• Quality upside is clear: the netted block averaged 79% Grade 1 in field assessments versus an average of 60% without net.

• Wind protection appears to be the main win: wind damage dropped from an average of 51% (no net) to 23% (net).

• Albedo may still need management: albedo damage was slightly higher under netting in this trial (15% vs 11%).

• Profitability is fit for purpose: modelling outcomes pivot on install cost and replacement period (e.g. 15 vs 25 years), plus the individual circumstances of price, packout and site.

One block of late lane navels were netted as part of the 5 year trial.

WHEN citrus is destined for the fresh market, cosmetic defects can be the difference between a premium carton and a downgrade. Over five seasons, a protected-citrus trial compared a block of navel orange trees under overhead netting with two un-netted blocks (one on the property edge and one away from the property edge). The headline result is hard to ignore — netting consistently increased the share of fruit meeting Grade 1 standards.

But better fruit doesn’t automatically mean a better overall financial position. The economic modelling shows viability swings with at least four variables growers can’t afford to ignore: the install cost of net per hectare, how often it needs replacing, price return for fruit and the level of packout without net. Add in other factors not included in the modelling such as hail protection, water savings, sunburn sprays, and labour comfort, and the business case becomes an intentional decision to use net rather than a default.

Quality results: netting lifted Grade 1 packout

Diving into more detail, across five years of field assessments, there was an increase of 20% Grade 1 fruit in the netted block, averaging 79% Grade 1 fruit. The average for the un-netted blocks was 60% (Figure 1). Packshed results over three years showed the same pattern, with the netted block again leading.

One practical takeaway is that location matters. The edge block, being more exposed to wind conditions, delivered the lowest proportion of Grade 1 in both assessment methods.

FIGURE 1. Average proportion of fruit in Grade 1 based on field assessments of fruit grown ‘without net’ and ‘under net’ over 5 years.

FIGURE 2. Average proportion of fruit with wind, albedo or sunburn from ‘without net’ and ‘under net’ blocks over 5 years.

Even moving one block in from the boundary improved results in packout. Suggesting that potentially not all blocks would benefit enough from netting.

From this trial, and others, wind was the biggest driver of downgrading fruit (Figure 2). The un-netted blocks recorded an average of 51% of fruit with minor to severe wind damage, compared with 23% under netting. Sunburn was at an average of 4% of fruit in un-netted blocks, which was also lower under netting (0% fruit showing sunburn). Albedo breakdown was the exception: the netted block showed slightly more albedo damage (15%) than un-netted blocks (11%). There were several ‘bad albedo years’ within the 5 years of the trial. Albedo breakdown requires a combination of management options but does have a seasonal weather influence.

No hail damage at the site was recorded during the five years of the trial. Although hail did impact other citrus orchards in WA during the trial period. There was also no increase in pruning or pest management practices required between the netted and un-netted blocks.

The economics: netting pays—sometimes

An industry decision tool and the trial’s packout figures, were used to analyse when overhead netting becomes financially attractive. Four factors were incorporated into the analyses:

• Netting costs in the analysis were $70,000/ha and $100,000/ha. Prices increased during the trial, and costs also vary by materials and construction method. Funding grants usually reduce the cost per hectare, and usually still require a reasonable grower co contribution, for example current funding grant in WA.

• Replacement periods modelled were 15 and 25 years. Over the five-year trial, net damage mainly came from kangaroos creating holes in side netting. The level of holes didn’t increase over 5 years. Leaf build-up from windbreak trees directly adjacent to the netted block also accumulated on the top net, causing some sagging. No maintenance, other than tidying up edges of the holes was done during the trial.

• Level of Grade 1 packout within blocks A Grade 1 packout level of 56% within blocks was used as a threshold, based on the observed Grade 1 packout levels in the un-netted trial blocks. This threshold was then applied to assess how variations in netting costs, replacement intervals, and price impacted the cost– benefit analysis, with the aim of achieving a positive return and a payback period of less than 10 years.

• Price of fruit was incorporated by using the average price for each grade over the 5 years of the trial, as well as the highest price for fruit received over the trial.

History of blocks and site. As the analyses used average figures in the first instance, asking ‘In how many seasons would netting be ‘worth it’ at the various settings? On that basis, netting would have cleared the viability bar in 3 of 5 years for the edge block, and in only 1–2 of 5 years when benchmarked against the inner block, due to its existing higher packout without net. This therefore would affect the payback period.

Assumptions of the analyses were that a payback period of up to 10 years was acceptable as well as a cost/benefit ratio greater than 1:1.

The result, with potentially no surprises: viability is highly sensitive to net cost, replacement period, existing packout, fruit price and history of the blocks and site. Under a 25 year replacement assumption, the model indicated netting could be viable. Under a 15 year replacement assumption, it generally required stronger fruit prices to keep the cost–benefit ratio above 1. If the cost of netting is lower, via shared investment from the grower and a funding grant investor, the use of net is also more viable.

Testing the concept of using net with a range of citrus growers across WA, a concern was the cost and lack of insurance however they could still see value to investigate the use of net further on a range of their varieties, and particularly those of high value. Access to grants was also limited by ‘timing’ — in relation to the availability of capital funds to invest at the time that Grants were available, or the priority of netting compared to other capital investment required. The performance of other citrus categories such as mandarins and lemons under net has also not been quantified to do an analyses.

Looking ahead, growers noted that the increased risk of more frequent wind events, heatwaves and hail, water efficiencies and better working conditions could strengthen the case for netting. The value of these risk reductions is not captured in the current analyses.

What are others doing?

This trial was not conducted without consideration of practices and research globally. Overseas, in South Africa, across their citrus production regions net has been increasingly used. It is installed over the higher value blocks such as mandarins to prevent wind or hail damage in most cases (Study Tour, 2025). Depending on the region, specific hail netting or flat overhead netting was used. Early research investigated the potential for different pest issues under net and that some varieties were not suited. Normal practices such as pest monitoring and block selection allow for this to be managed.

In the eastern states, netting is also used in citrus for bee exclusion to produce seedless mandarins. Some of this netting was established with support from grants. For lemons and afourer mandarins under net, extra growth needed managing (Citrus Congress Study Tour 2018). Both these categories normally need pruning so was not considered an extra cost. Water saving by up to 20% has also been recorded from the use of net.

Similarly, in other horticulture crops, such as cherries, stonefruit and apples, in regions where the risk of hail is high, the blocks are netted. Research in WA quantified the difference in temperature and humidity under net and fruit quality. A few comments from these growers added to our findings to date, referring to the ‘net financial position’ (pardon the pun) when net is installed could be summed up by:

“It’s a transfer from production risk to financial risk”.

“It means you have confidence you’re getting a marketable harvest every year.”

Background for the trial

This trial was established to investigate future options for improving fruit quality in WA citrus orchards. The trial site already had managed natural windbreaks and despite this was still getting wind blemish on fruit. The potential of netting to improve the packout of first grade fruit, the related higher returns, and then flexibility of market destinations was tempting. At this site albedo breakdown, a disorder of the rind, known to be affected by the level of light, was already an issue, so there was some concern that overhead netting could make the issue worse, but ‘to what degree’ or if at all.

The establishment of this trial was possible through investment of matching funding from the State Government, DPIRD and Moora Group. Data was collected over the 5-year trial by the industry development manager, DPIRD technical officer and the grower and packer.

The trial was designed to help add clarity to the role of net by providing figures on the impact on packout.

Bottom line

Overhead netting delivered the most consistent lift in Grade 1 fruit across this trial, largely by reducing wind-related blemish. The harder question is financial. For growers weighing up the investment, the next step is to run the numbers with local quotes and realistic replacement assumptions, then layer in site and block-specific packouts, prices and additional risks (hail, heat events). Lastly add operational savings that the current model hasn’t yet captured, including its role in adapting to climate change. Further research could seek to understand the potential of net for adaptation to climate change and for other varieties. 

More information Contact Bronwyn Walsh, industrymanager@wacitrus.com.au or 0400 873 875.