Peanuts grow well on sandy soils and are somewhat drought tolerant at certain growth stages. There are critical stages of growth that require higher levels of soil moisture or yields can be limited along with quality and lower grades. Table 3 shows four growth stages and the relative response of the plants to moisture during each stage.

The period of greatest water use occurs during pegging and is necessary to move Ca through soil solution to pegs and developing pods.

Peanuts are the least susceptible of any of the row crops in the Southeast to drought at planting since they will emerge from two to three inches deep if necessary. However adequate moisture is necessary for good, uniform stands.

Mid-season nut development is the most critical time for irrigation if there is a shortage of rainfall since it is the stage of maximum water use by the plant. In the Southeast the critical part of the development/fruiting period includes the latter part of July, August, and the first week or so of September.

Irrigation in the first two months after planting is usually not needed unless extremely dry conditions persist, because excess moisture can trigger excessive vine growth.

Irrigation in late September may result in excessive moisture during the peanut maturity stage and can increase the severity of CBR, Sclerotinia blight, and leaf-spot diseases.

In dry years, irrigation can suppress the outbreak of spider mites and lesser corn stalk borers, make digging operations easier and reducing the threat of aflatoxin contamination.