Yield of upland rice cultivars in rainfed and sprinkler-irrigated systems in the Cerrado region of Brazil

In upland rice, the reduced grain yield that originates from the moisture stress period is related to the plant's tolerance of water deficiency and may vary between cultivars. The purpose of the work presented here was to evaluate the performance of upland rice cultivars in both rainfed and sprinkler-irrigated systems. A split-plot scheme with 8 replicates in a randomised block design was used. The plots were composed of 2 cropping systems (rainfed and sprinkler-irrigated) and the split-plot consisted of 2 cultivars (IAC 201 and Carajas) which are suggested for cultivation in upland ecosystems. Carajas had a greater number of panicles per square metre, higher spikelet fertility and grain mass, and, consequently, a higher grain yield than IAC 201 regardless of cropping system. IAC 201 was more sensitive to water deficiency than Carajas. Sprinkler irrigation improved spikelet fertility, grain mass and upland rice grain yield. Even when cultivars with a higher tolerance of water deficiency are used, a sprinkler-irrigated system may be a viable method to increase upland rice yield throughout most of the Brazilian Cerrado.

Net melon cultivars productivity under different cultivation systems, during summer and winter

In order to access the effects of cultivation in soil, sand or a commercial substrate on the productivity of Bonus #2 cultivars, 'Don Carlos' and 'Hy Mark', two experiments were conducted in the greenhouse at FCAV-UNESP, Jaboticabal- SP, Brazil, 21° 15' 22 S, 48° 18'58 W, and altitude of 595 m, from November 1999 to April 2000 (summer), and from July to November 2000 (Winter). For cultivation in soil, chemical nutrients were added, and plants were irrigated with drip irrigation. Fertigation with recirculation of the nutrient solution was used on sand; slabs were used on commercial substrate with the fertigation with non circulating nutrient solution. Bonus #2 cultivar yielded the highest production of marketable fruit, but were later in production, while Hy Mark cultivar had early production but a lower number of fruit per plant. The winter planting yielded higher production of marketable fruit while summer plantings yielded lower number of fruit per plant, but with higher average weigh. The combination between cultivation systems and cultivars yielded higher fruit production in winter.

Effect of fungicides on the mite fauna of prunus persica L. cultivars in Presidente Prudente, SP, Brazil

The objective of this study was to characterize the diversity of phytophagous and predatory mites on peach cultivars either with or without fungicide treatment, in the city of Presidente Prudente, State of São Paulo, Brazil. In order to evaluate the effect of fungicides, leaf samples were colleted at random from treated and untreated plants of the Tropical, Aurora 1 and Aurora 2 cultivars, from June 2004 to February 2006. From the results obtained it can be concluded that: plants with or without treatment showed high populations of predatory mites, indicating that the treatments were innocuous on the mite populations. A diversified composition of the mite community was observed. The Phytoseiidae family had the highest richness in numbers and species of mites. Euseius citrifolius and E. concordis were the most abundant species. Plants with or without treatment had high abundances of predatory mites, with a predominance of E. citrifolius.

Plant density in production of mini lettuce cultivars in organic system management

Production of mini vegetables in organic system is a good alternative to improve profit, but there are no researches about the optimum plant density for these cultivars in Brazilian conditions. Two experiments were conducted to evaluate the production of mini lettuce cultivars in different plant densities. Experiment 1 was conducted from January 1th (sowing) to February 10th (harvesting), 2012. The experimental design was completely randomized blocks, with six treatments in factorial scheme, 3 mini lettuce cultivars (Tudela, Renoir and Sartre) x 2 spacing between plants (16 and 20 cm), with eight replications and plots (2.04 m(2)) with six rows, spaced 15 cm. Experiment 2 was conducted from June 6th (sowing) to July 18th (harvesting), 2012. The cultivars Sartre and Renoir were evaluated under four plant densities (444,444; 333,333; 266,667 and 200,000 plants ha(-1), corresponding to spacing of 15x15, 15x20, 25x15 and 25x20 cm, respectively). Eight treatments were defined by a factorial scheme 2 (cultivars) x 4 (plant densities) and arranged in a completely randomized block design, with nine replications and plots with 2.04 m2. The evaluated characteristics in both experiments were total and marketable fresh weight per plant, plant dry weight, plant diameter and height, marketable yield and discard percentage. In first experiment, during the summer, cultivar Sartre showed the highest marketable fresh weight (72 g plant(-1)). Heaviest plants (91.6 g plant(-1)) were obtained with the higher plant spacing, but the highest yield (2.51 kg m(-2)) was obtained with the smaller spacing. In winter, plants with higher total (190 g plant(-1)) and marketable (146 g planta(-1)) fresh weight were obtained with cultivar Sartre, and the same was observed in low plant density. However, the higher plant density, the higher the yield.

Germinação de sementes de guandu sob efeito da disponibilidade hídrica e de doses subletais de alumínio

O objetivo deste trabalho foi verificar a germinação de sementes das cultivares de guandu, IAPAR 43-Aratã e IAC Fava Larga, sob efeito da disponibilidade hídrica e de doses subletais de alumínio. Os experimentos foram instalados na Faculdade de Ciências Agrárias e Veterinárias-UNESP, em Jaboticabal (SP), no período de março a maio de 2002. As sementes foram colocadas em caixas de germinação, previamente esterilizadas, revestidas com uma folha de papel germitest umedecido com diferentes concentrações de PEG 6000 (0,0; -0,6; -0,9; -1,2 e -1,5 MPa) e de sulfato de alumínio (0,0; 2,5; 5,0; 7,5; e 10,0 mmol.dm-3). O delineamento experimental utilizado foi o inteiramente casualizado em arranjo fatorial 2 x 5 x 5 (cultivares x disponibilidades hídricas x alumínio), com quatro repetições de 50 sementes. Para complementar a análise estatística foram realizadas análises multivariadas de agrupamento e componentes principais. O experimento foi desenvolvido em câmara de germinação, na temperatura de 25 ºC. A porcentagem de germinação foi verificada no 4.º e 10.º dias após a semeadura. No 10.º dia, as plântulas foram separadas em plúmulas e raízes primárias, para determinar a massa seca. A disponibilidade hídrica foi limitante para a germinação e o crescimento inicial. O efeito do alumínio associado ao estresse hídrico foi evidenciado somente até -0,9 MPa. As concentrações menos elevadas de alumínio estimularam o desenvolvimento das plântulas em condições de estresse hídrico até -0,6 MPa. Os efeitos simultâneos da disponibilidade hídrica e do alumínio reduziram a germinação de sementes da cv. IAC Fava Larga e o crescimento das raízes da cv. IAPAR 43-Aratã.

Características produtivas, físicas e químicas de frutos de cultivares de pessegueiros sobre dois porta-enxertos no oeste do Estado de São Paulo

Objetivou-se avaliar as características físicas e químicas de seis cultivares de pessegueiros sobre os porta-enxertos Okinawa e Umê. O trabalho foi desenvolvido no Pólo Regional Alta Sorocabana-APTA, Presidente Prudente-SP, em 2004/2006. Foram avaliados a massa, comprimento, diâmetros sutural dos frutos, produção por planta, teor de sólidos solúveis (SS) e acidez titulável (AT). As avaliações permitiram concluir que os porta-enxertos influenciaram na massa dos frutos, tendo sobressaído o Umê, com frutos de maior massa média. em 2006, ocorreu aumento significativo na produtividade de todas as cultivares, sobressaindo-se as cvs. Talismã e Doçura 2, com valores acima da média. A cv. Doçura 2 sobre 'Okinawa' destacou-se por reunir melhores características físicas dos frutos e produção por planta. As cvs. Talismã e Dourado 2 produziram frutos com maiores valores de massa, comprimento e diâmetro sutural, sobre os porta-enxertos 'Okinawa' e Umê. A cv. Tropical destacou-se pelos atributos de qualidade, independentemente do porta-enxerto.

Espaçamentos entrelinhas e doses de nitrogênio em dois cultivares de feijoeiro irrigado no sistema plantio direto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Características dos substratos no desenvolvimento, nutrição e produção de gérbera (Gerbera jamesonii) em vaso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Variação granulométrica de casca de pinus no desenvolvimento e produção de gérbera (Gerbera jamesonii L.)

Pós-graduação em Agronomia (Horticultura) - FCA

Avaliação fenológica, caracterização físico-química e aspectos fitossanitários de cultivares de pessegueiros na Região Oeste do Estado de São Paulo

Pós-graduação em Agronomia - FEIS

Resposta do cafeeiro à inoculação de fungos micorrízicos arbusculares, em latossolo vermelho, do cerrado

The aim of this study was evaluate the response of two coffee cultivars (tolerant and sensitive to aluminum - Al), inoculated or not by two arbuscular mycorriza fungi (AMF), Gigaspora margarita and Glomus etunicatum, in cerrado Oxisol, with different base saturation. This experiment was conducted under greenhouse conditions, with a complete randomized design, in a 2x3x2 factorial scheme, consisting of 2 cultivars (tolerante and sensitive to Al), 3 treatments with mycorrhizal (inoculated with two species of AMF and without inoculation) and 3 levels of soil base saturation (30, 45 and 53 V%), with five replicates per treatment. The variables were: plant height, stem diameter, leaf area, shoot dry weight, root fresh weight, nitrate reductase activity, chlorophyll concentration, root colonization and number of AMF spores. Mycorrhizae isolates promoted greater response of coffee plants, in acid soil with high concentration of Al, but this response was observed for both cultivars when plants were colonized by G. margarita. The cultivars evaluated showed no differences in Al tolerance when non inoculated.

Infestation of guava by Anastrepha fraterculus (Diptera: Tephritidae): preferred ripening stages and influence of fruit peel coloration

The current study aimed to verify the preferred guava fruit ripening stage for egg laying by Anastrepha fraterculus (Diptera: Tephritidae) and to determine the influence of peel coloration of the fruits of 2 cultivars on infestation. The cultivars used were Paluma and Seculo XXI. The infestation level was evaluated in cages, considering 2 conditions: multiple-choice and nonchoice tests. The infestation levels of A. fraterculus differed between the green and the green-ripe stages in the multiple-choice test. In Paluma fruits with the nonchoice test, the infestation was highest during the ripe stage. There were no differences in infestation levels of A. fraterculus between the green and the green-ripe stages in Seculo XXI. In general, the green-ripe and the ripe stages were preferred for egg laying by A. fraterculus. In Paluma fruits there were significant correlations of infestation levels of A. fraterculus with luminosity (L) and chromaticity (C) in the nonchoice assay. In Seculo XXI fruits there was a significant correlation of infestation levels of A. fraterculus with color angle (h) in the nonchoice assay. No correlation was found between theses parameters in the multiple-choice test.

Características dos substratos na absorção de nutrientes e na produção de gérbera de vaso

The production systems on substrates have been employed in most commercial cultivation of flowers and ornamental plants, including gerbera. However, its introduction as potted flower is recent in Brazil and many studies, especially those related to the determination of substrates physical and chemical properties, which contribute to production quality are still needed. The present study aimed to assess the influence of substrates characteristics for nutrient absorption and production of potted gerbera. The experiment was carried out in greenhouse with the experimental design in randomized blocks, factorial arrangement 5x2 (5 substrates and 2 cultivars) and 4 replications. Treatments consisted of substrates with different physical and chemical characteristics and gerbera cultivars (Cherry and Red). Plants grown on substrate with pH above 7.0 had a reduction in iron absorption, resulting in lower intensity of green coloration in the leaves. Plants grown on substrate with pH below 5.0 showed toxic levels of manganese and lower dry mass. The characteristics of the substrate, especially the pH, influence the nutrients absorption and the production of potted gerbera, altering the final plant quality.

Biochemical and physiological responses of sugarcane cultivars to soil water deficiencies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of citrus sudden death on yield and quality of sweet orange cultivars in Brazil

Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize and quantify CSD damage, fruit yield and quality were assessed in each combination of sweet orange cultivar (Hamlin, Pera, Natal, and Valencia), age class (3 to 5, 6 to 10, and 11 to 15 years old), and CSD severity class (0 = no symptom, 1 = initial symptoms, and 2 = severe symptoms). For each combination, 10 trees were harvested and 20 fruit were taken for quality analysis. Damage was characterized by reduc_ tion of: (i) total weight of fruit/tree (36 and 67% for severity class 1 and 2, respectively), (ii) number of fruit/tree (27 and 55%), (iii) fruit size (13 and 25% in diameter and height [stem to styler distance]), (iv) fruit weight (32 and 56%), (v) total soluble solids (TSS)/fruit (18 and 42%), and increase of (vi) Brix (14 and 34%), (vii) acidity (16 and 41%), and (viii) TSS/90-1b. box (21 and 33%). There was no alteration on Brix/acidity ratio and percentage of juice on fruit of affected trees. Sweet orange cultivars did not differ in percentage of reduction or increase of all yield and quality variables, with the exception of Pera, which expressed increases of Brix and acidity. For more severe affected trees, the youngest plants showed a higher reduction in fruit number/tree, whereas plants 6 to 10 years old showed a higher increase in fruit acidity and TSS/box. However, no differences in percentage of reduction or increase for other variables were observed among different age classes. The damage to the above probably was associated with reduced water absorption capacity of CSD-affected trees.