IRAQ JOURNAL OF AGRICULTURAL RESEARCH

INTEGRATED DISEASE CONTROL OF FUSARIUM WILT ON TOMATO BY COMBINATION BETWEEN Pseudomonas fluorecens AND Trichoderma harzianum UNDER
FIELD CONDITION

This study was conducted to evaluate the efficiency of seeds powder of some cruciferae plants and the biocontrol fungus Trichoderma harzianum in suppressing the pathogenic fungi under lab. And field conditions. The results showed that Seeds powder of some cruciferae plants in 2% significantly inhibited radial growth of fungal isolates AZ7, AZ4, AZ1, AZ6 and AZ5. The percentage of growth inhibition was 8.75, 57.87, 53.12, 56.25 and 57.87 respectively compared to 0% in control treatment. Results of the antagonistic ability test between the biocontrol fungus Trichoderma harzianum isolate and the pathogenic fungi AZ1-AZ5 and AZ8 isolates in the PSA culture medium, showed the superior of the biocontrol fungus isolates which gave high antagonistic that reached one degree with all the pathogenic fungi isolates. Results also showed that cabbage seed powder in 2% gave high efficiency in inhibiting of biocontrol fungus growth, the percentage of inhibition in its treatment was 88.8% compared with 0% in the control treatment. The efficiency of biological and chemical agents in protecting date palm offshoots from the infection by the two fungi Cylindrocarpon destructans AZ1 and Chalaropsis radicicola AZ4 under field condition were varied. Beltanol fungicide 1 ml/l reduced the disease severity to 41.6 and 31.3% as compared to 86.6 and 63.3% in the treatments of the two pathogenic fungi isolates AZ1 and AZ4 individually respectively. While they were 53.3 and 38.3% in T. harzianum treatment and 61.6 and 41.6% in cabbage powder treatment respectively. The combination of Beltanol and cabbage powder significantly reduced disease severity to 25% as compared with any other protecting treatments.

A study was conducted on onion downy mildew caused by Peronospora destructor (Berk.) Casp. In Agric. College, Baghdad Univ., 2004. The disease has caused up to 47.99% loss. The local red onion was more resistance to the disease than Texas Early Grano cultivor , the rate of disease increase (r) value reached 0.041-0.015 and 0.048-0.141 respectively. The pathogen infected Amarllidaceac plants Garlic, Leek and Onion with no host specificity. The primary infection was the Oospore present with plant residues. The infection appeared 15 days earlier in soil naturally infested with onion residues than the field with bean residue.

Parasitization potential of isolates of Beauveria bassiana and Verticillium lecani were evaluated against nymphs and eggs of jasmine whitefly,Aleuroclava jasmini infested citrus trees under field conditions of three different locations. Results indicated that parasitization percentages of B. bassiana on eggs and nymphs were relatively comparable to that of V. lecani with some differences between locations. The parasitization percentages of eggs were ,in general significantly lower than that of nymphs. It was found that parasitization of both fungal species tested, increased significantly with time.

The computer program SUBROUTIN D-DAY was used for calculating degree-days requirement for the initial egg hatching,various hatching percentages and first adult emergence of dubas bug Ommatissus lybicus De Berg. under the prevailing field conditions of middle of Iraq (Baghdad) for both Spring and Autumn generations of the dubas bug in 2002 in order to establish an effective forecasting system depending on thermal units (degree-days) to determine optimum spraying timing.
The results indicated that the DDs required for the initial egg hatching was 170,68 ± 11,47 and 2167.07 ± 67.35 for Spring and Autumn generations, respectively. The average DDs required for first adult emergence was 691.58 ± 20.45 for Spring generation and 3064.58 ± 121.40 for Autumn generation. The results also showed that the DDs required for eggs hatching of 10,30,50,70 and 90% were 241.87  20.07 ,411.89  26.86, 552.2  20.37, 690.28  34.66 and 922.00  40.39 for Spring generation and 2383.8  37.39, 2760.48  53.68, 3131.63  38.19 ,3328.86  44.08 and 3424.00  51.37 for Autumn generation.

Field and Laboratory studies were conducted to evaluate the predation potency and population density of the predator Clitostethus arcuatus (Rossi) (Coccinellidae: Coleoptera) on jasmine white fly Aleuroclava jasmini Takahashi on Citrus.
Establishment of laboratory culture of C. arcuatus was achieved by using eggs, movable nymphs and stationary nymphs of A. jasmini as food which is considered the main step of mass rearing, the average number of eggs and nymphs consumptive by the larva and adult of predator were recorded.
Results indicated that larvae of C. arcuatus consumed an average of 966.2, 1050 and 460 of eggs, movable and stationary nymphs respectively during one week period.
In addition, Adult predator consumed an average of 1451 eggs, 980 movable nymphs, 367 stationary nymphs and 115 adults during one week period.
Predator potential as a part of pest management was discussed and results of this study can be used in the practical application of biological control to A. jasmini on citrus.

Field studies indicated that Orius albidipennis was the most dominant predator in cotton field during the growing season of 2003 and 2004 representing 26.12% and 36% respectively. The highest density was recorded at the second week of October at an average temperature 30 and 5ºC 44% R.H. The resultes also indicated the coincidence of the presence of the predator and the spiny boll worm Earias insulana eggs.

Result indicated the efficacy of four concentration, of three lsolates (H. K. J, B-JH-T2-53 and Jordanian isolate) of Beauveria bassiana (Balsamo) Vuill were used against the larvae of Angomis grain moth Sitrotroga cerealella (Oliver).
When dipping method of rice seed in fungal isolates Suspention were used, the highest larval mortality percentage were caused by fungus concentration of 1×106 spor/ml which reached 91,90 and 90% respectively,while the lowest mortality percentage were cased by the concentration of 1×103 spor/ml (81,78,75)respectively after 15 days of treatment.
Results revealed that the treatment of empty sacks of rice seed by using the concentration 1×106 spor/ml can protect the seed against infestation by this insect for 11 months compared with untreated one. Results of statistical analysis showd that no significant differences between isolates with others, but there were signifrcant differnces between fungus concentration and treatment times.

The study of population dynamics of Jasmine white fly Aleuroclava jasmini Takahashi was studied on Grape fruit trees during seasons2004-2005 in Abu-Graeb, Baghdad.
The results was showed that population density of insect fluctuated during the months of study, due to the fluctuation temperature, relative humidity and period of growth of grap fruit. The highest population records in Spring season during April which reached 3286,1132,913 individual/80 cm² of leaves for egg, crawling instar and constant nymph instars respectively, while in Autumn season during September and October reached to 1032, 327 individual/80 cm² for eggs and crawling instar respectively.
The study show that insect was passed Winter with eggs and constant nymphs and there are seven overlapping generations in the year on grap fruit trees in Iraq.
The predators was recorded in the study includes aphid lion Chrysoperla carnae and Clitostethus arcuathus with low density during April, June, August, September and November.

The effects of two isolates of Beauveria bassiana on the natural infestation and the hibernating larvae of the corn stem borer, Sesamia cretica Led. were studied. Results revealed a significant effect of the Chinese isolate as compared with Iraqi isolate, The percentage of dead larvae in the natural infestation were 63.30 , 46.00% for the Chinese isolates where as 5.66% for the control treatment , While in the artificial infestation the percentage of dead larvae were 73.66%, 59.33% and 7.66% respectively. Results also indicated that spraying corn plants twice in the season, by the suspension of the two isolates was significantly reduced the percentages of the corn plants infestation to 9.30%, 11.0% for the natural and artificial infestations respectively, as compared with control treatment (68.80%).

Sour orange seedling were artificially infested by citrus leaf miner Phyllocnistis citrella Stainton inside net – shade house at Abou-Ghraib during 2004-2005 season .Three level 10,15 and 20 pairs of the parasitoid, Ratzebrugiola incompleta Boucek were released on those seedlings. The average period of parasitoid egg, larvae, pupae and adult stage were 1.7, 4.9, 7.9 and 14.5 day respectively.
Result showed that parasitoid females have the ability to mate and eggs lying even if they stored for 40 days under temperature of 15±2 C˚ .Releasing of males and females parasitoids at different ratio have a noticeable role in reducing the pest density inside experimental cages.

Efficiency of field released of sunn pest, Eurygaster testudinaria (Geaffroy) egg parasitoids were investigated during 2007 and 2008 seasons at kuffa county wheat fields. The results indicated natural presence of Ooencyrtus sp., O. telenomicida (Vassiliev), Telenomus chloropus Thomson, Trissolcus rafiventris (Mayer) and Gryon fulviventre (Crawford) after about one week from the appearance of the first sunn pest egg mass during April. The discovery efficiencies of the released parasitods species were higher during 2008 and reached 13.77, 9.95, 4.07and 1.67 for G. fulviventre, T. chloropus O. telenomicida and Ooencyrtus sp. respectively. The parasitism efficiency was 100% for all parasitoids species at both seasons. The total impact of these parasitoids on sunn pest population was 6.92% during 2007 and 28.93% during 2008; the highest impact was for G. fulvirvntre. The results depicted that percentage of damaged seeds reduced to 3.33-3.35% after pasrasitoides released.

A field studies were conducted to evaluate the losses caused by capsule borer Antigastra catalaunalis (Dup.) in different sesame cultivars (Babel, Rafidain, Ashtar and local cultivar) of sesame in Iraq during the season of 2001 and 2002.
The highest yield loss of seed per plant was recorded in Rafidain (22.23, 18.18%), and the lowest percentages of loss were in local cultivar (5.70, 6.19%) during 2001, 2002 respectively. The quantities of yield loss of seed per plant were 6.09 , 4.42 , 5.70 and 1.16 gm / plant for the season 2002 in the cultivars Rafidain, Babel, Ashtar and local cultivar respectively. The result of field study have showed that the cultivars Babel and Rafidain were more susceptible to infestation by sesame shoot webber in comparison with Ashtar and Local cultivars for the two season (2001, 2002) according to the number of larvae and percentage of infestation recorded on these cultivars.

Laboratory and field studies were conducted to evaluate the susceptibility of 10 corn hybrids recently introduced from Texas - USA to Iraq to infestation by the stem borer Sesamia cretica Led. During the spring and fall season of 2005. Preference and Non-preference and Antibiosis were used as criteria in this experiment to evaluate their susceptibility to the stem borer. Results indicated that their was significant differences in females preference to lay eggs on the seedlings. The lowest percentage of eggs were laid on the seedlings of hybrids MSI 4328 and MSI 4391 )3.13, 3.5( for the spring and fall seasons of 2005 respectively, which was significanty different from the highest numbers laid on hybrid MSI 4148 (8.01, 8.71) respectively. There were no significant differences in terms of larval weight and peroids. The larval fed on these hybrids were ranged from 95-156 mg /larvae and 26-33 days respectively. The lowest survival rates of 50% were observed for the larvae fed on the hybrid MSI 4387 compared to 98 % for the local hybrid IPA 5012. The lowest growth index was 1.08 observed for the hybrid MSI 4387 which was similar to that of the well known tolerant hybrid IPA 3001.
Weight of pupa emerged from larvae fed on hybrids MSI 4387 and MSI 4317 were 50.6 and 77.0mg which significantly different from those fed on the local cultivars IPA 5012 and IPA 3001 (127.47) and (106.47) mg respectively. The lowest peroids 4 days obsered for larvae fed on hydrid MSI 4387 which was significantly different from larvae fed on other hybrids. Furthermore, adlults emerged from these pupae were small, weak, with slow motion and died after 3-4 days from their emergence. Therefore, it could be concluded that these impressive results encourge to do more field studies on hybrid MSI 4387 to determine its tolerance to the stem borer.

This study was conducted at the fields of College of Agriculture in Abu-Ghraib, to investigate the effect of spray of foliar fertilizer Nabata - LTB on the population density of the broad mite, Polyphagotarsonemus latus on potato plants, during the fall season of 2007-2008. Potato plants were sprayed at the age of 4-5 true leaves, followed by three successive applications of ten days interval. Results indicated that the numbers of eggs, larvae and adults were significantly different in some treated plants. The number of broad mite in 6th week of plant age was 8.66, 5.66, 9.33 eggs, larvae, adults/leaf respectively in control. Moreover, the higher density for eggs, larvae, and adults 23.00, 15.66, 19.66 eggs, larvae, and adults was in the 8th week of plant age. In the 14th week the density was reduced as the plant get 0.66, 0.66, 0.33 eggs, larvae, and adults respectively.

Bracon hebetor Say is an important ectoparasitoid of many lepidopterous larvae particularly those of the fig moth Ephestia cautella in dry date stores and the spiny bollworm Eraias insulana in the field.
Laboratory studies revealed that the parasitism and paralyzation percentages of both host larvae were different, which being 83.7 and 93.3% for E. cautella in normal and opened dry dates while 15.3 and 45.6% for Eraias insulana in normal and opened cotton bolls respectively.
A trial for mass rearing and releasing this parasitoid for the purpose of controlling the spiny bollworm in cotton fields was undertaken at two different regions (Baghdad and Diala). Filed survey revealed that the parasitoid was responsible in the reduction of 50% of infestation rate at the two localities which being 2.9 and 2.5% for the treatments while 6.1 and 4.8% for the control respectively.

This study was conducted to determine the efficiency of six isolates of Paecilomyces lilacinus as biocontrol agent for Rhizoctonia solani. Culture of filtrate of the six isolates induced significant reduction in growth and dry weight of R. solani biomass.The isolates PL3 and PL4 wer e superior in reducing the radial growth of R. solani (2.26, 1.55 cm ) as compared to the control treatment (5 cm). Isolates PL3 and PL4 induced significant decrease in dry weight of R. solani biomass (0.07, 0.12 gm) respectively as compared to the control treatment (0.63 gm). Under plastic house conditions soil treatment with P. lilacinus significantly reduced infection of tomato plants .Isolate PL3 showed the highest ability in reducing the percentage of pre and post emergence infection (26.66%) as compared to the control treatment (86.66%). Under field conditions all tested isolates of P. lilacinus significantly reduced both disease incidence and severity of tomato infection by R. solani, isolate PL3 was the superior in reducing both disease incidence and severity (29.90%, 0.14) as compared to control treatment (83.16%, 0.59) respectively.

The study included control sour orange root-rot disease caused by Fusarium solani by using some biocontrol and chemical agents compounds. Results of several treatments to control the fungus Fusarium solani under greenhouse conditions showed the efficiency of the biofungicide Biocont, the bacteria Bacillus subtilis and the Beltanol fungicide individually in decrease disease severity to 0% and revealed significant increase in the mean shoots and roots length and dry weight, Acibenzolar-S-Methyl treatment gave significant reduction in disease severity to 25%, compared to 75% in the control treatment (pathogenic fungus only). Results of the field experiment showed that Biocont and B. subtilis alone or in combination with foliar spraying with ASM solution gave significant reduction in disease severity to 25% as compared with 87.5% in the control treatment, in addition to that significant increase were recorded in sour orange seedlings growth parameters (plants height, branches number and the shoots and roots dry weight) in all tested control agents. The Beltanol fungicide showed significant decrease in disease severity similar to that caused by Biofungicide Biocont and the bacteria B. subtilis, and revealed significant increase in plant height, branch, numbers and shoot and root dry weight which were reached 52.3cm, 3.75branch, 11.24gm and 4.53gm respectively compared with the control. The treatment of ASM showed reduction in disease severity when used in the presence of the pathogenic fungus to 50% compared to 87.5% in the control treatment.

A study was conducted to evaluate the pathogenicity of entomopathogenic: fungi Beauveria bassiana (sixe isolates), Verticillium lecanii: fungi Fusarium solani, Penicillium sp., Aspergillus sp. and Paecillomyces sp as biocontrol agents for controlling Blattela germanica under laboratory condition. Results indicated that all entomopathogenic fungi appeared to be a good biocontrol agents its efficacy varied according to the fungi species and insect stage while early instars more effective late instars .Isolate Bb1, Bb3, Bb4 and Bb6 showed the highest percentage of parasitism (100%) on different instars after 8 days, compared with other treatments under controling condition .Toxic baits of isolates Bb1, Bb3, Bb4 and Bb6 induced highest percentage of mortality after 15 days of application under non controlling condition.

The green apple aphid, Aphis pomi (DeGeer) remains a real threat for apple and causes huge damage in spite of the annual pesticide application conducted against this pest. The biological methods have been used against economic insects. Two fungi were isolated from naturally infected green aphids collected from apple leaves in AL- Saniya region, Al-Qadisiya district–Iraq. The identified fungi were Alternaria porri and Fusarium sp. The effect of these two fungi on the apple leaf aphids was evaluated during the spring season -2002. A suspension of the fungal spores at the concentration of 3.5 x 105 spores / ml was sprayed weekly on the apple leaves infested with aphids from the first week of March until the third week of April, 2002. It was found that the average mortality of aphids on the treated leaves with A. porri were ranged between 52.4% and 93.3%, and with Fusarium sp. were between 21.5% and 39.6%, as compared with control (water treatment) which were between 11.4% and 23.3% in March and April-2002 respectively. The field results were confirmed with a laboratory experiment, in which the average mortality of aphids on the treated leaves with A. porri was 95.2% and with Fusarium sp. was 43.4% as compared with control which was 32.6%.

This study was carried out in fields of College of Agriculture, Abu-Gharib during autumn season 2000 to evaluate the activity of some insecticides in controlling cotton leaf-worm on potato crop (deseri variety). Results showed that the insecticides Fastak, Carbaryl and Presor were very effective in reducing the population density of larvae after 1, 3 and 7 days after application but the efficiency was reduced after 14 days. Although the chitin inhibitor Match was low activity in reducing larvae population after 1 and 3 days, Match showed higher activity after 7 and 14 days. The mixture of Presor and Match gave good results after two weeks of treatment, however the mixture of presor and Fastac achieved the best control of larvae compared when used each one alone. Regarding natural enemies results indicated presence of two species of porasitoides Exorista sp. (Diptera: Tachanidae) and another unidentified species belongs to Ichenumonidae and presence of two predators the wasp Ammophilla sp. (Hymenoptera: Sphicidae) and unidentified species of ant. Also the virus NPV was recorded on larvae of th e insect. According to the results of this study it can be recommended for controlling cotton leaf-worm to apply the insecticides at the first stages of plant and depend on natural enemies at late stages of plant.

The purpose of this study was to evaluate the compatiblity of the insecticide, Avaunt and the biocontrol agent B. bassiana in control cotton leaf worm Spodoptera littoralis. Results revealed a considerable compatibility between Avaunt and B. bassiana, the effective concentration (EC50) of Avaunt to the biocontrol agent was 275 mg/L. However Avaunt was active against the insect at rate of 10.5 mg ai/ L when combined with the biocontrol agent. Laboratory studies showed that larval stages were the most susceptible to Avaunt, which caused 100% mortality at first and third instar within 5 days while such percentage of control was achieved within 7 days after treatment for the 5th instar. Slow the activity of biocontrol agent B.bassiana against larvae was slow after treatment, however the percentage of mortality reached 100% at 14th days after application. There was no significant difference between the treatment of Avaunt at a half rate in combination with the biocontrol agent and treatment of Avaunt. The combination of Avaunt with biocontrol agent caused complete mortality for larval stages at the 7th day while treatment of Avaunt achieved complete mortality at the 5th day, Therefore the combination treatment of Avaunt with the Biocontrol agent was the best treatment because it reduced the quantity of insecticide that caused environmental pollution and caused the compelet mortality for larval stages after 7th day of treatment. It can be concluded that the application of Avaunt can be recommended in IPM program to control cotton leaf worm without harmful effect on the biological agent B.bassiana.

This study was conducted to evaluate the efficacy of isolates entomopathogenic fungi: five isolates of Beauveria bassiana, Verticillium lecani, Paecilomyces Sp. as biocontrol agents of termites Microceroterms diversus under laboratory and field condition. Labortory and field results indicated that the all entomopathologenic fungi showd highly effective in percentage of killing compared with control treatment, isolate Bb1, Bb6 showd highly percentage of killing 100% in laboratory and field trials after 10, 30 days after treatment respectively compared with the other fungal isolates.