mmg.com.au

Some Goulburn Valley growers stand to lose as much as 20 per cent of apple and other fruit crops to sunburn after recent prolonged hot weather.

While people sweltered in temperatures above 40°C, spare a thought for fruit. Bureau of Meteorology air temperature measurements are taken in shade, but sun-exposed fruit surface temperatures are normally 10º to 18ºC higher than the official measured air temperature.

Orchardist Rocky Varapodio at Ardmona uses kaolin clay-based products to spray the fruit for sun protection, but said due to the heatwave some of his fruit would be reduced to juicing apples — a borderline ‘‘break square’’ proposition.

He said the maths was not difficult: apples attract $2/kg as fresh produce and 15¢/kg for juicing.

‘‘That’s barely recovering costs,’’ Mr Varapodio said.

While it was a bit early to put a figure on it, he estimated 15 to 20 per cent of his apple crop was sunburned.

‘‘Pears are usually a bit more tolerant,’’ Mr Varapodio said.

Neighbour Chris Turnbull from Turnbull Orchards said the family’s large investment in protective netting over Granny Smith apples — which also helps against hail damage — would pay dividends.

‘‘We have only had them for one season. The nets aren’t 100 per cent effective, but they certainly do help — I imagine we will have some discolouration of the fruit,’’ Mr Turnbull said.

Not all Turnbull apples are under nets.

‘‘We have had a bit of damage; we get some sun damage every year and we are probably going to have a bit more this year,’’ Mr Turnbull said.

Horticulture experts say air temperature is normally the most convenient indicator of sunburn risk.

DPI says every year sunburn causes some damage to fruit growing commercially in northern Victoria, and while orchardists estimate fruit losses can vary from six to 30 per cent, depending on the season and the type of fruit, losses in susceptible varieties such as Granny Smith and Gala apples have been as high as 40 to 50 per cent in some years.

Ardmona grower Andrew Plunkett said: ‘‘We’ve not lost any burned fruit and haven’t had any problems with over-ripening. There’s been some burning here and there.

‘‘The heat may have slowed down fruit growth because the trees have been just trying to keep their leaves moist.’’

He said the excessive heat had arrived towards the end of the apricot canning season.