Similarly, the weight losses of cormels were least in (T7).
DISEASES
Study on severity of leaf blight in colocasia Out of six colocasia (taro) genotypes (Table 2), the highest yield was recorded from ML-1(22.13 t/ha) followed by ML-9 (19.13 t/ha) with least incidence of leaf blight 20.17% and 20.83%, respectively. However, the disease severity was highest in the genotype Megha-1 throughout the growing season.
Table 2 Severity of leaf blight in colocasia
Varieties Yield Leaf Disease severity index (t/ha) blight
(%) 2 4 6
(60 (120 (180 DAP)* DAP) DAP)
ML-1 22.13 20.17 14.58 22.92 35.42
ML-2 18.68 22.92 12.50 18.75 27.08
ML-9 19.13 20.83 10.42 18.75 29.17
Megha-1 17.51 45.83 20.83 33.33 50.00
BCC-1 12.51 31.25 14.58 25.00 39.58
Meghalaya local 17.00 22.92 12.50 18.75 27.08
S.E. (m) 1.28 2.90 3.18 1.86 2.46
CD (P=0.05) 2.85 6.46 7.09 4.14 5.48
* DAP: Days after planting
Only Mancozeb 63% + carbendazim 12% @ 4 g/L was effective in managing the Taphrina leaf spot disease but yield differences were non significant when compared to untreated check (Table1).
Table 1 Management of Taphrina maculans leaf spot disease of turmeric
Treatment PDI Yield of
(arc fresh sine rhizome values) (t/ha)
RCHE221 @ 2ml/L 53.70 15.2
Trichoderma viride @ 5g/L 63.50 15.8
Panchagavya @ 30mL/L 54.50 15.0
Mancozeb 63% + carbendazim12% 47.10 17.9
@ 4g/L
Untreated check 66.30 16.3
CD (P= 0.05) 12.04 NS
CV (%) 13.70 16.4
GINGER
Study on genotype x environment interaction on quality
Ten ginger (Zingiber officinale) genotypes were evaluated. All the genotypes were affected by soft rot.
Among the genotypes, highest plant height was found in Himgiri (62.30 cm) followed by Nadia (56.50 cm).
The yield per plant was highest in Suprabha (255.0 g) followed by Mahima (225.0g) with lowest crude fibre content (2.93%). Highest dry matter recovery was recorded in genotype V3S1-8 (25.20%) followed by Khasi Local (22.54%) and Suruchi (21.96%). The crude fiber content was highest in the genotype Himgiri (5.0%) followed by Suruchi (4.25%).
Cataloguing of ginger and turmeric collections IC number (IC-584322 to IC-584364) for 43 ginger germplasm collections (MLG-1 to 43) has been received from the NBPGR, New Delhi. The passport data of 32 genotypes of turmeric along with planting materials has been submitted to the NBPGR Regional Station, Umiam for granting of IC number. All the collected genotypes are maintained at experimental farm, Division of Horticulture, ICAR (RC) for NEH Region, Umiam.
DISEASES
Eco-friendly management of ginger diseases Two ecofriendly methods along with a fungicide check were evaluated. Trichoderma based formulations
viz., Trichostar and copper oxychloride were used for rhizomes treatment and Panchgavya was used as soil drench after germination. Total three sprays were at an interval of approximately one month. There was no difference in yield and given diseases a severity of Phyllosticta and Cercoseptoria leaf spots when compared to untreated check.
Soft rot of ginger - survey and surveillance Various districts of Meghalaya, Mizoram, Sikkim, Arunachal Pradesh and Manipur were surveyed. The pathogen (Pythium myriotylum) was isolated on Pythium specific media.
a) In–vitro testing of fungal antagonists: Among the seven native Trichoderma spp. tested in dual culture against Pythium isolate (114), T. harzianum, T.
viride, T. atroviride and T.virens were found effective after 4 days of inoculation.
b) Management of soft rot of ginger: Two sets of trials (containing a variety of treatment combinations) were conducted at two sites (one at the general field and the other at the soil science section) at Umiam to evaluate field efficacy of different treatments against soft rot of ginger.
i) At soil science, the highest germination (95.83%) was achieved in plots having ginger treated with hot water at 490C for 20 minutes (Table 1). The lowest per cent infection, highest yield and minimum yield loss was recorded in the plot treated with Poultry Manure (PM) @ 2.5 t/h + Mulching (Ambrosia spp.) + Ridomil MZ-72 @ 2 g/L.
ii) At the general field, the highest germination (84.62%) was achieved in Bhoomika (T. viride)
@ 5 g/L treated plots. The lowest infection and minimum yield loss was recorded in treatment of ginger treated with hot water at 49oC for 20 minutes. However, the plots having ginger treated with Ridomil gold @ 2.5 g/L yielded maximum yield (Table 2).
Bacterial wilt (Ralstonia solanacearum) of solanaceous crops and ginger
Survey for collection of samples and isolation of pathogen: Survey was conducted and 195 farmers were interacted. The villages were selected based on random sampling technique. Samples were collected for isolation of pathogen and their control by bio- control agents (BCAs). The pathogen (Ralstonia solanacearum) causing wilt disease of solanaceous crops and ginger was isolated. BCAs, Bacillus subtilis
and Pseudomonas fluorescens were isolated from collected soil samples.
Identification of R. solanacearum by PCR based molecular tools: R. solanacearum was identified using specific 16SRNA OLI1 and Y2 primers. The amplification of R. solanacearum was noted at 288 bp (Fig 3).
Biovar test of collected R. solanacearum isolates:
Forty-three representative isolates (12 from tomato, 7 from brinjal, 3 from capsicum, 6 from chilli and 15
from ginger) were subjected to Biovar test and grouped under Biovar-3, which indicated that Ralstonia from NEH states fall under Biovar-3 category (Fig 4).
Isolation of bio-agent (s) for R. solanacearum:
Rhizosphere soil samples of healthy tomato, maize, soybean, rice, groundnut, brinjal, cucumber, pumpkin, Table 1 Field efficacy of combination of nutrients, mulching and fungicides, bio-control agents & botanicals against soft rot of ginger at soil science field
Treatments Germination Infection Total yield Yield loss
(%) (%) (t/ha) (%)
Hot water 95.83 40.07 4.24 27.57
FYM +Indofil M-45 83.33 66.64 4.41 37.97
PM+Sanit 86.67 42.31 3.50 39.71
NPK+ FYM+ Bavistin 74.17 57.40 2.90 36.22
NPK+ PM+ Ridomil MZ-72 88.33 47.19 3.84 36.96
FYM+ Lime + Bhoomika 75.83 40.34 3.19 34.10
PM+Lime +Bhoomika 76.67 60.66 2.95 37.91
NPK+Lime +Agnee Plus 83.33 64.24 4.93 33.13
NPK + Mulching+Ridomil MZ-72 87.50 48.43 2.77 36.75
NPK + Mulching+Lime+ Bavistin 88.33 44.47 5.99 32.42
NPK + Mulching+ Indofil M-45 75.00 45.03 2.95 39.51
PM+Mulching+Ridomil MZ-72 94.17 39.88 6.75 27.07
Control 55.83 70.19 2.47 60.34
SE (d) 2.35 4.22 1.16 6.09
CD (P=0.05) 5.11 9.20 2.53 13.27
Table 2 Field efficacy of combination of nutrients, mulching and fungicides, bio-control agents and botanicals against soft rot of ginger
Treatments Germination Infection Total Yield
(%) (%) yield loss
(t/ha) (%)
Indofil M-45 68.38 71.46 2.68 36.60
Sanit 66.67 82.04 2.51 46.34
Bavistin 70.09 73.45 2.56 42.75
Ridomil MZ 72 69.23 78.67 3.70 40.91
Agnee 70.94 78.40 2.72 42.16
Ridomil gold 78.63 62.24 5.52 26.34
Bhoomika 84.62 54.85 3.64 20.73
Agnee plus 81.20 58.98 4.49 13.79
Hot water 61.54 46.15 3.09 10.27
Control 82.05 67.72 1.64 68.45
SE (d) 5.85 5.53 0.32 3.60
CD(P=0.05) 13.24 12.50 0.73 8.15
Fig 3 Identification of R. solanacearum by 16S RNA primers Lane 1-13 representative samples from Meghalaya, Manipur and Sikkim; Lane M -100 bp ladder
Fig 4 Biovar test of Ralstonia isolate RDRC-5
banana, chilli, pepper, and colocasia as well as fern plants along with the uprooted plants were collected from fields subject to various cultural practices, across Meghalaya, Assam and Arunachal Pradesh. The Pseudomonas fluorescens was isolated on KMB and Bacillus subtilis on LB medium.
In- vitro bio-efficacy of bio-agents against R.
solanacearum:The in-vitro bio-efficacy test of bio- agents was tested following agar diffusion method and paper disc method. P. fluorescens isolates 404, was found producing
clear zone of inhibition against R.
solanacearum (Fig 5) followed by 403 and 408. Similarly Bacillus subtilis isolates 507, was found producing clear zone of inhibition against R.
s o l a n a c e a r u m followed by 516 and 518.
Management of bacterial wilt of ginger, tomato and capsicum: Three field trials were conducted for the management of bacterial wilt of ginger, tomato and capsicum.
i) In ginger, the highest germination (82.14%) was achieved with treatment Agnee @ 5g/L, Lantana seed extract @ 40 ml/l, Streptomycin @ 0.2 g/L and Agnee plus @ 5 g/L (Table 3).
Table 3 Efficacy of antibiotics, bio-control agents and botanicals against bacterial wilt of ginger
Treatments Germination Infection Yield Yield
(%) (%) (t/ha) loss
(%)
Agnee 82.14 29.02 16.36 29.06
Lantana seed 82.14 33.44 14.15 34.94 extract
Hot water 77.38 29.33 12.97 37.21
ATW 80.95 24.97 12.67 33.10
Streptomycin 82.14 31.94 12.88 34.22
Agnee plus 82.14 29.02 14.17 40.08
ATWC 77.38 32.40 14.67 39.43
Control 54.76 58.47 9.33 62.54
CD (P=0.05) 3.47 1.91 0.53 1.31
The lowest per cent infection of disease was recorded in ATW (1:3:5) followed by Agnee @ 5g/L which was at par with Agnee Plus @ 5g/L followed by hot water (49oC for 20 minutes). The maximum yield was recorded with treatment ATWC, whereas minimum yield loss was recorded with Agnee @ 5g/
L.
ii) In the tomato var.Pusa Ruby (Fig 6), HEYC (1.2:4.0:8.0:8.0) was most promising followed by HEY (1.2:4.0:8.0) and Lantana seed extract (25 g/
L of water).
iii) In the capsicum var. Thai Wonder, pig slurry
@1.5kg/15 L of water was found better, followed by HEYC (1.2: 4.0: 8.0: 8.0) at par with Lantana seed extract (25g/L of water).
Screening of tomato genotypes against bacterial wilt
Altogether, 13 genotypes were screened against bacterial wilt under inoculated sick plot conditions.
The observations reveald that the incubation period in resistant genotypes ranged from 46.67 to 30.33 days, in moderately resistant 16.33 to 12.83, in moderately susceptible 14.00 and in susceptible 9.33 days (Fig 8).
‘Pusa ruby’ recorded maximum (75%) disease incidence (DI) and lowest yield (18.40 t/ha). The minimum (6.94%) DI with maximum (58.01 t/ha) yield was recorded with Meghalaya Tomato-1.
Fig 5 Inhibition of Ralstonia isolate by P. fluorescens
isolate 404
Fig 6 Field efficacy control agents against bacterial wilt of tomato
Fig 7 Field efficacy of control agents against bacterial wilt of capsicum
Areca nut bud rot (Phytophthora spp)
The pathogen (Phytophthora spp) was isolated from bud rot samples collected from various districts of Meghalaya.
In-vitro bio-efficacy of native Trichoderma spp.
against Phytophthora spp
Six isolates of Trichoderma spp. were isolated from different Arecanut habitats and tested in dual culture.
Of these T. viride isolated from phylloplane area of arecanut was found effective in inhibiting (92.1%) mycelial growth of pathogen followed by T.harzianum (Fig 9).