No, the whole point of the article is that for the workers it is always 7 days no matter whether it is 35, 40 or 48 "hours", since external costs like child care stay fixed. So the expensive resource decidedly is not labor but time.
On the other hand, it would then take them longer in terms of calendar days to get the same income, and all their other expenses are likely to stay the same. If they normally moved on to other jobs after the harvest, this would mean reduced overall income. Also, the difficulty of the job is factored into the pay they receive (the article specifically says their hourly wage is higher than normal farm labor), so they would likely be paid less for this less demanding crop. It still doesn't seem like much of a solution.