Biotic Stress and Yield Loss

More documents

Recommendations

Info

chronic injury. Acute injury results in immediate, noticeable damage (tissue removal,entrance holes, etc.), while chronic injury produces noticeable damage over longerperiods of time (leaf chlorosis, plant malformation, stunting, etc.). 5Additionally, arthropod injury has been placed into several groupings based onphysiological impact (response) to the plant (host). Pests producing similar physiologicalresponses have been grouped into like injury types. 5 Higley and Peterson 5 categorizedpests into ten groupings based on physiological impact on plants:population and stand reduction, leaf mass reduction, leaf photosynthetic rate reduction,leaf senescence alteration, light reduction, assimilate removal, water-balancedisruption, seed or fruit destruction, architecture modification, and phenological disruption.Arthropods injuring corn can be placed into the categories mentioned abovebased on physiological responses produced in the corn plant. However, I believe thata further simplified list of categories is appropriate for a discussion of key corn pests.The five categories to be used for purposes of this chapter will include: foliar feedinginjury (tissue removal), vascular feeding injury (sap/water/nutrient removal),vascular disruption injury (internal tunneling/tissue removal), root feeding injury(root pruning/tissue removal), and reproductive disruption injury (pollination disruption,seed damage/removal).4.3.1 FOLIAR FEEDING INJURYPhysical injury that removes foliar tissue from above-ground portions of the cornplant can have serious impacts on plant development and subsequent yields. Vigorand yield reductions result from reduced photosynthetic capacities within injuredplants. With extensive tissue removal, injured plants may develop abnormally, producinga barren stalk, or die, reducing overall plant stands.Foliar feeding injury typically occurs in two ways: (a) a partial removal of leaftissues from leaf margins and whorl areas of the plant, appearing as ragged edges orholes in exposed leaf surfaces; and (b) a total removal of all leaf tissues above the soilline that requires complete regrowth of the photosynthetic portions of the plant.In many ways, this type of arthropod feeding injury is similar to some physicalinjuries caused by weather events such as hail. With either source of injury, arthropodor hail, moderate injury levels incurred before V7 stage would generally have littleor no impact on yield. Likewise, with injuries incurred in older plants, nearertassel stage (V17–R1), yield reductions would be more likely, regardless of howinjuries were sustained. Also, injuries incurred before tassel stage might result inslight delays in corn maturity, while injuries incurred after tassel stage would likelyhasten maturity (as observed with hail injury).4.3.1.1 CutwormsCutworms constitute a large group of serious, yet sporadic foliage-feeding lepidopteranpests in North American corn production. These insects attack corn in earlygrowth stages when stand establishment is critical and plants are inherently more vulnerable.Cutworms can be grouped into three types based on the injuries they pro-
duce: the cutting species (such as black cutworm, Agrotis ipsilon, and claybackedcutworm, Agrotis gladiaria), the surface feeding species (such as dingy cutworm,Feltia ducens, bristly cutworm, Lacinipolia renigera, and sandhill cutworm, Euxoadetersa), and the climbing species (such as variegated cutworm, Peridroma sauciaand spotted cutworm, Xestia spp.). 15Although all cutworms can be injurious to corn, those causing simple leaf injuryare normally considered to be less injurious than those with feeding habits thatinclude plant cutting. This is evident from established economic injury levels for cutworms.Thresholds for surface-feeding cutworms are typically higher than thresholdsfor cutworms with cutting behaviors. 15 In general, corn leaf feeding from cutwormsis considered to be insignificant, with no evident effects demonstrated on yield. 16Cutworms that consume large amounts of leaf foliage (e.g., late stage surfacefeeders and climbing species) and cutworms with cutting behaviors are of significanteconomic importance in corn production. 15 These species have the potential toremove a majority, or all, of the above-ground foliage from young corn plants, dramaticallyaffecting plant growth and development. The cutting behavior removes allleaf tissue from smaller corn plants by larval chewing injury that produces notches orcomplete cuts through plant stems near or below the soil surface. Large surface feedersand climbing species can produce a similar result through the exaggerated effectsof grazing. Regardless of how the described injury occurs, impacts on plant healthand yield are the same. On smaller plants (V1 to V5) damage can be extensive enoughto cause wilting and death, particularly when injury occurs to the plant growing point.This leads to plant population reductions and reduced yield.Researchers have studied the effects of cutworm injury on corn grain yieldsunder Midwest corn-growing conditions. Collectively, these results have indicatedthat yield reductions are dependent upon the stage of plant development at the timeof cutting injury and the location of the cutting injury on the plant. 17–20 Plants in theV2 to V5 stage are generally most vulnerable to cutworm injury, with the window forpotentially serious damage ending at about the V7 stage, when corn stalks becometoo large to be cut. Cutting injury that occurs below the soil surface, a behavior oflarger larvae, is usually more serious than cutting injury that occurs above the soilline. 15 Researchers have determined that relationships between cutworm injury (cutplants) and yield losses are linear, with greater yield losses occurring when olderplants are damaged (V5 vs. V3 plants). Yield suppression is variable, with measuredlosses observed to range from 0 to 24% and 0 to 81% in V3 and V5 stage plants,respectively. 214.3.1.2 Armyworm and Fall ArmywormThe armyworm, Pseudaletia unipuncta, and fall armyworm, Spodoptera frugiperda,are two lepidopteran pests which can occasionally inflict severe injury to abovegroundfoliar portions of the corn plant. In the Midwest, these pests are typicallymore injurious to corn in the mid- to late-vegetative or early reproductive stages, dueto seasonal temperatures, migratory behaviors, and insect life cycles. 22 In the southernU.S., these insects may also attack younger whorl-stage corn.Armyworm infestations typically develop in nearby grass pastures, fence
Page 2 and 3:
Biotic Stressand Yield Loss
Page 4 and 5:
Library of Congress Cataloging-in-P
Page 6 and 7:
PrefaceThe idea for this book came
Page 8 and 9:
EditorsRobert K. D. Peterson, Ph.D.
Page 10 and 11: ContentsChapter 1Illuminating the B
Page 12 and 13: 1Illuminating the Black Box:The Rel
Page 14 and 15: increase plant tolerance, through p
Page 16 and 17: the action of a stressor on a plant
Page 18 and 19: The magnitude and duration of injur
Page 20 and 21: Plant part injuredrefers to the pla
Page 22 and 23: cific competition, while agricultur
Page 24 and 25: 2Yield Loss and PestManagementLeon
Page 26 and 27: direct relationships between the ac
Page 28 and 29: In keeping with the theme of this b
Page 30 and 31: egressions. Actually, the title “
Page 32 and 33: REFERENCES1. Teng, P. S., Crop Loss
Page 34 and 35: 3Techniques for EvaluatingYield Los
Page 36 and 37: number of species and stage of cutw
Page 38 and 39: especially if buried in soil, can d
Page 40 and 41: elationships for some pests. When m
Page 42 and 43: injury can be precisely controlled
Page 44 and 45: day. 81, 99 However, except for an
Page 46 and 47: the literature most likely are actu
Page 48 and 49: 20. Ba-Angood, S. A., and Stewart,
Page 50 and 51: 60. Stewart, J. G., McRae, K. B., a
Page 52 and 53: 99. Shields, E. J., and Wyman, J. A
Page 54 and 55: 4.3.3.1.3 Third generation European
Page 56 and 57: ing on the developmental stage at t
Page 58 and 59: 4.2.2.1.2 Temperature stressPlant s
Page 62 and 63: ows, roadsides, or small grain fiel
Page 64 and 65: numbers are present. Stink bugs, Eu
Page 66 and 67: Oligonychus pratensis, feed on corn
Page 68 and 69: ECB2. 224.3.3.1.4 The impacts of Eu
Page 70 and 71: stalk borer, Papaipema nebris, is a
Page 72 and 73: period prolonged with sufficient co
Page 74 and 75: Arthropod injuries to developing ea
Page 76 and 77: esponses to herbivory have been obs
Page 78 and 79: Midwest, Purdue University CES and
Page 80 and 81: 59. Bailey, W. C., and Pedigo, L. P
Page 82 and 83: 5Phenological Disruptionand Yield L
Page 84 and 85: ity by animal consumers is the agro
Page 86 and 87: ously, structural components (e.g.,
Page 88 and 89: FIGURE 5.2 Generalized alfalfa grow
Page 90 and 91: 601, 1972.9. Gordon, C. H., Derbysh
Page 92 and 93: do we know about how biotic stresso
Page 94 and 95: ing both large and small leaf veins
Page 96 and 97: population. Whole plants may respon
Page 98 and 99: temporally and spatially, are more
Page 100 and 101: some systems have allowed for a tra
Page 102 and 103: injury guilds would center on the f
Page 104 and 105: apple leaves, HortScience, 19, 815,
Page 106 and 107: 7The Influence of Cultivarand Plant
Page 108 and 109: unit ground area, and it indicates
Page 110 and 111:
without considering plant architect
Page 112 and 113:
photosynthesis. Regardless of the n
Page 114 and 115:
light interception. 45 Skeletonizin
Page 116 and 117:
Light interception, which intrinsic
Page 118 and 119:
var. Consequently, use of a single
Page 120 and 121:
19. Jarosik, V., Phytoseiulus persi
Page 122 and 123:
62. Caviness, C. E., Registration o
Page 124 and 125:
8Drought Stress, Insects,and Yield
Page 126 and 127:
humidity. Because the relative humi
Page 128 and 129:
temperature and precipitation. Prop
Page 130 and 131:
compared to well watered soybeans.
Page 132 and 133:
Changes in plant hormones, such as
Page 134 and 135:
plays a key role in promoting plant
Page 136 and 137:
In soybeans, a leaf area index (LAI
Page 138 and 139:
15. Schulze, E. D., Water and nutri
Page 140 and 141:
52. Meyer W. S., and Walker, S., Le
Page 142 and 143:
9The Impact of Herbivoryon Plants:
Page 144 and 145:
conditions of stress are themselves
Page 146 and 147:
are common, defenses to avoid herbi
Page 148 and 149:
plant tissue, resulting in gall for
Page 150 and 151:
found on cucumbers in polycultures
Page 152 and 153:
compensatory response. Also, more v
Page 154 and 155:
Costa Rica, and there are several g
Page 156 and 157:
ivory from white cabbage butterfly
Page 158 and 159:
made, while larger vertebrate herbi
Page 160 and 161:
important consequences to plant fit
Page 162 and 163:
de Entomol., 38, 421, 1994.32. Kare
Page 164 and 165:
chlorophyll content in spider mite
Page 166 and 167:
114. Karban, R., and Strauss, S.Y.,
Page 168 and 169:
10Stephen C. WelterCONTENTSContrast
Page 170 and 171:
Although literature is drawn from a
Page 172 and 173:
and wheat acres receiving some type
Page 174 and 175:
pattern to be true. 109 Because rel
Page 176 and 177:
used in the experiment influenced t
Page 178 and 179:
artificially elevated nitrogen leve
Page 180 and 181:
annual, landrace cultivars, or mode
Page 182 and 183:
settings are coupled with genotype
Page 184 and 185:
10. Kennedy, G. G., and Barbour, J.
Page 186 and 187:
53. Panda, N., and Heinrichs, E. A.
Page 188 and 189:
97. Gross, K. L., and Soule, J. D.,
Page 190 and 191:
143. Davidson, J. L., and Milthorpe
Page 192 and 193:
11Crop Disease andYield LossBrian D
Page 194 and 195:
The conditions listed above are opt
Page 196 and 197:
to associate the effects of disease
Page 198 and 199:
general relationship between LAI an
Page 200 and 201:
Biomassproduction(total dryweight)R
Page 202 and 203:
Y RUE(t)RI(t)[1 X]dt [11.12]wher
Page 204 and 205:
sue. The most accurate prediction o
Page 206 and 207:
tion. Two weeks before harvest, the
Page 208 and 209:
15. Spitters, C. J. T., Van Roermun
Page 210 and 211:
57. Richardson, A. J., Wiegand, C.
Page 212 and 213:
they were cheap, convenient, and ef
Page 214 and 215:
dW / W dtcauses and consequences of
Page 216 and 217:
(a)(b)Maize yield (Mg ha -1 )987654
Page 218 and 219:
Recall that c is a constant, so by
Page 220 and 221:
where the subscripts c and w repres
Page 222 and 223:
0.6Fraction yield loss0.40.2Eq. 16,
Page 224 and 225:
the leaf area index (LAI). Incorpor
Page 226 and 227:
can no longer be tolerated and, the
Page 228 and 229:
cide. Steckel et al. 68 showed that
Page 230 and 231:
A eq ∑ jN eq,ji 1YL n,j [12.31]1
Page 232 and 233:
samples per field. Thomas 85 sugges
Page 234 and 235:
external factors such as annual wea
Page 236 and 237:
38. Boznic, A. C., and Swanton, C.
Page 238 and 239:
weeds, Weed Sci., 44, 856, 1996.79.
Page 240 and 241:
competition and weed management. 3-
Page 242 and 243:
per unit biomass (1/W i)(dW i/dt) o
Page 244 and 245:
of light interception). Algorithms
Page 246 and 247:
where G a,iis the water limited pla
Page 248 and 249:
13.4 COMPETITION FOR SOIL NITROGENA
Page 250 and 251:
As with soil water, Equations 13.10
Page 252 and 253:
partitioning of nitrogen to leaves.
Page 254 and 255:
and stems to optimize photosyntheti
Page 256 and 257:
influence of enhanced UV-B conditio
Page 258 and 259:
Systems Approaches at the Field Lev
show all

Biotic Stress and Yield Loss

Create successful ePaper yourself

Delete template?

Save as template?