Horticulture Series # 218

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Principle Investigators: Jonathan R. Schultheis, Professor and Vegetable Extension Specialist and Keith D. Starke, Research Associate, Department of Horticultural Science, NC State University, Raleigh, NC 27695-7609

Acknowledgements: We gratefully acknowledge the assistance of Cathy Herring, (Superintendent), and Brandon Poole, (Horticulture Supervisor), from the Central Crops Research Station, Clayton, NC, as well as, the personnel at the research station for their help in establishing, maintaining, and harvesting the squash cultivar evaluation trial. We gratefully acknowledge our summer research assistants, Stephen Bajorek and Libby Indermaur. We would also like to thank Joy Smith for conducting the statistical analysis on the data collected in this trial.

Finally, we would like to thank the following seed companies for their financial support: Bejo, Enza Zaden, HM Clause, Rijk Zwaan, Seminis/Monsanto, and Syngenta. We also want to acknowledge, support for this study was provided by the US Department of Agriculture, National Institute of Food and Agriculture, for the CucCAP Specialty Crop Research Initiative grant under award number 2015-51181-24285.

General Cultural Practices

The squash trials were established on black plastic mulch. Pesticides used on all plots were chemicals labelled for that crop, 2016 North Carolina Agricultural Chemicals Manual.

Zucchini cultivars and Seed companies

Disclaimer

This publication presents data from the cultivar evaluation trials conducted during 2016. Information in this report is believed to be reliable but should not be relied upon as a sole source of information. Limited accompanying detail is included but excludes some pertinent information, which may aid interpretation.

Table 1. Zucchini Squash cultigen trial yields¹, number of 20 lb boxes per acre, per indicated harvests for replicated treatments. Clayton, NC, 2016.

¹ Total of 15 harvests. Planting was July 28, 2016. Harvests 1-5 occurred on 31 August; 2, 5, 7 and 9 September; Harvests 6-10 occurred on 12, 14, 16, 19 and 21 September; Harvests
11-15 occurred on 23, 26, 28 and 30 September; 3 October.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater surface area to be
affected by defects).
³Culls consisted primarily of misshaped fruit.
⁴Fruit were discolored or rough/disfigured due to virus.
*virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only presented as observations.
NS indicates data were not statistically different.

Table 2. Zucchini Squash cultigen trial yields, cumulative boxes, (20 lbs.), per acre, among all harvests¹. Clayton, NC, 2016.

¹Total of 15 harvests.
²Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to
be more mature and allows greater surface area to be affected by defects).
³ Culls consisted of primarily misshaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only
presented as observations.

Table 3. Zucchini Squash cultigen trial yields¹. Percentage marketable, cull, and virus symptomatic fruit per indicated harvests by fruit yield for replicated treatments, Clayton, NC, 2016.

Percentage of yield based upon grade.

¹ Total of 15 harvests. Planting was July 28, 2016. Harvests 1-5 occurred on 31 August; 2, 5, 7 and 9 September. Harvests 6-10 occurred on 12, 14, 16, 19 and 21
September. Harvests 11-15 occurred on 23, 26, 28 and 30 September; 3 October.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater
surface area to be affected by defects).
³ Culls consisted primarily of mishaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only presented as observations.

Table 4. Zucchini Squash cultigen trial yields¹, average number of fruit per plant, per indicated harvests for replicated treatments, Clayton, NC, 2016.

Number of Marketable³ fruit per plant per harvest period³

Total fruit harvested

¹ Total of 15 harvests. Planting was July 28, 2016. Harvests 1-5 occurred on 31 August; 2, 5, 7 and 9 September. Harvests 6-10 occurred on 12, 14, 16, 19 and 21 September.
Harvests 11-15 occurred on 23, 26, 28 and 30 September; 3 October.
² Average number of fruit harvested from each plant at each harvest period (i.e.: 1-5; 6-10; 11-15).
³ Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater surface area to be affected by defects).
⁴ Culls consisted primarily of misshaped fruit.
⁵ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only presented as observations.
NS indicates data were not statistically different.

Table 5. Zucchini squash cultigen trials. Cumulative fruit weight per plant and percent per plant among all harvests¹. Clayton, NC, 2016.

¹ Total of 15 harvests.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater surface area to be affected by defects).
³ Culls consisted primarily of mishaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore,
they are only presented as observations.
NS indicates data were not statistically significant.

Table 6. Zucchini Squash cultigen trial yields, cumulative fruit number per plant, among all harvests¹. Clayton, NC, 2016.

¹ Total of 15 harvests.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater surface area to be affected by defects).
³ Culls consisted of primarily misshaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.

Table 7. Zucchini squash cultigen trials. Cumulative fruit number per acre and percentages, among all harvests¹. Clayton, Fall, 2016.

¹ Total of 15 harvests.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more
mature and allows greater surface area to be affected by defects).
³ Culls consisted of primarily misshaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.

Table 8. Zucchini squash cultigen trial yields¹. Number of fruit per acre by grade per indicated harvests for replicated treatments, Clayton, NC, 2016.

¹Total of 15 harvests. Planting was 28 July 2016. Harvests 1-5 occurred on 31 August; 2, 5, 7 and 9 September; Harvests 6-10 occurred on 12, 14, 16, 19 and 21 September; Harvests 11-15 occurred on 23, 26, 28 and 30 September; 3 October.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater
surface area to be affected by defects).
³ Culls consisted of primarily misshaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only presented as observations.

Table 9. Zucchini squash cultigen trials¹. Percent fruit number per acre per indicated harvests, Clayton, NC, 2016.¹

¹ Total of 15 harvests. Planting was 28 July 2016. Harvests 1-5 occurred on 31 August; 2, 5, 7 and 9 September; Harvests 6-10 occurred on 12, 14, 16, 19 and 21 September; Harvests 11-15 occurred on 23, 26, 28 and 30 September; 3 October.
² Marketable fruit are graded into U.S. No. 1 (requires younger and more tender squash than U.S. No. 2 which are permitted to be more mature and allows greater surface area to be affected by defects).
³ Culls consisted of primarily misshaped fruit.
⁴ Fruit were discolored or rough/disfigured due to virus.
*Virus incidence was low in harvests weeks (1-5) and (6-10); these data were not statistically different, therefore, they are only presented as observations.

Table 10. Zucchini Squash cultigen trial – Percent plant stand and average fruit length and width among replicated treatments, Clayton, NC, 2016.

¹ Final plant stand count was taken on 31 August 2016.
² Fruit Size was obtained using the average length and width of 5 US No. 1 fruits from harvest 7 on
14 September 2016.