 If the marocca plants happened to die during transport, what would be one logical explanation for why they died based on the conditions they needed to survive in the article?
Transshipped seeds invariably failed to germinate, which explained its rarity. But when I offered them a sizable piece of cash plus a perpetual share of the profits for letting us take a load of marocca plants to Gloryanna III, they relented and, for the first time in history, gave their assent. But our tests showed that the plants had enough tolerance to cause no trouble in the trip in Delta Crucis ." "You'll remember that I warned you that we should take some marocca out into space and solve any problems we might find before committing ourselves to hauling a full load of it?" asked Captain Hannah. If we had gone through all of that rigamarole, we would have lost the franchise.
 An error on the spaceship caused the artificial days and nights to not be equal length.
 The temperature of the environment did not vary enough and was too stagnant for the plants.  The carollas decided to start eating the dingleburys instead of vice versa.  An error on the spaceship caused the artificial days and nights to not be equal length.  The spaceship was not correctly simulating all the seasons that the marocca needed to be subjected to in order to grow.