Fish-toxicity problems of pesticides in Japan - the present situation and the policies of the Ministry of Agriculture and Forestry

Abstract

A survey of termite damage to groundnuts and an estimation of loss in yield was made between 1977 and 1979 in northern Nigeria. The foliage was attacked by Odontotermes. Damage was restricted to the Sudan savanna and loss in yield was less than 5%. Much more important was the damage caused by Microtermes lepidus Sjöstedt which attacked the pods, the tap root and the haulms. There was a linear relationship between the percentage of stands with the tap root invaded by Microtermes and the loss in yield. Damage varied from year to year, but the higher yield losses (up to 40%) were consistently recorded in the Sudan savanna. There was a significant relationship between the level of Microtermes damage and rainfall, the latter having a marked influence on foraging behaviour and the level of foraging activity. The chemical control of termites is economically viable on mechanised farms in the Sudan savanna, but cannot be justified on peasant farms, where yields are too low.     

Investigations on avian pests of oil palm,Elaeis guineensis Jacq. in India†

Abstract

The common myna Acridotheres tristis Linn., the jungle crow Corvus macrorhynchus Wagner and the house crow Corvus splendens Viellot are the major pests of oil palm in India. Other birds like crow pheasant Centropus sinensis Stresmann, parrot Loriculus sp. and pariah kite Milvus migrans Sykes also feed on oil palm fruits. These birds feed on the fleshy mesocarp of the ripe fruits resulting in heavy fruit loss, significantly reducing oil yield. Gizzard and intestinal content analysis indicated that oil palm fruits are the major source of food for these birds. Observations on 1657 oil palm fruit bunches during 1985–86 revealed that 76% of the ripe bunches and 5.6% of the unripe bunches were damaged by birds. The damage by birds was either ‘partial’ or ‘complete’, where 40–50% and 80–100% respectively, of the individual fruit weight was lost. The partial fruit damage was more common in 130–160 day‐old bunches and the complete fruit damage increased after 150 days of fruit set. Fruit loss due to bird damage was higher in palms in the border area of the plantation (2.3 kg/bunch) than in the interior (1.3 kg/bunch). It is estimated that around 2.8 tonnes of fresh fruits/ha/yr, equivalent to 420 kg of palm oil, are lost due to bird damage.     

Past Studies on and Present Status of Lethal Yellowing Disease of Coconuts

Abstract

The symptoms and extent of lethal yellowing disease of coconuts are described. In research into the cause of the disease nutrient deficiencies, fungi, bacteria, nematodes and, more recently, viruses have been investigated without implicating any causal agent. Mechanical and insect transmissions were attempted by a number of methods. The incubation period was shown to be 3–9 months for young palms and 7–15 months for bearing palms. Experiments to control the disease have been unsuccessful.

Local and introduced coconut varieties and hybrids are being tested for resistance by field exposure. The Malayan Dwarf variety has been shown to have high resistance and is being used to replant the industry. No other variety or hybrid is deemed as yet to be sufficiently resistant for farm planting.

Mycoplasms were recently found associated with the disease. Future research must include confirmation of mycoplasm-lethal yellowing association, continuation of the search for the vector, experimental chemotherapy, and attempts to culture mycoplasms to develop an inoculation technique. Palms showing resistance will be used in the breeding programme. Promising hybrids will be produced in greater numbers for more extensive testing and further introductions will be made.     

Damage by Homalinotus depressus in commercial coconut palm crops in the Amazonian region of Brazil

The coconut palm (Cocos nucifera L., Arecaceae) has great economic and social importance for many industrial and non-industrial products. Pests can reduce its productivity and cause its death. In 2005, larvae and adults of a Curculionidae were observed damaging the floral stalk of coconut palms in commercial plantations in the municipality of Moju, Pará State, in the Brazilian Amazon. Insects were identified as the black coconut bunch weevil, Homalinotus depressus (L.) (Coleoptera: Curculionidae: Cholini). This is the first report of this pest damaging coconut palms in Brazil.     

Fine structure of phloematic trypanosomatid–coconut tree interaction

Phytomonas wilt or Hartrot is a fatal disease of palm (Arecaceae) species including Cocos nucifera (coconut) and is caused by a phloematic trypanosomatid, a promastigote parasite that inhabits phloem sieve elements of disease palms. In the present work, we described the morphology of the interaction between a phloematic trypanosomatid (Phytomonas staheli) and C. nucifera. Two varieties and one ecotype of the adult coconut palm from northeast and southeast Brazil were analyzed, totaling 34,000 plants. Coconut palm losses due to Hartrot varied according to the variety or ecotype and geographic area. Occurrence of Hartrot was insignificant in Rio de Janeiro state (southeast), but in Bahia state (northeast) losses were substantial when appropriate cultural practices were not applied. Symptomatic and healthy palm tissues were analyzed by light and electron microscopy. Laboratory diagnoses revealed the twisted promastigote form of phloematic trypanosomatids in the extracts of shoot apex, leaves, stems and inflorescence in diseased plants, but not in the healthy ones. No parasites were found in the roots. Although the general anatomy of healthy and diseased palms was similar, callose deposition in the sieve plates was revealed by histochemistry and immunocytochemistry in the diseased tissue. Plugging by the P-protein and plastid alterations was also observed. Our observations strongly suggest that parasite traffic between sieve elements took place, although their cell bodies were larger than the sieve pores. Phloematic trypanosomatid proliferation in the sieve tube elements might interrupt the transport of phloem or/and consume plant nutrients. In addition, an association between the percentage of sieve elements colonized by pathogen in palm tissues and disease severity was established.     

Phytoplasmas associated with disease of coconut in Malaysia: phylogenetic groups and host plant species

Coconut palm ( Cocos nucifera ), oil palm ( Elaeis guineensis ), Bermudagrass ( Cynodon dactylon ) and Madagascar periwinkle ( Catharanthus roseus ) with symptoms indicative of phytoplasma disease were collected from different locations in Malaysia. PCR assays employing phytoplasma universal rRNA gene primers P1/P7 alone or P1/P7 followed by R16F2n/R16R2 detected phytoplasmas in eight out of 20 Malayan Red Dwarf (MRD), nine out of 12 Malayan Yellow Dwarf (MYD) and 12 out of 12 Malayan Tall (MT) coconut palms displaying coconut yellow decline symptoms. Positive detections were also obtained from six out of six oil palm seedlings showing symptoms of yellowing and necrosis, from 10 out of 10 Bermudagrass samples with white leaf symptoms, and from eight out of eight periwinkle plants showing phyllody, virescence, little leaf, proliferation and foliar yellowing. Phytoplasmas were not detected in any of the symptomless plants tested. Sequencing and phylogenetic analysis of PCR products determined that phytoplasmas infecting both MRD and MT coconuts and Bermudagrass in Serdang, Selangor State, were all members of the 16SrXIV ' Candidatus Phytoplasma cynodontis' group, whereas isolates in periwinkle in Serdang were all members of the 16SrI ' Ca. Phytoplasma asteris' group. However, the phytoplasmas detected in MYD coconuts and oil palms from Banting, Selangor State, and in periwinkle from Putrajaya were collectively very similar (99%), but shared <97·5% similarity with 16S rDNA sequences of all other known phytoplasmas, indicating that they represent a novel taxonomic group. Thus, at least two phylogenetically distinct phytoplasmas are associated with the coconut yellow decline syndrome in Malaysia, both of which were also detected in other plant species.     

Can increasing infestations by Rhynchophorus ferrugineus threaten endemic Chamaerops humilis in Sardinia (Italy)?

The red palm weevil, Rhynchophorus ferrugineus, is the most devastating pest of the Canary palm, Phoenix canariensis, in the Mediterranean Basin. Sporadic infestations have also been observed in other cultivated palm species and, above all, in the endemic European fan palm, Chamaerops humilis. Considering the high ecological importance of C. humilis in coastal ecosystems, the present paper gives an update on the status of R. ferrugineus infestations on the European fan palm in Sardinia (Italy). Since the introduction of R. ferrugineus into Sardinia, attacks of this pest on C. humilis have been limited but have increased in the last 2 years, including infestations on eight naturally growing palms in a Natura 2000 site. Male and female red palm weevils that emerged from C. humilis were similar in size to those of P. canariensis, indicating that the quality of these two feeding substrates is similar. The limited number of infested European fan palms observed so far suggests caution when predicting a rapid spread of this pest in cultivated and non‐cultivated C. humilis palms. Nonetheless, natural populations of C. humilis along western Mediterranean shores should be monitored in order to highlight the potential establishment of R. ferrugineus in these habitats.     

Damage and Loss Caused by the Larger Grain Borer Prostephanus truncatus

An overview of information on damage caused by the larger grain borer is provided, including details of early studies examining commodities that might be attacked and the importance of LGB field infestations in relation to storage losses. In addition, examples are given from published information on the weight losses that can result from LGB infestation in maize and cassava, with case studies. Problems in applying conventional methods of loss assessment to commodities attacked by LGB are highlighted, to suggest the need to develop alternative techniques. Experiences in developing and applying novel approaches to loss assessment for LGB are reported. Examples are also given to show how loss and damage estimates have been used to describe the impact of the pest on farmers, and on local, regional and international grain trading.     

Aantasting van ui doorPhytophthora porri

Phytophthora porri was isolated from onion leaves causing leaf spots which resemble those of the white tip disease of leek. This is the first report of onion plants being attacked and damaged byP. porri.     

绿盲蝽对冬枣不同生长期的为害

为了解绿盲蝽对其重要果树寄主冬枣的为害特点,通过对各生长期叶、蕾、花、幼果等易受害部位接虫试验,研究绿盲蝽对冬枣的为害规律及其对冬枣坐果的影响。结果显示,不同生长期各部位的被害率和刺点数均随着接虫数的增加而增大。嫩叶期最幼嫩的部位顶芽和第1片叶被害率均为100%,第4、5片叶的被害率均为0;相同接虫密度下,花的刺点数显著高于蕾和幼果;花蕾并存时,花的刺点数显著高于蕾,而被害率无显著差异。花期受害后,坐果数显著降低,其中接1、2、3、4、5头绿盲蝽坐果数分别降低了49.49%、59.60%、84.85%、94.95%、94.87%。研究表明,绿盲蝽对冬枣的为害有明显趋嫩和趋花性,花期受害后对产量的影响最大,应加强对花、幼果期绿盲蝽种群的控制。     

Yield reduction in wheat by simulated rat damage

Abstract

A study of simulated rat damage was done to determine the loss of wheat yield when O (control). 10, 30 and 50% ot the wheat stems were cut at tillering, booting, dough and mature crop stages. The yields at harvest from each of 128 1‐m² plots were compared by analysis of variance and least significant difference tests. Yield at the tillering stages was not significantly different from the controls but yields at all other stages differed significantly. Yield losses in tillering and booting stages were not significant for the different damage levels except for 50% stem cutting at the booting stage. The yields from dough and mature crop stages at all damage levels were significantly lower than yields from controls. No significant differences in yield at all growth stages were observed between control plots and those receiving 10% damage, but 30 and 50% damage gave significant losses.     

Diseases of the Oil Palm

Abstract

Thirty two diseases and disorders affecting the oil palm in Africa, Southeast Asia and South America are described with their distribution, economic importance, etiology and control. Of these, nine diseases are considered to be of major economic importance, 19 are of minor importance, and four are due to nutrient deficiencies. The major diseases causing serious economic losses are freckle (Cercospora elaeidis), blast (Pythium splendens and Rhizoctonia lamellifera), vascular wilt (Fusarium oxysporum f. sp. elaeidis). Ganoderma trunk rot (Ganoderma spp.) and Armillaria trunk rot (Armillariella mellea) in Africa; Ganoderma trunk rot, Corticium leaf rot (Corticium solani). Marasmius bunch rot (Marasmius palmivora) in S.E. Asia; sudden wilt and spear rot in S. America. Some of the diseases and disorders of minor economic importance recorded in these areas are anthracnose (Botryodiplodia palmarum, Melanconium sp. and Clomerella cingulata), dry basal rot (Ceratocystis paradoxic), patch yellows (Fusarium oxysporum), crown disease, Cylindrocladium leaf spot (Cylindrocladium macrosporum), algal spot (Cephaleuros virescens), bronze streak, ring spot and little leaf in Africa; Curvularia leaf blight (Curvularia eragrostidis), Leptosphaeria leaf spot (Pestalotiopsis spp.) infectious chlorosis, upper stem rot (Phellinus noxius), stem wet rot, charcoal base rot in S.E. Asia and Leptosphaeria leaf spot and coconut wilt disease in S. America. Little is known, however, about the disease problems in the smaller but rapidly expanding oil palm growing areas of Thailand, Papua New Guinea, India and Sri Lanka. Infectious chlorosis, bronze streak and ring spot have a suspected virus etiology; little leaf, spear rot and stem wet rot are attributed to bacteria and leaf chlorosis, mid-crown yellowing, orange frond and hook leaf to nutrient deficiencies. The etiology of some minor disorders including brown germ, crown disease and several miscellaneous abnormalities is unknown.

Effective control measures, based on the application of various chemicals, have been devised for the leaf diseases but other than precautionary cultural operations, there are no such effective and practical control measures for the root and stem diseases. For this latter group of diseases field transplanting or resistant or tolerant varieties seems to be the best method of control. Seeds selected for tolerance to vascular wilt are being produced on a commercial scale at the Nigerian Institute for Oil Palm Research, Institut de Recherches pour les Huiles et Oleagineux in Ivory Coast and the Unilever Plantations in Cameroun Republic. These efforts need to be supplemented by breeding for resistance to the other major diseases.     

First report of the palm borer <Emphasis Type="Italic">Paysandisia archon</Emphasis> (Burmeister 1880) (Lepidoptera: Castniidae) in Cyprus

In October 2008 an insect palm borer was found for the first time on the island of Cyprus, in the Paphos district, on palms of Chamaerops humilis and Washingtonia filifera. By December 2008 the species was found on isolated palm plants of Phoenix roebelenii. The species was identified as the palm borer Paysandisia archon (Burmeister 1880) at the Agricultural Research Institute, Nicosia. Infested palm trunks and leaves were bored by the Paysandisia larvae. Bored trunk and crown were covered with plugs of debris.     

The use of sniffing dogs for the detection of Rhynchophorus ferrugineus

The red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae) is the most serious pest of Canary Island date palms (Phoenix canariensis Hort. ex Chabaud) and date palms (Phoenix dactylifera L.). Early infestations of this invasive weevil are difficult to detect under field conditions. The adults are very elusive and not visible inside the dense frond of the palms. Efficient methods for detecting this pest are needed for its successful management under field conditions and in particular at ports of entry to avoid its' spreading via infested imported palms. The present study evaluated the ability of Rottweiler and Golden Retriever dogs (Canis familiaris L.) to detect Canary Island palms that were baited with RPW adults or larvae under field conditions. During these experiments, the dogs successfully detected 78% of the baits hidden in the crown of the palms. These encouraging results need to be confirmed by evaluation of the performance of sniffing dogs in detection of naturally infested palms of different species.     

Distribution and characteristics of the damage of the Syrian woodpecker,Dendrocopos syriacus (HEMP. & EHR.) (Aves: picidae), in polyethylene irrigation pipes in fruit orchards

The Syrian woodpecker,Dendrocopos syriacus (Hemp. & Ehr.), was found to attack black polyethylene pipes of both sprinkler and drip irrigation systems in Israel. Nut crops and deciduous fruits are preferred by the woodpecker, and trees infested by boring insects are favored. Damage to pipes is frequent in plots of avocado, citrus and grapevine bordered by rows of windbreakers, with the pipes near the windbreaker being the most severely attacked. In orchards without windbreakers the distribution of damage seems to be random, or concentrated near trees infected by boring insects, or near other attractive objects (e.g. electric poles).     

Detection of lethal yellowing phytoplasma in embryos from coconut palms infected with Cape St Paul wilt disease in Ghana

This study investigated the potential of seed transmission of Cape St. Paul wilt disease (CSPWD) in coconuts. PCR amplification was used to assess the distribution of phytoplasmas in parts of West African Tall (WAT) palms infected with CSPWD. Employing phytoplasma universal primer pair P1/P7 in standard PCR, or followed with a nested PCR using CSPWD–specific primer pair G813f/AwkaSR, phytoplasma infection was detected in the trunks, peduncles, spikelets, male and female flowers of four infected WAT coconut palms. Through nested PCR, phytoplasma was also detected in four of 19 embryo DNA samples extracted individually from fruits harvested from three of the four infected palms and was confirmed as CSPWD by cloning and sequencing. Subsequently, CSPWD phytoplasma was again detected in five of 33 embryos from nine infected palms, and in one of eight fruits from two symptomless palms. Fruits from infected palms recorded higher percentage germinations in two field nurseries (average of 71·0%) compared to fruits from healthy palms (average of 57·6%), and matured fruits that had dropped from infected palms showed the same levels of germination as those harvested directly from the palms. This indicates that infected fruits retain the ability to germinate whether harvested or dropped. No phytoplasmas were detected in any of the resulting seedlings and plantlets obtained through embryo in-vitro culture. Therefore, although phytoplasma DNA can be detected in embryos, there is as yet no evidence that the pathogen is seed transmitted through to the seedling to cause disease in progeny palms.     

The dubas date tropiduchid,Ommatissus binotatus lybicus,a threat to date palms in Israel

The dubas “bug,”Ommatissus binotatus lybicus (Tropiduchidae), has become a threat to date palms in recent years. In Israel this bug was first observed in 1981 at Qetura, in the southern Arava. Within 2 years it had attacked an entire grove of 2,000 date palms, if the ‘Medjhool’ and ‘Deglet Noor’ varieties. The large number of planthoppers excreted great quantities of honeydew on the palms. This bivoltine planthopper overwinters in the egg stage.     

First report of leaf spot disease on oil palm caused by Pestalotiopsis theae in Thailand

A leaf spot on oil palm, caused by Pestalotiopsis theae, was found in a plantation of Elaeis guineensis for the first time in the world in Chiang Mai Province, Thailand. The fungus was isolated from lesions on leaves, and its pathogenicity was confirmed. Pathogenicity tests showed that P. theae could infect E. guineensis, which developed the same symptoms after inoculation as those observed naturally in the field. The fungus was identified based on morphological characteristics and confirmed using comparisons of DNA sequences of internal transcribed spacer (ITS)1, ITS2 and 5.8S rDNA. This report is the first on oil palm leaf spot disease caused by P. theae.     

First report of the nipa palm hispid <Emphasis Type="Italic">Octodonta nipae</Emphasis> on queen palms in Cyprus

In December 2009, numerous adults and larvae of the nipa palm hispid Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae: Cassidinae) were found for the first time on the island of Cyprus, in unopened young leaves of Syagrus romanzoffiana (Cham.) Glassman palm species. All infested palms of this species evinced serious decline with all young leaves showing signs of attack, but the beetles and larvae themselves were found only in fronds from the central shoot.     

Estimation of rice yield losses due to the African rice gall midge,Orseolia oryzivora Harris and Gagne

Abstract

The African rice gall midge, Orseolia oryzivora Harris and Gagne (Diptera: Cecidomyiidae), is an important pest of rice, Oryza sativa, in Burkina Faso as well as other countries in West and East Africa. In spite of its importance, little is known regarding the relationship between gall midge populations and grain yield losses. To determine yield losses the gall midge was reared in cages and adult midges were placed on caged plants of the rice variety ITA 123 at different population levels. The seven treatments consisted of different numbers of insects infested on the plants; 0 insect pairs (non‐infested check), and 1, 5, 10, 15, 20 or 25 midge pairs/cage. The loss in yield in relation to the non‐infested control was highly positively correlated (R² = 0.81) with the percentage of gall midge damaged tillers. The infestation by the insect on the plants resulted in the compensatory production of tillers which developed in response to the gall midge damage but the compensation was not sufficient to make up for the loss of yield due to the damaged tillers. Yield loss ranged from 0% in the control to 65.3% in the treatment with 25 pairs of adults. One per cent of tillers damaged resulted in 2% grain yield loss.