Effects of sodium molybdate foliar sprays on molybdenum concentration in the vegetative and reproductive structures and on yield components of Vitis vinifera cv. Merlot
Molybdenum deficiency(Mo-deficiency) has been suggested to be the cause of poor yield of own-rooted Merlot vines in Australia. The aims of these experiments were to quantify the effect of foliar molybdenum treatment (Mo-treatment) on vine molybdenum status and to identify which components of yield are affected by Mo-treatment. Methods and Results:
Experiments were conducted on own-rooted Vitis vinifera cv. Merlot in South Australia in 2003–07. Vines were sprayed with two rates of sodium molybdate (0, 0.101 and 0.202 g/vine) in the spring. Vine molybdenum status was assessed at flowering and juice molybdenum concentration was measured at harvest. The effects of Mo-treatment on vine growth and yield were also measured. Mo-treatment significantly increased yield of molybdenum deficient vines, a function of improved fruitset. Mo-treatment significantly increased the concentration of molybdenum in the petioles, shoot tips and inflorescences compared with the controls. Budburst was delayed on molybdenum-treated vines in the spring following Mo-treatment. The concentration of molybdenum in grape juice only increased in vines that had sufficient molybdenum. Conclusions:
Mo-treatment increased vine molybdenum status; however, yield only increased on Mo-deficient vines. The increase in yield was a function of improved fruitset. Significance of the Study:
This research demonstrates a significant positive relationship between vine molybdenum status and fruitset of own-rooted Merlot vines.
Document Type: Research Article
Affiliations: 1: School of Agriculture, Food and Wine, Faculty of Science, The University of Adelaide, PMB #1, Glen Osmond, SA 5064, Australia 2: Faculty of The Sciences, The University of New England, Armidale, NSW 2351, Australia
Publication date: 2010-10-01