Published issues

2007 to 2024

Volume 29 - Number 70

Year: 2010

Contents: PDF 629.8 KB (59 downloads)
Index of authors and thematic: PDF 155.7 KB (63 downloads)
PDF 778.5 KB (806 downloads)

The chickpea is a crop that grows in winter. Among the biotic factors that limit the production are the insects. The aim of this work was to determine the species and abundance of insect herbivores and its associated natural enemies to cultivars of chickpea (Chañaritos S156 and Norteño) in the northwest of Cordoba. During 2006-2007, from July to November, insects in different states of development were collected manually in thirty plants of each cultivar that were chosen, as well as leave with symptoms of leafminers. From the breading of insect herbivores, specimens of parasitoids were obtained. Fifteen species of herbivores and nine of natural enemies associated to them were determined. The communities of insects in both cultivars were dominated by Lepidoptera, being Heliothis virescens the most abundant species. Five species of aphids (Hemiptera) were collected and Acyrtosiphon pisum was the most abundant, four registered species of Thysanoptera constitute the first appointment on the chickpea and Liriomyza sp. (Diptera: Agromyzidae) in leaves mined. The predators were Coccinellidae (Coleoptera) and Reduviidae (Hemiptera). Parasitoids Hymenoptera: Ichneumonidae and Chalcididae emerged from H. virescens; Braconidae of aphids; Eulophidae of Liriomyza sp. and Scelionidae of eggs of bugs. Because the stage of the crop in which they are, direct damage and abundance H. virescens could be the most detrimental species in the zone of study. The research of the role of the potential pests of the main phytophagous insect species and the incidence of their natural enemies should be developed.

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For wholesaler and retailer distribution, quality problems are observed, the evaluation of new crop practices can help to reduce postharvest losses and damages. The objective of this work was to evaluate the impact of a new practices at harvest on posharvest losses and damages, for different tomato maturity stages and location inside the wooden box. It was held in Barrancas (33º south latitude) using the cultivar Elpida (Enza Zaden) produced in a greenhouse. The treatments were: conventional harvest and harvest good practice alternative, in two maturity stages: “turning” and “colour”. Weight loss (%), number of marks per fruit, number of bruising per fruit and total damages per fruit were mesured by 7 days (every 3 days) of storage, at room temperature. A Complete Randomized Design was used and the data were analyzed with ANOVA and Duncan test, when the location was not contemplated inside the wooden box, and Kruskal Wallis to assess the location of the fruits in the top position, middle and bottom and in turn placed them at the edges and center. The new harvest practice reduced 50 % of damage marks and bruises and a 4 % weight loss after 7 days. In the conventional harvest the fruit “color” from the edge showed a greater number of marks (3,2 and 1,4) than the new practice.

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Pollen germination populations of C. maxima was evaluated in 24 culture media combining three levels of sucrose, two levels of calcium nitrate and four levels of boric acid was evaluated. The medium containing intermediate levels of sucrose, presence of calcium, and low content of boric acid showed the best results on pollen grains germination of populations of C. maxima. It is proposed to formalize the use of this medium as a method for routine analysis of pollen grains germination of these populations.

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Curing is an effective alternative for the control of the green mold in citrus postharvest, but it’s necessary its incorporation to other common practices as the degreening for its practical application. The objective of this work was to evaluate the mold control by curing treatment previously to degreening and its effect on fruit quality. Nova mandarin fruits at commercial maturity stage and color index -13 were used. Fruits were inoculated with Penicillium digitatum to evaluate the control of rottenness. Fruits without inoculating were used to evaluate quality. Two curing times (24 and 48 h) were evaluated at 37 ºC and the control fruits were inmersed in sodium bicarbonate (3 %) and fruits without treatments were used as ionoculation control. After, fruits were stored for 7 days at 20 ºC. Physiologic and pathological alterations, loss of weight, color evolution and internal quality were evaluated. A good control of fruit rot was observed with curing 48 h treatment (71 % rottness inhibition) and 24 h (47 %), with 94 % of rotten fruits in the control treatment. Curing didn't stop the color development in the fruits during the degreening, although it increased the losses of weight and the acetaldehyde and ethanol contents, without the off flavors generation. Physiologic alterations were only observed in the curing 48 h treatment. Therefore, a curing 24 h treatment before degreening is effective in the control of rottenness without deteriorating fruit quality.