ENHANCEMENT OF GROWTH OF ONION (ALLIUM CEPA L.) BY BIOLOGICAL CONTROL AGENT TRICHODERMA SPP

2001 ◽  
Vol 49 (4) ◽  
pp. 393-395 ◽  
Author(s):  
E. PAYGHAMI ◽  
S. MASSIHA ◽  
B. AHARY ◽  
M. VALIZADEH ◽  
A. MOTALLEBI

The effect of Trichoderma harzianum and Trichoderma viride (isolated from mycoflora in the rhizosphere of onion) in increasing the growth of onion was studied in a completely randomized design in pots with 12 replications under greenhouse conditions at 21°C with a 12-h light/dark cycle (fluorescent and incandescent lighting). The biological control of Sclerotium cepivorum Berk, the causal agent of white rot of onion, was also investigated in this experiment. The addition of Trichoderma spp. to autoclaved soil (inoculation of 2/3 of the top soil in the pots with 4% (v/v) inoculum of T. harzianum and T. viride) significantly increased the growth and fresh weight of the onion plants (P=1%). The biological control of S. cepivorum was achieved with T. harzianum and T. viride, but no significant difference was observed between the two species.

2004 ◽  
Vol 57 ◽  
pp. 72-76 ◽  
Author(s):  
K.L. McLean ◽  
S.L. Dodd ◽  
B.E. Sleight ◽  
R.A. Hill ◽  
A. Stewart

The biocontrol isolate Trichoderma atroviride M1057 and a transformed hygromycin resistant biotype (M1057hygR) were compared using biological control rhizosphere competence and antibiosis studies to determine whether the transformed biotype performed in a similar manner to the wildtype strain In an onion growth chamber trial using soil naturally infested with the onion white rot pathogen Sclerotium cepivorum there was no significant difference (P>005) in the level of disease control given by the two T atroviride strains Similarly populations of T atroviride M1057 and M1057hygR were equivalent (P>005) in the rhizosphere of onion seedlings There was no significant difference (P>005) between the mycelial growth rates of S cepivorum when grown on agar amended with culture filtrate of T atroviride M1057 and M1057hygR Thus T atroviride M1057hygR has similar biological attributes to the wildtype isolate and can be used in future field studies looking at the population ecology of the biological control agent


2017 ◽  
Vol 114 ◽  
pp. 114-124 ◽  
Author(s):  
Daniel C. Burcham ◽  
Nelson V. Abarrientos ◽  
Jia Yih Wong ◽  
Mohamed Ismail Mohamed Ali ◽  
Yok King Fong ◽  
...  

2020 ◽  
Vol 113 (4) ◽  
pp. 1735-1740
Author(s):  
Md Arefur Rahman ◽  
Souvic Sarker ◽  
Eunhye Ham ◽  
Jun-Seok Lee ◽  
Un Taek Lim

Abstract The polyphagous predator Orius species is a dominant predator of thrips, mites, and aphids. Orius laevigatus (Fieber) is a well-known commercialized and effective biological control agent, whereas Orius minutus (L.) distributed widely over the world has not been commercialized. To assess potentials of developing O. minutus as a commercial biological control agent, we compared the biological parameters of O. minutus with O. laevigatus when reared on mixed stages of Tetranychus urticae Koch at 27.5°C. Nymphal development of O. laevigatus was shorter (11.30 d) than that of O. minutus (12.25 d), but there was no significant difference in survivorship between the two species. Also, no significant difference was found in either the preoviposition or oviposition periods, lifetime fecundity, or longevity between the two species. However, O. minutus eggs had a higher hatch rate (0.77) than O. laevigatus (0.71). In life table analysis, no difference was found in any parameters, i.e., R0, rm, λ, T, and DT, between O. laevigatus and O. minutus in two-tailed t-tests. In a predation bioassay, O. minutus consumed 1.39 times more adult T. urticae in 24 h than did O. laevigatus, although the predation rate on T. urticae eggs was similar between the two species. These results suggest that O. minutus native to Korea could be developed as a biological control agent against T. urticae.


2017 ◽  
Vol 16 (2) ◽  
pp. 115
Author(s):  
Johanna Taribuka ◽  
Christanti Sumardiyono ◽  
Siti Muslimah Widyastuti ◽  
Arif Wibowo

Exploration and identification of endophytic Trichoderma in banana. Endophytic fungi Trichoderma is an organism that can used as biocontrol agent. This study aims to isolate and identify endophytic Trichoderma in roots of healthy banana plants from three districts in Yogyakarta, which will be used as biological control agent against the pathogen Fusarium oxysporum f.sp. cubense. Isolation was conducted using TSM (Trichoderma Selective Medium). We obtained six isolates of endophytic Trichoderma spp., i.e., Swn-1, Swn-2, Ksn, Psr-1, Psr-2, and Psr-3. Molecular identification was done by using ITS1 and ITS2 primer pain and sequenced. The sequence of DNA obtained was analysed and compared with NCBI database by using BLAST-N programe. The results showed that all isolates were amplified at 560-bp. Phylogenetic analysis showed that isolates Swn-1, Swn-2 and Psr-1 are homologous to Trichoderma harzianum, isolate Ksn homologous to Trichoderma asperrellum, isolate Psr-2 homologous to Trichoderma gamsii, and isolate Psr-3 homologous to Trichoderma koningiopsis, with the homologous value of 99%.


HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 262-266 ◽  
Author(s):  
Ken K. Ng ◽  
Leslie MacDonald ◽  
Zamir K. Punja

The efficacy of Tilletiopsis pallescens Gokhale, a naturally occurring ballistosporeforming yeast isolated from mildew-infected leaves, was evaluated as a biological control agent against rose powdery mildew [Sphaerotheca pannosa (Wallr.:Fr.) Lév. var. rosae Woronichin]. Two trials were conducted on potted rose (Rosa sp.) plants (1-year-old cv. Cardinal Pink) under commercial greenhouse-growing conditions during the summer (June to September) when mildew was most severe. Mildew-infected plants were subjected to one of four treatments: a T. pallescens spore suspension applied three times (3–4 d apart), distilled water (applied three times), one application of T. pallescens spore suspension, or one application of culture filtrate without spores. Two weeks after treatment began, mildew development was evaluated by enumerating conidial density on sampled leaflets. Sporulation was significantly reduced (by 97%–98%) on plants treated with three applications of T. pallescens spore suspension, compared to a 47%–57% reduction on plants treated with three applications of distilled water. There was no significant difference in conidial density between plants treated with one application of T. pallescens spore suspension and plants treated with one application of its culture filtrate, with a 78%–94% reduction in conidia, which was significantly higher than for the water treatment. The mode(s) of action of T. pallescens appears to be eradicant and associated with enzymes or metabolites produced in the culture filtrate. The results from this study demonstrate the potential for biological control of rose powdery mildew under commercial growing conditions in British Columbia.


Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 426
Author(s):  
Ashley Toland ◽  
Holly Wantuch ◽  
Donald Mullins ◽  
Thomas Kuhar ◽  
Scott Salom

The hemlock woolly adelgid, Adelges tsugae Annand, is an invasive insect that threatens hemlock species in eastern North America. Several species from the genus Laricobius are predators of A. tsugae in its native areas of Asia and the western United States. Two Laricobius species have been released as biological control agents: Laricobius nigrinus Fender, and Laricobius osakensis Montgomery and Shiyake. Laricobius rubidus LeConte is an adelgid predator native to the Eastern United States, where it can feed and complete development on A. tsugae opportunistically. Laboratory assays were conducted to assess the cold hardiness of these three Laricobius species, including two distinct populations of L. osakensis, by measuring the supercooling points of each species from November 2016 through March 2017. This information may be useful for choosing the best-suited biological control agent for a particular region to control A. tsugae. There was a significant difference between the overall mean supercooling point of L. rubidus compared to the other Laricobius spp. There were also significant differences of supercooling points between L. rubidus and both strains of L. osakensis in January, and significant differences between L. rubidus and all other strains in February. L. rubidus appear better adapted to cold extremes in the eastern U.S. than imported Laricobius spp.


Sociobiology ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 477 ◽  
Author(s):  
Matheus Montefusco Oliveira ◽  
Flávia Batista Gomes ◽  
Alexandre Somavilla ◽  
Cristiane Krug

Wasps of the genus Polistes (Vespidae: Polistinae) are eusocial, considered valuable biological control agents. The objective of this work was to determine the resources collected by Polistes canadensis wasps, evaluate their performance and importance as a natural enemy and possible agent of biological control in the Brazilian Amazon. Between 8 October and 20 November of 2014, 20 evaluations were performed, totalizing 101 hours of observations of the foraging activity of an aggregation out in stage of development post-emergence with approximately 50 adult individuals distributed in 15 colonies. Additionally, observations of the predatory activity of Polistes canadensis on Plutella xylostella on a small organic plantation of kale (Brassica oleracea L. var. acephala DC), were also made. During the evaluations 1742 returns were recorded, 11.72% of them with prey, 3.10% with plant fiber, 16.76% with nectar, 45.17% with water and 23.25% without any visible load. All the preys identified were classified as Lepidoptera, belonging to ten morphospecies. Only one morphospecies was identified as Spodoptera frugiperda, which was the most commonly resource used by the wasps in 37 % in immature feeding. Only returns with nectar had statistically significant difference between the evaluated schedules.  Polistes canadensis wasps did not prey Plutella xylostella caterpillars. The wasp aggregation studied was able to prey an average of 10.2 caterpillars per day, which demonstrates the potential of this species for the biological control of pests in the Amazon region.


Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1210-1216 ◽  
Author(s):  
Chuanxue Hong ◽  
Themis J. Michailides ◽  
Brent A. Holtz

The effects of wounding, inoculum density, and three isolates (New, Ta291, and 23-E-6) of Trichoderma spp. and one isolate (BI-54) of Rhodotorula sp. on postharvest brown rot of stone fruits were determined at 20°C and 95% relative humidity (RH). Brown rot was observed frequently on wounded nectarine, peach, and plum fruits inoculated with two spores of Monilinia fructicola per wound, and occasionally on unwounded nectarine and peach fruits inoculated with the same spore load. Brown rot was observed on wounded plums only. A substantial increase in lesion diameter of brown rot was also recorded on wounded nectarines and peaches inoculated with suspensions of ≤20 spores and ≤200 spores per wound, respectively, compared with unwounded fruit. At concentrations of 107 and 108 spores per ml, all Trichoderma isolates substantially reduced brown rot on peaches (63 to 98%) and plums (67 to 100%) when fruits were inoculated with M. fructicola following the application of a biological control agent. Similarly, at 108 spores per ml, the yeast BI-54 also suppressed brown rot on peaches completely and on plums by 54%. Significant brown rot reduction was also achieved with the isolate New at a concentration of 108 spores per ml, even when the biocontrol agent was applied 12 h after inoculation with M. fructicola and under continuous conditions of 95% RH. The isolates Ta291 and 23-E-6 also reduced brown rot significantly under drier (50% RH) incubation conditions. These isolates provided the best control of brown rot on plums when they were applied 12 h earlier than inoculation with M. fructicola. Satisfactory control of brown rot on plums inoculated with M. fructicola at 8 × 104 spores per ml was achieved with New at 106 spores per ml and with Ta291 at 107 spores per ml. Measures taken to avoid injuring fruit will greatly reduce brown rot of stone fruit at any spore load for plum, but only at ≤50 spores per mm2 for peach, and at ≤5 spores per mm2 for nectarine. This study identifies two isolates (Ta291 and New) of Trichoderma atroviride, one isolate (23-E-6) of T. viride, and one of Rhodotorula sp. that show potential for further development as biocontrol agents of postharvest brown rot of stone fruits.


2015 ◽  
Vol 106 (3) ◽  
pp. 322-327 ◽  
Author(s):  
T. Kemmochi ◽  
S. Fujimori ◽  
T. Saito

AbstractThe koinobiont parasitoid Halticoptera circulus (Walker) is a potential biological control agent of leafminers, but it has only rarely been collected from the invasive leafminer, Liriomyza trifolii (Burgess), in Japan. To understand why this is the case, parasitism and development of H. circulus in L. trifolii was compared with parasitism and development in two indigenous leafminer species, Liriomyza chinensis Kato and Chromatomyia horticola (Goureau). There was no significant difference in parasitism rates by H. circulus in the three leafminer species and the eggs and larvae successfully developed in L. chinensis and C. horticola. However, H. circulus failed to develop in L. trifolii, where developmental stages were encapsulated by host haemocytes. This parasitoid may be a good agent to control indigenous leafminers such as L. chinensis and C. horticola but is unlikely to be useful for the biological control of the invasive L. trifolii in Japan.


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