Published issues

2007 to 2024

Volume 27 - Number 63

Year: 2008

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Although Senecio grisebachii exhibits attractive blossoms and long resistant floral stalks, its decorative use has not been yet developed. For this reason, experimental tests were implemented to assess the impact of different treatments on vase life, stature or stalk length, blossoming rate and number of days since planting to blossoming (DAF) for a population of genetically identical individuals. For the 2005 experiment, treated and non treated cuttings with and without root growing hormones from mother plants in 3 liter pots were tested. The plants remained under greenhouse facilities with and without cyclic lightingduring the night. The features studied were, length of the floral stalks, vase life DAF and daily flower bud opening. Treatments with additional light showed less DAF and duration in the flower pot. From 6, 14, 20, 23 and 28 October and 1 November dates, flower buds that opened in the flower pot were cut, finding significant differences between treatments in every case. Stalk length showed the effect of light and the hormone; by the other hand an interaction between both variables was detected with longer stalks in those plants exposed to light at night which had not been treated with hormone or nipped. The conclusion was that lighting during the night, is an appropriate practice to produce good sized floral stalks with commercial value. The treatment with light and no root growing hormone or nipping (L2SPSH) appeared very promising since it produced mature stalks early with less resource input. The suggestion is that S. grisebachii would be produced utilizing standard facilities, management and practices to obtain traditional cut flowers.

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The production of English and Japanese mint has suffered a great recession in Argentina. The main by products of the mint compound are menthol and essential oils which have important utilities in the pharmaceutical and food industry. The aim of this project is to analyse the imports and exports evolution and the Argentinean commercial balance of menthol and essential oils (EO) of the last decade (1996-2005). The data obtained from the INDEC has been processed determining the five year averages and the rate of the annual growth cumulative average (lineal regression method) of the import (M) and export (X) values. The menthol exports exceeded, in the 70 % of the years, US$ 300,000 representing the first five years a 180 % ahead of the second. The first five years imports represented the 216 % of the second. The M/X index was 3.1. The commercial balance was negative in the whole analysed series. The essential oil imports of the first five years exceeded 2.5 times the second and the imports of the second five years represented the 33.7 ahead of the first product of the imports’ general retraction of the devaluation after the crisis. Argentina does not characterise by the production and exportation of menthol and mint essential oil, the balances of trade indicate it. Until the late 90s the imports and exports of both products were greater than the first five years of the 2000 decade. The increase of the production and industrialisation of Mentha arvensis and M. piperita should be the basis to obtain a positive balance of trade.

Design of a module for natural drying of oregano and mint

AROMATICS | Ringuelet, J. - Martínez, S. - Ré, M.S. - Cerimele, E. - Henning, C.

Tags: Drying shed, aromatic plants, dried herbs, plastic cover

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An experimental drying module was designed with the purpose of drying fresh oregano and peppermint. It was constructed using polyethylene cover and lateral openings to regulate air circulation by natural convection. This experience took place in La Plata zone (Argentina) during summer 2006. Oregano (Origanum X majoricum) and peppermint (Mentha X piperita L.) were used in this study to determine time of drying, dry weight yield and quality of final product (humidity, colour and essential oil content). Oregano reached dry weight in 24 hours obtaining 70 kg in the 32 m2 structure, while peppermint took 48 hours and a yield of 60 kg of dry matter. Yields obtained and good quality of final product may suggest that this type of shed is usefull to dry oregano and peppermint in La Plata zone.

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Weed control in horticultural crops based only on the use of high doses of herbicides is very difficult because it implies a significant increase in production costs, higher pollution of the environment, and the growth of weeds which are not affected by these chemicals. The use of a reduced dose of herbicide is a very important alternative in order to reduce production costs and environmental damage, and basically to carry out effective weed control that will not affect the yield of the crop. The reduction of the doses of herbicides can be achieved with the replacement of these chemicals by the implementation of the use of other weed control methods or applying doses which are minimal or lower than the usually recommended ones. Adopting an integrated weed control technique requires thorough knowledge of the situation, the field to be used, main weed types and their stages of development as well as the appropriate management of the crop where it will be applied.

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Jerusalem artichoke (Helianthus tuberosus L.) belongs to the Asteraceae family. It is an annual crop from which tubers are mainly used. Yield ranges from 30 to 100 t·ha-1. Four uses can be given to this species: food, forage, industrial products (inulin) and fuel production (ethanol). It is not widespread as a vegetable crop, but it could be considered as a functional food because of its high inulin content (16 to 20 % in fresh weight). As a forage it is mainly used in pigs fatenning, it has no nutritional advantages compared with other species, but it grows better under poor conditions. It is considered one of the main sources of inulin, associated with its high tuber carbohydrate content and its high yield. It is also considered an energy crop for its potential to produce ethanol. Fifty tons of tubers could produce 4,500 liters of ethanol. The stablishment of the crop usually is done in early spring; plant population could range from 20,000 to 50,000 plants·ha-1. Tuber pieces sprout as well as entire tubers, optimum tuber piece size is around 50 g. Crop production needs large amounts of potassium, nitrogen and calcium. Tuber yield is highly sensitive to drought during emergence and late tuber growth. Weeds, insects and diseases are generally not a problem for Jerusalem artichoke. There are many cultivars of this species registered around the world, but not in Argentine, neither a characterization of the available materials in relation to the different uses that can be given to this species.