Effect of Cultivar, Fungicide Program, and Harvest Date on Germination and Vigor of Saved Peanut Seed.

Peanuts (Arachis hypogaea L.) are susceptible to many foliar and soil-borne diseases. In order to promote and maintain plant health and yield potential, fungicides are used to provide effective control against many of the diseases that negatively affect peanut. However, information is lacking these fungicides applied over the season affect germination and vigor of peanut seeds saved for the following season. A field experiment was conducted in Tifton, GA in 2019 to determine the effects of selected cultivars, fungicide programs, and harvest dates on peanuts grown for seed. Seed treatments consisted of two peanut cultivars, three fungicide programs, and four harvest dates. The cultivars were Georgia-06G and Georgia-09B. Fungicide programs were Bravo Weather Stik (chlorothalonil), Bravo Weather Stik plus Tebuconazole, and Elatus (azoxystrobin, Solatenol). The four harvest dates corresponded to 2400, 2500, 2600, and 2700 growing degree day units (GDDs). The experiment was arranged in a randomized complete block design with four replications of each treatment. Germination and cold germination percentages were assessed on seed from each treatment prior to planting. Stand counts were taken at 9 and 14 days after planting (DAP). Seedling vigor was evaluated at 9, 14, and 28 DAP. Results indicated that germination and cold germination were reduced when harvest was delayed until 2700 GDDs. Harvest date impacted stand counts at 9 DAP, with greater stand counts for seed from 2400 and 2500 GDDs than those from 2700 GDDs; however, by 14 DAP stands were not significantly different indicating slower emergence in seed from the later harvest dates. In addition, seedling vigor was significantly greater for seed from 2400 GDDs compared to seed from 2700 GDDs. Georgia-09B had significantly higher stand counts and greater seedling vigor than Georgia-06G. Fungicide program did not significantly affect any of the parameters assessed in this study.