Handbook for Irrigation of Wine Grapes in South Africa

*rapevine

0

A

30

60

90 150 120 90 60 30 0 30 60 90 120 150 Depth (cP)

0

B

30

60

90 150 120 90 60 30 0 30 60 90 120 150 Depth (cP) 0

C

30

60

90 150 120 90 60 30 0 30 60 90 120 150 Depth (cP) 0

D

30

60

FIGURE 4.29. Root distribution of Sultanina under (A) surface drip compared to subsurface drip irrigation installed at (B) 15 cm, (C) 30 cm or (D) 45 cm depths in alluvial soil in the Lower Orange River region (Myburgh, 2007a). Legend indicates roots per m 2 . 200 Distance IroP grapevine (cP) 200 - 400 400 - 600 ! 600 90 150 120 90 60 30 0 30 60 90 120 150 Depth (cP)

92 CHAPTER 4 – IRRIGATION SYSTEMS