Significance and Impact of the Study: Fusarium basal rot causes serious problems in onion production. To minimize post-harvest losses, a simple protocol based on FTA TM technology and a dual PCR test with Fusarium oxysporum species-specific and pathogenicity-specific primers was developed. By testing pooled onion samples using this method, latent infections with F. oxysporum can be screened from a representative sample of the harvest. This screening method could be a useful tool to manage the postharvest losses caused by latent infections with F. oxysporum and, with modification of the PCR protocol, with other Fusarium species pathogenic to onion. AbstractFusarium basal rot is a worldwide disease problem in onions, and causes substantial losses in onion production, both during the growing season and in the storage. To minimize the post-harvest losses, a protocol for screening of latent infections with pathogenic Fusarium oxysporum strains from harvested onions was developed. This protocol is based on a dual PCR test with primers specific for the fungal species and new SIX3 primers specific for the onionpathogenic F. oxysporum strains. A pooled sample containing pieces from 50 harvested symptomless onions was prepared for the dual PCR using microwave disruption of the filamentous Fusarium fungi and Whatman FTA TM filter paper matrix technology, or as a reference protocol, by extracting DNA with a commercial kit. The two sample preparation protocols gave consistent results with the tested onion samples. Detection limit of the dual PCR protocol was 100 pg of F. oxysporum DNA, in a mixture with onion DNA, when the FTA card was applied. The new protocol reported here is simple and sensitive enough for routine testing, enabling the detection of latent infections in harvest lots even at the infection levels under 10%.

Fruit firmness is one of the most important quality aspects in the production of pickling cucumbers (Cucumis sativus) for industry. This study compared the fruit firmness of different cultivars and evaluated the usability of different firmness variables. Firmness of fruit of five to six cultivars from a cultivar experiment was measured penetrometrically over 3 years. The maximum load needed to penetrate the skin, distance at maximum load, load at the end of the measurement, and the mean work during the whole measurement were recorded. Different variables gave a versatile impression of the fruit texture. Although there were some differences in the measured values each year, the ranking of the cultivars was similar each year. Cultivars Celine and Servus had the firmest skin and overall texture. `Aubade' and `Carine' had lower skin firmness but the inner part of the fruit of `Aubade' was very firm. `Etude' was similar to `Carine'. `B2590', measured in only 2 years, had lowest firmness both in skin and flesh. The results show that penetrometric measurement of fruit firmness is a suitable method for analyzing the texture of cucumbers intended for pickling.

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Finnish data on vegetable crops’ yield responses to phosphorus (P) applications are scarce, but P is usually applied in quantities that meet the crop demand with wide safety margins. We determined yield responses to P fertilisation of onion and cabbage at three sites in 3-year field trials. Only on a sandy loam with low P status did annual P applications give statistically significant yield increases, 7% and 20% over the P-unfertilised treatment for onion and cabbage, respectively. The maximum P rate allowed by national regulation for this soil is 80 kg ha-1, but P rates of 10–12 kg ha-1 were sufficient to produce 97% of the yield maxima. The results strongly suggest that the P demand of the studied vegetables is smaller than previously thought also in a boreal climate. Critical soil test P concentrations for vegetables should be established to avoid unnecessary build-up of soil P that may be uneconomical and elevate the risk for P losses to waterways. However, too few data exist for this at present.