Response of Different Cultivars of Radish (Raphanus Sativus L.) to Alternaria Leaf Spot on Seed Production during Winter at Rupandehi Nepal

Ambika Pokhrel,Jyotsna Nepal,Kanhaiya Prasad Singh,Laxman Aryal,Madhu Sudhan Ghimire,Pramod Thagunna,Prativa Khanal

doi:10.3126/ijasbt.v4i3.15170

Ambika Pokhrel, Jyotsna Nepal + Show 5 more

Open Access

https://doi.org/10.3126/ijasbt.v4i3.15170

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Abstract

A field experiment was laid out in randomized complete block design with three replications and seven cultivars of Radish as treatments for screening against Alternaria leaf spot for seed production. Disease scoring was done as percentage of leaf area infected on individual plant at 7 and 10 days intervals on leaf and siliqua respectively for 3 times, and disease severity and mean AUDPC were calculated and yield was recorded. Disease symptoms appeared first in Long Chetki 22 DAS and last in Green Neck Miyashige 38 DAS. Maximum mean AUDPC (886.7) on foliage was recorded in Long Chetki while minimum mean AUDPC (690.7) was recorded in Green Neck Miyashige Similarly, highest and lowest total mean AUDPC on siliqua were seen on cultivars 40 Days (1080) and Green Neck Miyashige (66.67) respectively. Highest yield was recorded in Green Neck Miyashige (695.2kg/ha) and lowest yield was recorded in cultivar Long Chetki (477.4kg/hac). Similarly, highest test weight was recorded in cultivar Mino Early (10.28gm) and lowest was recorded in cultivar 40-Days (8.4gm). Cultivar, All Season Green Long failed inflorescence formation hence no evidence of siliqua formation therefore bears value 0 for seed yield. Similarly, highest biomass yield excluding root was found in cultivar Subhra-32 (613.3gm/m2) and lowest biomass yield was recorded in cultivar Green Neck Miyashige (341.7gm/m2). Green Neck Miyashige was found resistant to Alternaria leaf spot disease with maximum seed yield (695.2kg/ha). The cultivars Subhra-32 and 40 days were highly susceptible to Alternaria leaf spot disease with minimum seed yield.Int J Appl Sci Biotechnol, Vol 4(3): 318-324

Highlights

Radish (Raphanus sativus L.), one of the most popular root vegetable crops, can successfully be grown throughout the year in the hills of Nepal (Poon et al, 2004)
Disease Incidence on Foliage Symptoms of Alternaria leaf spot disease was first observed on cultivar 40 Days (24 disease incidence (DAS)) followed by cultivar Long Chetki (27 DAS)
The percentage of disease for each plot was calculated using the formula of Townsend and Heuberger (1943) as, Fig. 1: Graph showing percentage disease incidence of 7 different radish cultivars

Summary

Introduction

Radish (Raphanus sativus L.), one of the most popular root vegetable crops, can successfully be grown throughout the year in the hills of Nepal (Poon et al, 2004). Crucifers encounter number of foliar diseases among them Alternaria blight is the most devastating causing yield loss of 35-38% (Kolte et al, 1987). Most of pods are devoid of seed, shriveled seeds and fail to germinate in year This disease is internally seed borne where pathogen infects pericarp and cotyledon of the seeds (Atkinson, 1949). Alternaria blight diseases of crop plants have been reported from all the continents of the world, cause average loss of 5-47% in India (Kolte, 1985; Kolte et al, 1987; Sharma and Kolt, 1994); 5% in Canada (Tewari, 1991); 57% in Nepal (Shrestha et al, 2005). There are no recommended varieties of radish resistant to Alternaria leaf blight for seed production in terai region of Nepal. There are no recommended varieties of radish resistant to Alternaria leaf blight for seed production in terai region of Nepal. (DADO Rupandehi, 2014)

Materials and Methods

Results and Discussion

Long Chetki

Subhra-32