Field experiments for the integrated management of early leaf spot (ELS) and late leaf spot (LLS) diseases of groundnut were conducted during 1988 to 1990 rainy seasons. All treatments had significantly lower disease severity of ELS and LLS than unsprayed sole crop. Corresponding to the significantly lower severity of both the diseases in various treatments, monetary returns were also significantly higher than that of unsprayed sole crop. The severity of both diseases was significantly different among treatments, between varieties, and due to their interactions. Almost the same trend was followed for monetary returns. The treatments, application of a mixture of fungicides (carbendazim 0.05% + mancozeb 0.2%) at 40, 55 and 70 d.a.s., groundnut intercropped with pigeonpea + two sprays of fungicides at 55 and 70 d.a.s., and groundnut intercropped with pigeonpea + one spray each of neem leaf extract, fungicides and cell-free culture filtrate of Penicillium islandicum at 40, 55 and 70 d.a.s., respectively were equally effective in controlling ELS and LLS. The latter two treatments, and groundnut intercropped with pigeonpea and sprayed separately with neem leaf extract and P. islandicum inoculum at 55 and 70 d.a.s., gave significantly higher net monetary returns (Rs. 9569-11561/ha) with cost-benefit ratios ranging from 1:2·99 to 1:3.63 for Girnar 1 and 1:2·67 to 1:3·48 for JL 24 cultiver.

All the varieties, advanced breeding lines, germplasm lines, and wild species used in the experiments differed significantly for their ability to allow invasion and aflatoxin production by an aflatoxigenicAspergillus flavus strain. Infection and colonisation were strongly correlated (r = 0.82), while there was no relation between infection and aflatoxin content or colonisation and aflatoxin content (r = 0.15). The varieties ICGS11 and S 206 supported less infection and colonisation (range 35 to 40%). Lowest aflatoxin content was recorded in Chitra (3,200 ppb), while it was highest in Kaushal (38,250 ppb). A cross derivative of GAUG1 × NC Ac 17133 R F showed lowest infection and colonisation (86,3 and 25,28%, respectively), and also supported moderate aflatoxin production (4,000 ppb). Among germplasm lines spancross supported lowest aflatoxin production (2,026 ppb) while both the wild species vz. ICG 8127 and ICG 8128 were highly susceptible to infection, colonisation, and aflatoxin production.

No abstract

No abstract

The effect of rock salts, NaCI, propionic acid, NCP.75, plant products - asafoetida, turmeric powder and aqueous leaf extracts ofAzadirachta indica, Lawsonia alba, Pongamia glabra andTridax procumbens on seed colonization and aflatoxin production byAspergillus flavus (NRRL-3000) was studied in two Spanish bunch groundnut varieties (J-11 and JL-24). All these treatments inhibited seed colonization and aflatoxin production to varying degrees. Inhibition of seed colonization with chemicals, plant products and aqueous leaf extracts was observed to range between 17 to 96%, 27 to 100%, and 8 to 75% while inhibition of aflatoxin production ranged from 14 to 74%, 42 to 71%, and 6 to 64%, respectively. In general, salts (20g/L), propionic acid (10mL/L), asafoetida (pure Ig/L and impure 20g/L), andAzadirachta indica aqueous leaf extract (20 g/L) are better in preventing aflatoxin contamination in both the groundnut varieties.

No abstract