ABSTRACT
Pod fly, Melanagromyza obtusa is an important emerging pest and a major constraint to increase the production and productivity of pigeonpea. The concealed mode of life of pod fly within the pod makes it difficult to control. Hence, host plant resistance is an important tool for the management of this pest. Therefore, a set of forty genotypes were screened for resistance to pod fly under field conditions and characterized for morphological and biochemical traits in the pods. The correlation studies revealed that, among morphological and biochemical constituents of pigeonpea, pod length (r=0.389*), pod width (r=0.380*), protein content (r=0.857**), total carbohydrates (r=0.782**), reducing sugars (r=0.848**) and total free amino acids (r=0.832**) in the pod walls were positively correlated with per cent pod damage, whereas pod wall thickness (r= -0.762**), trichome density (r= -0.745**) and phenol content (r= -0.871**) had significant negative correlation with pod fly damage. Therefore, these traits can be used as phenotypic and biochemical markers to identify pigeonpea genotypes with resistance to M. obtusa, and use in pod fly resistance breeding program.
ABSTRACT
The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan), two systemic fungicides (hexaconazole and tebuconazole) and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100%) in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.
ABSTRACT
Forty nine genotypes of pigeonpea representing the broad spectrum of variation were assessed for twelve characters using principal component analysis and cluster analysis. These genotypes were grouped into 8 clusters by using cluster analysis. Principal component analysis identified five principal components with eigen values more than one which contributed 80.10 per cent of the cumulative variance. The genotypes LRG-41 and SM- 97, MRG-1001, WRG 51-Y, RST-16 and ICP 7035 were selected from the above analysis appeared to be desirable for inclusion in crossing programme aimed for improvement of pigeonpea.
ABSTRACT
Success of any breeding programme depends on the efficiency of selection. Hence, the knowledge of nature of association of various traits among themselves and with seed yield is quite important for devising an effective selection criterion for yield. The present study was carried out to assess the nature and extent of interrelationship among component traits affecting seed yield in pigeonpea (Cajanus cajan (L.) Millsp). Forty nine genotypes from different states Andhra Pradesh, Karnataka and Maharastra were evaluated in a randomized block design with three replications and the data recorded on 12 traits were subjected to statistical analysis. The correlation studies revealed the positive and significant association of seed yield with number of pods per plant, number of secondary branches per plant, number of primary branches per plant and plant height. Path analysis revealed that the number of pods per plant was important in formulating selection criteria for improvement of seed yield in pigeonpea.