Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 19, 2007
Publication Date: October 1, 2006
Citation: Rowland, D., Faircloth, W.H., Butts, C.L. 2006. Effects of irrigation method and tillage regime on peanut reproductive processes. Peanut Science. 32:48-56. Interpretive Summary: Many concerns have been voiced by growers that conservation tillage would interfere with peanut reproduction, namely the formation of flowers and pegs. However, there are great benefits to conservation tillage via lowered soil erosion and water loss. Therefore, the objective of this study was to determine if there were any differences between a conventional tillage system and a conservation tillage system that had at least 30% cover over the surface of the ground. The effect of irrigation system was also tested by comparing overhead application with subsurface application of water through a tape system buried 10-12 inches belowground. Counts of the number of flowers, pegs, and pods formed were taken every 3-4 days for 6 weeks and simultaneously every 30 days for the entire season. In 2004, flowers were permanently tagged so that the production of pegs from flowers could be followed closely. Very few differences were detected between the two tillage systems with the only real detriment to conservation tilled peanuts under subsurface drip irrigation. Therefore, it was concluded that there were no ill effects of conservation tillage on the reproduction of peanuts.
Technical Abstract: Conservation tillage use in peanut (Arachis hypogaea L.) is becoming a favorite choice of many growers. However, grower concerns have arisen about the possible deleterious effects of minimum till systems on peanut reproduction, specifically in regards to interference of pegging by the cover crop residue. The interaction between tillage and irrigation could also play a major role in the final yield of the crop. Therefore, this study was conducted to determine what, if any, effects tillage (conventional tillage – CT and strip tillage – ST) and irrigation method (overhead – OH and subsurface drip – SDI) had on peanut reproductive processes. The main objectives of this study were to: 1) quantify the differences in flower, peg, and pod formation between ST and CT systems; 2) determine if irrigation treatments within these tillage systems affected these same processes in both OH and SDI irrigation treatments; and 3) correlate climatic conditions with reproductive processes to determine their effects and interactions with tillage and irrigation treatments on peanut reproduction. Reproductive counts were conducted on two time scales: every 3-4 days for six weeks during peak flowering and peg production; and season long starting at 30 days after planting and continuing until harvest. In 2004, flowers were permanently tagged and the percent and time elapsed for peg production was measured. Few differences between tillage treatments were found at the fine scale time series: ST peanuts produced significantly more flowers in 2004, but had lower percentages of peg formation from tagged flowers, thereby resulting in no differences in pod production between the two tillage systems. Season long counts revealed no significant effects of tillage or irrigation on flowers, pegs, and pods. Deleterious effects of SDI when combined with CT were found, suggesting the use of the two management systems together be avoided.