Durian is one of the most important tropical fruits and is often
referred to as the king of tropical fruits in South East Asia. Thailand
is regarded as the leader in durian cultivation and the largest supplier
and exporter of top quality durian (Food Market Exchange,
2003). However, the export industry has been faced with the problem
of immature durian. At present, fruit is harvested by evaluating
the number of days after anthesis (DAA), sound pitch after
tapping, stem flexibility, or spine tip color (Siriphanich, 2011).
DAA is an objective method but requires laborious flower tagging
at full bloom. The other mentioned techniques are subjective when
they are measured manually.