Water Conserv II Valencia & Midsweet Scion Trial

Dr. Bill Castle – Dr. Fred Gmitter – Dr. Jude Grosser
Posted May 12, 2020
CREC Citrus Plant Improvement

Water Conserv II Scion Trial – Description

The primary purpose of this trial was to conduct a semi-commercial scale evaluation of  Valencia and Midsweet scion selections [Table 1] in order to discover ones that could complement the existing scion cultivar range and provide a broader harvesting season. The scions consisted of advanced somaclonal Valencia selections along with irradiated budlines [seedless] of Midsweet from the CREC plant improvement group and an assortment of other selections including ones from Australia.  Of special interest were young line [juvenile] sources.

A secondary objective was to assess the response of the selections to HLB.

Water Conserv II Scion Trial – Summary

• Location: Lake County
• Scions: Valencia & Midsweet [see Table 1]
• Rootstock: Carrizo citrange
• Date planted: March 2000
• Design: Randomized complete-block, 4 replications
  • Plot size: 14 trees
  • Spacing: 15 x 25 ft. @ 116 trees/acre
• Data: [see Table 2]
• HLB: In the 2010-11 season, when the last data were collected, HLB had a minor visible impact on the project. Some leaf symptoms were present, but no serious effects on tree or fruit condition or fruit drop. The trees were rated in the 2017-18 season with little change from the 2010-11 season. The ratings are included in the 2017-18 annual data file available upon request.
• TRIAL STATUS: TERMINATED

Table 1. Scion selections.

Table 1 [cont’d].  Scion selections.

Table 2. Data collected.

Considerations regarding the data:

• Due to the large volume of data and, thus, ease of viewing, only mean data are presented.
• Individual season’s data are available upon request for seasons: 2003-04 to 2010-11.
• In order to better visualize the overall trial results, a summary table [Table 3 for Valencia and Table 4 for Midsweet] was created presenting mean juice Brix, acid, ratio, yield [box/tree; PS/acre] for all seasons and cumulative PS/acre. The data were color coded into statistically relevant groups as follows: green [best results]; yellow [intermediate] and red [worst results] based on statistical experience from this and other similar field trials.  Data are sorted by cumulative PS/acre.

Valencia: Overall Results

Table 3. Overall mean juice Brix, acid, ratio, yield [box/tree; PS/acre] and cumulative PS/acre.

Fig. 1. Water Conserv II scion trial – Valencia [V; Val] 6-year Yield [boxes/tree]: mean + std. dev., seasons: 2005-06 to 2010-11.

Fig. 2. Water Conserv II scion trial – Valencia [V; Val] 6-year cumulative Yield [boxes/tree], seasons: 2005-06 to 2010-11.

Fig. 3. Water Conserv II scion trial – Valencia [V; Val] 6-year PS/acre: mean + std. dev., seasons: 2005-06 to 2010-11 [darker blue bars: 5-year PS/acre mean – no data 2005-06].

Fig. 4. Water Conserv II scion trial – Valencia [V; Val] 5-year cumulative PS/acre, seasons: 2006-07 to 2010-11.

Fig. 5. Water Conserv II scion trial – Valencia [V; Val] 8-year Juice Brix: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 6. Water Conserv II scion trial – Valencia [V; Val] 8-year Juice Acid: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 7. Water Conserv II scion trial – Valencia [V; Val] 8-year Juice Ratio: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 8. Water Conserv II scion trial – Valencia [V; Val] 8-year PS/box: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 9. Water Conserv II scion trial – Valencia [V; Val] 8-year Color: mean + std. dev., seasons: 2003-04 to 2010-11.

Midsweet: Overall Results

Table 4. Overall mean juice Brix, acid, ratio, yield [box/tree; PS/acre] and cumulative PS/acre.

Fig. 10. Water Conserv II scion trial – Midsweet [MS] 5-year Yield [boxes/tree]: mean + std. dev., seasons: 2005-06 to 2008-09 & 2010-11.

Fig. 11. Water Conserv II scion trial – Midsweet [MS] 5-year cumulative Yield [boxes/tree], seasons: 2005-06 to 2008-09 & 2010-11.

Fig. 12. Water Conserv II scion trial – Midsweet [MS] 5-year PS/acre: mean + std. dev., seasons: 2005-06 to 2008-09 & 2010-11.

Fig. 13. Water Conserv II scion trial – Midsweet [MS] 5-year cumulative PS/acre, seasons: 2005-06 to 2008-09 & 2010-11.

Fig. 14. Water Conserv II scion trial – Midsweet [MS] 8-year Juice Brix: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 15. Water Conserv II scion trial – Midsweet [MS] 8-year Juice Acid: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 16. Water Conserv II scion trial – Midsweet [MS] 8-year Juice Ratio: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 17. Water Conserv II scion trial – Midsweet [MS] 8-year PS/box: mean + std. dev., seasons: 2003-04 to 2010-11.

Fig. 18. Water Conserv II scion trial – Midsweet [MS] 8-year Juice color: mean + std. dev., seasons: 2003-04 to 2010-11.