Juliana Cristina Sodário Cruz

Produtividade de três cultivares de cana-de-açúcar sob manejos de sequeiro e irrigado por gotejamento

This study aimed to evaluate the effect of drip irrigation technology in different sugarcane varieties in two crop cycles (plant cane and ratoon). The experimental design was in completly randomized blocks, in split-plot with four replications, constituted by three sugarcane genotypes: RB867515; RB855536 and SP80-3280 and two crop management: drip irrigation system and rainfed system, totalizing six treatments. The first cycle lasted for 336 days, with rainfall of 1,480 mm. The volume of water provided by the system of drip irrigation was 400 mm, totaling 1,880 mm. The second cycle lasted for 365 days, the volume of water through rainfall was 1,394 mm, added to 320 mm provided by the system of irrigation, totaled 1,714 mm. Interaction between management and cultivars was found significant for the variables: productivity of stalks (TCH) and sugar yield (TPH), in which the largest difference was observed for cultivar SP80-3280. There was significant response to drip irrigation, on average the increase of production of stalks and sugar was 24 and 23%, respectively.

Uso de reguladores de crescimento como potencializadores do perfilhamento e da produtividade em cana-soca

The use of plant growth regulators as ripeners in sugarcane has been an agronomic practice with well solidified results. However, the residual effect of these products over the next ratoon is still not very well studied. This research aimed to evaluate the residual effect of two plant growth regulators, applied before the harvest, in the stool regrowth and productivity of three sugarcane genotypes. The experiment was carried out near Jau (SP). The experimental design was a randomized complete block, in split-plot, with four repetitions, constituted by the genotypes IAC87-3396, IAC91-2195 and IAC91-5155, and by three crop management: 20 g ha-1 sulfomethuron-methyl; 480 g a.i. ha-1 ethephon and control. The growth regulators were applied 126 days before harvest. To quantify the action of growth regulators the following variables were evaluated: the number of tillers m-1 at 0, 90, 180, 270 and 360 days after the harvest; the final percentage of stalk number by meter in relation to the initial percentage; the mass of 10 stalks, the length and the diameter of stalks; the pol and the fiber% cane, the reducing and total recoverable sugars, and the productivity of stalks and sugar. It was concluded that there was stimulating effect on the emergency of tillering up to six months after the harvest. The ethephon promoted larger productivities of stalks and sugar. There were differences among genotypes in relation to growth regulators for stalk length. There was no effect on the technological quality over the subsequent ratoon crop.

Danos do complexo broca-podridão à produtividade e à qualidade da cana-de-açúcar fertirrigada com doses de nitrogênio

The objective of this work was to evaluate the effect of nitrogen-fertigation on the damage caused by the borer-rot complex to the productivity and quality of fertigated sugarcane. The experiment was carried out in field, using a randomized complete block design, with four replicates and five N doses (0, 50 100, 150, and 200 kg ha-1) applied through drip irrigation. The following variables were determined: number of holes caused by Diatraea saccharalis (Lepidoptera: Crambidae); number of internodes infected with red rot; incidence percentage of red rot; stalk productivity; and sugar content. In laboratory, the attractiveness and the consumption of culm fragments by fourth instar caterpillars, in trials with or without choice, were evaluated. Nitrogen fertigation increased the incidence of D. saccharalis and red rot. The number of holes produced by the larvae was correlated with the occurrence of red rot. Sugar percentage reduced with the increase in the number of red rot affected internodes. Nitrogen doses did not affect the attractiveness of sugarcane culm fragments; however, higher N doses increased the consumption of these fragments by D. saccharalis caterpillars. Despite the damages to quality, nitrogen fertilization expressively enhanced the productivity of stalks and sugar.

Caracterização patogênica e molecular de Plasmodiophora brassicae

Few studies have been conducted with clubroot disease in Brazil, caused by Plasmodiophora brassicae. Tests on severity of disease using different populations were carried out in brassica species (cauliflower, susceptible Chinese cabbage, resistant Chinese cabbage, broccoli, and cabbage). P. brassicae populations were obtained from infected roots in several commercial production regions in Brazil. Severity tests were conducted under greenhouse conditions (25±2oC) with inoculations (2 mL) of spore suspension at concentration of 107 spores. mL-1, applied in the collar root of each plant. Disease evaluations were performed 35 days after inoculation. DNA extraction and PCR-RAPD analyses for these populations were conducted to compare genetic traits. The populations obtained from the regions of Carandai MG and Colombo PR was more aggressive, and cause symptoms even in cultivars considered resistant. However, no specific genetic pattern was observed as to the place of origin or aggressiveness.

Preservação do inóculo de Plasmodiophora brassicae utilizando o método de congelamento

ABSTRACT The preservation of Plasmodiophora brassicae resistancestructures under laboratory conditions is difficult since this is anobligate parasite. The freezing method using an ordinary householdfreezer was tested to ensure the pathogen’s survival and thepreservation of its infective traits. Roots of different brassica speciesnaturally infected by P. brassicae , showing typical clubrootsymptoms, sampled in the same farm, located in the Pardinho County,State of Sao Paulo, were collected during different seasons and wereimmediately frozen at approximately 20°C. The treatments weredivided as follows: T1: clubroots frozen for 389 days (arugula); T2:clubroots frozen for 242 days (broccoli); T3: clubroots frozen for 21Cruz, J.C.S.; Souza, N.L.; Padovani, C.R.; Furtado, E.L. Preservation of Plasmodiophora brassicae inoculum using the freezing method. SummaPhytopathologica , v.35, n.1, p.57-59, 2009 Keywords: Clubroot, soilborne pathogen, pathogenicitydays (Chinese cabbage), and T4: control (without inoculum). Thepathogenicity tests were conducted under greenhouse conditions(25±2°C). Each plant of the susceptible variety of Chinese cabbage(Pak choi) was inoculated with 2mL of a spore suspension of eachtreatment at a concentration of 10

SOYA PROTEIN ISOLATED IN ALCOHOLIC FERMENTATION FOR THE PRODUCTION OF CACHAÇA

SOYA PROTEIN ISOLATED IN ALCOHOLIC FERMENTATION FOR THE PRODUCTION OF CACHACA The goal of this work was to evaluate the use of soya protein isolated as a proteic nitrogen organic source for sugar cane juice complementation and the effect in the yeast cell viability maintenance and cachaca quality. Batch fermentations of sugarcane juice with yeast recycling were performed, in scale pilot. The soya protein isolated influenced positively the cellular viability maintenance, and consequently resulted in a better recycled ferment and a reduction in time of fermentation. The proteic nitrogen addition in the juice didn’t affect the sensory acceptance of cachaca, and also didn’t result in different levels of volatile compounds. KEY-WORDS: Saccharomyces cerevisiae; CELULAR VIABILITY; VOLATILE COMPOUNDS; SENSORY ANALYSIS.

Efeito da temperatura e reação de genótipos de quiabeiro ao mofo branco

The okra plant is susceptible to several diseases that can cause losses to the farmer if not managed. This study aimed to evaluate the effect of temperature and the reaction of okra genotypes to white mold. Plants aged 30 days, inoculated in the collar region, injured or not, including two strains of Sclerotinia sclerotiorum, were maintained for two weeks at temperatures of 15, 20, 25, 30 or 35oC. Fourteen okra genotypes at one and two months after emergence, as well as fruits at commercial harvest time, had their behavior evaluated for the disease. Damping-off or dead plants were evaluated, as well as the injure length in the inoculated fruits. The disease was favored by temperatures between 15 and 20oC and, in general, no differences were observed between the isolates and the influence of the injury on the disease occurrence. There were no okra genotypes resistant to white mold, since all of them had more than 30% of incidence of dead plants; younger plants were more susceptible and the injure length in fruits was > 6.0 cm. However, differences in the susceptibility between genotypes were observed for plants aged 30 and 60 days, which could constitute useful information for producers in the choice of cultivars under moderate climate and could be explored in breeding programs.

First report of Lasiodiplodia theobromae on Macadamia integrifolia in Brazil

Macadamia tree (Macadamia integrifolia Maiden & Betche) is a plant native to the rainforests of Australia. Its nut is rich in monounsaturated oils and is considered an excellent energy source. In August 2013, samples of branches and bark of the trunk of macadamia plants were received for laboratory analysis; they were from an eightyear-old commercial orchard located in São João da Boa Vista, São Paulo State, Brazil, and presented symptoms of sunken canker on the bark (Figure 1A), while some plants had gum exudations, which culminated in dry terminal branches. At least 10 plants of the orchard were symptomatic. Fragments of diseased bark were previously surface-sterilized by immersion in 70% ethanol for 30 s and 1% sodium hypochlorite for 30 s, and then washed in sterile distilled water. Small sections (0.5 cm long) were cut from the edge of an advancing lesion on the diseased bark and placed directly on water agar medium. The developed fungal colonies were placed on potato dextrose agar (PDA) medium and, subsequently, identified based on morphologic characters. Formed cultures were dark grey colored after seven days. Pycnidia were stromatic, globose and ostiolate. Conidia were initially hyaline, 1-celled and subovoid. When mature, conidia were 1-septate, brown and measured 26-31 x 12-16μm, typical of Lasiodiplodia theobromae (Pat.) Griff. & Maubl. Presence of Botryosphaeria rhodina (Berk. & M.A. Curtis) (teleomorph of L. theobromae) was not detected in the bark with canker or in the culture medium. ITS1 and ITS4 sequenced region of the isolate showed 98% similarity to the isolate of L. theobromae (AY585345). Pathogenicity test was performed for three isolates through attachment with adhesive tape of PDA plugs containing mycelium of the fungus on the shoot in five healthy plants of macadamia aged four months. Plants were maintained in a humid chamber for the first 24 h after inoculation and conditioned in a greenhouse. After seven days of inoculation, necrosis on the shoot was observed (Figure 1B). Pathogenicity was confirmed by recovering inoculated isolates from infected tissues. In Australia, Lasiodiplodia sp. was reported causing husk rot of macadamia (Mayers, P.E. Epidemiology and control of husk spot of macadamia. Australian Macadamia Society News Bulletin, v.25, p.59-64, 1998). This is the first record of L. theobromae causing disease to macadamia plants in Brazil.

Estudos de três meios de cultura axênicos para a ferrugem das mirtáceas

Axenic cultivation has been shown as an important tool for studies related to the biology, the pathogenicity and the maintenance of pure cultures of biotrophic species. Therefore, the present study aimed to analyze the in vitro growth of Puccinia psidii uredospores, using enriched culture media that had success in the axenic cultivation of other rusts. Compounds such as salts, amino acids, carbohydrates and vitamins were selected for the preparation of three enriched culture media: ASZV Kuck (10), SH Schenk & Hildebrandt (21) and HG Harvey & Grasham (7), modified. Comparatively, enriched media were prepared from leaves of “jambeiro” (FJ) at four concentrations: 0.5; 1.0; 3.0 and 5.0 g L-1 (grams of leaves per one liter of distilled water). In this study, verification covered only the first stage of fungal growth, germ tube growth, not continuing in the pathogen development. The enriched media that provided greater P. psidii germ tube growth were the media ASZV, HG and FJ at 0.5 g L-1 concentration.