TY  - BOOK
AU  - Poudyal, Chanda 
AU  - Dipali Majumder
TI  - Etiology of ginger rhizome rot complex in mid-hills of Meghalaya and its management
U1  - 633.83 
PY  - 2014///
CY  - Umiam
PB  - CPGS, CAU
KW  - Ginger
KW  - Rhizome rot disease
KW  - Meghalaya
KW  - Control and management
N2  - Ginger (Zingiber officinale  Rosc.)  is a major spice crop  in India  and Meghalaya is the second largest producer in the country with total production of 46.59 thousand tonnes.   Rhizome rot, commonly known as soft rot is a major constraint in ginger cultivation in Meghalaya. Limited information is available on the association of organisms in rhizome rot complex from  the mid-hills of Meghalaya. The present study aims at the assessment of disease incidence in mid-hills of Meghalaya, etiology and in vitro evaluation of plant extracts, bio-control agents (BCAs) and chemicals against associated pathogens of ginger rhizome rot complex. Disease incidence of rhizome rot complex was recorded in 17 villages from the Ri-Bhoi district of the state and the highest incidence was noted from Rongskiong (62.7%), Rongiari (60.8%) and Longen (60.2%) under Umling block of Ri-Bhoi district of Meghalaya. Lowest disease incidence was recorded in Nongra (0.4%) and Umet (2.4%) villages of Umsning block. The study revealed the association of Pythium myriotylum, Fusarium oxysporum, F. solani (tentatively) and Ralstonia solanacearum based on morphological, biochemical and molecular detection. In vitro evaluation of plant extracts showed that Allium sativum (3, 5 and 10%) was most effective against all the pathogens except Fusarium sp. with mean inhibition of 68.1 and 50.1% in P. myriotylum and F. oxysporum respectively and with 11.0 mm of inhibition zone in R solanacearum. F. solani was effectively suppressed by Lantana camara (40.0 %) followed by A. sativum (38.60 %). Out of six tested BCAs, Trichoderma harzianum showed maximum inhibition against all the associated fungal pathogens, viz.  P. myriotylum,  F. oxysporum  and  F. solani  with inhibition of  44.5,  45.6 and  46.2 %  respectively, whereas Pseudomonas fluorescens showed maximum antagonism against R. solanacearum  (28.4 mm). On evaluation offour fungicides, viz. copper oxychloride, mancozeb, carbendazim and metalaxyl at the different concn.  (ranging from 0.05-0.5%)  against the fungal pathogens, all the chemicals showed 100% suppression of  P. myriotylum  at all the concn.,  whereas carbendazim and metalaxyl equally inhibited the mycelial growth of F. oxysporum (87.1 %) and F. solani (87.1 %.) at all the concentrations. Among all the chemicals tested against  R. solanacearum,  streptocycline was found highly effective  with inhibition zones  of 26.8,  28.6  and  32.5  mm  at the test concn.  of 300, 400 and 500  ppm respectively. Evaluation of plant extracts, BCAs and chemicals needs further in vivo evaluation to formulate effective management strategies against rhizome rot complex of ginger under Meghalaya conditions.  
 Key words: Rhizome rot complex, ginger soft rot, management, Meghalaya, Mid-hills

ER  -