Red Clover Varieties for North-Central Florida

Red Clover Varieties for North-Central Florida J.C.B. Dubeux, Jr. 1, P. Munoz 2, A.R.S. Blount 1, K.H. Quesenberry 2, L.E. Sollenberger, E.R.S. Santos 1 Synopsis Red clover varieties are an option for cool-season grazing. We tested nine red clover varieties in North (Marianna) and Central (Gainesville) Florida. Clover productivity varied with location, year, and harvest date, with maturity type being an important trait affecting productivity. Summary Red clover is an excellent option to increase species diversity in cool-season pastures, adding N to the systems via biological N 2 -fixation and providing high forage value. Two red clover variety trials were carried out, one at the North Florida Research and Education Center (NFREC) in Marianna during two seasons (2013-2014 and 2014-2015) and the other one at the Agronomy Forage Unit in Gainesville during one season (2013-2014). Nine red clover varieties were tested: Barduro, Bulldog Red, Cinnamon Plus, FL24D, Freedom!, Kenland, Marathon, Red Ace, and Southern Belle. The trials were planted in a randomized complete block design, with four replications per treatment. Each plot measured 6 x 15 feet. In Marianna, clovers were harvested twice in the 2014 season (4/24 and 6/3/2014) and three times in the 2015 season (4/3, 5/7, and 6/11/2015), at a four-inch stubble height. Due to high deer pressure the trial was harvested only one time (April 2014) in the Gainesville location at a two-inch stubble height. In Marianna, red clover total dry matter yield ranged from 2,290 to 3,420 lb/acre in 2014 and from 1,730 to 2,840 lb/acre in 2015. In 2014, the top red clover varieties were Barduro (3,420 lb/acre), Red Ace (3,340 lb/acre), and FL 24D (3,280 lb/acre). In 2015, top varieties included Southern Belle (2,840 lb/acre), Cinnamon (2,790 lb/acre), Red Ace (2,760 lb/acre), and Barduro (2,740 lb/acre). In Gainesville, total dry matter ranged from 1,690 to 2,510 lb/acre. In this location the best varieties were Red Ace (2,510 lb/acre), FL24D (2,070 lb/acre), and Southern Belle (2,000 lb/acre). Red clover varieties can be used in North-Central Florida, adding value to the grazing systems in the region. Introduction Legumes are an option to add N via biological N 2 -fixation during the cool season. Nitrogen fixed during this time of the year will be available for grazing livestock, and recycled back to the grassland, helping to reduce N fertilizer costs. Cool-season legumes also have greater crude protein and digestibility than many other forages, improving cattle performance. Red clovers are traditionally planted in Florida during the cool-season. These clovers are adapted to Florida conditions and are usually used in mixtures with small grains (e.g., oat, rye, and triticale) and/or annual ryegrass (Lolium multiflorum Lam.). Red clover varieties vary in their time of flowering, with early-, mid-, and late-maturity types. Timing of flowering influences seasonal production and typically varies with environmental conditions such as photoperiod, temperature, and soil moisture. Therefore, varieties that perform better in one location may not necessarily be the best variety for another location with different environmental conditions. In this 1 North Florida Research and Education Center, University of Florida, Marianna, FL 2 Agronomy Department, University of Florida, Gainesville, FL

research, we tested nine red clover varieties under North and Central Florida conditions in order to recommend to producers the best varieties for these regions. Materials and Methods Site description The studies were conducted in Marianna and in Gainesville, FL (Figure 1). The trial in Marianna was carried at the North Florida Research and Education Center (NFREC), Marianna, FL (30 52 N, 85 11 W, 34 m altitude). The soil at the research site in Marianna was an Orangeburg loamy sand (fine-loamy, kaolinitic, thermic Typic Kandiudults). Soil fertility results at the beginning of the trial at NFREC were ph=6.5, Mehlich-I P=48 ppm, K=78 ppm, Mg=157 ppm, Ca=625 ppm, S=29 ppm, B=0.22 ppm, Zn=3.3 ppm, Mn=52 ppm, Fe 13 ppm, Cu=1.8 ppm, SOM=1.36%, and CEC=7 meq/100 g. The trial in Gainesville was carried out at the Agronomy Forage Research Unit (AFRU), Hague, FL (29 48 N, 82 24 W). The soil classification at this location was a loamy, siliceous, subactive, thermic, Arenic Endoaquult. Soil fertility results at the beginning of the trial were: ph=6.3, P>328 ppm (high), K=17 ppm (low), Mg=95 ppm (high), and Ca=674 ppm. Planting and harvesting Trials were established in 2013 and 2014. The soil was plowed and harrowed before planting. Plots measured 6 x 15 ft. and were allocated in a randomized complete block design, with four replications per treatment. Planting dates were Nov. 22, 2013 and Oct. 27, 2014 for Marianna and Nov. 15, 2013 for Gainesville. Before planting, plots were cultipacked, seeds were broadcasted, and plots were rolled thereafter. Harvests were performed when at least 20% of the plots had flowering plants. Harvests at a four-inch stubble height were performed on 4/24/2014, 6/3/2014, 4/3/2015, 5/7/2015, and 6/11/2015 for Marianna, while the Gainesville location was harvested at a two-inch stubble in 4/30/2014. Yield was estimated by harvesting a central strip of the plot (3 x 12 ft.) after trimming the borders (1.5 ft. each side). Total fresh weight was recorded and a subsample was taken to estimate the moisture content of the sample. After recording its fresh weight, the subsample was placed into a forced air-dryer at 131 F for 72 h. Fertilization, Weed and Pest Control Marianna In 2014, plots were fertilized on 5/16 with 300 lb/acre of 0-20-20 (60 lb/acre of P 2 O 5 and 60 lb/acre of K 2 O) and 1 lb/acre of Boron. In 2015, at planting we applied 200 lb/acre of 0-5-20 mixed with 10 lb/acre micronutrient mixture, followed by another application of 400 lb/acre of 0-5-20 + micronutrient mixture in 4/3/2015. On 1/13/2015, Pursuit was applied at 3 fl. oz. per acre to control weeds. Gainesville Plots were fertilized on 11/5/2013 with 320 lb/acre of 0-0-50-18 using sulfate of potash. The trial at Gainesville had a high pressure of deer feeding on the clover plots. Even when a deer barrier (PlotSaver) was used under the recommended setups, it was not enough to keep the deer out of the plots and the plot yields were lower because of this. Statistics Data were analyzed using proc mixed from SAS (1996) using repeated measures. Fixed effects included variety, year, and harvest date. Random effects included blocks and its interactions with fixed effects. Lsmeans were compared using PDIFF procedure adjusted by Tukey (5%).

Results and Discussion Marianna Red clover varieties performed differently in the two years. Total dry matter yield ranged from 2,290 to 3,420 lb/acre in 2014 (Figure 2) and from 1,730 to 2,840 lb/acre in 2015 (Figure 3). In 2014, the top red clover varieties were Barduro (3,420 lb/acre), Red Ace (3,340 lb/acre), and FL24D (3,280 lb/acre). In 2015, top varieties included Southern Belle (2,840 lb/acre), Cinnamon Plus (2,790 lb/acre), Red Ace (2,760 lb/acre), and Barduro (2,740 lb/acre). Therefore, Barduro and Red Ace were consistently ranked among the top red clover varieties in both years and Southern Belle ranked well in both years. These three varieties are currently recommended by the UF/IFAS Forage Group (Blount et al., 2015). Marathon performance was inferior to that of the other varieties in both seasons. Consistent results of Barduro, Red Ace, and Southern Belle, in both seasons, place them among the recommended varieties for North Florida. Gainesville Total dry matter ranged from 1,690 to 2,510 lb/acre at this location (Figure 4). The top varieties were Red Ace (2,510 lb/acre), FL24D (2,070 lb/acre), and Southern Belle (2,000 lb/acre). However, yield of FL24D, Southern Belle, Kenland, Cinnamon Plus and Barduro did not differ by much. Marathon, Freedom! and Bulldog Red were lower performing varieties than Red Ace at the Gainesville site. Conclusions and implications Maturity type plays an important role in flowering, affecting as a result productivity and nutritive value. Early-maturing varieties will likely yield less than late-maturing ones, but harvest management might affect these responses. Since harvest timing was decided based on flowering of all varieties in the trial, the late maturing ones could probably yield more if they were harvested later in the season. These varieties, however, will likely be used under grazing conditions, where grazing frequency will likely be different than the cutting schedule used in this trial. In North Florida, Barduro, Red Ace, and Southern Belle performed consistently well, being the recommended varieties for North Florida. In Central Florida Red Ace and Southern Belle are the recommended varieties. FL24D is a new variety developed by University of Florida which will soon be in the seed market. Literature Cited Blount, A.R.S., et al 2015. Panhandle Ag e-news. Available online at http://nwdistrict.ifas.ufl.edu/phag/2015/08/14/2015-cool-season-forage-variety-recommendations-forflorida/ SAS Institute. 1996. SAS Inst., Cary, NC.

Figure 1. Red clover variety trial at the North Florida Research and Education Center (NFREC), Marianna, FL.

Dry Matter Yield (lb/acre) 2014 3500 3000 2500 2000 1500 1000 500 0 4/24/2014 6/3/2014 Figure 2. Biomass yield of red clover varieties measured in the 2013-2014 season; NFREC, Marianna, FL. Standard error=175 lb/acre.

Dry Matter Yield (lb/acre) 1600 1400 1200 1000 800 600 400 200 0 2015 4/3/2015 5/7/2015 6/11/2015 Figure 3. Biomass yield of red clover varieties measured in the 2014-2015 season; NFREC, Marianna, FL. Standard error=175 lb/acre.

Dry Matter Yield (lb/acre) 3500 3000 2014 -AFRU 2500 2000 a ab ab ab ab ab b b b 1500 1000 500 0 Cultivar Figure 4. Biomass yield of red clover varieties measured in the 2013-2014 season; AFRU, Hague, FL. a,b Means with different superscripts differ, P<0.05.