some plant pathogens in MOHIT NAGAR ICCPR FARM

some plant pathogens in MOHIT NAGAR ICCPR FARM

Mohitnagar Research Centre was established in the year 1958 as Regional Arecanut Research Station under Central Arecanut Research Station. Later the centre was merged with the Central Plantation Crops Research Institute, Kasaragod in 1970 and designated as one of the important Research Centre for conducting location-specific and need based research on crop improvement, production, protection and extension on plantation crops and spices, in particular, to cater to the needs of the farming community of Sub Himalayan Terai region and other parts of the country. The Centre is located at terai region of Easter Himalayan at Mohitnagar of Jalpaiguri District of West Bengal. It is 45 km of New Jalpaiguri Railway Station and 65 km away from Bagdogra Airport. Geographically, it is located at 260^/31^// N latitude and 880^/ 5^// E longitude with an altitude of 91.3 m above MSL. The area is experiencing a typical sub Himalayan Agro-Climate. It receives an average rainfall of 3200 mm annually, 90 % of which is received due to South West Monsoon. The maximum temeperature varies from 18⁰-38⁰ C and the minimum temperature ranges from 6⁰-18⁰ C. The soil is predominated with alluvium of the river Teesta, sandy loam in texture, rich in humus and acidic in nature (pH ranges from 4.5-6.0) Presently, the centre is having a total of 65 acres of land with full occupancy with arecanut, coconut, oil palm, cashewnut and buildings.It generally deals with the following projects

·         Evaluation of exotic and indigenous arecanut germplasm

·         Evaluation of coconut varieties for yield and cold tolerance

·         Development of plantation based cropping system.

·         Standardization of agro-techniques of plantation crops.

·         Standardization of propagation techniques for plantation crops and spices.

·         Transfer of proven technologies to the farming community.

1. Alternaria leaf spot of Almond: The almond tree, Prunus dulcis, is a deciduous tree in the family Rosaceae which is grown for its edible seeds (nuts). Almond leaves are 7.5–13 cm (3–5 in) long with a serrated edge and grow alternately on the branches. Alternaria leaf spot of Almond is caused by Alternaria alternate.Light brown lesions on leaves which expand to form circular lesions on leaf blade or semi-circular lesions on margin; leaves may develop light yellow necrosis which dries and turns tan in center of leaves; infected leaves dropping from tree; fruit does not drop from tree. Late spring treatment with appropriate fungicide if Alternaria symptoms are present

 2. Common leaf spot of Clove:

Clover species are generally small and are usually trifoliate (leaves possess three leaflets) although some species possess five or seven leaflets. One of the important disease of clove is Common leaf spot caused by Pseudopeziza trifolii.Major symptom of this disease include-small circular brow-black spots with uneven margins on leaves; leaves turning yellow and dropping from plant.The disease is Favoured by cool, wet weather; over winters on crop debris and high rainfall during flowering.

 

3. Algal disease of litchi : It is caused by an algal parasite Cephaleuros mycoides. The disease first appeared on the young unfolded tender branches. On the infected young leaves, small lesions of velvety white growth appear on the lower surface. On the upper surface, just the opposite site of the lesion, chlorotic patches occur. As the leaves unfold and increase in size, the velvety growth becomes more prominent and dense. Later larger areas of leaves are affected with this growth. Old and thick leaves show various types of malformation. The velvety growth turns light brown to brick-red.

 

4. Black pod rot Cocoa: Cocoa is the most economically important species in the genus Theobroma. Black pod rot of cacao is caused by a pathogen in the genus Phytophthora palmivora. When cacao is infected by P. palmivora, the pathogen penetrates the waxy cuticle and attacks the epidermis. A small brownish spot appears at the point of infectionInfection spreads rapidly across the outer surface,

covering the entire pod in a few days .

 

5.Cherelle wilt of Cocoa: Cherelle wilt is a devastating phenomenon in Theobroma cacao, a tropical understory tree that produces pods from which chocolate is manufactured. Approximately 60% of the pods succumbed to the condition known as cherelle wilt, on which relatively little research has been conducted. Cherelle wilt is so named because it affects the development of pods in the “cherelle” stage, when the pods are less than 10 cm long and younger than 40 days.Wilting pods were smaller, with the appearance of larger integuments than embryo sac in longitudinal section.