Almond yields hitting new highs with careful disease management
12 December, 2018
12 December, 2018
Image: Hugh and Scott take a closer look at the side pruning of trees, allowing more light into the Loxton almond orchard.
Century Orchards was established in 1998. The crop is processed through the Laragon Almond Huller and Sheller facility at Lindsay Point before being marketed by Nut Producers Australia.
The Loxton orchard comprises 480 hectares of fully mature trees, 60 ha of five-year-old trees and a further 60 ha that has been recently planted to almonds following the removal of grapevines.
Fifty per cent of the orchard comprises the Nonpareil variety, in addition to Carmel, Monterey, Price and Peerless pollinator lines, while three new varieties from the Almond Board of Australia, of which two are self fertile, have also been planted.
The main orchard comprises 260 and 285 trees/ha, incorporating 7-metre row widths by 5.5 m tree spacing, with 4.5 m spacing for newer plantings.
A dual drip irrigation system emitting 1 millimetre per hour is predominantly used on the property’s mainly sandy soils, while micro sprinklers throughout the orchard are used to help establish cover crops, for frost protection and to build early soil profiles and leach salts.
Technical / Operations Manager Scott McKenzie, originally from Swan Reach and who has been working at Century Orchards the past four years, said hull rot was the biggest concern in their almond crop.
“It (hull rot) really only came in after two wet years and with our high input program,’’ Scott said.
“In those two wet years, we had trouble getting the crop off and out of the orchard, which built-up mummy carryover and, in turn, hull rot spores. Growers are also increasing their fertiliser and water rates, which again can promote hull rot.
“If you have rain in January and February here, you will get hull rot. You get the primary infection and then you get the secondary infection from carob moth because of the mummies left in the trees.’’
He said they had successfully trialled the unique Luna® Sensation fungicide against the disease with Bayer and also had implemented other management strategies to help minimise hull rot.
Luna Sensation combines the active ingredient, fluopyram, a novel chemical within the SDHI family, with trifloxystrobin and was the first product registered in Australia to help with the management of hull rot, while it is also highly effective against blossom blight, shot hole and rust. It is already well established in the Californian almond industry.
Importantly, Luna Sensation provides another fungicide option for growers, helping to reduce the reliance on some older fungicides and assisting more sustainable disease management. It also targets the key diseases in apple, pear and stone fruit crops.
Scott said the product had been used as part of the full program at the Loxton property, applied at 40 mL/100 L of water through large Air-O-Fan air-blast sprayers featuring 114 spray jets.
“Luna (Sensation) is not controlling it 100%, but we are not seeing the dieback on the spurs. We were losing half a foot of wood in some spots.’’
Being a bit systemic, we are seeing a reduction in spur deaths with Luna (Sensation).
“We did some spur counting with the trial work and we were finding better spur retention. As a result, we have a lower mummy count now.
“We also noticed better leaf retention and so there was better uptake of post-harvest fertiliser – and we did have a better season the following year. We were putting the trees to bed better.’’
Bayer Business Development Manager Hugh Armstrong confirmed that using Luna Sensation helped overall shoot health and vigour in the first year of application, contributing to healthier and more vigorous trees in the following season.
Scott said after harvest, they have implemented a second shake of the trees during winter to remove any retained nuts and reduce disease carryover.
“We blow the old nuts into windrows and destroy them. We would rather spend money on shaking and windrowing than on another spray during the season,’’ he said.
The comprehensive management program is helping to increase yields. While the average industry yield is around 3 t/ha, Century Orchards’ Loxton property has achieved an average of 4 t/ha – including up to 5.3 t/ha – over the past five years.