Drought Effects on Annual Plants

Limited Plant Growth

• One of the ways annuals compensate for insufficient water is by slowing their metabolism way down, only distributing nutrients from water throughout the plant sparingly. This causes a reduction in their overall growth rate. “Productivity of annual plants generally will be reduced by drought more than that of perennial plants,” according to Texas A&M University Extension Specialist Larry Redmond. In "Effects of Drought on Plant Growth, he said that this is because annuals are not as deeply rooted as other plants, so they can't draw up as much water. Without enough water, plant growth is inhibited, resulting in minimized and delayed flowering and fruit production.

Pest Infestation

• Plants have different ways of protecting themselves. As they limit distribution of water during times of drought, their systems become weakened, making them susceptible to pests. Insects will invade malnourished plants for their own survival; eventually plants succumb to the onslaught of pests. When water is scarce, it is particularly important to protect plants against insects.

Inability to Heal Properly

• “When resources are limited, such as water during a drought, a plant must conserve its energy. It will favor growth and reproduction over protection because producing the protective, secondary chemicals requires so much energy,” said University of North Carolina Extension Specialist Barbara Fair in her article, “Coping with Drought.” Plant energy will work toward survival of the species by focusing on reproduction, as opposed to self healing.

Premature Death

• According to horticulturist James Burghardt, “Annual plants, those that germinate, grow, flower and seed and die within one growing season, are particularly at risk when drought conditions occur. The lack of soil moisture causes wilting and stunted growth, a hastened flowering and a shortened life.” Premature death can be the ultimate outcome when annual plants have insufficient water, Burghardt said in "Drought Effects on Annual Plants."