The bank - which had forecast that soft commodities would put in a firm end to 2013, contrasting with a weak finish by grains – maintained its forecast for New York cotton futures to average 85 cents a pound in the last quarter of 2013, up 9% from the first quarter.

On other soft commodities, it accentuated the idea of a recovery, notably for sugar, in which it raised its estimate for fourth-quarter prices, while lowering hopes for futures early in 2013.

"Our sugar forecast was lower for the first half of 2013 on expected mill selling, but higher in the second half on anticipated investor short-covering," the bank said.

Competition for cane

Mills in both Brazil and Thailand, the top two exporting countries, are "undersold", the bank said, implying delayed selling pressure yet to be released on to futures already suffering under the weight of three successive seasons of production surplus.

And the prospect of "another surplus in 2013-14 suggests prices need to encourage growers to reduce output", the bank added.

However, the surplus will be limited thanks to a switch in cane producers to making ethanol, rather than the sweetener, which will become apparent as the Brazilian crushing season unfolds, encouraging hedge funds to close short positions.

Managed money, a proxy for speculators, hiked its net short position to more than 25,000 lots in the week to last Tuesday, the biggest on record.

Rabobank - forecasting that ex-mill Brazilian ethanol prices will average R$1.27 a litre in 2013-14, equivalent to 18.8 cents a pound in sugar terms – estimated sugar attracting 46% of cane harvested in the country's key Centre South region in 2013-14, down 3.5 points year on year.

'Modest uptick'

For New York arabica coffee futures, the bank dropped its price forecasts throughout 2013, but in particular for the first two quarters.

"As the Brazilian harvest begins, we anticipate short-covering to result in a modest uptick in New York prices," with the outbreak of disease in Central America also boosting price sentiment.

Estimates for London robusta prices were left unchanged, underpinned by an estimate of a 7% drop in output from Vietnam, the top producer of the bean variety.

In cocoa, Rabobank cut its forecasts for prices near-term, citing pressure from producer hedging ahead of West Africa's mid-crop.

However, market dynamics for the second half of the year, "are more supportive", as selling from producers dries up, while grindings rise sufficient to leave a cocoa market deficit of 43,000 tonnes for 2012-13.