Technical Yearbook 2024

FIGURE 2. Effect of in-field fractional use of winery wastewater with raw water on (A) bunches per grapevine, (B) berry mass, (C) bunch mass, and (D) yield of Shiraz and Cabernet Sauvignon at harvest in 2018, 2019, 2020 and 2021.

the poor performance of the BR2 experimental plot. Results indicated that the grapevines at the LOR2 experimental plot had recovered to a certain extent after receiving only raw water for the last two years of the study. This indicated that the grapevines could recover from the detrimental effects that they had incurred from the in-field fractional use (augmentation) of winery wastewater with raw water for the first two seasons of the study. Yield components In the 2017/18 season, fertility ranged from 14 to 55 bunches per grapevine at the LOR2 shallow sand and the LOR1 deep sand experimental plots (Figure 2A), respectively. Unfavourable atmospheric conditions probably caused the low fertility at the LOR2 shallow sand experimental plot during bunch initiation in the preceding year. In the 2018/19 season, fertility ranged from 2 to 55 bunches per grapevine at the LOR2 shallow sand and LOR1 deep sand experimental plots (Figure 2A), respectively. The low fertility at the LOR2

shallow sand experimental plot was probably caused by unfavourable atmospheric conditions during bunch initiation in the preceding year, as well as saline soil conditions during winter. At three of the experimental plots, the number of bunches was substantially lower at harvest in 2018 compared to harvest in 2019 (Figure 2A). In the 2019/20 season, fertility amounted to 21 to 54 bunches per grapevine at the C1, BR2 and LOR1 experimental plots, respectively (Figure 2A). The number of bunches was substantially lower at harvest in 2020 compared to the 2018 and 2019 harvests for the BR2 sandy clay loam experimental plot. In the 2020/21 season, fertility amounted to 21 to 68 bunches per grapevine at the LOR2 shallow sand and LOR1 deep sand experimental plots, respectively (Figure 2). In the 2017/18 season, berry mass ranged from 0.65 - 1.81 g per berry (Figure 2B). In the 2018/19 season, berry mass ranged from 0.93 - 1.40 g per berry. Except for the LOR2 shallow sand experimental plot, the berry mass was

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TECHNICAL YEARBOOK 2024