Page 611 - Enders_Game_Full_Book

The new strain of potatoes was dying. Ender saw the telltale brown circles in the leaves, the plants broken off where the stems had turned so brittle that the slightest breeze bent them till they snapped. This morning they had all been healthy. The onset of this disease was so sudden, its effect so devastating, that it could only be the descolada virus.
Ela and Novinha would be disappointed-- they had had such hopes for this strain of potato. Ela, Ender's stepdaughter, had been working on a gene that would cause every cell in an organism to produce three different chemicals that were known to inhibit or kill the descolada virus. Novinha, Ender's wife, had been working on a gene that would cause cell nuclei to be impermeable to any molecule larger than one-tenth the size of the descolada. With this strain of potato, they had spliced in both genes and, when early tests showed that both traits had taken hold, Ender had brought the seedlings to the experimental farm and planted them. He and his assistants had nurtured them for the past six weeks. All had seemed to be going well.
If the technique had worked, it could have been adapted to all the plants and animals that the humans of Lusitania depended on for food. But the descolada virus was too clever by half-- it saw through all their stratagems, eventually. Still, six weeks was better than the normal two or three days. Maybe they were on the right track.
Or maybe things had already gone too far. Back when Ender first arrived on Lusitania, new strains of Earthborn plants and animals could last as long as twenty years in the field before the descolada decoded their genetic molecules and tore them apart. But in recent years the descolada virus had apparently made a breakthrough that allowed it to decode any genetic molecule from Earth in days or even hours.
These days the only thing that allowed the human colonists to grow their plants and raise their animals was a spray that was immediately fatal to the descolada virus. There were human colonists who wanted to spray the whole planet and wipe out the descolada virus once and for all.
Spraying a whole planet was impractical, but not impossible; there were other reasons for rejecting that option. Every form of native life absolutely depended on the descolada in order to reproduce. That included the piggies-- the pequeninos, the intelligent natives of this world-- whose reproductive cycle was inextricably bound up with the only native species of tree. If the descolada virus were ever destroyed, this generation of pequeninos would be the last. It would be xenocide.
So far, the idea of doing anything that would wipe out the piggies would be immediately rejected by most of the people of Milagre, the village of humans. So far. But Ender knew that many minds would change if a few more facts were widely known. For instance, only a handful of people knew that twice already the descolada had adapted itself to the chemical they were using to kill it. Ela and Novinha had already developed several new versions of the chemical, so that the next time the descolada adapted to one viricide they could switch immediately to another. Likewise, they had once had to change the descolada inhibitor that kept human beings from dying of the descolada viruses that dwelt in every human in the colony. The inhibitor was added to all the colony's food, so that every human being ingested it with every meal.