Harvest will be here before you know it and now is the time to focus on food safety issues that can be avoided at harvest by being proactive before harvest begins. This topic has appeared in the ‘In A Nutshell’ newsletter before, but is it a message that is worth repeating. Why? Our reputation in the market is built on providing ‘quality’ almonds. That means free of chips and scratches, mould, staining, damage from pests and kernel at moisture levels which safe for storage by minimising the introduction of storage moulds and aflatoxin. The Australian almond industry can’t compete on the world stage in regard to tonnage or price, but we can deliver quality almonds that attract premium prices e.g. Barossa Shiraz vs hot climate goon.
Similar to the comments regarding harvest machinery, ensure areas around stockpads are free of debris from last year’s crop. Any trash containing almonds should be incinerated or buried deeply. Carpophilus Beetle can fly long distances so dumping the trash on another part of the property is not an option. Make sure to check kernels for any signs of insect or beetle activity as this could be a warning sign for storage pests in this year’s crop. If you do see signs of insect or beetle activity, consider setting traps to monitor populations before control methods are considered. Likewise, all mummies and windfalls in the orchard from last year should have already been swept into the midrow and destroyed by flail mowing. It’s critical to remove the habitat and food source for Carob Moth and Carpophilus Beetle before hull split and this year’s harvest.
Ensure all irrigation system repairs are completed, especially drip lines, submains and around valve/filter assemblies. If these items are constantly leaking, ruts can be formed in the row causing problems with sweeping and picking up at harvest. Any crop that is harvested into excessive wet areas (even if the area is small) can cause staining or promote Salmonella or Aflatoxin contamination. Another factor that is often not thought about is tree stress. Excessively wet soils (even if only around one tree) can cause long term tree decline through the introduction of secondary pathogens. Tree stress caused by overwatering can lead to a weakening of the trees defence mechanisms and allow the entry of Phytophthora and Bacterial Cankers.
One aspect of food safety that is often overlooked is the maintenance of the orchard canopy. If the canopy is dense and overgrown it might be wise to consider starting an orchard hedging program. The best hedging program I’ve seen, based on a 7m row spacing, is a wide cut at the top (about 1.5-2m) angled to a narrower cut at the bottom (1-1.5m). Only half the orchard should be hedged at a time and only every second row. The aim is to hedge the orchard over 4 years and then reassess the need to re-hedge after that. Most growers would be hesitant to embark on such a big hedging cut but if only a quarter of the orchard is done per year the impact on yield is minimised. The amount of new growth in hedged rows and increase in spur bearing wood in the lower canopy helps to offset yield loss from hedging. Hedging helps to reinvigorate new growth in the tree and, if carefully managed, will maintain long-term yields whilst not contributing to excessive shading. Excessive shading in an orchard can lead to increased food safety risks through delayed drying of crop at harvest and increased risk of Salmonella contamination. If the canopy is excessively shaded, another way of speeding up the drying of the crop is to ‘condition’ the windrows after sweeping i.e. run the pickup over the windrow to remove the dirt and leaves and then place back into a windrow for further drying. A simple chute can be fitted to the back elevator on the pickup to put the crop back into a windrow. With the windrow now on top of the ground instead of half buried, it will dry faster. Alternatively, removing the crop from the orchard completely and spreading on headlands or vacant areas may be needed to dry the crop more quickly.
Check all machinery to make sure there is no residue of last year’s old crop that can contaminate this year’s new crop. Residue from the old crop that are mouldy and/or full of insects will put this year’s crop at risk. Mould spores could be transferred to the new crop if conditions are suitable and likewise storage pests can move from the old crop to new crop. Even if the new crop is not directly contaminated, there’s always the potential for quality downgrades at the processor if some of the old crop is mixed in with the new crop.
Food safety starts in the orchard! It should be the aim of every grower to produce and deliver the best quality almonds possible for the kernel market. If more product is needed for secondary processing those segments can be supplied accordingly. However, if almonds are delivered with Carob Moth damage it will never make the grade, hence reducing potential marketing options. Whilst all processors have adopted pasteurisation protocols to improve safety, it should not be an excuse to deliver poor grade product. Poor grade product adds to the cost of processing and slows down the production line i.e. instead of operating at a capacity of 7T/hr, processing is reduced to 3T/hr due to hand sorting required to removed defect almonds. In the worst case, marketers may have to sell an inferior grade specification product to a customer at a lower price. In the end, costs of production go up, revenue from sales go down and the reputation of Australian almonds in the world market takes another hit.