1.

Project Code

:

PRP-3122

2.

Title

:

Mulberry diseases and their management

3.

Investigators

:

Chandrashekar DS,  Srikantaswamy K,  

Sharma DD, Gupta VP.

4.

Project period

:

June 1997- Dec. 1999

5.

Institute/  University

:

CSR&TI, Mysore

6.

Project cost

:

2,60,000

7.

Objectives

• To demonstrate the developed technologies for management of soil borne diseases of mulberry to DOS and farmers fields [Nursery-Guard for management of nursery diseases in new plantations and Raksha & Bionema for management of root rot and root knot diseases, respectively in established gardens].
• To develop an eco-friendly methods for the control of leaf spot and leaf rust diseases of mulberry.
• To identify the root knot resistance source from the existing mulberry varieties under different recommended methods.
• To identify the resistant source for tolerance to leaf spot and leaf rust diseases of mulberry.

8.

Important findings

On-farm demonstrations were conducted for three technologies, such as Nursery-guard + Dithane M-45 for nursery disease management, Raksha + Dithane M-45  for root rot control and Bionema + neem oil cake for root knot control at  RSRS  farms and farmers field.  Nursery-guard + Dithane M-45 increased the saplings survivability to an extent of 23-40 % over untreated check. The Raksha + Dithane M-45 provided 64.7-82% control over untreated check. The technology Bionema + neem oil cake reduced the severity of root knot disease by 80-88%.

Twelve mulberry phylloplane microbes and 10 known biocontrol agents belonging to Trichoderma spp. were screened in vitro for their antagonism against Cercospora moricola and Cerotelium fici.  Trichoderma harzianum (Th-1), T. harzianum (Th-2) and T. pseudokoningii (Tp) were found effective against both the pathogens.  Th-1 and Tp reduced the disease severity of leaf spot by 45.1 and 41.3 % and leaf rust by 40.0 and 37.0 %, respectively in the field condition. In case of combined application, the disease was reduced to 50.0 and 44.0% respectively over the check. Bavistin (Carbendazim) and Kavach (Chlorothalonil) at 0.2% taken for comparison recorded significantly higher reduction up to 70.2 and 59.0 % leaf spot and leaf rust respectively.  

An experiment was conducted for two years in hot spot area having 300-320 nematode larvae/250 cc soil to know the impact of soil treatments of (i) Bionema (Verticillium chlamydosporium) + neem oil cake (NOC), (ii) Furadan, (iii) NOC and  (iv) VAM on seven popular mulberry varieties for the control of root knot nematode. 

Among 7 mulberry varieties, K-2, Local, V-1 and MR-2 were highly susceptible, S-36 as susceptible and S-34, and S-13 were moderately resistant against root knot disease.  The varieties, which showed moderately resistant reaction, had significantly less number of root knots and egg masses/plant and nematode population in soil. Bionema + NOC showed significantly less disease and maximum leaf yield as compared to sole application of Furadan and NOC as well as VAM. With regards to interaction, the moderately resistant varieties (S-13 and S-34) with combined soil application of Bionema + NOC reduced the root knots/plant by 85.01-97.08%, egg masses by 89.13-98.03 %, nematode population by 92.51-99.22% and improved leaf yield by 26.34-36.12%.

Screening were carried out under natural condition at field in thirteen promising mulberry genotypes (six Alkaline resistant, AR-1 to AR-6; five Resource constraint, and check genotypes S-36 and V-1) for the tolerance to leaf spot and leaf  rust  diseases.  Among the 13 genotypes, AR-1 to AR-6 and Resource constraint genotypes (63, 519, 1133 and 1138) were found resistant to leaf spot with PDI below 5%. Check genotypes S-36 and V-1 were moderately resistant with PDI up to 20%. Resource constraint genotype 566 was found to be susceptible with PDI from 21 - 50%. In case of leaf rust, genotypes S-36 and V-1 were found to be moderately resistant (PDI up to 20%). Rest of the genotypes like AR-series, and Resource constraint genotypes were susceptible (PDI from 21 - 50%).