Foreword - CCS HAU, Hisar

More documents

Recommendations

Info

A sigmoid or S-shaped relationship (Fig. 1B) If the relation between y and i is examined over a full range of values of i , there is often a threshold value below which no reduction in yield occurs, mostly due to compensation by unattacked parts or by clean plants for attacked ones. The result is a sigmoid curve, with a central, straight-line section, and a final flattening at high values of i when some yield is often produced, Rate of loss b changes with the value of i. Sometimes only the convex half of the curve is found, when attack is early, on vegetative parts, leaves, etc., and compensation can occur. Sometimes only the concave curve is found, when attack is on reproductive parts, such as grain, and compensation is impossible. It is difficult to fit a formula to a sigmoid curve, unless summed and a probit transformation of the normal probability distribution of yields is used to linearize the relationship, as with dosage-mortality curves. A logarithmic relationship (Fig. 1C) Yield may be related to the logarithm or a power of the number of pests, where their effects are multiplicative rather than additive. Examples are mobile or rapidly multiplying pests, such as whiteflies or aphids. There may be compensation for attack. Transformation of pest density, for example ( i ) to log ( i + l), may be needed. Rapid yield loss at low rates of infestation (Fig. 1D) Small numbers of pests sometimes can cause a disproportionate reduction in yield, for example, if the pest is a disease vector, as in the effect on rice yield of brown planthopper, the vector of grassy stunt disease (Dyck 1974). Cosmetic damage, such as scale on citrus, is another example. Gradients of disease attack are discussed by Thresh (1976). An increase in yield (Fig. 1E) Low infestations can cause an increase in yield; yield falls with a further increase in infestation. Pest attack may stimulate growth and yield. Destruction of the growing point of tillering plants such as rice, or of plants with continuous production of fruiting points such as cotton, will cause a yield increase if growing conditions are favorable. If there is too much foliage and not enough light, reduction of leaf area by leaf-eating pests may increase light falling on the plants and increase yield. Pest attack also may increase drying at maturity, increasing the sugar content of sugarcane. Or pests may selectively attack higher yielding plants, giving a positive relationship between infestation and yield. The subject is reviewed by Harris (1974). No relation between infestation and yield (Fig. 1F) Sometimes, unaccountably, no relationship is found. This may result from trying to average highly variable data, from not having a full range of infestations (such as no zero attack) or from some other effect. Variation should be reduced by altering plot or sampling design, by stratifying sources of variation into types of farming, soil, or other cause of variation, or by improving the techniques of measuring infestation, control, or yield. A model for predicting yield from the amount of pest infestation can be improved by including factors that affect pest population. Biocontrols such as parasitoids or disease, temperature as degree days, and rainfall can be used. For example, loss of forage due to grasshoppers has been forecast from grasshopper development (Hewitt and Onsager 1982). That prediction depended on temperature summation (Gage and Mukerji 1971). Such models must take into account the distribution and probability of attack and a possible nonlinear response of the pest to a controlling factor (Feldman and Curry 1982). 29
Fig. 1. Pest-loss relationship (Source : P. T. Walker, 1977). A. A straight-line relationship B. A sigmoid or S-shaped relationship C. A logarithmic relationship D. Rapid yield loss at low rates of infestation E. An increase in yield F. No relation between infestation and yield. Duration of pest attack Crop yield reduction depends on the duration of pest attack as well as pest density. This can be quantified by relating yields to bug days, the number of pests multiplied by the number of days they are present. This method has been used for brown planthopper. 30
Page 3 and 4: Vice-Chancellor CCS Haryana Agricul
Page 5 and 6: Prof. & Head Department of Entomolo
Page 7 and 8: 18. DIAGNOSTIC SYMPTOMS OF MACRO AN
Page 9 and 10: nutrients unavailable to the plants
Page 11 and 12: Reception) service provides access
Page 13 and 14: INSECT' NOMENCLATURE, IDENTIFICATIO
Page 15 and 16: The junior homonym is always reject
Page 17 and 18: The biological classification may b
Page 19 and 20: wings (in length and width) or grea
Page 21 and 22: A SYSTEMATIC APPROACH TO DIAGNOSING
Page 23 and 24: insects is often seen by uneven or
Page 25 and 26: Faint yellow speckling of leaves ma
Page 27 and 28: on roots as in wireworms, weevil gr
Page 29 and 30: METHODS OF ESTIMATING CROP LOSSES D
Page 31 and 32: Exclusion of pests, or reduction of
Page 33 and 34: So from the above example, if the g
Page 35: The system is plastic and dynamic.
Page 39 and 40: Bardner R, Fletcher K E (1974). Ins
Page 41 and 42: Describing the sampling site would
Page 43 and 44: (iii) Butterflies and moths : Kill
Page 45 and 46: suggested treatment. Treatment sugg
Page 47 and 48: and the Philippines, Thailand, Indi
Page 49 and 50: difficulty is to relate the number
Page 51 and 52: Number and size of samples Factors
Page 53 and 54: SUGGESTED READING Atwal, A.S. and S
Page 55 and 56: Economic Threshold (E.T.) : 5.3 % i
Page 57 and 58: in Gujarat (Patel, 1994), Muskmelon
Page 59 and 60: DIAGNOSITIC SYMPTOMS AND ASSESSMENT
Page 61 and 62: mustard aphid, Lipaphis erysimi, pe
Page 63 and 64: aised for seed purpose. The caterpi
Page 65 and 66: against the pest. In endemic areas,
Page 67 and 68: are attacked. The grubs make large
Page 69 and 70: DIAGNOSTIC SYMPTOMS OF INSECT-PESTS
Page 71 and 72: Damage is caused by both nymphs and
Page 73 and 74: Ber Beetles Adoretus pallens Arrow
Page 75 and 76: 1.5 Mango fruit fly : Dacus dorsali
Page 77 and 78: Estimation of losses : Investigatio
Page 79 and 80: 7.3 Tailed mealy bug : Ferrisa virg
Page 81 and 82: DIAGNOSTIC SYMPTOMS AND LOSS ASSESS
Page 83 and 84: leaves. It also secrets copious qua
Page 85 and 86: DIAGNOSTIC SYMPTOMS AND ASSESSMENT
Page 87 and 88:
DIAGNOSTIC SYMPTOMS OF INSECT-PESTS
Page 89 and 90:
DIAGNOSTIC SYMPTOMS AND LOSS ASSESS
Page 91 and 92:
Tabel 2. Grain damage caused by lep
Page 93 and 94:
extensive damage. Damage in cotton
Page 95 and 96:
DIAGNOSIS AND CROP LOSS ASSESSMENT
Page 97 and 98:
DIAGNOSTIC SYMPTOMS OF ECONOMICALLY
Page 99 and 100:
viii) Lesion : It refers to the dis
Page 101 and 102:
Page 103 and 104:
Vegetable crops like tomato, brinja
Page 105 and 106:
Infected seedlings show basal swell
Page 107 and 108:
covering the plant, enter the leave
Page 109 and 110:
DIAGNOSTIC SYMPTOMS OF MACRO AND MI
Page 111 and 112:
Amelioration : i. Drill/place basal
Page 113 and 114:
Amelioration : i. Apply soil test b
Page 115 and 116:
NUTRIENTS' DEFICIENCY SYMPTOMS IN D
Page 117 and 118:
ii. Yellowing first appears on olde
Page 119 and 120:
iii. Manganese deficiency symptoms
Page 121 and 122:
DIAGNOSTICS AND ASSESSMENT OF LOSSE
Page 123 and 124:
Foreign Grain Beetle, Ahasverus adv
Page 125 and 126:
Angoumois Grain Moth/Grain moth, Si
Page 127 and 128:
which hatch in about 20-30 days. Gr
Page 129 and 130:
12. Apple fruit moth, Argyresthia c
Page 131 and 132:
Page 133 and 134:
A. lycopersici - curling of leaves,
Page 135 and 136:
Table 1. Crop wise Status of Major
Page 137 and 138:
PREDICTING INSECT POPULATIONS USING
Page 139 and 140:
where, y = Size of population, r =
Page 141 and 142:
2.1.6.1 Lotka-Volterra model for co
Page 143 and 144:
changes by ‘“x’. The developm
Page 145 and 146:
DIAGNOSTIC SYMPTOMS AND LOSSES CAUS
Page 147 and 148:
trachea pair of the thorax of 10-da
Page 149 and 150:
e due to several causes: malnutriti
Page 151 and 152:
DIAGNOSTIC SYMPTOMS AND ASSESSMENT
Page 153 and 154:
Pest populations and crop losses Th
Page 155 and 156:
compared with that obtained from th
Page 157 and 158:
Page 159 and 160:
II. COWPEA AND CLUSTERBEAN a) Aphid
Page 161 and 162:
DIAGNOSTIC SYMPTOMS AND ASSESSMENT
Page 163 and 164:
Leaf hoppers : In India, Amrasca bi
Page 165 and 166:
Page 167 and 168:
VI. LINSEED Linseed gall-midge, Das
Page 169 and 170:
Page 171 and 172:
Whitefly (Bemisia tabaci) : is a po
Page 173 and 174:
Aural method : Insect infestation c
Page 175 and 176:
emote sensing and active remote sen
Page 177 and 178:
Spatial Resolution : spatial resolu
Page 179 and 180:
workers for developing vegetation i
Page 181 and 182:
USE OF ADVANCED COMPUTER TOOLS IN S
Page 183 and 184:
Adobe Premiere Adobe Premiere is a
Page 185 and 186:
List of Search Engines Worldwide Th
Page 187 and 188:
METHODOLOGY OF PESTICIDE RESIDUE ES
Page 189 and 190:
Chromatography It is a process of s
Page 191 and 192:
1. Estimation of Pesticide Residues
Page 193 and 194:
3. Estimation of Multiresidues in F
Page 195 and 196:
DIAGNOSTICS AND LOSS ASSESSMENT DUE
Page 197 and 198:
Scale insect, Melanaspis Minor Tami
Page 199 and 200:
Table 2. A profile of losses in can
Page 201 and 202:
varied from 5.5 per cent in Co 419
Page 203 and 204:
Cutworms, Agrotis spp. Cutworms are
Page 205 and 206:
Assessment of losses The following
Page 207 and 208:
Saw toothed grain beetle (Oryzaephi
Page 209 and 210:
DIAGNOSTIC SYMPTOMS OF INSECT-PESTS
Page 211 and 212:
3. Thousand-grain mass (TGM) method
Page 213 and 214:
MOLECULAR MARKERS : CONCEPTS AND TH
Page 215 and 216:
cloned mRNA, and the resulting sequ
Page 217 and 218:
Under optimal conditions, approxima
Page 219 and 220:
Very abundant in plants (several th
Page 221 and 222:
APPLICATIONS OF MOLECULAR MARKERS I
Page 223 and 224:
esearch goals. Biologists have now
Page 225 and 226:
Loss : A loss of 36.5 per cent in U
Page 227 and 228:
central whirl of the plant. Both ny
Page 229 and 230:
LIST OF PARTICIPANTS UNDER CAFT TRA
Page 231:
Dr. Tarun Verma, DES (Entomology) A
show all

Foreword - CCS HAU, Hisar

Create successful ePaper yourself

Delete template?

Save as template?