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Why do herbicide-resistant crop varieties produce higher yields?
Literal
Herbicide-resistant variety [with-で] why yield [subject-が] increase [explanatory-の][question-か]?
A short technical question, the kind you'd find heading a research article or popular-science piece. 除草剤耐性品種 stacks four sino-Japanese morphemes: 除草剤 ('herbicide,' lit. 'weed-removing agent') + 耐性 ('resistance, tolerance') + 品種 ('variety, cultivar'). This kind of heavy compound is typical of technical vocabulary, where Japanese routinely builds new terms by chaining morphemes rather than borrowing. The で here is the locative/instrumental — 'in/with [the variety],' marking the subject of inquiry. The のか ending is the explanatory question form, asking for the underlying reason rather than a yes/no answer.