Historical reference to Singapore's lack of food sufficiency

Voyagers (Wang Dayuan) in the 15th century have observed that the island did not have much cultivar or padi (Wheatley, 1966)
Wheatley P (1966) “The Golden Khersonese: studies in the historical geography of the Malay Peninsula before A.D. 1500” Kuala Lumpur: University of Malaya Press, pp. 82

Dutch officer, Colonel Nahuijs, in a letter to his superior in Holland, wrote:
"The cost of living is very high as the island produces little or nothing"
Eze Nathan (1986) "The history of Jews in Singapore (1830-1945)" Herbilu Editorial: Singapore, p. vi