SEMNAS Hortikultura Buku 2 - Departemen Pertanian

Application of Chemical and Bio-Fertilizers in Relation to String Bean (Phaseolus vulgaris L.) Yield and Soil-Borne
Pathogen
Mulyadi, Pustika, A. B. and Iswadi, A
Verticillium and Thielaviopsis and various nematodes by AM fungal colonization of the plant root.
Slezack et al. (1999) also reported that A. euteiches infection could be suppressed by Glomus
fasciculatum AM. Until now, several potential mechanisms have been described concerning bioprotection
by AM fungi, including improvement of plant nutrition, damage compensation,
competition for photosynthates, competition for colonization or infection sites, anatomical or
morphological modifications of the root system, induction of changes in mycorrhizosphere microbial
populations, are cell wall modifications, enhancement of secondary metabolism, and accumulation of
proteins including pathogenesis-related (PR) proteins. It has been suggested that AM symbiosis could
predispose the plant to respond more rapidly to pathogenic attacks of the roots (Gianinazzi, et al.,
1992). In a time-course study of the symbiotic interaction between bean roots and G. mosseae and
Fusarium solani, covering all stages of mycorrhiza development, Mohr et al. (1998) detected a
changing of the expression of the defense-related genes chitinase, -1,3-glucanase and phenylalanine
ammonia-lyase compared with non-mycorrhizal control roots.
The Effect of Bio-fertilizers on Soil borne Pathogens Inoculums
Fusarium spp. and Ralstonia spp. are well known as the common soil borne pathogens that
can cause wilt disease on most plants. Therefore, decreasing of the inoculums population of those soil
borne pathogens will be potential to reduce wilt disease attack on the plants. During the string bean
cultivation period, it has been observed on the population change of the two soil borne pathogens and
the results as presented in Table 5.
Table 5. The change of Fusarium spp. and Ralstonia spp. in the soil before and after applying biofertilizer
during string bean cultivation period
Biofertilizer
Treatment
Fusarium spp. Inoculums
(cfu/g of soil)
Ralstonia spp. Inoculums
(cfu/g of soil)
Before At Harvest Reduction Before At Harvest Increasing
Planting
Planting
E1 14.999 0.111 14.889 a 8.333 8.667 0.334
E2 21.111 1.667 19.444 a 6.222 7.444 1.222
MU 8.000 0.889 7.111 b 4.222 6.000 1.778
MC 21.555 1.667 19.888 a 5.889 9.778 3.889
Control 18.667 14.778 3.889 b 6.111 13.333 7.222
Remark: * reduction or increasing population based on early value before planting
The result in Table 5 indicated that during the string bean cultivation period, there was
significant reduction on Fusarium spp. inoculums in the soil treated with the bio-fertilizers. The
decreasing of Fusarium spp. inoculums as a result of E1, E2 and MC application was significantly
higher than MU and Control during string bean cultivation period. In contrast, microbial consisted in
the three bio-fertilizers could not reduce the inoculums of Ralstonia spp. It has been suggested that
AM symbiosis could not predispose the plant to respond pathogenic bacterial attacks of the roots
because there were no competition for colonization or infection sites between microbial fungi (biofertilizer)
applied and pathogenic bacterial in soil. In spite of no infection site competition, it has been
suggested that the defence-related genes chitinase, -1,3-glucanase and phenylalanine ammonia-lyase
produced by mycorrhizal roots (Mohr et al., 1998) was failed to be worked against bacterial
inoculums which do not have chitin as much as pathogenic fungi (Goodman et al., 1986).
CONCLUSIONS
Application of N, P, and K source chemical fertilizers with the rate of 23 kg N + 54 kg
P 2 O 5 +60 kg K 2 O/ha (100 kg of Urea+150 kg of SP36+100 kg of MOP/ha) could increase the pod
yield of string bean planted on the soil developing from volcanic sediment in the medium altitude land
while addition of bio-fertilizers tested in this research did not influence to the crop yield.
The application of tested bio-fertilizers (Emas, MU and MycoApplyTM Micronized endo) has
potential effect in suppressing Fusarium spp. inoculum in the soil during string bean cultivation
period but they could not suppress to Ralstonia spp. inoculum. Emas, MU and MycoApplyTM
96│
Prosiding SeminarNasional Pekan Inovasi Teknologi Hortikultura Nasional: Penerapan Inovasi Teknologi Hortikultura
dalam Mendukung Pembangunan Hortikultura yang Berdaya Saing dan Berbasis Sumberdaya Genetik Lokal,
Lembang, 5 Juli 2012