Strawberry cultivars (Fragaria ananassa Duch.) suitability to sugarcane (Saccharum officinarum L.) harvest residue as an alternative to plastic mulch was evaluated at the INTA Famaillá, Tucumán province, Argentina, in 2008. The experimental design was a complete randomized design with three replications, arranged in split plot, evaluating short-day (Camarosa and Sabrosa) and dayneutral (Aromas and Albion) cultivars, growing on vegetal mulch (about 1 cm thick), and 25 mm thick black plastic mulch. At the beginning of cycle, soil moisture content was maintained in easily usable water under both mulch types, but was higher under plastic mulch. The harvest period in vegetal mulch started later than in plastic mulch, but harvest season was more extended towards the end of cycle. During months with less than 20 °C average daily temperature, yields were higher under plastic mulch in all cultivars, more pronounced in short-day cultivars. During months with more than 20 °C average daily temperature, no difference in yields between mulch types were found, with higher yields tendency in day-neutral cultivars on vegetal mulch. The study remarks the importance of considering the cultivar when you choose a mulch type.

The cauliflower crop (Brassica oleracea Linn. Var. Botrytis) has specified environmental requirements which complicate to obtain a good quality product when plants are growing in summer, a period of lower production and higher prices. While there is a broad range of cultivars with different climate adaptation, they are not always accompanied by supporting information on the production characteristics assessed under local conditions. The aim of this work was to evaluate the productive capacity and adaptability of 10 commercial cultivars of early or intermediate crops at the horticultural area of Santa Fe. Three experiments were carried out with transplanted seedlings on rows at 0.7 m at density of 3.2 plants·m-2, in winter (greenhouse and field) and in summer. The experimental design was in random plots with three replications. Significant differences were observed between the information supplied by producers and consultants and with regard to suggested by commercial companies, this emphasize the need for screening the performance of different cultivars under local conditions, in order to improve the recommendation of planting. In Julia and Smilla cultivars, as well as Candid Charm and Bonny cultivars, produced curd of good quality pellets when they were transplanted both in winter and summer. Large curds was yielding for Julia and Smilla and medium size in the others. In Memphis and Incline cultivars the curds yielding were large and with very good quality only when plants were growing in summer, while Madrid and White Magic curds were of very good quality only when harvested in spring.

In Rosario, supply much of the vegetable to consumers is through traditional retail shops, usually with low-tech and high postharvest losses. The objective was to evaluate losses during the traditional vegetable retail distribution system and in an improved one (with refrigeration, refreshing and own provision of vegetables) in summer period. Evaluated vegetables were: swiss chard, celery, green onions, crisp and butterhead lettuce, pepper, leek, arugula, tomato and carrot. Variables measured: weight loss by discard, water loss and total losses, in percentage, for 4 consecutive days. The experimental unit, with six replicates taken from different packages, was: one bunch for swiss chard, arugula, green onions and leeks, lettuce five plants; six tomato fruits, pepper three fruits and carrots three roots. A repeated measures model in time with MIXED procedure of SAS was used. It was found a significant interaction between systems and time, being higher in the traditional and as time passes for total losses in all vegetables evaluated. Differences between systems were observed every day, for most vegetables, with higher total losses at the end of the trial, in the traditional (65 %) than in the improved (20 %). In consecutive days within each system, the differences were highly significant for the traditional system. Losses by discard have similar behavior to the total and represent a high percentage of them (82 % traditional and 86 % improved, the average for all vegetables and moments). The improved system allowed significantly reduction in postharvest losses.

Bacterial canker (Clavibacter michiganensis subsp. michiganensis, Cmm) is one of the most important tomato diseases in Uruguay. Crop rotation with non susceptible hosts is recommended to decrease soil inoculum level. Its efficacy depends on pathogen survival in the field, on trellising materials or on its re-introduction. Cmm survival in pieces of polypropylene ties and of giant reed cane (Arundo donax L) artificially inoculated was studied in laboratory conditions. They were inoculated by immersion in a 2 x 108 ufc·mL-1 Cmm solution in saline buffer for two hours. The presence of Cmm was analyzed 0, 1, 7, 14, 30, 60, 90, 180, 240 and 365 days post inoculation by plating on each date ten plates of nutrient agar dextrose media containing five pieces each. Concentration of bacteria developed on each plate was estimated by the OD 590 nm after resuspension in 7 mL saline buffer. Data were analized on a randomized block design with ten replications (plates). Cmm survival in cane was less than seven days and lower to 100 %, while that of the ties exceeded one year and was 100 % until 240 days. OD 590 nm decreased with days post inoculation. It was confirmed a longer pathogen survival on ties.

In arid or semi-arid zones, where the quality and/or quantity of water available for watering is inadequate to eliminate the excess of soluble salts, the soil salinity could affect the yield and/or quality of oregano crops. The objective of this study is to evaluate the productivity of biomass and of two genotypes of oregano when exposed to five different levels of water salinity. An experiment was carried out in pots with a completely random design and four replications. The plants were grown in a greenhouse in sandy-loam soil. They were irrigated with water salinized with NaCl, CaCl2 and MgCl2 with levels of electric conductivity (EC) of 2, 4, 6 and 8 dS·m-1 and a control of 0.35 dS·m-1 (no salt added). After 90 days the plants were harvested, and the biomass of the different organs was measured, as well as the yield and concentration of the essential oils in the leaves. The genotype Origanum vulgare L. sp. viridulum yielded a 40 % or more leaves and more than double the essential oil than Origanum x majoricum Cambess for the majority of the EC measurements. If these results are similar to field experiments, the use of O. vulgare with respect to O. x majoricum would be recommendable for both leaf and essential oil yields with salinity of up to 6 dS·m-1, in the first harvest.