Articles
INTERACTION OF JUGLANS SPECIES WITH PRATYLENCHUS VULNUS AND MELOIDOGYNE INCOGNITA
Article number
705_59
Pages
417 – 423
Language
English
Abstract
Nematode-free micropropagated own-rooted English cultivars Vina and Chandler and seedling rootstocks Northern California black (NCB) and Paradox hybrid were planted into a 0.5 m3 hole of sandy loam soil containing 100 Pratylenchus vulnus and two Meloidogyne incognita per 250 cm3 of soil volume.
Trees were farmed using micro-sprinkler irrigation with a 3 m by 4 m plant spacing.
Trees were removed from the field site after 7 months and all new root growth partitioned into three size groupings including fleshy root tips, secondary roots (<7 mm diameter), and primary roots (>7 mm diameter). These two nematodes preferred the fleshy root tips supporting 172, 293, 369 and 882/gram of root on NCB, Paradox, Vina, and Chandler, respectively.
Secondary roots supported 22, 117, 204 and 239/gram of root on NCB, Paradox, Vina, and Chandler, respectively.
Few nematodes were present in primary roots although these roots were produced in the presence of inoculum.
All Juglans spp. tested were susceptible or highly susceptible to P. vulnus. NCB was a poor host and non-galled by M. incognita, Paradox was intermediate, and the two J. regia cultivars proved susceptible.
When present, the root knot galls were normal-sized and occurred across the root system, but never on the fleshy root tips.
Paradox and J. regia cultivars occasionally developed 3 to 5 cm diameter galls on their secondary roots.
Planting into high populations of these nematodes can greatly restrict early root exploration by Juglans spp. Total tree biomass at termination of the experiment ranged from 3.9 kg/tree for the more vigorous Paradox to 2.3 kg/tree for own-rooted Vina. This difference was significant at P ≤ 0.05 with other growth differences being intermediate and non-significant.
Trees were farmed using micro-sprinkler irrigation with a 3 m by 4 m plant spacing.
Trees were removed from the field site after 7 months and all new root growth partitioned into three size groupings including fleshy root tips, secondary roots (<7 mm diameter), and primary roots (>7 mm diameter). These two nematodes preferred the fleshy root tips supporting 172, 293, 369 and 882/gram of root on NCB, Paradox, Vina, and Chandler, respectively.
Secondary roots supported 22, 117, 204 and 239/gram of root on NCB, Paradox, Vina, and Chandler, respectively.
Few nematodes were present in primary roots although these roots were produced in the presence of inoculum.
All Juglans spp. tested were susceptible or highly susceptible to P. vulnus. NCB was a poor host and non-galled by M. incognita, Paradox was intermediate, and the two J. regia cultivars proved susceptible.
When present, the root knot galls were normal-sized and occurred across the root system, but never on the fleshy root tips.
Paradox and J. regia cultivars occasionally developed 3 to 5 cm diameter galls on their secondary roots.
Planting into high populations of these nematodes can greatly restrict early root exploration by Juglans spp. Total tree biomass at termination of the experiment ranged from 3.9 kg/tree for the more vigorous Paradox to 2.3 kg/tree for own-rooted Vina. This difference was significant at P ≤ 0.05 with other growth differences being intermediate and non-significant.
Publication
Authors
T. Buzo, M. McKenry, J. Hasey
Keywords
J. hindsii, J. regia, J. hindsii × J. regia, own-rooted, micropropagated, primary roots, secondary roots, fleshy roots, nematodes/gram root, susceptible
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