient reserves, particularly potassium (K). In addition, the remaining K is predominantly confined to the surface 10 or 15cm of the soil profile, a feature commonly refered to as nutrient stratification. Dry periods during the summer cropping season are common due to the highly variable, summer-dominant rainfall pattern of the South Burnett. As topsoil dries out, crops forage for moisture and nutrients from lower in the soil profile where K reserves are smaller. It is therefore suspected that the combination of dry periods and stratified K reserves have resulted in an increasing incidence of K deficiency symptoms in summer crops. To investigate these issues, K relations of Ferrosols of the South Burnett were studied using soils from two representative sites. The pools of soil K that are important to crop growth in Ferrosols, and their interaction was examined through fractionation of soil K pools, and determination of quantity/intensity relationships, charge characteristics and clay mineralogy, and a leaching column study. A rapid K uptake period was identified for peanut and the effect of profile distribution and soil moisture during this period on K accessibility was studied in a divided column experiment. Finally, on-farm trials were used to evaluate commercial-scale options for improving K distribution in field profiles. It was found that the immediately available exchangeable K pool in these soils was the most important source of soil K, and was poorly buffered by slowly available non-exchangeable K. However the leaching column study revealed that K was preferentially adsorbed onto soil cation exchange sites, displacing calcium (Ca) and magnesium (Mg) ions, and therefore was not susceptible to vertical movement within the soil profile. These observations helped to explain the development of stratified K profiles in these soil types. Peanut (cv. Streeton) was found to take up most of its K requirement between 25-70 days after planting. The divided column study showed that profile distribution, and topsoil iv moisture content during this rapid K uptake period, were able to affect the ability of peanut plants to access K. Plants that grew in low K soil, or where soil was dry at the site of K supply, had reduced access to K. However, improving access to K did not result in improved growth, but rather in a significant reduction in dry matter (DM) production, apparently due to interference in the availability of other nutrients, possibly phosphorus (P), magnesium (Mg) or boron (B). Field studies showed that application of K and profile inversion improved K uptake and DM production of various crop species. However, in most instances improved K uptake and DM production was not reflected in increased yield. It was suggested that a combination of agronomic factors, seasonal conditions and crop type prevented the expression of yield responses to improved K nutrition and these influences need to be understood. The findings of this project have important consequences for nutrition of crops grown on Ferrosols in the South Burnett region. Surface applied K cannot be expected to increase exchangeable K in the subsoil unless it is incorporated to depth. Similarly, band applied K will remain close to the site of application as a result of only limited vertical or lateral movement. This may affect the ability of roots to access band applied K. The ability of surface applied K to displace Ca and Mg from soil exchange sites may have negative implications for the Ca nutrition of developing peanut pods. On the other hand, it could present an opportunity for the movement of Ca into deeper soil layers to address the amelioration of acid subsoils. The unexplained negative responses to potassium chloride application and apparent effect on P, Mg or B nutrition need to be investigated.

The South Burnett region of Queensland is Australia's most important rainfed peanut (Arachis hypogea L.) production area. It also produces a considerable amount of cereal and grain legume crops. The cropping soils of the region are red, acid to neutral, clay loams that are classified as Ferrosols (Australian Soil Classification). Over 50 years of cropping on these soils has resulted in severe depletion of nutrient reserves, particularly potassium (K). In addition, the remaining K is predominantly confined to the surface 10 or 15cm of the soil profile, a feature commonly refered to as nutrient stratification. Dry periods during the summer cropping season are common due to the highly variable, summer-dominant rainfall pattern of the South Burnett. As topsoil dries out, crops forage for moisture and nutrients from lower in the soil profile where K reserves are smaller. It is therefore suspected that the combination of dry periods and stratified K reserves have resulted in an increasing incidence of K deficiency symptoms in summer crops. To investigate these issues, K relations of Ferrosols of the South Burnett were studied using soils from two representative sites. The pools of soil K that are important to crop growth in Ferrosols, and their interaction was examined through fractionation of soil K pools, and determination of quantity/intensity relationships, charge characteristics and clay mineralogy, and a leaching column study. A rapid K uptake period was identified for peanut and the effect of profile distribution and soil moisture during this period on K accessibility was studied in a divided column experiment. Finally, on-farm trials were used to evaluate commercial-scale options for improving K distribution in field profiles. It was found that the immediately available exchangeable K pool in these soils was the most important source of soil K, and was poorly buffered by slowly available non-exchangeable K. However the leaching column study revealed that K was preferentially adsorbed onto soil cation exchange sites, displacing calcium (Ca) and magnesium (Mg) ions, and therefore was not susceptible to vertical movement within the soil profile. These observations helped to explain the development of stratified K profiles in these soil types. Peanut (cv. Streeton) was found to take up most of its K requirement between 25-70 days after planting. The divided column study showed that profile distribution, and topsoil iv moisture content during this rapid K uptake period, were able to affect the ability of peanut plants to access K. Plants that grew in low K soil, or where soil was dry at the site of K supply, had reduced access to K. However, improving access to K did not result in improved growth, but rather in a significant reduction in dry matter (DM) production, apparently due to interference in the availability of other nutrients, possibly phosphorus (P), magnesium (Mg) or boron (B). Field studies showed that application of K and profile inversion improved K uptake and DM production of various crop species. However, in most instances improved K uptake and DM production was not reflected in increased yield. It was suggested that a combination of agronomic factors, seasonal conditions and crop type prevented the expression of yield responses to improved K nutrition and these influences need to be understood. The findings of this project have important consequences for nutrition of crops grown on Ferrosols in the South Burnett region. Surface applied K cannot be expected to increase exchangeable K in the subsoil unless it is incorporated to depth. Similarly, band applied K will remain close to the site of application as a result of only limited vertical or lateral movement. This may affect the ability of roots to access band applied K. The ability of surface applied K to displace Ca and Mg from soil exchange sites may have negative implications for the Ca nutrition of developing peanut pods. On the other hand, it could present an opportunity for the movement of Ca into deeper soil layers to address the amelioration of acid subsoils. The unexplained negative responses to potassium chloride application and apparent effect on P, Mg or B nutrition need to be investigated.