Isolates of Trichoderma spp., a soil fungus, has been used to control diseases and promote plant growth, reducing the use of chemicals in the production of seedlings of different plant species. We evaluated the effect of some Trichoderma spp. isolates on seed treatment and seedling production of Theobroma cacao. Five isolates from the Amazon region were tested. In laboratory, the following variables were evaluated for seed treatments: germination, germination speed index, radicle and hypocotyl lengths, and fungi incidence. In nursery, the following forms of application were tested: via seeds; in the substrate at pre-planting; monthly in post-planting substrate, and also their combination. The following was evaluated: height, diameter, number of leaves, root length, leaf area, and shoot dry mass and root system. Inoculation with Trichoderma increased the length of the radicle and hypocotyl and showed no fungi in the seeds. In seedlings, some treatments increased height and plant root dry mass. The use of Trichoderma was beneficial for seeds and appeared favorable for T. cacao production.
Treatment | Germination (%) |
SG | Radicle (cm) |
Hypocotyl (cm) |
Incidence of Fungi (%) |
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Control | 97.0 | ab | 58.3 | a | 1.2 | c | 1.3 | ||
15.8 | |||||||||
Treatments | Height | Collar Diameter | Number of Leaves | Aerial DM |
Root DM |
Root Length | Leaf Area | ||||||||||||||||||||
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3rd month | 6th month | 3rd month | 6th month | 3rd month | 6th month | ||||||||||||||||||||||
Tc applied to seeds | 26.0 ns | 27.9 ns | 5.4 ns | 6.2 ns | 7.7 ns | 9.3 ns | 2.8 ns | c | 1.9 ns26.5 | ||||||||||||||||||
49.1 | ns | 613.1 | ns | Trichoderma sp. Tc | 98.0 | ||||||||||||||||||||||
Tc applied to pre-planting substrate | a | 24.9 ns29.5 | 61.7 | 29.6 nsa | 5.2 | abAns | 31.2 | aA4.3 | a | 2.6 | a | 6.4 0.0 | |||||||||||||||
ns | 7.5 | ns | 10.6 | ns | 3.3 | ns | 2.0 | ns | 54.4 ns | 437.7 ns | 29.7 | bA | 31.3 | abA | 30.2 | aA | Trichoderma sp. Tce | 97.5 | b | 61.7 | a | ||||||
Tc applied monthly to post-planting substrate | 25.7 ns | 30.3 ns | 5.7 ns | 6.5 | 4.2 | a | 2.2 | ab | 0.0 | ||||||||||||||||||
ns | 7.8 | ns | |||||||||||||||||||||||||
Monthly Aplication | 12.7 | ns | 4.1 | ns | 2.2 | ns | 3 | 47.0 | 30.3ns | abAB | 30.6 | aAB | 34.2 | aA613.1 ns | 29.4 | bB | 29.9 | aAB | T. asperellum Tam01 | 96.5 | ab | 61.9 | a | 4.1 | a | 2.3 | ab |
Tc seeds + substrate + monthly | 0.0 | ||||||||||||||||||||||||||
28.2 | ns | 32.3ns | 5.5 ns | 6.3 ns | 8.8 ns | 11.2 ns | 3.3 ns | 2.1 ns | 54.9 ns | 448.7 ns | T. asperellum Tam02 | 98.0 | a | ||||||||||||||
Tce applied to seeds | 54.4 | a | 3.2 | b | 1.6 | bc | 27.0 ns | 0.0 | |||||||||||||||||||
30.4 | ns | 5.2 | ns | 6.4 ns | 7.2 ns | 10.3 ns | 3.6 ns | 2.3 ns | 51.1 ns | 551.8 ns | T. asperellum Tam03 | 95.0 | b | 52.6 | a | 3.1 | b | ||||||||||
Tce applied to pre-planting substrate | |||||||||||||||||||||||||||
Seed + Subs. + Mon.Ap. 4 | 32.3 | aA | 31.0 | aA | 31.5 | abA | 32.4 | abA | 31.1 | aA | |||||||||||||||||
CV (%) 10.5 | 26.5 ns | 31.2 | 2.4 | ns | a | 0.0 | |||||||||||||||||||||
5.2 | ns | 6.2 | ns | 8.0 | ns | 10.2 ns | 3.0 ns | 1.8 ns | 51.7 ns | 539.1 ns | CV(%) | 1.3 | 7.7 | ||||||||||||||
Tce applied monthly to post-planting substrate | 24.5 ns | 30.6 ns | 5.0 ns | 6.2 ns9.8 | 8.8 ns | 11.1 ns | 3.4 ns | 2.0 ns | 54.9 ns | 438.6 ns | |||||||||||||||||
Tce seeds + substrate + monthly | 26.0 ns | 31.1 ns | 5.4 ns | 6.3 ns | 9.0 ns | 10.5 ns | 3.6 ns | 2.3 ns | 52.8 ns | 413.6 ns | |||||||||||||||||
Tam01 applied to seeds | 26.9 ns | 32.3 ns | 5.4 ns | 6.7 ns | 8.5 ns | 11.0 ns | 3.6 ns | 1.9 ns | 52.3 ns | 514.1 ns | |||||||||||||||||
Tam01 applied to pre-planting substrate | 26.8 ns | 29.8 ns | 5.1 ns | 6.0 ns | 8.0 ns | 10.6 ns | 2.8 ns | 1.9 ns | 53.4 ns | 380.6 ns | |||||||||||||||||
Tam01 applied monthly to post-planting substrate | 30.0 * | 34.2 * | 5.0 ns | 6.5 ns | 8.7 ns | 11.8 ns | 3.8 ns | 1.8 ns | 50.0 ns | 585.5 ns | |||||||||||||||||
Tam01 seeds + substrate + monthly | 27.6 ns | 31.5 ns | 5.8 ns | 6.6 ns | 9.5 ns | 11.1 ns | 3.4 ns | 2.8 * | 55.2 ns | 559.2 ns | |||||||||||||||||
Tam02 applied to seeds | 27.9 ns | 34.3 * | 5.2 ns | 6.3 ns | 8.8 ns | 11.2 ns | 3.4 ns | 1.7 ns | 59.6 ns | 529.9 ns | |||||||||||||||||
Tam02 applied to pre-planting substrate | 25.7 ns | 31.4 ns | 5.2 ns | 6.2 ns | 8.6 ns | 11.5 ns | 3.9 ns | 2.1 ns | 61.9 ns | 491.4 ns | |||||||||||||||||
Tam02 applied monthly to post-planting substrate | 27.3 ns | 29.4 ns | 5.1 ns | 6.1 ns | 7.8 ns | 9.2 ns | 2.9 ns | 1.6 ns | 53.1 ns | 442.2 ns | |||||||||||||||||
Tam02 seeds + substrate + monthly | 28.8 ns | 32.4 ns | 5.5 ns | 6.5 ns | 8.8 ns | 9.6 ns | 3.5 ns | 2.1 ns | 56.1 ns | 464.0 ns | |||||||||||||||||
Tam03 applied to seeds | 25.8 ns | 28.3 ns | 5.3 ns | 6.2 ns | 7.8 ns | 9.6 ns | 3.2 ns | 2.0 ns | 43.6 ns | 494.4 ns | |||||||||||||||||
Tam03 applied to pre-planting substrate | 26.5 ns | 30.2 ns | 5.3 ns | 6.3 ns | 7.2 ns | 10.3 ns | 2.8 ns | 1.5 ns | 53.2 ns | 425.4 ns | |||||||||||||||||
Tam03 applied monthly to post-planting substrate | 27.0 ns | 29.9 ns | 5.2 ns | 6.0 ns | 7.7 ns | 10.7 ns | 3.3 ns | 1.7 ns | 51.1 ns | 422.8 ns | |||||||||||||||||
Tam03 seeds + substrate + monthly | 26.8 ns | 31.1 ns | 5.5 ns | 6.4 ns | 7.8 ns | 9.2 ns | 3.1 ns | 1.9 ns | 56.4 ns | 385.1 ns | |||||||||||||||||
Control | 25.6 | 28.4 | 5.1 | 6.0 | 7.6 | 10.7 | 3.4 | 1.7 | 51.5 | 484.1 | |||||||||||||||||
Coefficient of Variation (%) | 9.9 | 10.5 | 10.4 | 11.4 | 18.6 | 22.1 | 28.0 | 31.9 | 23.2 | 20.7 |
Modes of Application | Trichoderma Isolates | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Tc | Tce | Tam01 | Tam02 | Tam03 | ||||||
Seeds 1 | 27.9 | bB | 30.3 | aAB | 32.3 | abAB | 34.3 | aA | 28.2 | aB |
Substrate 2 |