Showing papers in "International Journal of Pest Management in 1981"
TL;DR: Traditional sorghum cultivars in the tropics are generally photoperiod sensitive, flowering just as or after the rains cease, so that their grains fill and mature during dry weather, but the earlier flowering often results in the exposure of developing grain to wet conditions in which it can deteriorate rapidly.
Abstract: Traditional sorghum cultivars in the tropics are generally photoperiod sensitive, flowering just as or after the rains cease, so that their grains fill and mature during dry weather. Improved cultivars have been developed which flower and mature earlier in the season, when soil moisture levels are generally more favourable for grain filling, which potentially gives higher grain yields. However, the earlier flowering often results in the exposure of developing grain to wet conditions in which it can deteriorate rapidly. Grain moulds are a major component of the sorghum grain deterioration complex, and have become a widespread problem of improved sorghums in temperate and tropical regions. Many fungi have been isolated from mouldy grain, the most commonly occurring genera being Fusarium and Curvularia, and vary from those such as F. moniliforme Sheldon which are pathogenic on young developing inflorescences, to many saprophytic fungi which develop on the mature grains. The review covers terminology...
92 citations
TL;DR: This review includes the three major weed species in this family, Commelina benghalensis L., C. diffusa Burm.
Abstract: The Commelinaceae is chiefly a tropical family, present in all the major continents and extending into the temperate zone in parts of America, E. Asia and Europe. The review includes the three major weed species in this family, Commelina benghalensis L., C. diffusa Burm. f. and Murdannia nudiflora (Linn. Brenan. The synonymy of each species is listed and the importance of the weeds discussed in relation to their biology. The results of trials in cereals, broadleaved and plantation crops are summarised. The most successful methods of herbicide application are pre-emergence or early post-emergence. Herbicides should be applied in the early stages of the growth cycle as single or sequential applications. Bentazone applied as an early post-emergence treatment, either alone or in mixtures is one of the most successful herbicides in controlling Commelina species. Metribuzin applied pre-emergence alone or in mixtures is another chemical giving satisfactory control in many parts of the world. Esters or a...
67 citations
TL;DR: 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.
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 Sjostedt 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.
62 citations
TL;DR: Although each country studied or a region within a country has a particular set of weeds causing severe infestation, in general the species of greatest importance common to the whole of the area studied include Cynodon dactylon, Cyperus rotundus, Phragmites australis, and Setaria verticillata.
Abstract: A list of weeds of agricultural areas in the central, southern and eastern Arabian Peninsula is presented along with the maximum intensities of weed infestation resulting from these plants. Although each country studied or a region within a country has a particular set of weeds causing severe infestation, in general the species of greatest importance common to the whole of the area studied include Cynodon dactylon (L.) Pers., Cyperus rotundus L., Phragmites australis (Cav.) Trin., Convolvulus arvensis L., Portulaca oleracea L., Amaranthus graecizans L., Dactyloctenium aegyptium (L.) P. Beauv. Echinochloa colonum (L.) Link. and Setaria verticillata (L.) P. Beauv.
51 citations
TL;DR: Ephorbia heterophylla Linn, commonly known as wild poinsettia, is widespread in the tropics and causes serious loss of yield and quality in a wide range of crops as it competes successfully by growing rapidly and forming a dense canopy over the crop.
Abstract: Euphorbia heterophylla Linn., commonly known as wild poinsettia, is widespread in the tropics. It occurs as a major weed in six tropical countries, an important weed in 22 tropical countries and is present in a further 37 countries. It causes serious loss of yield and quality in a wide range of crops as it competes successfully by growing rapidly and forming a dense canopy over the crop. Dormancy is an important factor in the persistence of seed reservoirs in the soil and American and Nigerian work show light and temperature are important factors in germination. Pre-emergence herbicides do not give effective control for the whole growing season and as the weed becomes larger it is more difficult to control with post-emergence herbicides. In general the phenoxy-type herbicides give effective control, the triazines, ureas and uracils are variable and the acetanilides and anilines are poor. Some herbicide mixtures will suppress E. heterophylla long enough to allow the establishment of the crop and m...
47 citations
43 citations
TL;DR: The incidence of termite-scarified groundnut pods and resulting kernel contamination in field and market samples were studied in northern Nigeria and found that scarification was more common in the Sudan Savanna vegetation zone.
Abstract: The incidence of termite-scarified groundnut pods and resulting kernel contamination in field and market samples were studied in northern Nigeria. Scarification was caused by Microtermes lepidus Sjostedt and restricted to the more mature pods. In the field, scarification was more common in the Sudan Savanna vegetation zone. The incidence of scarification was much higher (40.9-87.9% of the pods) in the dead stands where the tap root had been invaded by Microtermes, than in healthy stands (7.9-31.6% of the pods). In the market samples, the number of scarified pods rarely exceeded 5%. 85-91% of the kernels from scarified pods were infected, the dominant fungi being Macrophomina phaseoli (Maubl.) Ashby (37-61%) and Fusarium spp. (8-26%). Less than 5% of kernels were infected by Aspergillus sp. The fungi carried by the termites bore little relation to those contaminating the kernels. 67% of the kernels from undamaged pods taken from dead stands were infected, indicating that - compared with premature ...
31 citations
TL;DR: Endosulfan at 200 g/ha was the most effective in controlling G. tachinoides, and other treatments were less, but the reinvasion problem is discussed.
Abstract: The results of discriminative spraying of endosulfan and decamethrin from a Bell 47G-4A helicopter to fringing riverine forest habitats of Glossina tachinoides in the Komoe Valley, Upper Volta, are described. The insecticides, diluted with diesel oil were applied from the helicopter through a unilateral (left-side) arrangement of four rotary atomisers. Three experimental blocks were each sprayed twice at an interval of about one month, one with endosulfan at individual swath dosages of 100 g (a.i.)/ha, the second with endosulfan at 200 g (a.i.)/ha and the third with decamethrin at 12.5 g (a.i.)/ha. In spite of aerially applied dieldrin barriers there was extensive reinvasion by G. tachinoides during the inter-spray period, consequently conclusions were largely drawn from the data collected before and after the second cycle of insecticide applications. The reinvasion problem is discussed. Endosulfan at 200 g/ha was the most effective in controlling G. tachinoides. Other treatments were less, but p...
28 citations
TL;DR: Methods of weed control in current use and which are undergoing research and development are described, which include hand cultivations, animal-drawn equipment, herbicides and fallow management.
Abstract: The climate, soil types, vegetation, land use and crops of The Gambia are briefly introduced. The most important weeds are commented on and a checklist of 219 species is appended. Methods of weed control in current use and which are undergoing research and development are described. They include hand cultivations, animal-drawn equipment, herbicides and fallow management. Current training of farmers and agricultural staff is mentioned.
28 citations
TL;DR: Virus-free material of IITA elite clones of sweet potato is available for distribution and can be stored in tissue culture for one year without transfer to fresh medium.
Abstract: Sweet potato vein clearing disease agents have been eliminated from 20 elite clones of sweet potato through meristem tip culture. Meristem tips of 0.25 to 0.4 mm length were cultured in a modified Murashige and Skoog medium. Plantlets were obtained after two months and transferred to soil. Indexing was accomplished by approach grafting to Ipomoea setosa. About 80% of the plants obtained by meristem tip culture indexed negatively. Rapid multiplication was accomplished using single node cutting in vitro. A multiplication rate of 4.2 /month was obtained. The material can be stored in tissue culture for one year without transfer to fresh medium. Virus-free material of IITA elite clones of sweet potato is available for distribution.
28 citations
TL;DR: The relevance of pheromones to the needs of agriculture in developing countries are discussed with particular reference to work by the Scientific Units of the British Overseas Development Administration.
Abstract: Strategies for the use of pheromones for the control of insect pests have generally been developed in countries of advanced technologies. In this paper the relevance of pheromones to the needs of agriculture in developing countries are discussed with particular reference to work by the Scientific Units of the British Overseas Development Administration.
TL;DR: The effect of weeds on crops is discussed, with particular reference to the Commonwealth Caribbean, and the most serious weeds in the region are Cyperus rotundas, Cynodon dactylon, Commelina spp.
Abstract: The effect of weeds on crops is discussed, with particular reference to the Commonwealth Caribbean. The most serious weeds in the region are Cyperus rotundas, Cynodon dactylon, Commelina spp., Parthenium hysterophorus, Portulaca oleracea, Cleome spp. and Amaranthus spp. Serious weeds include Eleusine indica, Echinochloa colonum, Euphorbia spp., Brachiaria mutica, Paspalum conjugatum, Sporobolus indicus and Ipomoea tiliaceae. Brief notes are given for these species and also for the locally serious weeds, Rottboellia exaltata, Digitaria sanguinalis, Mimosa pudica, Scleria reflexa, Cenchrus echinatus. Control measures include macheting, hand weeding, flooding, mulching and short-term fallows. Herbicides are used especially by larger vegetable growers and in sugarcane and citrus groves. Paraquat is the most widely used. Other chemicals used in specific situations are listed. Knapsack sprayers are the commonest application method but granular and c.d.a. application is likely to increase. Weed control ...
TL;DR: A comprehensive list of the insect prey of 47 species of Syrphidae from India and neighbouring countries is presented, including a total of 542 individual records, including the author's own rearings and other unpublished data from the CIBC Indian Station, which total 46 new prey records.
Abstract: A comprehensive list of the insect prey of 47 species of Syrphidae from India and neighbouring countries is presented, including a total of 542 individual records. The introduction includes a detailed summary, with references, of different insect groups known to be preyed upon by syrphids from all over the world, this being the first time that such a summation has been attempted for the Syrphidae. Pertinent information on predacious syrphids, their role as biocontrol agents, and a short historical account of Indian work on their biology and ecology is provided. The syrphid-prey list details recorded information on the 47 species of syrphids for whom prey have been recorded. This includes the author's own rearings and other unpublished data from the CIBC Indian Station, which together total 46 new prey records. Incorrect prey data and doubtful predator identifications are indicated or corrected. The prey-syrphid index gives the syrphid species recorded as preying upon the 77 prey species listed. T...
TL;DR: Tanzania is one of the largest producers of Upland cotton (Gossypium hirsutum L.) in Africa and the crop is raingrown by smallholders over a large ecologically diverse area with a variety of disease problems.
Abstract: Tanzania is one of the largest producers of Upland cotton (Gossypium hirsutum L.) in Africa. The crop is raingrown by smallholders over a large ecologically diverse area with a variety of disease problems. The main diseases are Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum (Atk.) Sny. & Hans.) and bacterial blight (Xanthomonas malvacearum (E. F. Smith) Dowson). Fusarium wilt is established over much of the area close to Lake Victoria where the soils are sandy and acidic. The disease is seed borne but spread is reduced by issuing seed produced in Fusarium free villages. Bacterial blight has become less important due to success in breeding resistant varieties. Verticillium wilt (Verticillium dahliae Kleb.) and root-knot nematode are potentially serious in some areas. Many other diseases occur at the seedling stage or on leaves and bolls but cause crop loss only under unusual environmental conditions or after insect damage. Alternaria macrospora is the most common cause of leaf spot and Colle...
TL;DR: This report gives details of research work carried out during 1978 and 1979, and includes seven new compounds, decamethrin, cypermethrin plus amitraz, sulprofos, profenofos,Profen ofos plus DDT, thiofanox and thiodicarb RH 0994, for bollworm control.
Abstract: A continuing research programme of chemical control on major cotton pests in Thailand has been conducted since 1960 to discover the most effective insecticides. Before 1978 twelve systemic insecticides for controlling the cotton leafhopper, Amrasca devastans (Dist.), and the cotton aphid, Aphisgossypii Glov., and eight insecticides for controlling the cotton bollworm, Heliothis armigera (Hbn.), were identified and sent for official recommendation. This report gives details of research work carried out during 1978 and 1979, and includes seven new compounds, decamethrin, cypermethrin plus amitraz, sulprofos, profenofos, profenofos plus DDT, thiofanox and thiodicarb RH 0994, for bollworm control. The bollworm resistance to synthetic pyrethroids and the increase in whitefly, Bemisia tabaci (Genn.), after using the synthetic pyrethroids are also discussed.
TL;DR: Insect pests, other arthropods and rodents causing damage on cassava crops in south India are listed comprehensively with nine photographs, and tetranychid mites and rodents can be classified as ‘key’ pests of cassava in India.
Abstract: Insect pests, other arthropods and rodents causing damage on cassava crops in south India are listed comprehensively with nine photographs. Information is given on their distribution, nature of damage, economic importance and control measures. Twenty three species of pests attack cassava in the field and of these 17 are first records on cassava. Although several cause damage, tetranychid mites and rodents can be classified as ‘key’ pests of cassava in India. Future research strategies should be directed towards the development and use of resistant varieties, biological control, improved agronomical and management practices, including judicious use of mineral fertilizers.
TL;DR: It is believed that the principal maize virus and mycoplasma-like diseases in Peru have been identified, an accomplishment unrealised in other Latin American countries at present.
Abstract: Surveys of maize for virus and mycoplasma-like diseases were conducted in Peru in 1978 and 1980. The following pathogens were discovered and identified: aphid-borne maize dwarf mosaic virus, beetle-borne maize chlorotic mottle virus, Peregrinus maidis-borne maize mosaic and maize stripe viruses, and Dalbulus maidis-borne maize rayado fino virus, corn stunt spiroplasma (CSS) and maize bushy stunt mycoplasma (MBSM). Some of these insect-borne pathogens are important constraints to maize production in Peru. Maize chlorotic mottle in the department of Lima and Cajamarca and ‘puca poncho’, a disease caused by CSS and/or MBSM, in Ayacucho significantly limit maize yields. As a result of these surveys, we believe that the principal maize virus and mycoplasma-like diseases in Peru have been identified, an accomplishment unrealised in other Latin American countries at present.
TL;DR: Trends in rice yields for different damage levels showed that the later damage occurred, the greater the yield loss.
Abstract: The effects of simulated rat damage (stem cutting) on IR-8 rice yield was examined Fields were subjected to four damage levels: 0 (control), 10, 25 and 50% of the stems cut A modified split-plot sampling design was used with ten 1 m2 plots tested at each damage level in three growth stages: tillering, booting and maturity Each of the 120 plots (2,400 hills) was harvested and yields compared by Analysis of Variance and Least Significant Difference (LSD) tests Ten perpent of all stems removed during the tillering stage produced growth compensation and a higher yield resulted Trends in rice yields for different damage levels showed that the later damage occurred, the greater the yield loss An LSD analysis of yields for the damage levels revealed no significant differences during tillering At booting, significant differences (P 10% of the stems cut At maturity, yields for all damaged levels differed significantly (P < 001) The results of this study demons
TL;DR: The paper reports the outbreak of two new cassava pests, the mealybug Phenacoccus manihoti and the green spider mite Mononychellus tanajoa (Bondar) in Nigeria.
Abstract: The paper reports the outbreak of two new cassava pests, the mealybug Phenacoccus manihoti and the green spider mite Mononychellus tanajoa (Bondar) in Nigeria. Apart from describing the outbreak areas, symptoms, spread and control recommendations are mentioned.
TL;DR: Pest control recommendations in Papua New Guinea cocoa plantings are based on an integrated approach to insect pest and disease management and the selection of shade types and levels and the introduction of antagonistic ant colonies can reduce populations of the main insect pests to low and stable levels.
Abstract: Pest control recommendations in Papua New Guinea cocoa plantings are based on an integrated approach to insect pest and disease management. The most damaging problems are Pantorhytes weevils, black pod and bark canker disease (both caused by Phytophthora palmivora) but vascular streak dieback (VSD) disease is important in some areas of the country. Most other insect pests can be kept to insignificant levels by cultural or biological controls, but occasional outbreaks causing crop loss or tree damage may require spot treatments mainly of non-persistant insecticides. Recent investigations have shown that certain cocoa environments are unfavourable to Pantorhytes and some other major pests. In particular, the selection of shade types and levels, the spot treatment of borer channels with penetrant insecticides and the introduction of antagonistic ant colonies can reduce populations of the main insect pests to low and stable levels. These measures would decrease the incidence of P. palmivora pod rot b...
TL;DR: It is shown that tiller density is the main non-rodent factor affecting yield and by using a partial regression equation to hold tillerdensity constant a statistically significant relationship was established between yield and damage counts made at harvest.
Abstract: The effect of pre-harvest rodent damage on the yield of rice is difficult to demonstrate because other factors affecting yield tend to obscure the effect and because examination of the crop, unless carried out on the day of harvest, fails to give an accurate picture of damage. Here we show that tiller density is the main non-rodent factor affecting yield. By using a partial regression equation to hold tiller density constant a statistically significant relationship was established between yield and damage counts made at harvest. In ten rice fields the average yield reduction attributable to rodents was 19% and ranged from 2% to 43%. Losses to rodents may be assessed more easily by comparing actual yield with potential yield as estimated from tiller density, provided that the relationship between yield and tiller density is known, for a series of fields that differ primarily in the degree of rodent attack.
TL;DR: The positive results and favourable cost effectiveness obtained in nearly all the trial situations demonstrate that under certain farming conditions methiocarb can be an economical method of reducing crop losses due to birds.
Abstract: This paper summarises the results of field evaluations during the past several years of the chemical methiocarb to protect ripening crops from birds in the East African countries of Somalia, Tanzania, Ethiopia, and Kenya. Methiocarb was applied in edge, alternate band, or spot treatments using ground spraying equipment to fields of rice, wheat, sorghum and sunflowers ranging in size from 0.5 ha to 1125 ha. The positive results and favourable cost effectiveness obtained in nearly all the trial situations demonstrate that under certain farming conditions methiocarb can be an economical method of reducing crop losses due to birds.
TL;DR: The Western Ghats squirrel, Funambulus tristriatus Waterhouse; the South Indian palm squirrel; and the black rat, Rattus rattus Linnaeus were observed to be causing much damage to cocoa in South India; the palm civet, Paradoxurus hermaphroditus Pallas and the bonnet monkey, Macaca radiata Geoffroy were causing minor damage.
Abstract: The Western Ghats squirrel, Funambulus tristriatus Waterhouse; the South Indian palm squirrel, F. palmarum Linnaeus and the black rat, Rattus rattus Linnaeus were observed to be causing much damage to cocoa in South India; the palm civet, Paradoxurus hermaphroditus Pallas and the bonnet monkey, Macaca radiata Geoffroy were causing minor damage. Monthly surveys made for one year in Karnataka showed that the percentage of damage caused by rodents was 29.0; that by civets and monkeys 0.4 and 0.3 respectively. In Kerala and one district of Tamil Nadu rodents were estimated to be causing 15% damage and civets 3%; no monkey damage was found.
TL;DR: Droplets of water and water + oil emulsions from a spinning disc were sampled simultaneously at 10, 30 and 200 cm below the disc on magnesium oxide coated slides to show the addition of oil affects the initial droplet size and reduces the change in size due to evaporation of the water.
Abstract: Droplets of water and water + oil emulsions from a spinning disc were sampled simultaneously at 10, 30 and 200 cm below the disc on magnesium oxide coated slides. The addition of oil affects the initial droplet size and reduces the change in size due to evaporation of the water.
TL;DR: In a commercial planting of onion, root and basal rots, fusarium oxysporum contributed to poor establishment andBenomyl decreased basal rot and increased yields but captan and thiram treatments were ineffective.
Abstract: In a commercial planting of onion, root and basal rots reduced establishment of sets to 44%, which with 30% basal rot in harvested bulbs, represented an overall numerical loss of potential yield of 69%. Fusarium oxysporum, already present in sets at planting, contributed to poor establishment. Isolation from seedlings grown for sets in virgin soil at three locations yielded infection rates of 80 to 90%. In two field trials to evaluate fungicide treatments mean establishment was 47%. In the first trial involving dusting of the sets before planting Granosan 200 (benomyl 15% + mancozeb 60%) increased establishment by 28%, reduced basal rot of harvested bulbs by 77% and increased yield by 106%. Benomyl decreased basal rot and increased yields but captan and thiram treatments were ineffective. When bulbs from this trial were stored for six weeks under ambient conditions losses were 94% in controls and 45% in the benomyl + mancozeb treatment, with losses from other treatments intermediate. In the secon...
TL;DR: Results confirm the existence of at least two distinct mechanisms of resistance to bacterial blight in cowpea, and recommend adopting a different inoculation method for each syndrome to establish the relationship between the resistance of different plant parts withincowpea genotypes.
Abstract: The evaluation of greenhouse and field screening methods for the identification of resistance to bacterial blight (Xanthomonas vignicola Burkh.) amongst germplasm and breeding lines of cowpea (Vigna unguiculata(L.) Walp.) is described. A stem injection technique and a leaf infiltration method were found reliable under greenhouse conditions while foliar spray inoculation was appropriate for use in both greenhouse and field experiments. A seed inoculation technique for evaluating seedling mortality may prove useful although only one susceptible cowpea accession was used in this study. Since distinct syndromes of bacterial blight (seedling mortality, stem canker and foliar blight) are recognised, it may be advantageous to adopt a different inoculation method for each syndrome to establish the relationship between the resistance of different plant parts within cowpea genotypes. Results confirm the existence of at least two distinct mechanisms of resistance to bacterial blight in cowpea. Hypersensitiv...
TL;DR: Yield losses due to grassy stunt and the brown planthopper in the period 1974–77 were more than US$510 million and individual farmers have suffered 100% yield loss in infected fields.
Abstract: Grassy stunt disease, ragged stunt virus and rice tungro virus, are among the most widespread and damaging rice diseases in Indonesia. Yield losses due to grassy stunt and the brown planthopper (Nilaparvata lugens) in the period 1974–77 were more than US$510 million. Ragged stunt virus is a new disease which is widespread in Indonesia and has been reported in several rice growing countries in Asia since 1977. Loss figures for ragged stunt are not available, however, individual farmers have suffered 100% yield loss in infected fields. Tungro and grassy stunt are controlled by resistant varieties but there are no commercially available varieties with resistance to ragged stunt.
TL;DR: The recent spread of coffee rust, sugarcane rust, black leaf streak of banana and Alternaria blight of wheat are recorded and the implications of new disease records are discussed.
Abstract: The recent spread of coffee rust, sugarcane rust, black leaf streak of banana and Alternaria blight of wheat are recorded and the implications of new disease records are discussed.
TL;DR: There were no significant differences between Superacide, Basudin and Nuvacron, and at five weeks after insecticide application, mean percentage knock-down figures were Rogor, 20 and Supracide, 45.
Abstract: A field trial on a moderately infested four-month old cassava plot was initiated at Ugwuoba field station of National Root Crops Research Institute, to determine the efficacy of five insecticides for control of cassava mealybug (CMB), Phenacoccus manihoti Mat-Ferr. The insecticides were Rogor 40 (dimethoate), Supracide 40 (methidathion), Basudin 60 (diazinon), Nuvacron 40 (monocrotophos) and Dimecron (phosphamidon) and were applied at the rate of 0.05 percent active ingredient (500 ppm). A CP3 type sprayer was used to discharge the insecticides. The treatments were replicated five times. Knock-down effect on the crawlers (nymphs) and adult mealybugs was recorded 24 hours after insecticide application. Mean percentage knock-down figures were Dimecron, 25; Nuvacron, 37; Basudin, 40; Rogor, 20 and Supracide, 45. Although the highest knock-down was recorded in Superacide, there were no significant differences between Superacide, Basudin and Nuvacron. At five weeks after insecticide application, mean ...