Planting Recommendations & Suggestions for or Louisiana Sugar. oducers

Transcription

1 Sugar arcane Planting Recommendations & Suggestions for or Louisiana Sugar arcane Producer oducers 1999

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3 Sugar arcane Planting Recommendations and Suggestions for Louisiana Sugar arcane Producer oducers The success of a sugarcane farming operation depends on the ability to produce good stands of plant cane and maintain suitable stands for stubble crops. This publication provides information to help growers make management decisions about planting practices that should result in excellent plant cane stands. Keeping good records is an essential part of the wise decision making and management of a sugarcane production operation. Growers are urged to keep good records of all planting practices as well as pest management practices. The recommendations are based primarily on research results. Where research results were not available or were inconclusive, current farming practices were considered in making suggestions. The planting information does not include land preparation recommendations. It is essential that proper land preparation is carried out and that rows are built up and ready for furrow opening. Recommendations are made on variety selection, furrow width, planting rate, weed control and soil insect control. Suggestions are made on depth of cover, depth of planting, dates of planting, succession planting and use of starter fertilizers. Healthy Seed Cane For varieties to yield up to their full potential, it is essential that plantings be made with seed cane that is free or nearly free of diseases. To accomplish this, nurseries should be established with seed cane from a heat treatment program or certified seed cane that has been produced to meet the requirements for certification by the Louisiana Department of Agriculture and Forestry. Seed cane nurseries of all varieties expected to be grown should be planted with cane obtained from one of these sources every year. Special care should then be taken to minimize infection of seed cane by sugarcane pathogens. Ratoon stunting disease (RSD) will cause substantial yield losses in all of the varieties recommended for major planting. This disease can be controlled only by the continuous planting of RSD-free seed cane. In addition, RSD is spread mechanically, so equipment should be carefully cleaned before handling seed cane. Since RSD has no visible symptoms, growers do not know when they are introducing or spreading the disease. Therefore, seed cane should be propagated as few times as is economically feasible. A common mistake made by growers is to assume that cane grown from heattreated or certified seed cane that has been cut repeatedly is still disease free. 3

4 Cane of any variety containing more than 2% smut-infected shoots should be avoided as a seed cane source. Where practical, smut-infected plants should be rogued early in the season. Avoid planting seed cane nurseries of smut-susceptible varieties next to smut-infected cane. Most recommended varieties are susceptible or moderately susceptible to leaf scald with the exception of LCP The highest incidence of the disease in commercial planting has been in LCP82-89 and HoCP Because of susceptibility to leaf scald and other diseases, LCP is no longer recommended. Leaf scald is transmitted through infected seed cane, mechanically on equipment and, to some extent, in windblown rain. Care should be taken to plant healthy seed cane. The heat treatment used to control RSD does not cure stalks of leaf scald. Planting healthy seed cane also means using cane for seed that has low levels of damage caused by the sugarcane borer. Good borer control helps to reduce damage by stalk rots following planting and helps to increase stands. Seed cane nurseries of highly susceptible varieties, such as LCP and HoCP , should not be planted where insecticides cannot be applied, and cane to be used for seed should be monitored closely for borer presence. Variety Recommendations for Planting Variety recommendations are based on results from research conducted by personnel of the Louisiana Agricultural Experiment Station of the LSU Agricultural Center, the USDA-ARS, SRRC, Sugarcane Research Unit and the American Sugar Cane League. Seven varieties are recommended for 1999 (CP70-321, LCP85-384, HoCP85-845, CP72-370, CP79-318, LHo and HoCP91-555). Growers should consider three varieties for major plantings, including CP70-321, LCP and HoCP The varieties CP72-370, CP and LHo are also recommended, but for limited acreage planting only. CP and LHo have less than desirable harvestability for soldier harvesters. CP has only moderate stubbling ability, and stubble crops often give low sugar yields. LHo also suffers from drought susceptibility and matures later than desired in some situations. Consider these limitations when selecting these varieties. The varieties LCP82-89 and LCP were dropped from the recommendations because of problems with leaf scald and other diseases in LCP82-89 and poor yields and stubbling in LCP CP65-357, although previously dropped, is still grown by some growers, especially in areas where spraying for borer control is restricted. Other varieties to consider where insecticide use may be restricted include LHo83-153, HoCP and LCP The variety HoCP was released in Planting of this variety is expected to be limited by low seedcane supply this year. Variety Performance The variety recommendations consider both the good and less-than-desirable traits of each recommended variety. Multi-year outfield test means of plant cane through 4

5 third ratoon crops provide relative yield information about the recommended varieties (Tables 1-4). Actual yields and the relative performance of the varieties on your farm may vary from those reported. Traits other than yield such as harvestability, insect and disease resistance must also be considered in choosing a variety. Brief descriptions of each of the recommended varieties follow Table 4. Table 5 summarizes variety characteristics. Table 1. Three-year plant cane performance means from 1996 through 1998 outfield tests Varieties 1 Sugar Yield lbs/a Cane Yield tons/a Theoretical recoverable sugar lbs/ton Stalk Number no/a Stalk weight lbs. CP , , LCP , , HoCP , , HoCP , , Some recommended varieties were not included in all tests and are not included in this table. Table 2. Two-year first stubble performance means from 1997 through 1998 outfield tests Varieties 1 Sugar Yield lbs/a Cane Yield tons/a Theoretical recoverable sugar lbs/ton Stalk Number no/a Stalk weight lbs. CP , , LCP , , HoCP , , HoCP , , Some recommended varieties were not included in all tests and are not included in this table. Table 3. One-year second stubble performance means from 1998 outfield tests Varieties 1 Sugar Yield lbs/a Cane Yield tons/a Theoretical recoverable sugar lbs/ton Stalk Stalk Number weight no/a lbs. CP , , LCP , , HoCP , , HoCP , , Some recommended varieties were not included in all tests and are not included in this table. 5

6 Table 4. Two-year third stubble performance means from 1997 through 1998 outfield tests Varieties 1 Sugar Yield Ibs/A Cane Yield tons/a Theoretical recoverable sugar lbs/ton Stalk Number no/a Stalk weight lbs. CP , , LCP , , HoCP , , Some recommended varieties were not included in all tests and are not included in this table. Varieties Recommended for Major Plantings CP was selected from a cross of CP x CP and released in CP is early maturing. CP tends to lodge but less than LCP It is resistant to smut and post-freeze deterioration of the stalk. It is susceptible to RSD and a complex of foliar diseases. It is moderately susceptible to leaf scald and does not stubble well after a severe freeze or a late spring frost. Research shows that CP is resistant to the establishment of the sugarcane borer. LCP was selected from a cross of CP x CP and was released in LCP is a high yielding, excellent stubbling variety. The variety produces a large number of small stalks and exceeds most others in sugar per acre. This variety is slow to emerge after planting. Planting this variety in poorly drained areas or covering seed cane of this variety too deeply can result in reduced stands. This is an early maturing variety with a fiber content similiar to CP This variety frequently lodges and is brittle and difficult to harvest when lodged. It is better suited for combine harvesting. LCP exhibits symptoms of a complex of foliar diseases but is resistant to smut and resistant to sugarcane mosaic virus, rust and leaf scald and post-freeze deterioration. RSD has caused significant yield reductions in stubble crops. The variety is susceptible to the sugarcane borer and should not be grown in areas where insecticides cannot be applied. LCP is tolerant to common sugarcane herbicides but has exhibited susceptibility to the ripener glyphosate and may be injured by excessive application rates. HoCP was selected from the cross CP x CP and was released in HoCP is erect in growth habit and suited to soldier harvesting. HoCP is superior to CP in yield of sugar per acre in the plant-cane crop and yield of cane per acre. HoCP is slightly poorer than CP in sugar per ton of cane and early in maturity. It has good resistance to post-freeze deterioration. The variety has acceptable fiber content. The variety is moderately resistant to mosaic and resistant to smut and rust. It is susceptible to leaf scald, and RSD has caused significant reductions in yield in the stubble crops. HoCP is resistant to the sugarcane borer and tolerant to most herbicides. Planting in August will normally result in higher sugar yields (TRS) in the plant cane crop of this variety. 6

7 Varieties Recommended for Limited Acreage Plantings CP was selected from a cross of CP x CP and released in It is early maturing and well adapted to soldier harvesting. It has good resistance to smut but is susceptible to mosaic and moderately susceptible to leaf scald. It has moderate to poor stalk cold tolerance and should be harvested before freezes. To maximize sugar per acre yields, harvest this variety before November 15. CP yields are similar to CP It is moderately damaged by the sugarcane borer under heavy borer pressure. Because of its erect canopy, weed problems are increased and this variety is damaged by late applications of Asulox. Growers are cautioned about planting CP in areas known to have heavy weed pressure. CP was selected from a cross of CP x L and released in CP exceeds CP in tons of cane per acre, sugar per ton and sugar per acre. CP is a moderately early maturing variety with good stubbling ability that is moderately resistant to smut and leaf scald. The variety has shown some tolerance to RSD. However, it is susceptible to infection and can serve as an inoculum source for spread to other varieties. CP is similar to CP in its reaction to the stalk borer. It is a variety with moderate resistance to the establishment of the borer in the stalk, but under heavy borer pressure, it may sustain extensive damage. This variety is brittle and difficult to harvest with a soldier harvester but its early maturity, good stubbling ability and response to Polado make it a good candidate for heavy soil areas where early harvesting is necessary, regardless of crop age. Planting this variety in poorly drained areas or covering seed cane of this variety too deeply can result in reduced stands. CP is extremely susceptible to post-freeze deterioration and should be harvested before a killing frost (below 26 degrees F). LHo was selected from a cross of CP x CP and released in LHo is a high yielding, good stubbling variety. Data indicate LHo is superior to CP in yield of sugar and cane per acre in stubble crops. It is later maturing than other recommended varieties and has a moderate fiber content. The variety is sometimes brittle and is not well suited to soldier harvesting. LHo is resistant to rust and mosaic and moderately resistant to smut and leaf scald. RSD causes substantial reductions in cane and sugar yields in stubble crops. The variety is susceptible to drought injury but is resistant to the sugarcane borer and tolerant to herbicides. It has good resistance to postfreeze deterioration. 7

8 Table 5. Characteristics for recommended sugarcane varieties Variety Varietal CP CP CP LHo LCP HoCP HoCP Characteristics Year Released Sugar Per Acre M M G G VG G-VG G-VG Harvestability* M G P-M P-M P-M G G Erectness P-M G P-M P-M P-M G G Brittleness M G P P-M P-M G G Sucrose (TRS) G G G M-G G M G Maturity E VE M-E M E E E Fiber G M M M G M M Tonnage M-G M G G VG G G Stubbling M M G G VG G M Borer resistance R1 M M R S R S Smut resistance R R MR MR R R R Mosaic resistance M S M R R MR R RSD tolerance P P G P P P P Leaf scald M M M M R S M Rust resistance M R R R R R R Post freeze deterioration VG P-M P G G G U Herbicide tolerance M-G M2 G G M-G2 M-G2 U Shading G P G G G G G Ripener response M-G VG G M-G G3 M U VG=Very Good R=Resistant G=Good S=Susceptible M=Moderate, Medium MR=Moderately Resistant P=Poor E=Early VE=Very Early T=Tolerant U=Unknown 1Research shows less tolerant to borer damage than other resistant varieties. 2Can be injured by late applications of Asulox. 3Rates exceeding 8 oz. have caused damage in succeeding stubble crops. 8

9 New Variety Release HoCP is a new high yielding sugarcane cultivar released for commercial use in Louisiana. HoCP is a product of the cross CP X LCP82-94 made at Canal Point (CP), Florida, and selected at Houma (Ho), Louisiana, and has a high population of small, green to brownish stalks. HoCP is mostly erect in growth habit and suited to both whole-stalk "soldier" and combine harvesting. Yield data from 44 mechanically harvested trials on both light- and heavy-textured soils indicate that HoCP is similar to LCP85-384, the leading commercial cultivar, in sugar per acre yields in plant-cane and first-stubble crops but significantly lower than LCP in the second-stubble crop. But HoCP is similar to CP70-321, the second leading commercial cultivar, in sugar per acre yields in the second-stubble crop. HoCP is a high sucrose, early maturing cultivar with acceptable fiber content (13.6%). The cultivar is moderately resistant to sugarcane mosaic virus, is resistant to smut and is resistant to rust under field conditions. The cultivar is susceptible to leaf scald by artificial inoculation, but it has shown adequate field resistance to natural infection. Ratoon stunting disease has caused significant reductions in yield of cane and total recoverable sugar per acre of this cultivar in the stubble crops. Therefore, for HoCP to yield up to its full potential, it is essential that plantings be made with seed cane free or nearly free of this disease. HoCP is considered susceptible to the sugarcane borer. Sugarcane Variety Production Update The annual sugarcane variety census is conducted cooperatively by the Louisiana Cooperative Extension Service and provides acreage data on variety plantings by growers. A better understanding of variety evaluation by growers can be seen in a comparison of several years of variety surveys. Table 6 shows the variety survey results as compiled and reported by agricultural agents in the 23 sugarcaneproducing parishes of Louisiana. The portion of the total statewide acreage made up by each variety and sugarcane variety trends over the last five years are shown in Table 6. The leading variety for 1998 was LCP85-384, with 43% of the total acreage, and the second leading variety was CP70-321, with 29% of the acreage. This is the first time LCP has been the leading variety, a result of the rapid buildup that has occurred for this variety during the last few years. One of the most obvious trends is the declining contribution of CP over this period. It has dropped from 22% of the total acreage in 1994 to 3% in During the same five-year period, CP dropped from 47% to 29% of the total acreage. Acreage devoted to LCP82-89 increased from about 8% of the acreage in 1994 to 16% of the total in 1996 before dropping to 7% in On the other hand, acreage of LCP has increased from 1% in 1994 to 43% in These changes indicate that growers have become less enthusiastic about growing some of the older varieties, particularly CP and to a lesser extent CP These varieties are being replaced by newer, high yielding varieties with better stubbling ability, a trend noted the last two years. The movement toward combine harvesting also is stimulating interest in growing LCP

10 Table 6. Louisiana Sugarcane Variety Trends, * % of state total acreage by year Variety yr. change CP CP CP CP CP <1 <1 <1 <1 0 CP LCP LHo LCP HoCP < LCP <1 <1 <1 1 0 Others 1 <1 <1 <1 1 0 Total *Based on annual variety survey reports from county agents in sugarcane-producing parishes, Planting Recommendations and Suggestions Selection of Seed Cane: As discussed previously, growers should plant seed cane that is as close to disease free as possible. Cane that is growing well and is free of borer and mechanical damage should be selected as seed cane. Healthy seed cane will provide the best possible stands if adverse environmental conditions such as drought, water logging or freezes occur. Stalk cold tolerance should be considered when selecting varieties, especially in the northern parishes. CP , LHo83-153, LCP and HoCP have shown better stalk cold tolerance than other varieties. Billet Planting: Research has shown that the highest yields will be obtained by planting whole stalks. When cane is badly lodged, however, it may be necessary to cut and plant billets. Current varieties vary in tolerance of billet planting. Stand problems in billet plantings have been encountered most frequently with CP Plantings of whole stalks have out-yielded billet plantings of LCP in plant cane in most experiments, but stubble crop yields have been comparable. The impact of stalk rot is greater in billets because of their shorter length and the wounding that occurs during cutting and planting. In addition, stalk rot is more severe under stress conditions. This means billet plantings are more sensitive to any type of planting problem, and the risk of stand problems is greater. Research continues in the areas of variety selection, cultural 10

11 practices and disease control to identify practices that can improve the consistency of billet planting. The greatest chance of success will result from planting longer billets (20-24 inches) with the least amount of damage, good drainage and the best possible planting practices. At present, planting cane as billets is not recommended. Planting Furrow Width: Research has shown good yield increases in tonnage and sugar per acre when the planted row was widened from the V-furrow to the 15" to 18" furrow. It further showed some increases as the furrow width was increased from 15" to 18" to 24". Based on this research and the problems encountered by growers in handling furrow widths greater than 18", it is suggested that growers use a 15" to 18" width furrow for planting in Growers who can successfully handle the 24" width furrow are encouraged to do so. It is also suggested that the furrow opener be constructed to leave a wide bottom with a slight indentation on each side of the furrow and a slight ridge of loose soil in the middle of the furrow bottom. This opening configuration can be obtained by attaching a single disk on each side of the row opener to dig out the furrow sides and deposit the soil in the furrow middle. Some growers have found that packing rows ahead of opening will give a more uniform furrow when opening with a three-row opener. Planting Rate: For planting, growers should plant the best seed cane available. (See section on selection of seed cane.) Based on research results and field observations, the planting rate recommendation is three stalks and a lap of at least two mature joints. Where sufficient seed cane is not available for optimum planting rates, growers may be able to obtain acceptable stands by planting two stalks and a lap of at least two mature joints. These recommendations are based on using good seed cane. Additional seed cane should be used to compensate for poor quality seed cane. Planted cane stalks should be spread to cover the entire width of the planting furrow. Date of Planting Planting date trials from middle August to middle October have been conducted in recent years. Results have been variable but generally showed an advantage of mid- August over mid-october planting. Planting date trials over the last three years also indicate significantly higher yields in sugar per ton of cane for HoCP in plantcane crops when planted in mid-august. Based on such results, mid-august to mid- September planting is suggested. 11

12 Table 7. Combined plant cane yields from different planting dates during Dates Sugar/A Cane/A Sugar/T St.Wt. Population (Lbs.) (tons) (lbs) (lbs.) (no.) CP Aug Sept Oct CP Aug Sept Oct LCP Aug Sept Oct LHo Aug Sept Oct LCP Aug Sept Oct HoCP Aug Sept Oct Amount of Soil Cover Over Seed Cane Research on depth of soil cover over seed cane indicates that soil cover in excess of 4" can cause yield losses even if it is removed. Heat-treated cane should be covered with 2" of packed soil. After the cane is up to a good stand and before freezing weather occurs, add an additional 2" of soil to protect from freeze damage. Do not cover heat-treated cane with more than 2" of packed soil at planting. For regular late August, September and October planting, cover with 3" to 4" of packed soil at planting time. Farmers in the southern part of the belt can normally get by with 3" of packed soil covering. On farms in the northern part of the sugarcane belt, 4" of packed soil may be better. Growers should use a fluke on the covering tool to keep from covering with more than 4" of packed soil. Growers who cover with much more than 4" of packed soil should be prepared to remove the additional soil early in the spring. 12

13 Growers should use a covering tool that will cover the cane without pushing the cane closer than the width it was planted. Packing of rows should be done immediately after covering. Clean quarter drains before spraying herbicides. Where soil washing occurs in the fall before a hard freeze, it is suggested that the middles be sunk and rows rebuilt for winter protection. Depth of Planting with Relation to Water Furrow To avoid water damage to seed cane, it should be placed at least 3-4" above the final water furrow or middle. In soils with poor internal drainage, the seed cane should be placed even higher above the final water furrow. Growers should be aware of the need to keep the seed cane above the area where water levels will hurt cane stands. Low row height at planting time could be a problem, especially with billet seed cane. Starter Fertilizer Application Recent fertilization trials have often shown yield responses to starter fertilizers applied in the planter furrow for cane planted after a fallow year. Yield responses have been obtained in both plant cane and stubble cane crops with an application of lbs/a of N-P 2 O 5 -K 2 O. Based on these recent findings, it is suggested that growers apply lbs/A of N-P 2 O 5 -K 2 O into the planter furrow ahead of planting. Levels of nitrogen above 15 lbs/a in the fall could be harmful. Weed Control at Planting The importance of early control of johnsongrass and bermudagrass cannot be overstated. Johnsongrass established from seed begins to develop rhizomes within a few weeks. These rhizomes have a large number of buds, each capable of producing a johnsongrass plant. Heavy infestations of johnsongrass can reduce yields by 50% or more. Bermudagrass is also a perennial that produces rhizomes and stolons. Bermudagrass can reduce sugar yields about 5% to 17% per year over a three-year cane cycle. Sugarcane is most susceptible to weed competition during the first eight to 10 weeks after cane emergence. Once established johnsongrass and bermudagrass become more difficult to control. In contrast, itchgrass is an annual weed which reproduces only by seed. Season-long itchgrass interference has reduced sugar yield by 43%. In earlyplanted cane, the growing season is sufficient to allow for itchgrass seed production to occur. Control of these weeds may be enhanced by keeping ditches clean, preventing movement of rhizomes and seed into fields and by implementation of an effective fallow program. Herbicides to control weeds are essential to prevent weed competition and losses in sugarcane production. Unless herbicides are applied immediately after planting, weed seed present in the soil following a fallow program will germinate, producing viable seeds and/or rhizomes. As a result weeds can quickly reinfest a field, with the benefits of weed control in the fallow period rapidly lost. 13

14 Selection of preemergence herbicides should be based on soil texture and organic matter content, weed problem and the variety of sugarcane. For best results, apply preemergence herbicides immediately after planting. Louisiana Cooperative Extension Service publication 2314, "Controlling Weeds in Sugarcane," provides additional weed control strategies and recommendations. You can obtain it from your county agent. NOTE: Herbicide rates are presented on a formulated broadcast basis. A. Preemergence Control of Seedling Johnsongrass and Itchgrass Table 8. Herbicide rates for preemergence control of seedling johnsongrass and itchgrass. Rate/A (Broadcast) Light Medium Heavy Herbicide Soil Soil Soil (Johnsongrass only) Sencor pts 3.0 pts 3.0 pts Sencor/Lexone DF 2.0 lbs 2.0 lbs 2.0 lbs Sinbar 80W* lb lb** lb (Johnsongrass and Itchgrass) Treflan, Trifluralin Trilin or Tri-4**** 4.0 pts*** 4.0 pts*** 4.0 pts*** Prowl 3.3 EC**** pts pts pts *Do not apply sinbar on sugarcane varieties or soils that have shown previous Sinbar injury. **Use higher rates where heavy johnsongrass infestations are expected. ***4 lbs. per gallon formulations. ****Additional herbicide treatments should be applied to control winter weeds (Table 9). NOTE! If Prowl is surface applied (not incorporated), apply at the higher rate. Herbicides may be applied on a band or broadcast. Broadcast applications may be more beneficial where cane is planted in August and early September. Band Rate = Band width (in) X Broadcast Rate Row width (in) B. Preemergence Control of Summer and Winter Annual Weeds The following herbicides control some annual grasses and most broadleaf weeds but may not control johnsongrass, itchgrass or browntop panicum. Table 9. Herbicide rates for preemergence control of summer and winter annual weeds. Herbicide Rate/A (Broadcast) Atrazine 80W lbs Atrazine/AAtrex 4L 4-8 pts AAtrex Nine-O lbs Karamex DF lbs Direx 4L pts NOTE! Use higher rates on heavier soils. 14

15 C. Alternate Procedure for Heat Treated Sugarcane Generally heat treated cane and some early planted cane are lightly covered (2 inches of packed soil), with more soil added before winter. Since additional soil will be added, two herbicide applications will be needed. The first treatment after planting should be one of the herbicides in Table 8 or 9. Do not incorporate Treflan, Trifluralin, Trilin or Tri-4 with only a 2-inch soil cover. For the second treatment, after additional soil is added, apply one of the herbicides listed in Table 9. D. Supplemental Practices 1. Escaped johnsongrass should be spot treated with Asulox using a spray gun at a 5% V/V solution of Asulox (1 gallon per 20 gallons of water). Alternatively, Asulox may be applied at a broadcast rate of 8 pints per acre. Apply to actively growing johnsongrass 12 to 18 inches tall when the average air temperature is 60 degrees F or higher. Add nonionic surfactant at.25% to.50% V/V or 1.0% V/V crop oil concentrate. 2. When bermudagrass is a problem, apply one of the herbicides listed in Table 8 immediately after planting, and apply Roundup at 2 ½ to 4.0 pts per acre using a 48- inch shielded sprayer to control bermudagrass developing in the wheel furrow. 3. If herbicides are applied on the band to the top of the row, cultivate the middle and sides of the row to control weeds. 4. Where fields are planted in late July or early August, it may be beneficial to apply one of the herbicides listed in Table 9 in late October or early November to control late emerging winter weeds. Herbicide Rates Rates of herbicides presented here are based on amount of formulated product on a broadcast basis. To calculate the band rate: Band Rate = Band Width (in) X Broadcast Row Width (in) Rate. Follow Label Directions If herbicides are handled or applied improperly, or if unused portions are not disposed of safely, they may injure humans, domestic animals, desirable plants, and fish or other wildlife, and may contaminate water supplies. Use herbicides only when needed and handle them with care. Follow the directions and heed all precautions on the container label. Expected Weed Control The values listed are estimates of the degree of weed control that should be obtained with a specific herbicide(s) and are based on research and personal observations. Many factors such as soil texture, moisture, temperature and spray coverage of the weeds will 15

16 affect the results obtained. This information may help you to develop the most effective control program for the weeds on your farm. Table 10. Expected control of selected weed species by specific herbicides Seedling Johnsongrass Rhizome Johnsongrass Itchgrass Bermudagrass Browntop Panicum Annual Grasses Morningglory Winter Grasses Winter Broadleaf Weeds Other Broadleaf Weeds Herbicides Fallow Fields Roundup E G G-E F E E F - - G Atrazine P P P P P P-F G - - G Sencor/Lexone G P P P F G-E G - - G Planted Fields Preemergence Sinbar G-E P P F P E G G E G-E Sencor/Lexone G-E P P F F-G E G-E G E E Treflan, Trifluralin, Trilin and Tri-4 E P G-E F-G G-E E P G P P Prowl E P G-E F-G* G-E E P G P P Atrazine P P P P P G G-E G E E Karmex/Direx F P P P F G-E F-G G G F-G Postemergence 2,4-D P P P P P P G-E P G G Banvel P P P P P P G-E P G-E G-E Weedmaster P P P P P P E P E E Evik P-F P F-G P G G F-G F-G G G Atrazine P P P P P P-F F F G F-G Asulox G G P-F P G G P F-G P P Karmex/Direx F P G P F G F-G F G F-G Control Rating Scale Poor - less than 49%; Fair %, Good %; Excellent %; - does not apply or not rated. * When incorporated 16

17 Succession Planting Sugarcane (cane planted without fallow) Succession planting is an alternative planting system that has been investigated for several years at the St. Gabriel Research Station and is being used by some growers. It has the advantages of allowing growers to maintain more of their cane land in production and is beneficial in adjusting the cane rotation for growers who do not have a good balance of their acreage in each year of the crop cycle. It is best suited for light soils and small farms. Because of its limitations, succession planting should be considered only on better drained soils that do not have serious infestations of johnsongrass or bermudagrass and on farms where equipment and labor are available for planting during the harvest season. Weather often becomes unsuitable for planting during the harvest season and some varieties are not tolerant of late planting. Research has shown that fall fertilization at planting time has increased yields of succession planted cane. In most tests succession planted cane that received fall-applied N-P-K fertilizer produced yields similar to cane planted conventionally after a fallow period. Research on this practice is continuing. Growers who plan to use succession planting should follow the procedure suggested below. Suggested Procedure for Succession Planting of Sugarcane (Please note: Growers should select succession planting areas that do not have heavy johnsongrass or bermudagrass infestations.) 1. Shave stubble deep. This will divide the cane stubbles into smaller, more manageable pieces. 2. Roto-till rows. 3. Subsoil in each row. 4. Rebuild rows with disk chopper. 5. Culti-pack and then open planting furrow 15" to 18" as recommended. 6. Apply fertilizer in planting furrow. Research results indicate that or lbs/a of N-P 2 O 5 -K 2 O should be applied in the planting furrow before planting succession cane. In addition, the normal recommended N-P 2 O 5 and K 2 O rates for stubble cane should be applied in the spring of each crop year, depending on soil type and soil test results. 7. Plant seed cane of a variety that tolerates late planting and cover as recommended. 8. Pack rows after planting. 9. Apply preemergence herbicides as recommended. 17

18 Soil Insect Control at Planting Time Growers should be ever mindful of those practices that they can use to decrease the possibility of soil insect damage. (The following is reprinted from Louisiana Cooperative Extension Publication 1982, Pest Management of Sugarcane Insects.) Only two crop conditions require use of a soil insecticide in Louisiana sugarcane fields and usually only in sandy soils. These are: (a) When pasture, turf or grass-infested land is brought into cane production for the first time or after being out of cane production for several years. There are usually enough grubs or wireworms already established in this type of land to warrant a preventive application of insecticide at cane planting time. However, a soil insecticide application may not be needed with the second plant cane crop if the field has been kept reasonably free of grass during the ratoon crops. (b) When cane fields are extremely grassy and particularly when cane is planted in a field that was not kept free of heavy grass infestation when fallow. Ongoing wireworm and white grub infestations will persist in grassy fields. Again, this may be needed only on light or mixed soils. The key to successful management of most soil insect problems in sugarcane fields is to plant healthy seed cane in well-drained land that is free of weeds and kept weed-free as much as possible during the ratoon crops. Growers with fields similar to those described should consider control measures for soil insects at planting time and base chemical control on verification of soil insect pest infestations (with fermented corn baits). Based on new research data, the economic threshold is slightly above 1 wireworm per bait sample before planting. Soil insecticides have had a suppressive effect on beneficial predators in sugarcane studies. County agents have additional recommendations on soil insects and control. 18

19 Notes 19

20 Visit the website: Sugarcane producers who want additional information on the practices covered in this publication should contact their county agents. Prepared by Wade F. Faw, Extension agronomist, LSU Agricultural Center. This information was obtained from research data by scientists at the LSU Agricultural Center s Louisiana Agricultural Experiment Station, the USDA-ARS, SRRC, Sugarcane Research Unit and the American Sugar Cane League agronomists with consultation by LSU Agricultural Center Extension specialists in agronomy, weed science, plant pathology and entomology and county agents in sugarcane-producing parishes. Growers comments were considered as well. Louisiana State University Agricultural Center William B. Richardson, Chancellor Louisiana Cooperative Extension Service Jack L. Bagent, Vice Chancellor and Director Pub (3M) 6/99 Rev. Issued in furtherance of Cooperative Extension Service work, Acts of Congress of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. The Louisiana Cooperative Extension Service provides equal opportunities in programs and employment.