Journal American Society of Sugar Cane Technologists, Vol. 31, 2011 EFFECTS OF CULTIVAR AND ENVIRONMENTAL CONDITIONS ON BILLET PLANTING TOLERANCE

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1 Journal American Society of Sugar Technologists, Vol. 31, 2011 EFFECTS OF CULTIVAR AND ENVIRONMENTAL CONDITIONS ON BILLET PLANTING TOLERANCE J.W. Hoy 1*, C.F. Savario 1, A.E. Arceneaux 2, and W.A. Barrera 1 1 Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA * Corresponding author address: jhoy@agcenter.lsu.edu ABSTRACT Billet planting is a desirable but problematic planting option for sugarcane in Louisiana. Higher costs and greater risk of stand failure have limited adoption of billet planting. The extent of variation in due to genotype and environmental factors is not known. Therefore, sucrose and its components were compared for billet and whole stalk plantings of eight sugarcane cultivars in four multiple-year crop cycles. Comparison to s obtained with whole stalk planting was used to assess tolerance to billet planting among cultivars. Billet planting s were lower compared to whole stalk plantings for some cultivars but were equivalent for others. Lower s in billet plantings were most evident in the plant cane crop. Results varied among cultivars and between experiments. Environmental conditions varied after planting in different years, and stressful conditions differentially affected stand establishment in billet plantings of different cultivars. The results indicate that tolerance to billet planting varies among cultivars with the performance in some cultivars being affected by conditions after planting. Environmental stress increases the likelihood of reduced stands and in billet plantings for some cultivars. Drought or wet conditions after planting, cold and wet winter weather, and freezes are contributing stress factors. The results also suggest tolerance to billet planting may decrease in some cultivars over time. Tolerance to billet planting is apparently a complex and variable trait that will need to be determined for individual cultivars. INTRODUCTION Sugarcane (inter-specific hybrids of Saccharum) is a vegetatively propagated crop. In Louisiana, sugarcane is typically planted as whole stalks at a high rate to insure adequate stand establishment despite adverse environmental conditions and seedcane damage due to stalk rots (LSUAC, 2001). Planting takes place in late summer once stalks have elongated. Bud germination and initial shoot development occur, then plants must survive the winter and reestablish a stand the following spring. Failure to establish an adequate stand would result in the loss of an entire production season along with the cost of the seedcane. The risk of such an extreme loss has required farmers to utilize an expensive planting method. The planting of three to six whole stalks running in the planting furrow is expensive but regarded as necessary insurance against a severe economic loss. Red rot, caused by Colletotrichum falcatum, is the most common stalk rot affecting planted seedcane in Louisiana (Abbott, 1938; Edgerton, 1911; Steib and Chilton, 1951). Environmental conditions adverse for stand establishment, such as drought or water-logging, 1

2 Hoy et al.: Billet Planting Tolerance increase the damage caused by red rot (Yin and Hoy, 1997 and 1998), and this enhanced damage increases the chance of stand failure. Winter frosts and freezes interspersed with periods of temperatures favorable for shoot growth result in further depletion of energy from the developing plants. Those plants with less vigor due to rotting of the seed-piece are less likely to survive until spring. Sugarcane was mostly harvested as whole stalks in Louisiana until the 1990s. The conversion of the industry to chopper harvesters created interest in stalk section, or billet, planting. In most regions of the world where sugarcane is grown, the crop is planted as billets. However, cutting seedcane into billets depletes carbohydrate reserves in intact internodes and causes mechanical damage which creates more infection sites for stalk rot pathogens (Benda et al., 1978; Coleman and Abbott, 1954). As a result, s obtained from billet plantings in Louisiana may be lower compared to whole stalk plantings (Hoy et al., 2004; Viator et al., 2005), and costs of planting are higher (Salassi et al., 2004). Despite the potential for lower s and higher costs, farmers sometimes plant billets because of lodged seedcane or the lack of labor and equipment. Comparing s obtained from billet planting to those obtained from whole stalk planting, the standard planting practice in Louisiana, can provide an assessment of tolerance to billet planting in different cultivars. Evidence from previous field experiments with limited numbers of cultivars and crop cycles suggested cultivars can vary in tolerance to billet planting (Hoy et al., 2004) or respond similarly to billet and whole stalk planting (Viator et al., 2005). Knowledge about the level of tolerance to billet planting in different cultivars is essential for farmers to make informed decisions when choosing a planting method. Therefore, additional field experiments were conducted with eight cultivars over multiple crop cycles to determine the extent of variability in tolerance to billet planting among sugarcane cultivars and the factors involved. MATERIALS AND METHODS Yield components were compared in four multiple-year crop cycles for billet and whole stalk plantings of Louisiana sugarcane cultivars. Field experiments were initiated in 2004, 2005, 2006, and All experiments were planted at the Sugar Research Station of the Louisiana State University Agricultural Center at St. Gabriel, LA. In 2004, six cultivars, LCP (Milligan et al., 1994), Ho (Tew et al., 2005a), HoCP (Tew et al., 2005b), L (Gravois et al., 2008), L (Gravois et al., 2009), and L (Bischoff et al., 2009) were planted. In 2005, the same six cultivars were planted along with L (Gravois et al., 2010) and the recently released L In 2006, the same eight cultivars were planted. In 2007, the same cultivars, except LCP , were included in the experiment. The experiments required more than one day to establish. Planting dates were September 2-3, 2004; September 14-15, 2005; September 5-7, 2006; and September 4-6, Data were collected from the experiments initiated during for a 3-year crop cycle (plant cane crop through second ratoon), while data were only collected for plant cane and first ratoon for the experiment initiated in

3 Journal American Society of Sugar Technologists, Vol. 31, 2011 Billets and whole stalks were both cut for planting with mechanical harvesters. Drum blades were removed to cut billets with a length of cm with 3-4 buds per billet. Every other slat in the elevator was removed to accommodate the longer billets. No other harvester modifications were made. Billets and whole stalks were planted in paired plots in a randomized complete block design with four replicate blocks. Plots were two-row with lengths varying from m in different experiments with a 1.5 m alley between plots. Whole stalks were handplanted with a four stalk planting rate. Billets were mechanically planted with a single-row, front-mounted rotating drum planter. Billets were planted with 4-6 billets running continuously in the planting furrow, except for the 2007 planting that had a 6-8 billet planting rate. The billet planting rate was adjusted to establish uniformity by re-arranging planted billets to the appropriate rate from the beginning to the end of each plot row. Extra billets were placed into a single buffer row between each set of two plot rows. Planted cane was covered with approximately 7.6 cm of packed soil. The experiments were planted in Cancienne silty clay loam (fine-silty, mixed, superactive, nonacid, hyperthermic Fluvaquentic Epiaquepts). Recommended production practices were followed during the growing season for weed and insect control and fertility (LSUAC, 2001). Yield data collected included stalk population, stalk weight, stalk sucrose content (kg of sucrose per ton of cane), cane tonnage (Mg ha -1 ), and sucrose (Mg ha -1 ). All millable stalks were counted in each plot during August. Stalk weight was determined from a 10-stalk sample collected at one site in each plot just prior to harvest. content was determined from the same 10-stalk sample by near-infrared reflectance spectroscopy of a bulk shredded sample (Berding et al., 1991). tonnage was determined by weighing the cane cut from each plot row by a chopper harvester using a high-dump wagon with load cells in the tongue and axle. was calculated from the tonnage and sucrose content estimates. Environmental variable data were available from a weather station located at the Sugar Research Station. Daily maximum, minimum, and mean temperature and daily rainfall data were evaluated to compare weather conditions after planting in the different experiments. Variables were considered as monthly rainfall and number and duration of winter freezes. Results were compared to 30-year averages calculated for the period from to provide a reference point for conclusions about normality of weather conditions. Yield data were analyzed using the Proc GLM procedure of SAS (SAS Institute, Inc., Cary, NC). Data sets were analyzed to determine treatment (planting method), cultivar, and year effects and interactions. Means for billet and whole stalk planting components were compared for individual cultivars within experiments with a t-test. RESULTS Differences between s obtained from billet and whole stalk plantings varied by crop year. Lower s in billet compared to whole stalk plantings were detected in plant cane for some cultivars in some experiments, while ratoon crop s were usually not significantly affected by planting method across cultivars and experiments. 3

4 Hoy et al.: Billet Planting Tolerance In a combined analysis of plant cane data for all four experiments, treatment (planting method), cultivar, and year effects were highly significant (P < ). Planting method x cultivar and cultivar x year interactions were highly significant (P < ). A significant planting method x year interaction was detected for cane tonnage (P < 0.05) but not total sucrose (P < 0.38). The planting method x cutivar x year interaction was not significant. Therefore, results are presented for each experiment separately for all components of individual cultivars in plant cane and then for the composite components, cane and sucrose, in all crop years. In the experiment with plant cane during 2005, cane and sucrose s were lower in billet compared to whole stalk plantings for LCP , Ho , HoCP , and L (Table 1). Stalk population also was lower for all of these cultivars, except HoCP Ho exhibited the greatest reductions with 48, 47, and 51% reductions in billet plantings for stalk population, cane, and sucrose, respectively, and was the only cultivar to have lower sucrose content. Stalk weight was equivalent for billet and whole stalk plantings for each cultivar. All components were equivalent for billet and whole stalk plantings of L and L Table 1. Comparison of mean plant cane components for billet and whole stalk plantings of six cultivars during Cultivar Treatment Population (x1000) y Stalk weight (kg) content (kg) y (Mg ha -1 ) y (Mg ha -1 ) y LCP Billet 81.0 B B 8.1 B Whole A A 11.6 A Ho Billet 46.2 B B 41.7 B 4.9 B Whole 89.4 A A 78.8 A 10.1 A HoCP Billet B 11.5 B Whole A 14.0 A L Billet Whole L Billet 78.8 B B 9.8 B Whole 91.1 A A 14.6 A L Billet Whole y Values of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). Significantly lower s in billet plantings were observed in first and second ratoon crops of Ho only (Table 2). Although not observed for L in plant cane, lower cane and sucrose s occurred in first ratoon of billet plantings. Yields were equivalent for billet and whole stalk plantings of L in second ratoon. In the experiment with plant cane during 2006, stalk population, cane, and sucrose were lower in plant cane of billet than whole stalk plantings for Ho and L but not LCP , HoCP , L , L , L , and L (Table 3). 4

5 Journal American Society of Sugar Technologists, Vol. 31, 2011 content also was lower for billet planted Ho Stalk population was higher in the whole stalk planting of LCP Billet and whole stalk planting s were equivalent for each cultivar in first and second ratoon, except that cane tonnage was higher in first ratoon for billet planted L (Table 4). Table 2. Comparison of mean components for billet and whole stalk plantings of six cultivars in 2005 plant cane, 2006 first ratoon, and 2007 second ratoon. Plant cane First ratoon Second ratoon Cultivar Billet vs. whole LCP Billet 63.6 B 8.1 B Whole 90.0 A 11.6 A Ho Billet 41.7 B 4.9 B 48.8 B 6.1 B 45.7 B 5.3 B Whole 78.8 A 10.1 A 75.5 A 9.3 A 81.8 A 9.7 A HoCP Billet 88.3 B 11.5 B Whole A 14.0 A L Billet Whole L Billet 79.5 B 9.8 B Whole A 14.6 A L Billet B 9.2 B Whole A 11.0 A y Values (Mg ha -1 ) of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). In the experiment with plant cane during 2007, components were lower in billet plantings for LCP , Ho , HoCP , L , L , and L , whereas billet and whole stalk planting s of all components were equivalent for L and L (Table 5). tonnage was the component most frequently affected with reductions detected in five cultivars. Stalk weight and sucrose content were not affected by planting method for any of the cultivars. A lower was only detected in the ratoon crops for cane tonnage of L in first ratoon (Table 6). In the experiment with plant cane in 2008, components were lower in billet plantings for five of seven cultivars, including Ho , HoCP , L , L , and L (Table 7). Both cane and sucrose s were lower in billet plantings of Ho , L , L , and L Yields for L and L were equivalent for billet and whole stalk plantings. For all cultivars, reductions associated with billet planting were not evident in first ratoon (Table 8). Environmental conditions following planting varied from 2004 to 2008 (Table 9). For the experiment planted in 2004, only trace amounts of rain were recorded for 38 days after planting (data not shown), and rainfall was below average through November in Temperatures were above average during this period. High rainfall with freezing temperatures occurred during December. The number of hours with below freezing air temperatures during the winter was the highest recorded in the study. In contrast, air temperature was above normal 5

6 Hoy et al.: Billet Planting Tolerance during January and February indicating a high degree of fluctuation in daily temperatures during those months. Table 3. Comparison of mean plant cane components for billet and whole stalk plantings of eight cultivars during Cultivar Treatment Population (x1000) y Stalk weight (kg) content (kg) y (Mg ha-1) y (Mg ha-1) y LCP Billet B Whole A Ho Billet B B 78.6 B 10.6 B Whole A A A 14.7 A HoCP Billet Whole L Billet 89.9 B B 11.0 B Whole A A 14.2 A L Billet Whole L Billet Whole L Billet Whole L Billet Whole y Values of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). In the experiment planted during 2005, October was dry, and the recorded total rainfall was the lowest in the study. However, drought conditions did not occur as above average rainfall occurred in September after planting. More days with freezing temperatures occurred in than in , but the total for hours below freezing was less. January was warmer than the 30-year average. During the experiment planted during 2006, no drought conditions occurred, and above average rainfall occurred during December and January, particularly during December. The number of freezing days and hours below freezing were both high during December and February. In the experiment planted during 2007, above average rainfall occurred during September and October. Severe freezing conditions did not occur, but three frosts occurred during March, the latest on March 25 th. DISCUSSION Sugarcane is grown at the northern limit of its cultivation range in Louisiana. Therefore, the potential always exists for stressful environmental conditions and diseases to adversely affect initial stand establishment and winter survival of the crop. As a result, the planting of whole stalks at a high rate became the routine planting method. Billet planting can be accomplished 6

7 Journal American Society of Sugar Technologists, Vol. 31, 2011 more quickly and with less labor (Salassi et al., 2004), and the shift to harvesting with chopper harvesters during the 1990s greatly increased interest in billet planting. Research has focused on comparing s obtained with whole stalk and billet planting and the factors that can reduce s obtained from billet planting (Hoy et al., 2004; Hoy et al., 2006; Viator et al., 2005). Table 4. Comparison of mean plant cane components for billet and whole stalk plantings of four cultivars in 2006 plant cane, 2007 first ratoon, and 2008 second ratoon. Plant cane First ratoon Second ratoon Cultivar Billet vs. whole LCP Billet Whole Ho Billet 78.6 B 10.6 B Whole A 14.7 A HoCP Billet Whole L Billet 83.6 B 11.0 B Whole A 14.2 A L Billet Whole L Billet A Whole B L Billet Whole L Billet Whole y Values (Mg ha -1 ) of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). In this study, field experiments comparing s obtained from billet and whole stalk planting of eight cultivars over four crop cycles demonstrated that cultivars vary in tolerance to billet planting and that environmental stress can affect the amount of reduction in billet compared to whole stalk plantings. Some cultivars, such as LCP , Ho , and L , have lower s in billet compared to whole stalk plantings regardless of conditions after planting. Other cultivars, such as HoCP and L , experience greater reductions in billet plantings when stressful environmental conditions occur. The most recently released cultivars, L and L , have thus far exhibited tolerance to billet planting. L exhibited tolerance to billet planting in early experiments, but significant reductions in billet plantings were detected in the last two experiments. LCP exhibited more tolerance to billet planting in some earlier experiments (Hoy et al., 2004; Viator et al., 2005). These results suggest the possibility that a decrease in tolerance to billet planting not associated with a seasonal stress impact might occur in some cultivars over successive plantings and an evaluation of tolerance may therefore require on-going characterization. 7

8 Hoy et al.: Billet Planting Tolerance Table 5. Comparison of mean plant cane components for billet and whole stalk plantings of eight cultivars during Cultivar Treatment Population (x1000) y Stalk weight (kg) content (kg) (Mg ha -1 ) y (Mg ha -1 ) y LCP Billet 96.1 B B 7.3 Whole A A 8.7 Ho Billet 85.2 B B 8.5 B Whole A A 11.8 A HoCP Billet 93.9 B B 13.0 Whole A A 13.8 L Billet 71.6 B B 8.3 B Whole 99.5 A A 12.0 A L Billet B 11.1 B Whole A 13.5 A L Billet B Whole A L Billet Whole L Billet Whole y Values of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). Results indicated lower s in billet plantings were due to weak stand establishment and lower stalk population at harvest. Stalk weight and sucrose content were generally equivalent in billet and whole stalk plantings. This confirms the results from previous studies (Hoy et al., 2004; Viator et al., 2005). In the most recent experiments, the reductions in stand establishment did not result in large gaps without plants, probably because of the high billet planting rate. As a result, the differences between s obtained from billet and whole stalk plantings usually diminished in the ratoon crops. The degree of recovery varied among cultivars and experiments. As an example, the reduction in billet compared to whole stalk planted LCP was 29% in plant cane in the first experiment, and the reduction for all three crop years combined was 21%. In comparison, the reduction of 30% in plant cane for L diminished to 15% for the 3-year crop total. While some recovery is typical for billet planting s in ratoon crops, the overall reduction for the cycle would be economically detrimental for the grower. The planting rate for billets used in this study approximates that used by most growers in Louisiana. It minimizes the chance of an unacceptable stand failure, but the high cost (Salassi et al., 2004) coupled with the potential for reduced s makes billet planting the planting option of last resort. However, severe lodging of seedcane sources and scarcity of labor sometimes results in the need for billet planting. Difficulty in maintaining a whole stalk harvester no longer being manufactured just for cutting seedcane is another factor that makes whole stalk planting less feasible now, and this will become more problematic in the future. 8

9 Journal American Society of Sugar Technologists, Vol. 31, 2011 Table 6. Comparison of mean plant cane components for billet and whole stalk plantings of eight cultivars in 2007 plant cane, 2008 first ratoon, and 2009 second ratoon. Plant cane First ratoon Second ratoon Cultivar Billet vs. whole LCP Billet 65.0 B Whole 84.0A Ho Billet 73.2 B 8.5 B Whole A 11.8 A HoCP Billet 86.9 B Whole A L Billet 75.3 B 8.3 B Whole A 12.0 A L Billet 91.8 B 11.1 B 74.1 B Whole A 13.5 A 82.0 A L Billet B Whole A L Billet Whole L Billet Whole y Values (Mg ha -1 ) of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). Several factors appear to be associated with the variation observed in billet planting tolerance among cultivars. Genotypic variation was evident, as would be expected for any trait. Detrimental effects of environmental stress were apparent, but the impact of adverse weather conditions varied among genotypes. Vigor is a trait often associated with youth. High vigor in newly developed cultivars has not been well documented experimentally in sugarcane, although empirical evidence suggests potential decreases over time in cultivars. The study results suggest the possibility that some newly released cultivars may have more tolerance to billet planting than later in their life-span. Additional testing is needed to monitor recently released cultivars and those released in the future to determine whether tolerance to billet planting can decrease over time. A comparison of weather conditions in different seasons and the variation detected in billet planting performance suggests that stress factors, including drought or excessive soil moisture after planting and the occurrence of cold, wet weather during winter are associated singly or in combination with reductions in billet planting s in some cultivars. Drought occurred after planting in 2004, and adverse, variable winter conditions followed. The least amount of stressful conditions occurred during Wet and cold conditions were prevalent during the winter. Wet soil conditions occurred after planting during , and three frosts occurred during March. During the four plant cane crops, four of six (67%), two of the same six (33%), six of six (100%), and four of the same five (80%) cultivars, respectively, had lower cane tonnage and/or total sucrose s in billet plantings. The percent reductions across all cultivars with significantly lower billet planting s for the four plant 9

10 Hoy et al.: Billet Planting Tolerance cane crops were 31, 20, 26, and 28%, respectively. The two cultivars that exhibited the greatest negative effect of stressful conditions, HoCP and L , had lower billet planting s in and , and L had a reduction in Table 7. Comparison of mean plant cane components for billet and whole stalk plantings of seven cultivars during Cultivar Treatment Population (x1000) y Stalk weight (kg) y content (kg) y (Mg ha -1 ) y (Mg ha -1 ) y Ho Billet B 7.9 B Whole A 10.5 A HoCP Billet 78.1 B Whole 96.6 A L Billet 70.1 B B 56.4 B 7.4 B Whole 84.2 A A 75.9 A 10.5 A L Billet 64.0 B B 7.5 B Whole 85.2 A A 12.3 A L Billet B 7.5 B Whole A 10.1 A L Billet Whole L Billet Whole y Values of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). Red rot can impose a disease stress that may reduce stand establishment or cause a reduction in association with environmental stress factors. Sugarcane cultivars are known to vary in susceptibility to red rot (Abbott, 1938; Yin et al., 1996), and red rot severity is increased by the occurrence of drought (Yin and Hoy, 1997) or water-logging (Yin and Hoy, 1998). In addition, cutting stalks into billets creates more infection sites for the red rot pathogen. A consideration of these facts and the suggested association between drought or water-logging stress and lower s in billet plantings suggests a link between billet planting performance and damage due to red rot, but stalk rot severity was not determined in this study. The detrimental effect of freezes is not directly linked to increased red rot but may be worse when planted seedcane has been damaged by the disease. The degree of linkage between red rot resistance and billet planting tolerance likely varies among sugarcane genotypes. The frequency of resistance to red rot is low in the breeding and selection populations in Louisiana (Yin, et al., 1996). Recent research has identified new genetic sources of resistance to red rot (Hale, et al., 2010), but basic breeding to improve disease resistance is a long-term project. The advantage in selecting for red rot resistance is that it is a moderately heritable trait (Yin et al., 1996), and it can be relatively easily evaluated by inoculating detached stalks. 10

11 Journal American Society of Sugar Technologists, Vol. 31, 2011 Table 8. Comparison of mean components for billet and whole stalk plantings for seven cultivars in 2008 plant cane and 2009 first ratoon. Plant cane First ratoon Cultivar Treatment Ho Billet 55.6 B 7.9 B Whole 75.0 A 10.5 A HoCP Billet Whole L Billet 56.4 B 7.4 B Whole 75.9 A 10.5 A L Billet 58.0 B 7.5 B Whole A 12.3 A L Billet 54.4 B 7.5 B Whole 72.1 A 10.1 A L Billet Whole L Billet Whole y Values (Mg ha -1 ) of components for billet and whole stalk comparisons within a cultivar followed by different letters were significantly different (P = 0.05). Tolerance to billet planting is a complex trait. Despite the importance of the trait, direct breeding and selection for billet planting tolerance will be difficult. In addition, logistics factors, including the requirements for a large amount of seedcane and the comparison of billet and whole stalk s in multiple-year field experiments, make early selection impossible. The seedcane, space, and time constraints are so great that even attempting to evaluate heritability of the trait would not be feasible. The lower s detected in billet compared to whole stalk plantings and variation detected among sugarcane cultivars indicate an on-going need to determine the degree of tolerance to billet planting in new cultivars. Knowledge about this attribute needs to be provided to sugarcane growers so that they can make informed planting decisions when billet planting becomes necessary. Research is needed to identify treatments that can improve s and possibly allow the planting of billets at a lower rate. 11

12 Hoy et al.: Billet Planting Tolerance Table 9. Comparison of monthly weather variables: total rainfall, daily temperature (maximum, minimum, and mean), and freeze days and duration, for each experiment from the time of planting until resumption of plant growth during April. Plant cane crop years for four experiments Rainfall (mm) yr avg. x September October November December January February March Total Temperature y September 32/20/26 33/22/27 31/19/25 31/21/26 31/20/25 October 29/18/24 28/13/20 27/14/20 27/15/21 27/13/20 November 23/12/17 23/9/16 22/7/14 22/9/16 22/9/15 December 17/4/11 17/4/10 18/6/11 21/9/15 17/5/11 January 18/9/14 20/7/14 15/7/11 15/5/10 16/4/10 February 19/10/14 18/6/12 18/5/11 20/7/14 18/6/12 March 21/9/15 24/11/17 24/11/18 23/9/16 22/10/16 Freezes z September October November 0 2 (2) 2 (6) 1 (3) 2 December 11 (68) 10 (38) 8 (54) 4 (15) 7 January 5 (47) 3 (10) 1 (8) 8 (49) 9 February 1 (1) 5 (28) 8 (35) 1 (6) 5 March 0 1 (3) 1 (5) 3 (1) 1 Totals 17 (116) 21 (81) 20 (113) 17 (74) 24 x Thirty-year averages calculated for data from y Maximum/minimum/mean daily temperatures in o C. z Days during month with freezing temperature recorded, and total hours with freezing temperatures (in parentheses). REFERENCES Abbott, E.V Red rot of sugarcane. U. S. Dep. Agric. Tech. Bull Benda, G.T.A., H.P. Fanguy, J.E. Irvine, and R.D. Breaux Field planting of short sugarcane pieces in Louisiana. Proc. Amer. Soc. Sugar Technol. 8: Berding, N., G.A. Brotherton, D.G. le Brocq, and J.C. Skinner Near infrared reflectance spectroscopy for analysis of sugarcane from clonal evaluation trials: I. Fibrated. Crop Sci. 31:

13 Journal American Society of Sugar Technologists, Vol. 31, 2011 Bischoff, K.P., K.A. Gravois, T.E. Reagan, J.W. Hoy, C.M. LaBorde, C.A. Kimbeng, G.L. Hawkins, and M.J. Pontif Registration of L sugarcane. J. Plant Reg. 3: Coleman, R.E., and E.V. Abbott Size of seed piece in relation to rapid increase of a variety. Sugar Bull. 32: Edgerton, C.W The red rot of sugarcane. La. Agric. Exp. Sta. Bull Gravois, K.A., K.P. Bischoff, C.M. LaBorde, J.W. Hoy, T.E. Reagan, M.J. Pontif, C.A. Kimbeng, G.L. Hawkins, D.R. Sexton, and D.P. Fontenot Registration of L sugarcane. J. Plant Reg. 4: Gravois, K.A., K.P. Bischoff, J.W. Hoy, T.E. Reagan, C.M. LaBorde, C.A. Kimbeng, G.L. Hawkins, and M.J. Pontif Registration of L sugarcane. J. Plant Reg. 3: Gravois, K.A., K.P. Bischoff, S.B. Milligan, F.A. Martin, J.W. Hoy, T.E. Reagan, C.A. Kimbeng, C.M. LaBorde, and G.L. Hawkins Registration of L sugarcane. J. Plant Reg. 2: Hale, A.L., J.W. Hoy, and J.C. Veremis Identification of sources of resistance to sugarcane red rot. Proc. Int. Soc. Sugar Technol. 27:1-8. Hoy, J.W., A.E. Arceneaux, and C.F. Savario Effects of date and rate of billet planting on sugarcane. J. Amer. Soc. Sugar Technol. 26: Hoy, J.W., C.A., Richard, W.R. Jackson, and H.L. Waguespack, Jr Effects of cultivars, fungicides, and fertilization at planting on s obtained from whole stalk and billet planting in Louisiana. J. Amer. Soc. Sugar Technol. 24: LSUAC Louisiana State University Agricultural Center Sugarcane Production Handbook. Available online at: tion+handbook.htm Verified 26 January Milligan, S. B., F.A. Martin, K.P. Bischoff, J.P. Quebedeaux, E.O. Dufrene, K.L. Quebedeaux, J.W. Hoy, T.E. Reagan, B.L. Legendre, and J.D. Miller Registration of LCP sugarcane. Crop Sci. 34: Salassi, M.E., J.B. Breaux, and J.W. Hoy Estimated cost differences between whole-stalk and billet planting methods in Louisiana. J. Amer. Soc. Sugar Technol. 24: Steib, R.J., and S.J.P. Chilton Infection of sugarcane stalk by red rot fungus Physalospora tucumanensis Speg. Phytopathology 41:

14 Hoy et al.: Billet Planting Tolerance Tew, T.L., D.M. Burner, B.L. Legendre, W.H. White, M.P. Grisham, E.O. Dufrene, D.D. Garrison, J.C. Veremis, Y.-B. Pan, and E.P. Richard, Jr Registration of Ho sugarcane. Crop Sci. 45:1660. Tew, T.L., W.H. White, B.L. Legendre, M.P. Grisham, E.O. Dufrene, D.D. Garrison, J.C. Veremis, Y.-B. Pan, E.P. Richard, Jr., and J.D. Miller Registration of HoCP sugarcane. Crop Sci. 45: Viator, R.P., D.D. Garrison, E.O. Dufrene, T.L. Tew, and E.P. Richard Jr Planting method and timing effects on sugarcane. Online. Crop Management doi:1094/cm xx-02- RS. Yin, Z., and J.W. Hoy Effect of stalk desiccation on sugarcane red rot. Plant Dis. 81: Yin, Z., and J.W. Hoy Effects of oxygen deprivation and Pythium root rot on sugarcane red rot. Plant Dis. 82: Yin, Z., J.W. Hoy, and S.B. Milligan Evaluation and heritability of resistance to sugarcane red rot. Phytopathology 86: