Fresh-Market Tomato Variety Performance in 2009

To test recently released fresh-market tomato varieties, which had not been evaluated in Kentucky, alongside varieties already commonly grown in the state.

Production system. Field, raised beds under black plastic mulch, drip tape irrigation.

Analysis. Analysed in SAS, with data tested for normality and transformed where necessary. The methods section states a significance threshold of P < 0.5 while the table footnotes state P > 0.05; the discrepancy is the report's own and is reproduced here rather than silently corrected. Letters beside each value are the report's mean-separation groups.

The report describes 2009 as a challenging season with severe disease pressure throughout. Despite regularly scheduled sprays the trial was heavily impacted by a bacterial spot outbreak from late June into early July, and the authors attribute the high cull rates and depressed marketable yields across the whole trial to that outbreak. Cull rates here therefore measure a season, not a set of varieties.

USDA U.S. No. 1 grade and size classification. Harvested fruit is graded for quality and size against the USDA U.S. No. 1 standard. Marketable yield counts only fruit meeting the grade; everything else is a cull. Cull rate is the weight of non-marketable fruit as a share of total harvested weight, so it rises with disease and disorder pressure and is not a fixed property of a variety. Standard: USDA standards for U.S. No. 1 tomatoes.

Per-acre yield extrapolated from small research plots. Yields are not measured per acre. They are measured on research plots of roughly 8 to 200 plants and multiplied by a correction factor to estimate a per-acre figure. The publication states the consequences of this plainly: small errors are greatly amplified by the multiplication, and because drive rows are excluded from the calculation the resulting per-acre yields are typically much higher than what a commercial farm achieves. A yield produced by this method is therefore a comparison between varieties grown side by side, not a forecast of what a grower will harvest. Standard: University of Kentucky Fruit and Vegetable Research Report, "Our Yields vs. Your Yields".

Mean fruit weight from the marketable lot. Average fruit weight is calculated as total marketable yield divided by the total number of marketable fruit. Because culled fruit is excluded from both terms, this figure describes the fruit a grower would actually pack in that season, not the average of everything the plant set.

This trial grew 24 entries. AMSeed publishes results for 7 of them. The rest are listed by name below with the reason their numbers are withheld, so the trial is represented as what it actually was rather than as the slice we happen to cover.

The authors' own caution: this trial tested varieties in one location for one year, and variety performance can vary from one year to the next. Yields are per-acre extrapolations from eight-plant plots at an assumed population of 4,800 plants per acre. Because a bacterial spot epidemic ran through the trial, no figure here should be read as the yield potential of a variety under ordinary conditions.