農家によりますと、ことしはスイカが成長する5月中旬から下旬にかけて寒暖の差が激しかったことから数は少なめですが、しまの入り具合など品質は例年並みだということです。(source)
1)I'm not sure if しま means "island" (because it is written in kana and I don't think this word is generally written in kana but maybe I'm mistaken )
2)I don't find 入り具合 in the dictionary(and jisho.org tells that it can be a suffix but not a prefix so I don't think it is a word that is not supposed to be in the dictionary), I think it means the general conditions (of the cultivation) but it doesn't make sense because apparently 品質 is only used for talking about things that are in the 品物 category.
(I consider "しまの入り具合など" as a relative clause of 品質, maybe it is wrong)