Rainout Shelter-Induced Water Deficit Negatively Impacts Peanut Yield and Quality in a Sub-Humid Environment

Abstract

Water deficit significantly reduces yield potential of peanut ( Arachis hypogaea L.) worldwide. This study investigated the effect of water regime on yield, grade, and oil composition of eleven peanut genotypes in a sub-humid environment. Water regimes were achieved by covering the plots from mid-July to early Sep with rainout shelters and irrigating the plots to pre-determined levels: well-watered (WW) regime received full irrigation of 40 mm weekly, moderate deficit (MD) 17 mm weekly, and severe deficit (SD) only 40 mm in one “survival” irrigation in late Aug. Results showed that MD and SD negatively impacted peanut yield and grade, with consequent reduction of the economic value. Compared with WW, economic value was 24% less under MD and 68% less under SD. Small seeded runner cultivars, ‘Florida 07’ and ‘Georgia 06G’, had higher yield and grade than Virginia-type cultivars under deficit irrigation, in particular under SD. Among the Virginia-type, ‘Sugg’ had highest yields under SD but was out yielded by ‘Bailey’ and ‘Phillips’ under MD. ‘Wynne’ and ‘Spain’ are the largest seeded Virginia-type cultivars; they performed poorest for yield and grade. Water deficit reduced the relative proportion of oleic (C18:1), and increased linoleic (C18:2) fatty acid and total saturated oils of the seeds with intensities depending on the genotype. Finally, the rainout setting used provided comparative results with real farm peanut production in the region; this is important for breeding programs in Virginia and Carolinas, where rainfall unpredictability does not allow for drought screening in an open field setting.

Tolerance to mid‐season drought in peanut can be achieved by high water use efficiency or high efficient use of water

“…Among the drought‐tolerant genotypes, PI 502120 and PI 493329 in 2019, and AU16‐28 and G06G in 2020 were the highest yielding genotypes. Our results coincide with previous research that showed PI 493329 and G06G as drought tolerant (Balota, 2020; Otyama et al., 2019). On the other hand, genotypes PI 339960, PI 390428, and AP‐3 (in 2020) showed the lowest yields under drought in both years (Tables 2 and 3), therefore demonstrating that these genotypes are drought sensitive.…”

“…This study consisted of irrigated and drought treatments. The mid‐season drought treatment was successfully achieved by the utilization of the rainout shelters, causing mean yield losses of 57.5% and 35.2% in 2019 and 2020, respectively, which is similar to other peanut trials under true drought field conditions (Balota, 2020; Rucker et al., 1995). Some greenhouse studies indicated that mid‐season drought, the type of drought that was implemented in this experiment, can cause a decrease in yield of approximately 35% (Carvalho et al., 2017; Junjittakarn et al., 2014).…”

Phenotyping Peanut Drought Stress with Aerial Remote-Sensing and Crop Index Data

“…Drought severely constrains peanut (Arachis hypogaea L.) production worldwide [1]. Reduced soil moisture during peanut flowering and pegging causes a severe reduction in the pod yield [2][3][4][5][6][7][8][9]. Drought stress reduces seed germination and vigor [8], impedes calcium (Ca) uptake [10,11], reduces nodulation and nitrate reductase activity [12,13], increases Aspergillus flavus mold contamination [14][15][16], and decreases oleic-to-linoleic fatty-acid ratios in seeds, which is detrimental to peanuts' shelf life and nutritional qualities [17].…”