ABIDJAN, Aug 16 (Reuters) - Heavy rains across most of Ivory Coast's cocoa-growing regions last week have rekindled hopes for an early start to the October-to-March main crop, farmers said on Monday.

The world's top cocoa producer is in its rainy season, which runs from April to mid-November.

After several weeks of cold weather and below-average rainfall, farmers across the cocoa belt welcomed last week's storms with enthusiasm.

If similar weather stretches into September and October, it could bode well for the size and duration of the upcoming main crop, farmers said.

In the centre-western region of Daloa, which produces a quarter of Ivory Coast's national cocoa output, farmers said their trees were heavy with fruits of different sizes. Some are already planning to begin harvesting by mid-September.

"The main crop is looking good. With a lot of sun and rain in the coming weeks, we will have a lot of picking to do in October," said Jean Akessi, who farms near Daloa, where 51.4 millimetres (mm) of rain fell last week, nearly double the five-year average.

Rainfall was also well above average in the central regions of Bongouanou and Yamoussoukro, where farmers expressed similar enthusiasm for the main crop.

Others stressed that while good rains are important, adequate sunshine would also be needed to ensure healthy development.

In the western region of Soubre, the southern regions of Agboville and Divo, and the eastern region of Abengourou, farmers said more sunny spells would be needed in order to stop disease from spreading through their plantations.

"There is too much moisture under the trees. More heat will be needed for enough pods to survive," said Salame Kone, who farms near Soubre, where 20.2 mm of rain fell last week, 5.2 mm above the average.

Average temperatures across Ivory Coast last week ranged from 24.6 to 26.7 degrees Celsius. (Reporting by Loucoumane Coulibaly; Editing by Cooper Inveen and Jan Harvey)