A na-emepụta ihe ngwọta ntụ ọka anyị nke ọma dịka ọka wit America na ọka wit siri ike nke Australia.Mgbe a na-egwe ọka wit, ọnụego mmịpụta ntụ ọka bụ 76-79%, ebe ntụ ntụ bụ 0.54-0.62%.Ọ bụrụ na emepụtara ụdị ntụ ọka abụọ, ọnụego mmịpụta ntụ ọka na ọdịnaya ntụ ga-abụ 45-50% na 0.42-0.54% maka F1 na 25-28% na 0.62-0.65% maka F2.