IDENTIFYING IMPROVED ROOT AND POD MATURITY TRAITS IN PEANUT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1008766
• Project Start Date: Nov 19, 2015
• Project End Date: Nov 6, 2018
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016

Performing Department
Crop & Soil Sciences

Non Technical Summary
Peanut is a remarkable crop with the ability to rebound from adverse weather and pest conditions and produce respectable yields. Within the collection of peanut germplasm there is diversity in root growth, peg distribution on the vine, pod maturity, seed size, abiotic and biotic stress tolerance/resistance. Our goal in this project is to identify peanut germplasm with improved root and pod maturity traits for SE U.S. peanut production. We expect this information to be used by growers, extension and research scientists - particularly genetics and breeding. Consumers will benefit from improved food quality, as better harvest timing leads to improved flavor and nutritional charteristics.

Animal Health Component

40%

Research Effort Categories

Basic

30%

Applied

40%

Developmental

30%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
206	1830	1020	25%
201	1830	1081	25%
201	1830	1080	25%
102	1830	1020	25%

Knowledge Area
206 - Basic Plant Biology; 102 - Soil, Plant, Water, Nutrient Relationships; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1830 - Peanut;

Field Of Science
1081 - Breeding; 1080 - Genetics; 1020 - Physiology;

Keywords

arachis hypogaea

drought tolerance

harvest timing

water use efficiency

Goals / Objectives
Gather/generate peanut genotype-specific information on root and shoot growth, pod growth and maturity profiles, peg strengths and lengths, pod and seed size, yield, quality, and pod loss information that will enhance genotype selection for both production and plant breeding.

Project Methods
We will use the following peanut varieties in the root and maturity studies- Georgia - 06G, Tifguard, Georgia 09B, Georgia 12-Y, Georgia 13M, Georgia 14N, Georgia Greener, and TUFRunner 511. We will also assess another 12 breeding lines that are close to release.Traditional techniques for the field study of root growth usually require extensive monitoring devices and a large labor force. We have developed a simple field technique to study root growth and uptake of water from different soil depths using the carotene-inhibiting herbicide, fluridone. This herbicide does not move in the soil, and by placing underground bands of the herbicide using a subsoil tine with a nozzle at different depths (7", 14", and 21" below the surface) we know when peanut roots reach those depths because the leaves will bleach out. After the bands of herbicide are placed, we work the soil above the band to prevent roots from simply following the subsoil slot. We then hand plant the peanut lines in 10 ft long rows at a 23° angle to the band. As the plant roots grow into the band and absorb water - and the herbicide - the new growth turns white (see white in small plant). Three times a week for the entire season, we measure the horizontal distance from the band (using a string on soil surface) to the farthest plant showing leaf bleaching, and this gives us the information we need to generate a root growth profile for each peanut line.We will compare these field root growth results with root and shoot development measurements from the same lines using 3 and 5 foot long sand columns in which we will plant the peanut lines mentioned above. Growth measurements (shoot and root) in these columns will be made at 30, 60 and 90 days after planting by removing the plants, washing out the roots. Because it has long been known that seed size also plays a key role in early plant development, we will also determine its effect on root growth within and between varieties.To develop the data needed to produce variety specific hull-scrape maturity profile charts we will use large replicated plots and gather the following information on each variety/breeding line from these plots:Days to 1st flower, and flowering patternNumber of days from flower to peg entering soilNumber of days in white, yellow, orange, brown and black categoriesIndividual seed development periodPod stem strength after seeds are fully maturedEffect on yield when optimum harvest is missed5 harvest dates - 1 & 2 weeks early, optimum, 1 & 2 weeks latePods lost in soil during harvest (during digging - during combining)The math imbedded in the hull-scrape chart is cultivar dependent, and the above information will provide the needed information to adapt the chart for each variety. The current chart has 25 columns - each representing 3 ½ days of development time after the peg enters the soil. Full seed weight occurs when the pod first enters the black category (the 20th column - which represents 70 days of seed growth). Back when we first developed the profile board we determined from multiple digging date experiments, that the Florunner pod stem was likely to be too weak to harvest the pod, 21 days after the seed reaches maturity - thus there are 6 columns in black - representing 21 days. The chart uses the first column on the right with 3 pods in it to predict best harvest date. This column represents the break-even point - when pod weight loss equals the weight gained by the rest of the pods. The reason for 3 pods is that the chart is based on the use of approximately 200 pods. Three pods (each with 65 to 70 days of growth) represent the same amount of weight gained by the rest of the pods on the chart gain each day.Using the above information gathered on each genotype, we will adapt the current hull-scrape maturity profile chart for current SE peanut varieties. Adjustment of the chart for earlier and later maturing varieties can be accomplished easily by developing a variety specific "days to digging" bar that can be laid over the current numbers at the bottom of the chart - making it simple for farmers and Extension agents to use the same chart for many varieties. Thus for earlier maturing lines each column may represent less than 3.5 days, and for later genotypes or ones with stronger pod stems or smaller seed the columns may represent more than 3.5 days.In our trials we will conduct additional cultivar specific yield impact research using large plots and multiple digging dates at several locations - thus helping provide supplemental information on the effect of soil type. Of course other information including plant health, impending weather, acres to be covered, labor and equipment constraints and status of other fields are other considerations that must be taken into consideration along with pod maturity when scheduling peanut harvest.

Progress 11/19/15 to 11/06/18

Outputs
Target Audience:Growers amnd Extension agents Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Presentatiojns at Extension and Professional Society meetings provided those attending with up-to-date information on how to best adapt the hull-scrape chart to new varieties. How have the results been disseminated to communities of interest?Through Extension production guides, journal articles, Extension meetings, and popular print and broadcast medias. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The hull-scrape peanut maturity profile chart has been used for decades to predict optimum harvest date windows for peanut varieties. The chart, developed for the Florunner cultivar, is still used for current cultivars, yet adjustments to the chart improve its function. Cultivars with improved disease resistance, and production practices that reduce disease incidence will increase the harvest window, and enable growers to delay harvest for 7 to 10 days beyond the chart's prediction date. This generally results in increased yield and quality. Severe weather events at harvest can significantly alter yield and quality. For example, in 2017 studies, the increased rainfall and humidity from Hurricane Irma drastically increased disease pressure, and those cultivars with improved disease resistance, and the production practices with improved disease control (rotation and plant protectants used) resulted in significant gains. Vine condition is as important as hull color when using the hull-scrape to determine when to dig, If the vines are in good shape, the harvest window for optimum yield and quality will be longer. Proper harvest scheduling can result in yield increases of 20% or more when compared to digging dates only 14 days before or after optimum. Yet, along with an assessment of the maturity profile, disease control, weather and labor and equipment are key to establishing the best harvest date for a field. To evaluate a select group of genotypes for root system development we used single row plots, 3 m long, planted at a 23-degree angle to a band of the carotenoid-inhibiting herbicide fluridone (a minimally water-soluble compound not subject to leaching). The herbicide was banded at three depths using a technique much like the installment of plastic subsoil drip tubing, except that the herbicide band was sprayed into the soil at the base of the subsoil shank. Using this arrangement, one hectare of land could host 5,500 plots. Thus a root growth screening program using three band depths and 6 replications could include 300 genotypes per hectare, or 900 genotypes if only one band depth was used. Observations and measurement of the plots was relatively quick at 160 plots per hour per observation date. Field preparation of the site including banding of the herbicide and tillage before and after banding was relatively easy, yet, hand planting of the rows at an angle to the band required additional time. Genotypes included breeding lines previously selected for drought tolerance or for drought sensitivity. The effective volume of water extraction for drought sensitive genotype A100 was less than half the volume of the drought tolerant selections C431-1-1, C431-1-7, and C75-13. The results established the feasibility of using this method in a drought tolerant breeding program.

Publications

• Type: Other Status: Published Year Published: 2018 Citation: Monfort, W. S., Pilon, C., Kvien, C. K., Prostko, E. P., Kemerait, R. C., Brenneman, T. B., . . . Abney, M. (2018). Georgia Peanut Production Guide. W. S. Monfort (Ed.). https://indd.adobe.com/view/66d34c10-df72-4e32-8d4d-5ceb468f8117

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Growers and Extension agents. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Presentations at meetings with Extension and growers provided those attending with up-to-date information on how to best adapt the Hull-Scrape Technique to current varieties. How have the results been disseminated to communities of interest?Through state production guides, print, broadcast and extension meetings. What do you plan to do during the next reporting period to accomplish the goals?Continued assessment of newly released cultivars, additional research on peanut root anatomy.

Impacts
What was accomplished under these goals? Seven peanut varieties (O6G, 14N, 16HO, TifNV, AU-NPL 17, TR 297, TR 511), two fungicide programs (Chlorothalonil every 2 or 4 weeks - and 2 sprays of Convoy) were evaluated at 7 digging date for maturity, disease control, yield and grade. Irma, helped improve disease pressure. The penalty for harvesting one or two weeks early or one or two weeks late varied by variety, with the more disease resistant varieties preforming significantly better, and by fungicide program with the 2 week schedule of chlorothalonil yielding higher. Vine condition is as important as hull color when using the hull-scrape to determine when to dig,

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Kvien, C. K., Brenneman, T. B., Culbreath, A. K., Pilon, C., Ozias-Akins, P., Holbrook, C. C., . . . Sorenson, R. (2017). Know when to hold them. In Proceedings of the American Peanut Research and Education Society Vol. 49. Monfort, W. S., Pilon, C., Kvien, C. K., Prostko, E. P., Kemerait, R. C., Brenneman, T. B., . . . Abney, M. (2017). Georgia Peanut Production Guide. W. S. Monfort (Ed.). Kvien, C., Holbrook, C., Ozias-Akins, P., Pilon, C., Culbreath, A., & Brenneman, T. (2017). Chapter 8: Peanut Physiology: Georgia Peanut Production Guide. Holbrook, C. C., Ozias-Akins, P., Chu, Y., Culbreath, A. K., Kvien, C. K., & Brenneman, T. B. (2017). Registration of TifNV-High O/L Peanut. Journal of Plant Registrations, 11(3), 228. doi:10.3198/jpr2016.10.0059crc Annibon, C., Jogloy, S., Vorasoot, N., Nuchadomrong, S., Holbrook, C., Kvien, C., . . . Patanothai, A. (2017). Variability of arginine content and yield components in Valencia peanut germplasm.. Breeding Science, 67 (3), 207-212. Holbrook, C. C., Ozias-Akins, P., Chu, Y., Isleib, T. G., Clevenger, J., Chavarro, C., . . . Guo, B. (2017). Phenotyping and genotyping of RIL populations for gene discovery and marker development. In AAGB. Cordoba, Argentina. Thangthong, N., Jogloy, S., Jongrungklang, N., Kvien, C., Pensuk, V., Kesmala, T., & Vorasoot, N. (2017). Root distribution patterns of peanut genotypes with different drought resistance levels under early season drought stress. Journal of Agronomy and Crop Science, 00, 1-12. ANINBON, C., JOGLOY, S., VORASOOT, N., NUCHADOMRONG, S., HOLBROOK, C., KVIEN, C., & PATANOTHAI, A. (2017). Change of arginine content and some physiological traits under midseason drought in peanut genotypes with different levels of drought resistance. TURKISH JOURNAL OF AGRICULTURE AND FORESTRY, 41, 285-293. doi:10.3906/tar-1609-41

Progress 11/19/15 to 09/30/16

Outputs
Target Audience:Target audience is peanut farmers, Extension agenets, peanut industry personnel, and other research, Extension and teaching personnel. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training of Extension personnel during annual reporting days, field days, Extension and scientific meetings. How have the results been disseminated to communities of interest?Training of Extension personnel during annual reporting days, field days, Extension and scientific meetings, Extension publication is now under review. What do you plan to do during the next reporting period to accomplish the goals?Continue development of the outlined research goals. Dessimination of results through Extension and scientific meetings, field days, and publications

Impacts
What was accomplished under these goals? We are now adapting the hull-scrape maturity profile chart for current SE peanut varieties. Determining the best harvest date requires growers to balance expected weight gain from immature pods and weight loss they expect from mature pod stems weakening, the state of leaf and limb disease in the field, expected weather, labor and equipment resources. New varieties with improved disease resistance and new disease control chemicals have improved pod stem strength. These improvements result in the plants being able to hold their most mature pods longer. We noted that the current Hull- Scrape chart (with no modification) predicted TUFRunner 511 and Georgia-14N accurately (at 128 days and 148 days after planting, repectively). The current hull-scrape chart predicted both Tifguard and Georgia-06G 12 days too early (123 days instead of the optimum date of 135 days. Georgia-12Y was predicted 22 days early (126 days instead of the optimum date of 148 days). Perhaps the most confusing peanut variety was Georgia-13M. The mesocarp of this variety does not further darken after reaching initial pod maturity, instead it remains an early black classification indefinitely. Thus at 121 days, two weeks from the optimum harvest date of 135 days, the chart predicted 144 days - or 9 days later than it should be. The best predictions for this line came at the 100 and 106 day samplings - predicting 131 and 137 days respectively. Our root samples for the 2016 season have been collected, yet sample analysis and data collection from these samples have not been completed. This information will be provided in our next report.

Publications