The Roman goddess Robigo (or perhaps god Robigus; the gender is uncertain) was invoked to protect grain fields from diseases such as mildew and wheat rust. She was seen as a very ancient, and destructive, goddess. The festival in her honor, Robigalia, was held on April 25, when the crops were most susceptible to disease. Rituals included burning the entrails of a red dog and a sheep, and offerings of incense and wine.
The Roman poet, Ovid, quotes the ceremony's flamen (priest) as follows:
"Cruel Robigo, do not injure the young wheat; let its tender tip quiver on the surface of the ground. I beg you to allow the crop, nurtured under heaven’s propitious stars, to grow until it is ripe for harvest. Yours is no gentle power. The wheat which you have marked, the sorrowful farmer counts as already lost. Neither winds nor rain harm the wheat so much, nor does the nip of the white-glistening frost so fade it, as the sun scorches the wet stalks. Then this is the occasion for your anger, dread goddess. Forbear, I pray you, and take your rough hands from the harvest; and do not harm the farmer’s work. It is enough that you have the power to do harm."
When I first learned that Robigo was the goddess of mildew, I chuckled. It seemed oddly specific, and I wondered if maybe she was a little miffed that she didn't get a better job. Goddess of love, maybe. Or wine. Or chocolate. But after I read Ovid's account, I thought, wow, she sounds like a badass, and the Romans were really afraid of her. It makes sense that they would want to safeguard their crops from her influence, because a few years of bad harvests can lead to famine and all kinds of societal ills.
I'm not 100% sure the statue above is Robigo, but she looks pretty intimidating. Dread goddess, indeed!