Production Practices and Quality Assessment of Food Crops. Vol. 1

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To calculate the hydrostatic pressure, the following procedure is used: the relative rate of volume (V) growth of the fruit compartment is presented by Lockhart’s equation (Lockhart, 1965) dV dt = V f(P f – Y) if P f > Y dV dt = 0 if P f ≤ Y Modelling Fruit Quality 53 where f is the coefficient describing the extensibility of the cell walls and Y is the threshold value that the hydrostatic pressure of the fruit has to exceed before irreversible expansion occurs. The change in fruit volume can also be calculated from equation 1 (with D w the water density) as dV dt = U x + U p – T f D w Under the condition of steady irreversible growth, equations 5 and 6 must be equal. Setting equations 5 and 6 equal, and inserting the flux from equation 2, the resulting equations for P f can be solved. The time-step in the model is one hour. Total fruit mass, volume, and water content may be calculated using the state variables W water(t) and W dry(t). 4.1.1.2. Using SWAF to explain seasonal and diurnal patterns of peach fruit growth A set of model computations was performed to simulate the combined effect of water stress and crop load in peach trees (Figure 1). Sugar content in the phloem directly influences the rate of its uptake by the fruit and results in lower dry fruit mass and respiration under conditions of high crop load. In this case, the osmotic pressure is lower than with a low crop load, which leads to high fruit water potential and low water uptake. Turgor pressure is lower with a high crop load, mainly in the first period of fruit development, which results in a low growth. Although transpiration decreases with the increase in fruit load, the decrease in water uptake is such with a high crop load that fresh fruit mass is always lower than with a low crop load. Water stress causes a significant decrease in fresh fruit mass but the change in dry fruit mass is negligible because carbon uptake through mass flow is assumed to be low. The occurrence of water stress increases the osmotic pressure which leads to a decrease in fruit water potential and water influx into the fruit. The patterns of variation of carbon and water uptake are quite different, with a maximal carbon uptake occurring one month before the maximal water uptake. This important water uptake during the last month of the fruit development is related to the high transpiration of the fruit during this period. The diurnal patterns of fruit growth show additional features of the growth process (Figure 2). The model predicts that diurnal patterns of dry and fresh masses of the fruit are not directly correlated. It can be noted that during daytime, when transpiration reaches its maximum value, fresh mass does not increase and even (5) (6)
54 M. Génard and F. Lescourret Figure 1. Evolution during the growing season of peach carbon and water components simulated by SWAF as a function of crop load and water stress. Water potential was chosen to vary within the ranges –10 to –2 bar and –12 to –4 for normally watered (NW) and water stressed (WS) trees, respectively. Sugar content in the phloem was chosen to vary within the ranges 0.14 to 0.22 and 0.04 to 0.12 for light (LC) and heavy (HC) crop load, respectively. decreases, whereas dry matter increases during this period. When transpiration increases, the hydrostatic pressure in the fruit decreases, which causes growth to slowdown and, eventually, to stop. The low plant water potential during daytime reduces the water uptake so that it cannot compensate for the high rate of fruit transpiration; therefore, water balance is equal to zero or is negative during daytime. The most intensive increase in fresh fruit mass takes place during the night. In conclusion, the SWAF model of fruit growth takes into consideration the fundamental processes and their response to external signals. As SWAF is based
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Production Practices and Quality As
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Production Practices and Quality As
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CONTENTS Preface List of Authors Ef
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PREFACE Today, in a world with abun
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LIST OF AUTHORS Rufaro M. Madakadze
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EFFECT OF PREHARVEST FACTORS ON THE
Page 14 and 15: 2.1. Temperature Effect of Preharve
Page 16 and 17: e beneficial to the water economy a
Page 18 and 19: Other responses that can also be ca
Page 20 and 21: 06. Failure of fruits to ripen in t
Page 22 and 23: of more than 13 hours of night temp
Page 24 and 25: temperatures. Some show serious int
Page 26 and 27: Effect of Preharvest Factors 15 bet
Page 28 and 29: 1) High rainfall conditions where B
Page 30 and 31: increase in the release of P i from
Page 32 and 33: however, more severe when foliage i
Page 34 and 35: temperatures and luxuriant growth a
Page 36 and 37: development of chilling injury symp
Page 38 and 39: conditions followed by sudden high
Page 40 and 41: season. The main environmental fact
Page 42 and 43: 4.4.5.2. Water blisters Storage roo
Page 44 and 45: Effect of Preharvest Factors 33 REF
Page 46 and 47: Effect of Preharvest Factors 35 men
Page 48 and 49: EFFECTS OF AGRONOMIC PRACTICES AND
Page 50 and 51: Effects of Agronomic Practices 39 F
Page 52 and 53: Effects of Agronomic Practices 41 6
Page 54 and 55: Effects of Agronomic Practices 43 F
Page 56 and 57: Effects of Agronomic Practices 45 R
Page 58 and 59: MODELLING FRUIT QUALITY: ECOPHYSIOL
Page 60 and 61: Modelling Fruit Quality 49 the dens
Page 62 and 63: Is it the only level to be consider
Page 66 and 67: on an analysis of the biophysical p
Page 68 and 69: Modelling Fruit Quality 57 fructose
Page 70 and 71: Modelling Fruit Quality 59 Figure 4
Page 72 and 73: f(dd) = dd max - dd dd max - dd min
Page 76 and 77: which depends on climate and irriga
Page 80 and 81: distributed over the period during
Page 84 and 85: Modelling Fruit Quality 73 Pruning
Page 86 and 87: with Fo, Pe and Pr being local ‘d
Page 88 and 89: Modelling Fruit Quality 77 than in
Page 90 and 91: Modelling Fruit Quality 79 Dann, I.
Page 92 and 93: Modelling Fruit Quality 81 Huguet,
Page 94 and 95: SPRAY TECHNOLOGY IN PERENNIAL TREE
Page 96 and 97: Spray Technology in Perennial Tree
Page 98 and 99: With centrifugal energy systems dro
Page 100 and 101: fruit orchards is described as 1000
Page 102 and 103: According to Furness (2000), the nu
Page 104 and 105: sprayers which were developed prima
Page 106 and 107: air-blast sprayers in an attempt to
Page 108 and 109: Most agricultural chemicals have be
Page 110 and 111: educing dosage rates to one quarter
Page 112 and 113: Spray Technology in Perennial Tree
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Spray Technology in Perennial Tree
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CHESTNUT, AN ANCIENT CROP WITH FUTU
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2. WORLD AREA OF CHESTNUT AND PRODU
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Table 2. Chestnut production in the
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vineyards and north facing to chest
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Chestnut, an Ancient Crop with Futu
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Table 5. Continued. Chestnut, an An
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Table 6. Continued. Chestnut, an An
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size. When the trees develop too mu
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6.5. Management of old orchards Che
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the disease is already established
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where ink disease is rampant, disea
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8.4. Micropropagation Several in vi
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9.3. Hybrids Chestnut breeding in E
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IMPROVEMENT OF GRAIN LEGUME PRODUCT
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Improvement of Grain Legume Product
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2.8. Field experiments The greenhou
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IMPACT OF OZONE ON CROPS S. DEL VAL
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Impact of Ozone on Crops 191 observ
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Impact of Ozone on Crops 193 1996).
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Impact of Ozone on Crops 195 Figure
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Impact of Ozone on Crops 197 al., 1
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Impact of Ozone on Crops 199 techni
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species show a progressive decline
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Impact of Ozone on Crops 203 Chaime
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Impact of Ozone on Crops 205 Junge,
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Impact of Ozone on Crops 207 Polle,
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SAFFRON QUALITY: EFFECT OF AGRICULT
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1.2. Commercial interest Saffron Qu
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1.3. Uses Saffron Quality 213 There
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oriental-type perfumes (Sampathu et
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Saffron Quality 217 Figure 5. Chemi
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Straubinger et al., 1997; Straubing
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and Micheli, 1979; Curro et al., 19
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Saffron Quality 223 Figure 9. Chemi
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(1984) gives the following data: δ
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Saffron Quality 227 Table 3. HPLC a
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Saffron Quality 229 464/2001, OJ L6
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Saffron Quality 231 Saffron in fila
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Saffron Quality 233 sium were the q
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Saffron Quality 235 Figure 11. The
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Saffron Quality 237 Figure 12. Harv
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Morocco. Ait-Oubahou and El-Otmani
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and Micheli, 1979a; Sampathu et al.
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Saffron Quality 243 Table 8. Drying
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Saffron Quality 245 space for sorti
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unpleasant sensory characteristics
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Saffron Quality 249 The effect of
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Saffron Quality 251 Table 10. Effec
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Saffron Quality 253 Alonso, G. L.,
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Saffron Quality 255 Escribano, J.,
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Saffron Quality 257 tion combined w
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Saffron Quality 259 Selim, K., M. T
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FRUIT AND VEGETABLES HARVESTING SYS
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3. PRINCIPLES AND DEVICES FOR THE D
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exert a vertical pulling force to t
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Fruit and Vegetables Harvesting Sys
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- fingers or spikes; - oscillatory
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- frequency and - amplitude of vibr
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To calculate the number of directio
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For the cleaning and separation of
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