Biologia de Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) em algodoeiro

Leaf discs obtained from the first or second non-cotyledonal leaf of cotton (Gossypium hirsutum L.) seedlings were used for the study of the biology of Polyphagotarsonemus latus on cotton IAC-20 cultivar. Seedlings were grown in pots and placed on a layer of cotton moistened with distilled water. The assays were carried out at 28.5 ± 0.3°C, relative humidity of 71.0 ± 2.6% and a 14 h photophase. The duration of immature phases was 4.1 ± 0.1 days for females and 4.1 ± 0.3 days for males, with a survival of 91.2%. After a pre-oviposition period of 1.1 ± 0.2 days, the females deposited 4.5 ± 0.9 eggs per day during 6.8 ± 1.3 days, i.e., 29.6 ± 7.3 eggs per female. The longevity was 10.0 ± 1.5 days for females and 8.8 ± 1.1 days for males. The intrinsic rate of increase (rm) was 0.323; finite rate of increase (λ) 1.38 individual per female per day; mean generation time (T) 9.54 days and net reproductive rate (Ro) 21.73.

Comportamento do cafeeiro apoatã em consórcio com culturas anuais

This study was conducted in Adamantina, region of Alta Paulista, São Paulo State, Brazil, from 1989 to 1993. Yield of Apoatã coffee (Coffea canephora Pierre ex Froehner) was evaluated during four years of intercropping with five plant species: IAC 20 - cotton (Gossypium hirsutum L.); cv. Tatu - peanut (Arachis hypogaea L.); IAC 165 - rice (Oryza sativa L.); cv. Guarani - castor bean (Ricinus communis L.) and IAC 100-B - corn (Zea mays L.). The crops were seeded 50 cm apart from coffee canopy. The treatments were arranged in randomized complete block design with five replications. Yield was significantly decreased when coffee was intercropped with castor bean, corn, cotton and peanut, but height and diameter of orthotropic branches were not affected. Linear correlation analysis showed that coffee yield was inversely correlated with the dry biomass of the intercrops.

Comparación de tres métodos para estimar estabilidad del rendimiento en nueve variedades de algodón

With the purpose of selecting and recommending promissory cultivars of cotton, Gossypium hirsutum (L) with high yield potential and stability, for crop areas in Venezuela, the yield (seed included) of nine cotton varieties was evaluated. The data from the 1995-96 and 1996-97 cycles was used. The experimental design was a randomized completed block design with four repetitions on twelve environments. Parameters of stability offered by the methods of Eberhart and Russell, (1966), Cruz et al. (1989) and the AMMI model were estimated and compared to determine the best method or combination. There was no coincidence between the best yield varieties, Unellez-2 and the commercial variety Delta Pine 16, in relation to stability criteria. According to Eberhart and Russell, these were classified as stable, while according to Cruz et al. they were adaptive to favorable environments and according to AMMI they were unstable with high interaction,.Of the three methods studied, the AMMI model allowed associating the response of high yield varieties to specific environments, gave more information and was easier to interpret.

Cotton root volume and root dry matter as function of high soil bulk density and soil water stress

Soil compaction reduces root growth, affecting the yield, especially in the Southern Coastal Plain of the USA. Simulations of the root restricting layers in greenhouses are necessary to develop mechanisms which alleviate soil compaction problems. The selection of three distinct bulk densities based on the Standard Proctor Test is also an important factor to determine which bulk density restricts root penetration. This experiment was conducted to evaluate cotton (Gossypium hirsutum L.) root volume and root dry matter as a function of soil bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6 g cm-3), and two levels of water content (70 and 90% of field capacity) were used. A completely randomized design with four replicates in a 3×2 factorial pattern was used. The results showed that mechanical impedance affected root volume positively with soil bulk density of 1.2 and 1.6 g cm-3, enhancing root growth (P>0.0064). Soil water content reduced root growth as root and shoot growth was higher at 70% field capacity than that at 90% field capacity. Shoot growth was not affected by the increase in soil bulk density and this result suggests that soil bulk density is not a good indicator for measuring mechanical impedance in some soils.

Desenvolvimento de metodologia de criação e multiplicação de Aphis gossypii: Avanços e sucessos

Estudos sobre as mais diversas formas de controle de pragas e utilização de inimigos naturais, exigem artrópodes em quantidade e qualidade. Mediante essa necessidade, o processo de criação e multiplicação de artrópodes, vem ao longo dos anos, passando por significativas transformações. As técnicas de criação e multiplicação de insetos são muito importantes em estudos de biologia e de métodos de controle. A criação e definição de uma metodologia para multiplicação tem sido um grande desafio nos estudos da biologia e da criação de insetos, principalmente, devido a dificuldade de estabelecimento de populações em casa de vegetação e campo. Visando otimizar e adequar uma metodologia de multiplicação de Aphis gossypii (Hemiptera: Aphididae) em condições de laboratório, foi estabelecida uma colônia sobre plantas de algodoeiro (Gossypium hirsutum L. raça Latifolium Hutch) objetivando uma melhoria nas condições de sobrevivência e multiplicação desses insetos, menores influencias dos fatores abióticos, e a potencialização do uso das plantas por um período mais longo. Com o desenvolvimento dessa técnica e dos recursos utilizados na criação, notou-se um incremento na quantidade de indivíduos obtidos, melhor aproveitamento das plantas e diminuição de custos. Dessa forma evitou-se também a migração e infestação de outras espécies de pulgões e a ação de inimigos naturais. Após o estabelecimento da criação, verificou-se que o controle do parasitismo de A. gossypii foi de acordo com as condiçõ es submetida.

Absorção de nitrogênio pelo algodoeiro herbáceo em dois sistemas de cultivo

The study of nutrient uptake is of fundamental importance to plant nutrition, as well as tell the time (growth stage) being absorbed by the culture, also signals to the levels of fertilizer to be used. Aiming to establish the uptake of nitrogen for cultivation of cotton (Gossypium hirsutum L. r. latifolium Hutch.) led to an experiment in a Alfissol under randomized block design with two treatments, sowing conventional tillage and after tillage on the straw of previous crop (millet), with five replicates. Samples were taken according to the phenology and plants development. The dry matter accumulation in cotton is linear and increasing until the period of large boll, being more intense with the appearance of flowers and boll, or 50 to 100 days after emergence. The nitrogen content is higher in newly emerged plants, having peaks at the beginning of the appearance of squares and flowers, and from the appearance of small boll, the nitrogen content in the plant decreases linearly. The extraction of nitrogen is bigger from the appearance of flowers (55-60 days after emergence).

Reação de cultivares de algodoeiro a Ramularia areola Atk

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pontas e velocidade de deslocamento na deposição de gotas da pulverização na cultura do algodão

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Resistência de cultivares de algodoeiro sobre Spodoptera frugiperda e Alabama argillacea (Lepdoptera: Noctuidae) e efeito na biologia e comportamento de Podisus nigrispinus (Hemiptera: Pentatomidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Interação trófica entre cultivares de algodoeiro colorido, Aphis gossypii Glöver, 1877 (Hemiptera: Aphididae), Harmonia axyridis (PALLAS, 1773) E Eriopis connexa (German, 1824) (Coleoptera: Coccinellidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade física em um latossolo vermelho sob sistema de semeadura direta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Períodos de interferência de plantas daninhas em algodoeiro cultivares BRS Safira e BRS Verde

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biologia de Paracoccus marginatus (Hemiptera: pseudococcidae) e de seu parasitóide Acerophagus papayae (Hymenoptera: encyrtidae ) em diferentes plantas hospedeiras e levantamento de inimigos naturais em Barbados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hábito alimentar e morfologia do aparelho digestivo de espécies de Carabidae (Insecta: Coleoptera) associados a plantas herbáceas e ao algodoeiro colorido

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Efeitos de cultivares de algodoeiro que expressam as proteínas Cry1Ac e Cry1F nos parâmetros biológicos de Chrysodeixis includens (Walker, 1857) (Lepidoptera: Noctuidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV