Forecasting the effects of insects and other pests on perennial biomass crops

Transcription

1 Forecasting the effects of insects and other pests on perennial biomass crops Jarrad Prasifka Energy Biosciences Institute Jeff Bradshaw U. of Nebraska, Entomology Mike Gray U. of Illinois, Crop Sciences

2 Pests and biomass crops: overview Economics of pest management (insects) Forecasting for biomass crops Insects in emerging perennial crops Switchgrass Miscanthus spp. Lessons from other energy & novel crops Sugarcane and soybeans

3 Economics of pest management What are normal crop losses & what determines pest status in biomass crops?

4 Economics of pest management Losses in common food & feed crops Global estimates: CABI Potential and actual losses (%) Maize: (P) 68 (A) 32 Wheat: (P) 50 (A) 28 Insect, pathogen & weed losses (A%) Maize: (I) 10 (P) 10 (W) 11 Wheat: (I) 8 (P) 8 (W) 13 J Ag Sci 144: 31-43

5 Pest management for biomass crops Advantages relative to food crops No high-value structures Except seed? Crops close to natural state Some (Miscanthus) w/ pest resistance

6 Not all pests require management (IPM) Act at threshold levels for economic return Loss Potential yield Yield Damage boundary Gain threshold Economic loss Injury

7 Not all pests require management (IPM) Act at threshold levels for economic return Potential yield Yield Damage boundary Gain threshold Biomass Food Injury

8 Challenge: forecasting for pests All species for biomass are novel crops Cost-benefit: fuel feed food Scale of crop production Problems increase with area in biomass Desire for long-term projections US: advanced biofuels peak in 10+ years Evolution of insect, pathogen populations

9 Challenge: forecasting for pests Potential for change and redirection New range for crops (e.g., cold hardiness) Incentives for specific crops (e.g., natives) Severity of pest species can change Economic value of commodity Higher value = increased sensitivity to pests Costs of management Lower cost = increased sensitivity to pests

10 Insects in emerging biomass crops Which insects should we be monitoring as area of feedstock plantings expands?

11 Insects in emerging biomass crops Surveys in CFAR, DOE, etc. Switchgrass Miscanthus x giganteus

12 Insects in emerging biomass crops Few species shared between feedstocks SG Mxg Most shared with food & feed crops About 70% are known as crop pests Others are specialists on switchgrass

13 Aphids on Miscanthus giganteus Corn leaf aphid Rhopalosiphum maidis Yellow sugarcane aphid Sipha flava

14 Corn leaf aphids Migrate to Midwest Whorls of 1 st year Mxg Yellowing of new leaves Transmit viruses BYDV (PAV to Mxg) More risk in southern US

15 Lower leaves Yellow sugarcane aphid Sorghum, Saccharum Transmit viruses Sugarcane mosaic Cause leaf death Infrequent losses but 6% in cane

16 August 2008 Yellow sugarcane aphid Mead, NE Establishment year Healthy in 2009

17 Stem borers in switchgrass Species in Illinois

18 Tiller-killer Blastobasis repartella In South Dakota, 2004 Infestations of 20%? Biology mostly unknown

19 Switchgrass tiller-killer Switchgrass specialist? Parasitoids, winter kill Eggs protected

20 Blastobasis repartella repartella distribution Described from Colorado (1910) One generation per year in Illinois Another Blastobasis known from South

21 Blastobasis repartella abundance Location Symptomatic tillers With Blastobasis Savoy, IL 3.2 ± ± 0.4 Mead, NE (1) 1.0 ± ± 0.5 Mead, NE (2) 7.2 ± ± 1.3 Arlington, WI 3.0 ± ± 1.0 Bristol, SD 3.6 ± * Another early-season borer in Savoy Potential for plant compensation

22 Armyworms in switchgrass, Mxg Many armyworm spp. Foliage of grasses Regional or national Fall armyworm (FAW) Found in Mxg whorls Migrate from TX, FL Late-season corn pest Corn & rice strains

23 Fall armyworm survival, development 100% 80% 60% 40% day Pupa Adult 20% % Rice Corn Rice Corn M. x giganteus Switchgrass

24 Fall armyworm survival, development Leaf tissue Strain Pupal mass (mg) Development (d) Switchgrass Rice ± 5.1 a 33.7 ± 0.3 c Corn ± 5.9 a 35.0 ± 0.4 b Miscanthus Rice ± 5.8 ab 33.1 ± 0.4 c Corn ± 7.6 b 36.5 ± 0.6 a Relative to corn (preferred host) Pupal mass 10 mg less Total development time 14 d more

25 Potential FAW risk to biomass crops Relatively low in Midwest and for Mxg Migration = only one late generation Mxg = poor survival, >> leaf tissue Higher in South, cut switchgrass Several generations may be present Young switchgrass (regrowth) preferred

26 Lessons: pest management in biomass How could problems change as scale and intensity of biomass crops increase? John Wozniak

27 Lessons: pest management in biomass Sugarcane in Louisiana Not-native, but grown 215+ years in LA Perennial, germplasm base for energy-cane Soy & common beans in S. America Soybean expansion from 1970s Shared pests present challenges History of how duration, scale of cropping impacts pest management

28 Lessons: Louisiana sugarcane Similarities to Miscanthus x giganteus Perennial with complex parentage Bred with Miscanthus for pest resistance Cultivar history, development Until 1900s, new cvs for frost tolerance 1920 present, recurring pest outbreaks Slow to select for sugar, pest resistance

29 Lessons: Louisiana sugarcane Selection and propagation Advancing crosses may be 10-year process Build up of new cane cvs slow, inefficient Constant for pathogen, insect resistance Assume 8-fold expansion / yr ha Tissue culture Cultured seed cane Propagated seed cane Plant cane + 3 ratoon years ha ha

30 Lessons: Louisiana sugarcane Cultivar changes necessary 1993: LCP released 2003: LCP common rust problems apparent 2004: L and Ho released, LCP on 91% of LA sugarcane 2006: Ho brown rust resistance fails 2007: LCP still 46% of LA cane

31 Lessons: soybean in S. America Common bean 1970s, Brazil leading 5 million ha Brazilian soybean growth million ha million ha million ha USDA Shared insect, viral pests among beans Arch Virol 146:

32 Lessons: soybean in S. America Sweetpotato whitefly, Bemisia tabaci Common bean an unattractive host Soybean preferred for reproduction As soybean expanded in Brazil More whitefly, moving onto common bean Transmit bean golden mosaic (BGMV) Decreased common bean plantings Arch Virol 146:

33 Lessons: soybean in S. America In Argentina, similar pattern Increasing soybean production Detection of geminiviruses in 1980, 1983 Changed production for common bean 20% ( 40,000 ha) lost due to BDMV Remaining 150,000 ha have recurring problems from BGMV and BDMV Arch Virol 146:

34 Expectations: pests in biomass crops John Wozniak

35 Expectations: pests in biomass crops Insect pest species Some new and some shared w/ food crops So far may not require management Effects of time and space Pests will react to new resources Evolve over many years (e.g., US soybeans) Insects may act through plant pathogens

36 Expectations: pests in biomass crops Interactions with other crops important - Exacerbate existing problems (-) - Provide beneficial insects (+) - Refuge against insecticide resistance (+) Breeding for resistance is best defense - Use planted diversity to hedge against pests with very high reproductive capacity (pathogens, aphids, etc.)

37 Questions and discussion John Wozniak