Showing papers in "Journal of Plant Protection Research in 2008"

Bakanae disease of rice in Malaysia and Indonesia: etiology of the causal agent based on morphological, physiological and pathogenicity characteristics

Abstract: Bakanae disease on rice has been recorded almost in all countries where paddy is grown commercially, especially in Asian countries, including Malaysia and Indonesia. Bakanae disease was widespread in Peninsular Malaysia and three provinces of Indonesia with the range of disease sever- ity from scale 1 to 5 and disease incidence from 0.5 to 12.5% during 2004-2005 main growing seasons. A total of five Fusarium species belonging to section Liseola and their allied i.e. Fusarium fujikuroi, F. proliferatum, F. sacchari, F. subglutinans and F. verticillioides were isolated and identified on the basis of their morphological characteristics. Literature data showed that the bakanae disease of rice all over the world is caused by F. fujikuroi and probably some other Fusarium species from section Liseola or allied. However, from pathogenicity tests that have been carried out by using variety MR 211 of rice it was evident that F. fujikuroi was highly virulent and the only species involved in causing bakanae dis- ease. Therefore, this species was the only one detected to be able to produce gibberellic acid - (GA3) with Rf value 0.40 and 0.62, developed in solvent systems isopropanol:ammonia:water (10 : 1 : 1), v/v/ v and chloroform:ethyl acetate:formic acid (5 : 4 : 1), v/v/v, respectively. This knowledge would be in- valuable in developing our understanding on the interaction between F. fujikuroi and the host plants.

Fumigant Toxicity of Essential Oil from Carum Copticum Against Indian Meal Moth, Plodia Interpunctella

Abstract: Fumigant toxicity of the essential oil derived from Carum copticum C.B. Clarke (Apiaceae) were assessed against growth stages of Indian meal moth, Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae). Seeds of the plant were collected from Tehran, Iran and hydrodistilled to extract their es- sential oil. The essential oil was analyzed by GC and GC-MS. Thymol (64.51%), γ-terpinene (17.52%) and p-cymene (16.16%) were the main components among the eight constituents characterized in the oil, representing 98.19% of the total components detected. All bioassay tests were conducted at 25 ± 1°C, 65±5% RH and photoperiod of 16:8 h (light:dark). After preliminary dose-setting experiments, LC50 and LC90 values of four growth stages including eggs, larvae, pupae and adults were calculated. Results showed that the toxicity on the growth stages of Indian meal moth was differed markedly. Adult insects were about 500 times (LC50 = 257.83 µl/m 3 air

Effects of titanium dioxide on the diseases, development and yield of edible cowpea

Abstract: Titanium dioxide (TiO2) is being considered as a growth promoter that plays the function of antibiotics in cowpea (Vigna unguiculata Walp) production in Nigeria. Field trials were conducted at the Institute of Agricultural Research and Training, Moor Plantation, Ibadan, Nigeria in 2006 and 2007 to evaluate the influence/effect of TiO2 on the development yield and diseases of cowpea. Two treatments of TiO2 at 125 cc/ha significantly improved the development and yield and reduced the severity of foliar and pod diseases of cowpea compared to a single treatment at lower concentra- tions. Irrespective of the number of sprays and concentrations TiO2 increased the yield of cowpea by 8.74-36.11%, and 10.33-51.31% respectively, in both years.

Production of Cell Wall Degrading Enzymes and Toxins by Colletotrichum Capsici and Alternaria Alternata Causing Fruit ROT of Chillies

Abstract: The virulent isolates of Colletotrichum capsici and Alternaria alternata produced more cellulolytic enzymes viz., C1 and Cx in vitro than the avirulent ones and the activity of these enzymes increased with the increase in age of culture. The virulent isolates of C. capsici and A. alternata produced more pectinolytic enzymes (macerating enzymes, pectin methyl esterase and endo polygalacturonase) than the avirulent ones. All the pectinolytic enzymes were highly active in 10-day-old culture and the activities decreased with the increase of culture age. Whereas the activity of enzymes produced by avirulent isolate of pathogens did not decrease and these enzyme activities increased with the increase in the age of culture. These pathogens also produced nonspecific toxic metabolites in culture filtrate which reduced seed germination, root length, shoot length and vigour index of the seedlings of chilli, rice, mungbean, maize, cotton, groundnut, okra, egg plant, cucumber and tomato. The toxins of the pathogens reduced seed germination and caused mortality of chilli seedlings in pot culture. The toxins also produced phytotoxic symptoms in the treated ripe and green chilli fruits and leaves.

Growth promotion and charcoal rot management in chickpea by trichoderma harzianum

Abstract: The strains of Trichoderma harzianum were assessed for their effect on chickpea growth and control of charcoal rot caused by Macrophomina phaseolina in greenhouse assay. T. harzianum strain 25-92 significantly increased the fresh and dry weights by 50-63% and 24-42%, respectively, whereas strain 29-92 increased the fresh weight of chickpea cv. Radhey and Vishwas by 12-30% but not the dry weight in the absence of M. phaseolina. A marked increase in root length was caused by both the strains. In M. phaseolina infested pots, number of lateral roots and branching decreased with non- significant change in weight. Significant (P = 0.05) reduction in charcoal rot disease was observed in the pots amended with T. harzianum at all the concentrations. Moreover, 60-40% reduction in disease was recorded after 14 and 28 days in chickpea varieties Radhey and Vishwas. The resistant variety Vijay does not show significant disease. The reduction in disease was more pronounced at higher inoculum concentrations of T. harzianum (10 7 -10 8 cfu/g). Overall, Trichoderma strain 25-92 improved plant growth and reduced damage in presence of the pathogen. Besides disease control the growth promoting properties of the strain improve the efficacy for commercial application.

Interaction of root-knot nematode (meloidogyne javanica) and tomato as affected by hydrogen peroxide

Abstract: The effect of hydrogen peroxide (H2O2) on root-knot nematode (RKN, Meloidogyne javanica) in tomato was investigated. Soil drenching with exogenous H2O2 was done using seven H2O2 con- centrations (1, 10, 100, 250, 500, 750 and 1 000 mM) at different application times (24 hours before the time of plant inoculation with the RKN (T1), at the time of inoculation (T2), and 24 hours after the inoculation time (T3). The nematode reproduction rate (eggs/g fresh root) was significantly reduced in all H2O2 treatments compared with the untreated control. The lowest reduction in nematode re- production occurred at 10 mM H2O2. The application times T1 and T2 were significantly higher in reducing the reproduction rate than T3 at 250, 750 and 1 000 mM H2O2. The content of endogenous H2O2 in the treated plants was significantly higher than in the non-treated plants. Some phytotoxic- ity was apparent at the higher concentrations of H2O2 (≥ 500 mM) in the treated plants due to the accumulation of the endogenous H2O2. The treatments with 1 and 10 mM H2O2 did not differ from the untreated control in plant chlorophyll content while the content was significantly reduced at the higher concentrations. Exogenous application of H2O2 may have a direct effect on the nematode reproduction and an indirect effect on the treated tomato plants that can be elicited by H2O2 to resist the nematode infection.

Influence of some inert diluents of neem kernel powder on protection of sorghum against pink stalk borer (sesemia calamistis, homps) in nigerian sudan savanna

Abstract: Neem (Azadirachta indica) kernel powder (NKP) mixed 1:1 (weight basis) with some inert diluents (fine-sand, kaolin-dust, and saw-dust) were applied into the whorls of sorghum seedlings at 20, 30, 40, 50, days after sowing to provide protection against pink stalk-borer in field trials in 2002 and 2003. Carbaryl (Sevin 85) and untreated seedlings were used as check. Results showed that diluted NKP and carbaryl significantly (p ≤ 0.01) reduced leaf puncturing, dead hearts, stalk and peduncle boring below the untreated check. Although sole NKP caused scorching of leaves (phyto- toxicity), this was not observed on plants treated with diluted NKP and absent with carbaryl. Mean yield increases above the untreated check for the two seasons were: 40.0% (NKP + fine-sand), 36.4% (NKP + kaolin-dust), 35.5% (sole NKP), 35.3% (NKP + saw-dust) and 29.4 % (carbaryl). Cost-benefit analysis shows that it was financially most beneficial to use NKP + fine-sand to control S. calamistis on sorghum in Nigerian Sudan savanna.

Management of collar rot of chickpea (cicer arietinum) by trichoderma harzianum and plant growth promoting rhizobacteria

Abstract: Collar rot (Sclerotium rolfsii) of chickpea (Cicer arietinum) is one of the devastating soil-borne diseases of fungal origin, due to which 10-30% yield loss is recorded annually according to severity of the disease. Management of collar rot of chickpea is not feasible in the absence of effective soil fungicides. However, Trichoderma harzianum and plant growth promoting rhizobacteria (PGPR) have shown high efficacy against this disease in vitro as well as in the field. We used T. harzianum (10 4 , 10 6

Assessing the Suitability of Morphological and Phenological Traits to Screen Sesame Genotypes for Fusarium Wilt and Charcoal Rot Disease Resistance

Abstract: Since sesame genotypes differ significantly in many morphological and phenological traits, some of these traits could be suitable for direct selection among the sesame genotypes for Fusarium wilt and charcoal rot disease resistance. Forty-eight sesame genotypes that originated from different geographical regions were screened for their response to infection by Fusarium oxysporum f. sp. sesami (FOS) and Macrophomina phaseolina (MPH), the Fusarium wilt and charcoal rot pathogens in 2005 and 2006 seasons, respectively. The seed yield and infection percentage by Fusarium wilt and charcoal rot pathogens were determined. Branch number and days to maturity as morphological traits and seed colour as phenological trait which represented the proposal for diversity among sesame genotypes were correlated with infection percentage and were used to examine the performance of these traits as screening criteria for Fusarium wilt and charcoal rot disease resistance. Our results showed that 57, 67 and 67% in 2005 and 77, 77 and 62% in 2006 of resistant genotypes for FOS, and 68, 77 and 64% in 2005 and 80, 76 and 60% in 2006 of resistant genotypes for MPH had a medium branch number, and were of medium maturity and having creamy seed colour, respectively. According to the analysis of regression, branch number and seed colour were significantly correlated with infection percentages by FOS and/or MPH. Therefore, these traits may be used as indices for direct selection for resistance of sesame genotypes to Fusarium wilt and charcoal rot disease. However, no significant correlation was found between days to maturity and infection percentage by both fungi. Linear regression be- tween infection percentage and three groups of branch number and seed colour indicated that the sesame genotypes had medium branch number and having creamy or white seed colour were the only covariant which significantly correlated with the infection percentage by FOS and/or MPH.

Occurrence of soilborne diseases and root knot nematodes in strawberry plants grown on compacted rice straw bales compared with naturally infested soils

Abstract: The present investigation deals with a possible use of rice straw bales as "soilless" cultiva- tion medium, thus escaping the problems inherent in the natural soils and avoiding a serious pollution when disposed about 5°C million tons of rice straw annually by burning. Strawberry fruits of good quality and quantity were harvested from plants cultivated on compacted rice straw bales in compari- son with the control plots under natural soil conditions. A higher temperature of 2 to 5 in comparison to natural soil conditions favours all physiological activities including the absorption of nutrients by roots and thus stimulating the vegetative and the generative growth of strawberry plants. The pH values around the roots in straw bales ranged from 5.5 to 6.5, while values obtained around the root system in natural soil ranged from 7.5 to 8.5. So, growing strawberry on rice straw bales helps avoid and overcome the problem of alkalinity and salinity in the rhizosphere. This is very important, as strawberries are very sensitive to salinity. Fruit rot diseases reached 0.8% on rice straw bales while on the control plots these were about 52% of fruits were infected with fungi. Cultivating strawberry on rice straw bales keeps the fruits away from contacting the soil and thus limits the possibility of injec- tion by soilborne fungi. The occurrence of damping-off, root rot, crown rot and root knot nematodes in strawberry plants grown on rice straw bales reached 4.0, 0.85, 0.35 and 0.0%, respectively. However, the corresponding figures for strawberry plants grown in natural soil under the same conditions were 27.0, 16.15, 11.70 and 13.20%, respectively, 135 days after planting. Isolation from strawberry plants grown in natural soil showing symptoms of crown rot and black root rot yielded several fungi identi- fied as Phytophthora cactorum, Colletotrichum fragariae, Pythium ultimum, Rhizoctonia solani and Fusarium oxysporum. The wilt symptoms observed on few strawberry plants on rice straw bales might be attrib-

Effectiveness of Azoxystrobin in the Control of Erysiphe Cichoracearum and Pseudoperonospora Cubensis on Cucumber

Abstract: The bioefficacy of azoxystrobin (Amistar 25 SC) was tested against cucumber downy mil- dew and powdery mildew diseases. The two season trials of field studies revealed that the disease progression of cucumber downy mildew and powdery mildew was successfully arrested by azoxys- trobin. Spraying of azoxystrobin at various doses (31.25, 62.50 and 125 g a.s./ha) revealed that 125 g a.s./ha (500 ml/ha) was considered as the optimum dose for the control of these diseases of cucumber. The treatment also recorded the highest yield of 13.23 and 14.46 tonnes/ha in the first and second season, respectively. No phytotoxic effect of azoxystrobin was observed in the both field trials even at four times of the recommended dose 125 g a.s./ha. The persistence of azoxystrobin at 250 and 500 g a.s./ha was observed up to seven days after last spraying. However, the persistence of azoxystrobin at 31.25, 62.50 and 125 a.s./ha was observed up to three to five days after last spraying. The safe waiting period for the harvest of cucumber fruits was 1.53 days in the first field trial and 2.37 days in the second field trial, respectively at azoxystrobin 125 g a.s./ha. The residues of azoxystrobin were at below detectable level (BDL) in the harvested cucumber fruits.

The Use of Fungicide Alternatives for Controlling Postharvest Decay of Strawberry and Orange Fruits

Abstract: Control measures of postharvest diseases of strawberry and navel orange fruits using hy- drogen peroxide, calcium chloride and chitosan were evaluated under in vitro and in vivo conditions. All tested concentrations of chemicals used were able to reduce the linear growth and spore germina- tion of B. cinerea; R. stolonifer; P. digitatum and P. italicum. Complete inhibition of linear growth and spore germination was obtained with concentrations of 1.5 and 2.0% of all treatments. Under storage conditions, significant reduction in descending order of mould incidence was observed in strawberry and orange fruits treated with ascending concentrations of calcium chloride, hydrogen peroxide and chitosan. Obtained data revealed significant reduction in mould incidence in fruits when treated by calcium chloride and chitosan 12h before artificial inoculation with the mould pathogens, while hy- drogen peroxide showed the opposite result. The present study demonstrated that the application of hydrogen peroxide is superior to treatment with calcium chloride or chitosan enhanced the control activity against mould pathogens which as it expressed was as either percentage of diseased fruits or decay development as rotted tissue weight of strawberry and navel orange. The applied tested chemi- cal might act as contact and systemic fungicides which have a protective or therapeutic effect.

Phytophthora cryptogea and P. citrophthora: new pathogens of Forsythia intermedia in Polish ornamental hardy nursery stocks

Abstract: Phytophthora cryptogea and Phytophthora citrophthora were isolated from rotted stem base of Forsythia intermedia cv. Minigold and from substratum, respectively. Additionally Botrytis cinerea and Fusarium spp. were often isolated from diseased tissues. In the laboratory trials P. cryptogea from F. intermedia colonised and incited disease of leaf blades and stem parts of all tested cultivars.The species caused necrosis development of leaves and stem of Ligustrum vulgare, Sambucus nigra and Syringa vulgaris after 3 days of inoculation. The isolates from 7 different host plants colonised (except from Sempervivum arachnoideum) leaves and stem parts of F. intermedia cv. Minigold with the fastest spread of necrosis on plant parts inoculated with isolate from forsythia. P. citrophthora from substra- tum colonised leaves and stem parts of 5 tested cultivars with the quickest spread of necrosis on cv. Goldzauber and Spectabilis.

Susceptibility of the selected crops in storage to sitophilus zeamais motschulsky in southwestern nigeria

Abstract: Susceptibility of the selected Nigerian cultivars of twelve crops to Sitophilus zeamais Motschulsky was evaluated in the laboratory (28 ± 2°C temperature and 69 ± 5% relative humidity). The crops were: maize (Zea mays L.), millet (Pennisetum glaucum (L.) X R. Br.), sorghum (Sorghum bicol- or (L.) Moench), rice (Oryza sativa L.), and yam (Dioscorea rotundata Poir). Others were cassava (Mani- hot esculenta Crantz), pepper (Capsicum annuum L.), cowpea (Vigna unguiculata (L.) Walp), groundnut (Arachis hypogaea L.), melon (Citrullus lanatus (Thunb.)), soybean (Glycine max (L.) Merr.) and bambara groundnut (Vigna subterranea (L.) Verdc). The result of antixenosis prescreen shows that S. zeamais preferred cereals and tubers to legumes and oil crops. S. zeamais preference for maize was highest at 1, 24 and 48 hours after infestation (HAI) and was not significantly different from its preference for pepper, millet, sorghum and yam. At 48 HAI, S. zeamais preference for cereals, tubers and pepper was not significantly different. Soybean and bambara groundnut were the least preferred species. The highest level of damage was observed in cereals and tubers. Millet suffered significantly greater damage than maize at 2-8 weeks after infestation (WAI). Damage done to maize was not signifi- cantly different from damage done to tubers at 6 and 8 WAI. Pepper, legumes and oil crops suffered significantly lower levels of damage than maize throughout the experimental period. Cumulative number of adult was significantly higher in small-seeded cereals than maize and was of the order: sorghum>millet>rice. Cowpea, soybean and pepper did not support reproduction and longevity of S. zeamais. Longevity was best supported by cassava. The results show that in storage, cereals and tubers were more susceptible to S. zeamais infestation than legumes, spices and oil crops.

Isolation and Identification of Xathomonas Oryzae PV. Oryzae the Causal Agent of Bacterial Blight of Rice in Iran

Abstract: Bacterial blight caused by Xanthomonas oryzae pv. oryzae is one of the important bacterial diseases on rice. This disease causes typical symptoms on infected rice such as leaf blight which ap- pears on leaves of young plants, after planting out, as pale-green to grey-green water-soaked streaks near the leaf tip and margins. In this research, during the period from 2004 to 2005, samples of in- fected plant were collected from different areas of Guilan province (Rasht, Lahijan, Foman, Anzaly, Talesh, Roudsarm Roudbar and Astara), to identify the causal agent of disease. For isolation of bacte- ria, infected tissue of leaves, stems and roots were crushed in pepton water then 100 µl of homogenate were cultured on nutrient agar (NA) and yeast dextrose carbonate (YDC) containing cyclohexamid antibiotic (50 µg/ml). Isolates of bacteria rod-shaped, gram negative bacteria and aerobic bacterium were obtained. The former isolates produced levan on media including sucrose. All isolates induced hypersensitive reaction (HR) on tobacco and geranium leaves. All of the isolated bacteria were oxi- dase, nitrate, urease, Tween 80 hydrolysis and indole negative and could not produce rot on potato tuber slices, produced H2S and grew in 36°C. The isolates could use citrate, L-lysin and cystein. The isolates produced acid from arabinose, galactose, myo-inositol, fruoctose, trehalose and mannose and hydrolyzed gelatin. Based on morphological, physiological, biochemical tests, PCR method with spe- cific primers and pathogenicity properties, the predominant pathogenic type was identified as X. ory- zae pv. oryzae. To the best of our knowledge, this is the first record of bacterial blight of rice in Iran.

Effect of chitin and abamectin on Meloidogyne incognita infesting rapeseed

Abstract: The tested rates of chitin (2, 4 and 8 g/m 2 ) significantly (p ≤ 0.05 and 0.01) reduced the num- ber of galls, egg masses, females and the second stage juveniles (J2) in oilseed rape cvAD201 under field conditions. The plant growth parameters as length and weight of shoots increased at all rates of chitin compared to the untreated check. When using abamectin at the concentrations of 500, 1000 and 1500 ppm, it significantly (p ≤ 0.05) reduced the above listed nematode criteria and enhanced the plant growth criteria. Scattered notes appear in the literature on the effect of chitin amendment on plant growth, microbial populations and certain parasitic nematodes in the soil. Brown et al. (1995) determined the effects of soil amendment with three rates of chitin (0, 0.5 and 1.0% by weight) and pre-incubation of soil with chitin for 0, 3, 6, and 9 weeks on the growth of white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.) and on populations of soil bacteria, fungi and plant-parasitic nematodes. Ryegrass yield increased in 0.5 and 1% chitin amended pots compared to the control. White clover yield decreased with increasing of chitin content, probably due to phy- totoxic effects of chitin. Pre-incubation with chitin increased ryegrass yield but had no effect on white clover. Populations of micro-organisms but the fungal counts were unaffected by pre-incubation. The numbers of plant-parasitic nematodes, Meloido- gyne spp. and Heterodera trifolii were reduced by chitin. Pre-incubation had no effect on nematode numbers. Hallmann et al. (1999) showed that addition of chitin to the *Corresponding address:

Non-Chemical Control of Some Important Pests of Sweet Cherry

Abstract: Some non-chemical insecticides were tested for efficacy of control of fall webworm, Hyphan- tria cunea (Drury), and of cherry weevil, Rhynchites auratus (Scop.) in the laboratory and black cherry aphid, Myzus cerasi (Fabr.) under field conditions. Hendreson & Tilton formula was applied for eval- uation of efficacy. NeemAzal T/S (azadirahtin) at the concentration 0.5% and Naturalis (Beauveria bassiana) used at 0.2% or 0.3% have shown the best results against black cherry aphid. Good results were also obtained with Pyrethrum FS (pyrethrin + sesame oil + soft potassium soap) used at 0.05% or 0.1%, with NeemAzal T/S at 0.3%, PreFeRal WG (Paecilomyces fumosoroseus) at 0.2% and with Natu- ralis at 0.1%. The effect of PreFeRal WG, applied at 0.1% was unsatisfactory. Against the fourth instar larvae of fall webworm, excellent results were noted for Pyrethrum (0.05% and 0.1%) and Naturalis (0.1% and 0.2%). Very good effects were also obtained with the BMP 123WP (Bacillus thuringiensis), used in concentration of 0.1%. NeemAzal T/S - 0.5% had still good, albeit lower, efficacy. Against the cherry weevil only Pyrethrum FS was tested. This insecticide resulted in a very good efficacy, when used at the concentration 0.1% and still satisfactory - at 0.05%.

The problems of weed management by herbicide systems applied in maize

Abstract: Detailed recognition of weed infestation state and degree in south-western region of Poland provided the basis for starting field experiment on three types of soils aiming at the assessment of weed control effectiveness by means of suitably selected herbicide systems. High efficiency of weed elimination on alluvial soils was obtained due to herbicide mixture mesotrione + nicosulfuron in split doses. In the experiment established on brown soils the mentioned weed species were most satisfactorily controlled by herbicide mixture applied according to infestation degree: mesotrione + nicosulfuron i rimsulfuron + adjuvant + dicamba applied once in full doses. The mixture rimsulfuron + adjuvant + dicamba showed to be the most efficient regarding the weeds typical for alluvial soils, except for Elymus repens, numerously occurring in the experiment, which exhibited medium sesitivity, as well as winter forms of Anthemis arvensis. Mixture of rimsulfuron + adjuvant + florasulam + 2,4D allowed to eliminate undesired plants on that soil stand in the most efficient way and to achieve the highest grain yield.

Antagonistic Effects of Trichoderma Species in Biocontrol of Armillaria Mellea in Fruit Trees in Iran

Abstract: Root and butt rot caused by species of Armillaria is one of the most serious diseases of fruit and forest trees in Iran In this study, antagonistic effects of Trichoderma in biocontrol of Armillaria were investigated Armillaria mellea was isolated from infected roots and butts of cherry and almond trees and identified with pairing tests method Trichoderma species were recovered from rhizomorphs and around soil of Armillaria infected roots Trichoderma species identified were T virens (nine isolates) and T harzianum (three isolates) Trichoderma discs were placed onto cultures of Armillaria to study an- tagonistic effects All isolates of Trichoderma colonized Armillaria colonies within 5-7 days Volatile compounds of Trichoderma isolates inhibited Armillaria colony growth and rhizomorph formation Mechanisms of biocontrol were investigated by light and scanning electron microscopy, these in- cluded penetration of Trichoderma hyphae in rhizomorphs, colonization of rhizomorphs by Tricho- derma mycelia, colonization of apex meristemic center and apical buds of rhizomorphs, sporulation of Trichoderma in outer and inner surface of rhizomorphs, degeneration and lysis of rhizomorph tissue, and discharge of rhizomorph content

Furfural Approaches as Control Measures against Root Rot and Root-Knot Incidence of Tomato under Greenhouse and Field Conditions

Abstract: The fungicidal and nematicidal activity of an emulsifiable formulation of furfural (2-furan- carboxaldehyde) against root rot and root-knot pathogens was studied in laboratory, greenhouse and field experiments. The linear growth of tested soilborne pathogenic fungi was dramatically reduced with the increasing of furfural concentrations added to the growth medium up to 4 000 ppm where no growth was observed, while the bacterial and fungal bioagents showed more tolerance to these concentrations and failed to grow at 6 000 and 7 000 ppm, respectively. Pot and field experiments indicated that furfural at 6 000 ppm combined with bioagent treatments proved to have superior suppressive effect against tomato root rot incidence, caused by Fusarium solani and Rhizoctonia so- lani, comparing with each individual treatment. Numbers of nematodes in soil declined sharply in direct response to furfural application with the sharpest reductions in its population. No symptoms of root-knot incidence, caused by Meloidogyne incognita as well as no detected galls and eggmasess were observed in the root system of tomato plants grown in either artificially or naturally infested soil with the parasite at the same concentration under greenhouse and field conditions. Results from these experiments indicate that a variety of effective broad-spectrum formulations of furfural can be developed for control of economically important soilborne pests.

Impact of Strains of Entomopathogenic Fungi On Some Main Groups of Soil Microorganisms

Abstract: The influence of entomopathogenic fungal strains - one Metarhizium anisopliae (Metsch.) So- rok. and seven Beauveria bassiana (Bals.-Criv.) Vuill. on some main groups of soil microorganisms was studied after introduction of their conidia into the soil. The soil samples were analyzed for densities of bacteria, actinomycetes and fungi by decimal dilutions of soil suspensions grown on selective media. The presence of conidia of fungal strains in the soil after a month from introduction was proved by bait method. Three of the strains of B. bassiana were established to be of the highest persistence, this being expressed by mortality of Galleria mellonella L. (Lepidoptera, Pyralidae) larvae from 70% to 90%, followed by strains 224Re of B. bassiana and 31 of M. anisopliae. The obtained results showed that examined strains of the entomopathogenic fungi manifested dif- ferent in manner and varying in degrees of impact on density of the main groups of soil microor- ganisms. Relatively insignificant changes were established under the influence of the strains 224Re B. bassiana and 31 M. anisopliae. The other strains of B. bassiana caused alterations in microbial balance expressed in different manner - stimulation or suppression on density of free-living nitrogen-fixing microorganisms, mineral nitrogen utilizing bacteria, spore-forming bacteria, cellulose degrading mi- croorganisms, actinomycetes, soil fungi. So each strain could be characterized by specific impact on

A Pheromone-Based Trapping System for Monitoring the Population of Cosmopolites Sordidus (Germar) (Coleoptera: Curculionidae)

Abstract: The banana root borer Cosmopolites sordidus (Coleoptera: Curculionidae) is native to Malaysia and Indonesia but is found in nearly all banana-growing areas of the world Studies were conducted to determine the pheromone trap efficacy, effect of shade on trap catches and to monitor the popu- lation of C sordidus using pheromones in Guam In Guam, pheromone traps were used to monitor the population level of C sordidus Before monitoring began, two basic studies were carried out, which established that pheromone-baited ramp traps positioned in the shade of the banana crop canopy caught significantly more adults than those placed in sunlight and that ramp traps baited with pheromone lures caught significantly more adults than did identical traps without pheromone lures Ramp traps baited with pheromone lures were set up at each of 10 locations throughout the island in November 2005 Weekly counts were made of the borers caught by the pheromone traps The data indicated higher population levels (>10 per week) in the northern region and low (<5 per week) to medium level (5-10 week) populations in the southern part of the island These differences among sites were highly significant Linear and quadratic effects of rainfall on the number of borers captured were statistically significant, but according to quadratic regression models, the significance was due to differences at just one site

Outbreaks and Natural Viral Epizootics of the Satin Moth Leucoma Salicis L. (Lepidoptera: Lymantriidae)

Abstract: Long standing systematic observations on Leucoma salicis populations revealed numerous occurrences of outbreaks and natural viral epizootics. Number of insects appearing in outbreaks at peak density ranged from 450 to 3250 on 10 examined poplar trees (up to 2 m height). Abundance of virus within population of such a high density increased along with an increase of insect population. Populations with high density and high level of nucleopolyhedrovirus (LesaMNPV) and cypovirus did not last long and collapsed suddenly. Outbreaks of the satin moth were favored by warm and humid conditions while warm and dry spring, summer months were conducive to viral epizootic. Most outbreaks happened in the years with mean temperatures of spring and summer months above 15°C and 50-60% RH while, most epizootics were recorded at similar temperature conditions but lower RH, i.e. 40-50%.

Host-pathogen interaction in rice- bacterial blight pathosystem

Abstract: Virulence pattern among 52 isolates of Xanthomonas oryzae pv. oryzae, the causal organism of bacterial blight disease was tested on 16 rice genotypes possessing 11 known Xa genes conferring resistance. Significant differences among the host genotypes as well as the pathogen isolates and in their interaction, suggested that the host genotypes differed in vertical resistance and the pathogen isolates differed in virulence. None of the genotypes exhibited resistant reaction against all the iso- lates, while one Japanese and two IRRI differentials were knocked down by all the isolates. The set of 16 rice genotypes possessed the Xa genes viz. Xa1, 2, 3, 4, 5, 6, 7, 10, 11, 12 & 13. The isolates carried 4-11 virulence factors, out of a total number of 11 v-factors that could be evaluated from this set of host genotypes to overcome the resistance offered by the corresponding Xa genes. The pattern with virulence to Xa1, 2, 4 & 11 and avirulence to the genes Xa6, 7, 5, 13 & 10 was very common. The wide distribution of the virulence factors over different states of India suggested nonparallelism between virulence pattern and geographical distribution of the isolates. The 52 isolates could be classified into five groups using hierarchical agglomerative method of cluster analysis based on the number of v-factors possessed by each of them viz. 11, 10, 8, 7 & 4, which were equivalent to the pathotype grouping of 1, 4, 7, 14+15 & 16, respectively. The application of the methods of numerical taxonomy emerged as a valuable tool in classification of bacterial isolates into virulence groupings.

The occurrence of pathogenic fungi during flax growing season in central lithuania

Abstract: Experiments designed to study the variation of diversity of pathogenic fungi occurring in fibre flax agrocenosis during the growing season were conducted at the Lithuanian Institute of Agri- culture Upytė Experimental Station during 1999-2002. The Upytė Experimental Station is situated in Central Lithuania. Phytopathological analyses of seed, soil and plants were done at the laboratory of the Upytė Experimental Station as well as at the Biodestructor Research Laboratory of the Institute of Botany. There were identified in the rhizosphere 9 fungal species belonging to 9 genera. On flax seedlings were identified fungi belonging to 13 genera. On flax leaves at green maturity stage was identified only Oidium lini. On flax stems at green maturity stage were identified fungi belonging to 12 genera. On mature flax stems were found fungi belonging to 15 genera. On flax seed during the experimental years were identified fungi belonging to 16 genera. The number of fungi identified on seeds varied each year, depending on the year's weather conditions during the seed ripening period. Having summarised the results, we can assert that pathogenic fungi Fusarium spp. and Colletotrichum lini, were found both on seed and plant vegetative parts during the whole assessment period. Species composition of fungi present on seed differed depending on the weather conditions. A larger number and more diverse species were found on the seed that ripened during the years with wet growing sea- sons (2000 and 2001) whereas the seed that ripened during dry growing seasons (1999 and 2002) was less infected with fungi. The spread of fungi on stems and leaves was also determined by the weather conditions. Many species of fungi were identified in 2001, when flax crops were lodged; stems and capsules were damaged by hail, and in 2000, when there was much rainfall.

Survey of Plant-Parasitic Nematodes Associated with Yams in Ogun and Osun States of Nigeria

Abstract: A survey was conducted to determine the types, frequency and population of plant para- sitic nematodes associated with the soils and roots of Yam (Dioscorea species) in all the Local Govern- ment Areas of Ogun and Osun States of Nigeria using random sampling soil and root and pie pan modification of Baerman funnel for plant parasitic nematode extraction. Ten and nine genera of plant parasitic nematodes were encountered both from the soils and root samples from the two States. Plant parasitic nematodes recovered included Scutellonema spp., Meloidogyne spp., Pratylenchus spp., Trichodorus spp., Helicotylenchus spp., Radopholus spp., Longidorus spp., Xiphinema spp., Rotylenchulus spp and Aphelenchoides species. Scutellonema spp., Meloidogyne spp., and Pratylenchus spp were most widely distributed with frequency ratings of 70, 65 and 60% respectively in soil samples from Ogun State and in the root samples the three genera predominated with 60, 55 and 45% frequency ratings respectively. Meloidogyne spp., Scutellonema spp., and Pratylenchus spp were most widely distributed with frequency ratings of 65, 45 and 35% respectively in soil samples from Osun State and in the root samples the three genera predominated with 55, 35 and 35% frequency ratings respectively.

Mycoflora Associated with Decomposition of Rice Stubble Mixed with Soil

Abstract: Fungi inhabiting rice stubble mixed with soil were isolated by dilution plate technique. Moisture content of decomposed rice stubble mixed with soil was 25.32% in the month of August and minimum (5.35%) in the month of April and pH varied between 6.8-7.2. The highest (47.68 x 10 4 ) fungal population in 1 g of rice stubble mixed with soil was recorded in the month of October and the lowest (16.88 x 10 4 ) in the month of May. A total of twenty-nine fungal species were recorded during the entire period of decomposition. Dueteromycetous fungi constituted 75.86 per cent of total fungal population followed by zygomycetous, oomycetous and ascomycetous fungi. Monthly variation in fungal population was correlated with substrate availability and climatic factors. Dominance of Rhi- zopus stolonifer, Aspergillus flavus and Trichoderma harzianum was recorded during the decomposition while Pestalotia mangiferae, Torula graminis and Alternaria solani were obtained as rare fungal species.

Assessment of yield loss of roselle (hibiscus sabdariffa l.) due to root-knot nematode, meloidogyne incognita under field conditions

Abstract: Root-knot nematode Meloidogyne incognita (Kofoid & White) Chitwood is an economically important pathogen of many agricultural crops, and the frequency of occurrence, abundance and importance of this nematode in resource-poor agricultural production systems make control neces- sary. Field studies were conducted in 2004 and 2005 to determine yield loss of Roselle due to natural infestation by M. incognita using Carbofuran 3G at 2 kg a.i./ha and untreated as check. The yield of Roselle was found to be higher with the application of nematicide-Carbofuran 3G at 2 kg a.i./ha. The percentage increase over control was 48.7 and 40.8% in the years 2004 and 2005, respectively. A sig- nificant reduction in the yield of Roselle in untreated plots was mainly attributed to direct damage of the root system by the feeding of root-knot nematode M. incognita. Root-knot nematode population in carbofuran treated plots was significantly lower than in untreated check in the two years, also at harvest. In the check the nematodes multiplied many folds during the cropping season. High nema- tode population in the untreated check decreased plant growth and ultimately reduced the number of seeds and weight of seeds.

Differences in Acceptability of Herb Plants and Oilseed Rape for Slugs (A. Lusitanicus, A. Rufus and D. Reticulatum) in Food Choice Tests

Abstract: The following slug species, Arion lusitanicus, Arion rufus, and Deroceras reticulatum were included in laboratory-based multi-choice food tests consisting of 19 herb plants and oilseed rape. Rates of damage to plants at the growth stage of 2-4 leaves were estimated for each slug species and all tested herb plants using oilseed rape as a reference. The following indices were calculated: ac- ceptability index (A.I.), palatability index (P.I.) and consumption index (C.I.). Based on the obtained results four groups of plants were designated: unacceptable, lowly acceptable, moderately acceptable and highly acceptable. Brassica napus, Ocimum basilicum and Coriandrum sativum were accepted by all three examined slugs while Potentilla anserina and Chamaenerion angustifolium were rejected. The ac- ceptance degree for remaining plants varied according to slug species.

Combination of Mating Disruption and Granulosis Virus for Control of Codling Moth in Bulgaria

Abstract: An application of mating disruption by use of Ecodian CP dispensers (ISAGRO, Italy) in combination with the granulosis virus product Carpovirusine 2000 (Arysta LifeScience, France) against Codling moth (CM), Cydia pomonella, was tested near Plovdiv, Central South Bulgaria. In 2007, the method was applied in an orchard where in the previous year fruit damage reached 18.7% and the CM population was high, as indicated by 3.83 diapausing larvae per tree. Carpovirusine was applied 11 times in the trial plot in combination with Ecodian CP dispensers installed twice during the season. Before harvest, fruit damage in the trial plot amounted to 0.9% and the overwintering population in autumn 2007 was only 0.46 larvae per tree. At the same time in the reference orchard, where 15 insec- ticide treatments were applied during the season, fruit damage before harvest reached 12.3% and the hibernating population was 7.97 larvae per tree. So, it has been confirmed that combination of both methods might be an effective tool for control of codling moth in the orchards with high population density and resistance to conventional insecticides. This study is being continued.