An attempt is made to obtain fruit yield data in a manner that relates to typical grower practices. The grower’s harvester and harvesting crew are used and fruit from individual plots is weighed in a hydraulic dump trailer equipped with an electronic weight scale device. Mechanical harvesting necessitates harvesting all of the plots on one date, which involves compromises. Some varieties may be over-mature, while others are under-mature. The harvest date is determined by the grower, based on the maturity of the field variety. These were ‘H8892', in the early test and, ‘H9491', in the mid-season test. These tests had average replicated variety yields of 39.2 and 38.0 tons per acre, respectively (Tables 1 & 7). The observational varieties averaged 24.6 and 34.7 tons per acre (Tables 4 & 10). The plant growth and fruit yields for the early season observational varieties were poorer than those of the replicated varieties. Although there were no specifically identified problems, something was different in this portion of the field. This is substantiated by comparing the Colusa observational yields with those from the combined three locations ( Table 6).

The top yielding replicated varieties in the early test were ‘H 9280' (44.2 tons), ‘CXD204' (42.5 tons) and ‘H9661’ (41.7 tons). The top replicated yielders in the mid-season test were ‘H9492' (46.6 tons), ‘ABP721' (42.7 tons) and ‘H8553' (42.1 tons). Tables 5, 6, 11 and 12 report fruit yields from all of the test locations.

Fruit quality samples are hand-harvested shortly before harvest and submitted to state grading stations for analysis. Samples only include sound, red ripe fruit. The sampling process excludes breakers or cull fruit, and is intended to identify the maximum varietal potential, rather than results which might be obtained from "field-run" fruit. The following brief explanations of the quality tests may aid in their understanding.

Brix: This measures the amount of soluble solids in the fruit, and is expressed as a percentage. Soluble solids are mostly composed of sugars. High soluble solids are desired to maximize recoveries and case-yields of final product. Brix for the early season replicated and observational varieties averaged 4.9 and 5.2, respectively (Tables 2 & 4). Brix for the mid-season replicated and observational varieties both averaged 5.0 (Tables 8 & 10). The early season replicated varieties with the highest soluble solids were ‘Hypeel 45' (5.6), ‘ASG410' (5.3) and ‘Red Century 32' (5.2). The top soluble solids for replicated varieties in the mid-season test were ‘APTX539' (5.5) and ‘CXD179'/’Hypeel 65', both at 5.4. Tables 5, 6, 11 & 12 report soluble solids for all of the test locations.

Brix-Yield: This value is calculated by multiplying the brix by the yield. In some regards, it has more meaning than either factor considered separately, as it takes both into account. Note that the rankings of varieties change when comparing yields to brix-yields. The early season test replicated and observational brix-yields averaged 1.90 and 1.26 tons per acre, respectively (Tables 2 and 4). The mid-season average replicated and observational brix-yields were 1.90 and 1.60 tons, respectively (Tables 8 and 10). The highest replicated brix-yield varieties in the early test were ‘ASG410' (2.14 tons) and ‘Hypeel280'/‘H9280' (2.02 tons). The highest replicated brix-yields in the mid-season test were ‘H9492' (2.32 tons), ‘ABP721' (2.17 tons) and ‘CXD179' (2.15 tons). Tables 5, 6, 11 & 12 report brix-yields for all of the test locations.

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Copyright © 1999 Colusa County Cooperative Extension, Univ. of California
Last modified: August 16, 2000