berry to another in a cluster leaving behind brown, hollow berries and beans. As
compared to Coffee Berry Moth, the larvae of Coffee Berry Butterfly (Deudorix
lorisona) make a single hole in berries and eat the beans [248].
Nematodes are the Arabica coffee loving parasites since most of the Robusta
varieties are resistant to some extent. Even in case of nematodes attack, the symptoms are not enormous and yield and quality of Robusta coffee are not compromised
[59, 60]. Nematodes (Root Lesion Nematodes: Pratylenchus spp. and Root-knot
Nematodes Meloidogyne spp.) generally dwell in soil or roots of plant, suck the sap,
cause lesions or open wounds providing sites for infection by fungus and bacteria,
weaken the plant, prevent the nutrient absorption even in fertilization application,
and fallen the yield and quality of beans [261, 262]. There are also reports of
obliteration of feeder roots and necrosis [248]. The reduced supply of nutrients
leads to chlorosis and necrosis of leaf tips and stems and up to 40% reduction in
yield [248]. Bertrand et al. [70] demonstrated that interspecific grafting of C. arabica
with rootstock from C. robusta is a significant approach to protect the tree roots from
root knot nematodes with lowering the physical and cup quality of coffee. Further,
the invasion of fungi (i.e., Fusarium spp., Meloidogyne spp., Rhizoctonia spp., and
Phytophthora spp., etc.) results in withering and finally death of plant [263, 264]. In
fungal diseases, the most common fungal diseases in coffee plantations and fruits are
coffee berry diseases (CBD), coffee wilt disease (CWD), coffee leaf rust (CLR), grey
leaf rust (GLR), root rot disease (RRD), Phtiriosis, coffee canker, American leaf spot
(ALS), and Brown eye spot (BES) [248, 251]. All the fungal diseases result in the
foliage loss, blockage of sap supply, ratting of fruits, etc., but the mode of action of
each fungi and periodic symptoms may slightly vary as follows. CBD
(Colletotrichum kahawae) is characterized by color spots on berries. The lighter
spots or scabs are not taken as serious, while darker spots or wounds are considered
as serious disease. The fungi feed on the pulp leaving behind empty, dry, wrinkled
pouches which usually fall off. CBD can attack on all mature and green berries
without any visual impact on leaves or branches [265, 266]. RRD is caused by any of
these fungi, i.e., Rosellinia bunodes, Rosellinia pepo, Phellinus lamoensis,
Leptopows lignosus, etc., and involves rotting of roots and leaves, withering of
foliage, decaying of branches, and loss of yield and quality [267]. In CWD (causal
organisms: Fusarium xylarioides, Gibberella xylarioides, or Carbuncularia
xylarioides), fungal mycelia occupy the sap vessels thus blackening them causing
yellowing and drying of leaves which finally fall and tree die. Berries of affected
trees turn red and appear to ripen prematurely. Dark brown-black necrosis of
younger branches may be pronounced and laterally restricted, while a similar
necrosis may also be apparent along leaf veins [268]. Coffee canker also causes
the withering of plant, but in this the causal fungi (Ceratocystis fimbriata) decay the
woody tissues of plant [269]. CLR (Hemileia vastatrix) is the cause of physiological
activity loss in affected plants leading to withering and loss of survival. Brown
lesions first appear on the downside of leaves through which fungi attack and
penetrate, producing orange color under-spore at later stage, causing the lesions to
become necrotic [242]. CLR attacks are more austere on high yielding plant, and in
most of the cases, the attacks are undetected due to disease and plant interaction
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
687
compared to Coffee Berry Moth, the larvae of Coffee Berry Butterfly (Deudorix
lorisona) make a single hole in berries and eat the beans [248].
Nematodes are the Arabica coffee loving parasites since most of the Robusta
varieties are resistant to some extent. Even in case of nematodes attack, the symptoms are not enormous and yield and quality of Robusta coffee are not compromised
[59, 60]. Nematodes (Root Lesion Nematodes: Pratylenchus spp. and Root-knot
Nematodes Meloidogyne spp.) generally dwell in soil or roots of plant, suck the sap,
cause lesions or open wounds providing sites for infection by fungus and bacteria,
weaken the plant, prevent the nutrient absorption even in fertilization application,
and fallen the yield and quality of beans [261, 262]. There are also reports of
obliteration of feeder roots and necrosis [248]. The reduced supply of nutrients
leads to chlorosis and necrosis of leaf tips and stems and up to 40% reduction in
yield [248]. Bertrand et al. [70] demonstrated that interspecific grafting of C. arabica
with rootstock from C. robusta is a significant approach to protect the tree roots from
root knot nematodes with lowering the physical and cup quality of coffee. Further,
the invasion of fungi (i.e., Fusarium spp., Meloidogyne spp., Rhizoctonia spp., and
Phytophthora spp., etc.) results in withering and finally death of plant [263, 264]. In
fungal diseases, the most common fungal diseases in coffee plantations and fruits are
coffee berry diseases (CBD), coffee wilt disease (CWD), coffee leaf rust (CLR), grey
leaf rust (GLR), root rot disease (RRD), Phtiriosis, coffee canker, American leaf spot
(ALS), and Brown eye spot (BES) [248, 251]. All the fungal diseases result in the
foliage loss, blockage of sap supply, ratting of fruits, etc., but the mode of action of
each fungi and periodic symptoms may slightly vary as follows. CBD
(Colletotrichum kahawae) is characterized by color spots on berries. The lighter
spots or scabs are not taken as serious, while darker spots or wounds are considered
as serious disease. The fungi feed on the pulp leaving behind empty, dry, wrinkled
pouches which usually fall off. CBD can attack on all mature and green berries
without any visual impact on leaves or branches [265, 266]. RRD is caused by any of
these fungi, i.e., Rosellinia bunodes, Rosellinia pepo, Phellinus lamoensis,
Leptopows lignosus, etc., and involves rotting of roots and leaves, withering of
foliage, decaying of branches, and loss of yield and quality [267]. In CWD (causal
organisms: Fusarium xylarioides, Gibberella xylarioides, or Carbuncularia
xylarioides), fungal mycelia occupy the sap vessels thus blackening them causing
yellowing and drying of leaves which finally fall and tree die. Berries of affected
trees turn red and appear to ripen prematurely. Dark brown-black necrosis of
younger branches may be pronounced and laterally restricted, while a similar
necrosis may also be apparent along leaf veins [268]. Coffee canker also causes
the withering of plant, but in this the causal fungi (Ceratocystis fimbriata) decay the
woody tissues of plant [269]. CLR (Hemileia vastatrix) is the cause of physiological
activity loss in affected plants leading to withering and loss of survival. Brown
lesions first appear on the downside of leaves through which fungi attack and
penetrate, producing orange color under-spore at later stage, causing the lesions to
become necrotic [242]. CLR attacks are more austere on high yielding plant, and in
most of the cases, the attacks are undetected due to disease and plant interaction
27 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
687