ABIDJAN, April 15 (Reuters) - A lack of rain combined with heat last week in most of Ivory Coast's main cocoa regions could reduce the size of the April-to-September mid-crop and and damage its quality, farmers said on Monday.

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

While the centre-western region of Daloa experienced above-average rains last week, most farmers across the other cocoa regions said a prolonged lack of adequate rainfall, combined with heat, could damage the development of small pods.

Farmers said some small pods were drying out on trees, but the situation was not yet alarming. They said if rains became regular and abundant from this week until June, growing conditions would improve.

"Now we need rain; the small pods are in danger," said Sebastien Koffi, who farms near the western region of Soubre, where 20 mm fell last week, 1.5 mm below the five-year average.

Similar growing conditions were reported in the southern regions of Agboville and Divo and in the eastern region of Abengourou, where rains were below average. Farmers there said they expected the mid-crop to be more abundant by mid-May, but that the weather could affect the size of beans.

In the centre-western region of Daloa, where rains were above the average, farmers said the weather was encouraging. But in the central regions of Bongouanou and Yamoussoukro, where rains were below the average, farmers had concerns.

"We will have quality problems because the dry spell has been long," said Etienne Aka, who farms near the central region of Bongouanou, where 19.3 mm fell, 4 mm below the average.

The weekly average temperature ranged from 28.9 to 32.2 degrees Celsius. (Reporting by Loucoumane Coulibaly; Editing by Portia Crowe and Kevin Liffey)