ABSTRACT
Evaluation of the relative efficacy of powdered leaf extracts of Aloe vera(Linn) and Aloe schweinfurthii(Baker) in the control of some plant pathogens was undertaken in this work. Antimicrobial activities ofthe extracts obtained using cold water, hot water and ethanol were tested against four fungal spp., namely, Alternaria solani,Colletotrichum lindemuthianum, Sclerotium rolfsiiand Trichophyton rubrum. The phytochemical screening of the leaf extracts of the two aloe species revealed the presence of bioactive compounds such as alkaloids, tannins, saponins, flavonoids, cardiac glycosides, phytates and oxalates. The extracts were observed to exhibit varying inhibitory effects on the selected fungi. Ethanolic extract of A. veraat 50mg/ml and 100mg/ml had the greatest impact on A. solaniand C. lindemuthianum respectively.Similarly, cold water extract of A. schweinfurthiiat 100mg/ml was the most effective against S. rolfsiiandT. rubrum.However, hot water extract of A. vera wasleast effective against C. lindemuthianum. Also, the efficacy of cold water extract of A. schweinfurthii at 50mg/mlwas very low against T. rubrumand A. solani. The hot water extract of A. schweinfurthii at 20mg/ml also showed the least effect against S. rolfsii. Consequently, extracts from both Aloe species can be recommended in the management of the four fungal pathogens evaluated in this study. It is hoped that in no distant future, botanical fungicides would be developed from the two Aloe species
ABSTRACT
Aim: To determine the possible effects of environment and genotypic differences on root yield and other related traits. Methodology: 43 improved cassava genotypes were evaluated for root yield, root number, root dry matter, cassava mosaic disease and Cassava bacterial disease. The experiments were conducted using a randomized complete-block design with four replications for two years in three representative agro-ecological zones (Mokwa, Ibadan and Onne) in Nigeria. The data collected were subjected to combined analyses of variance using the GLM procedure of Statistical Analysis System (SAS 9.2) to determine the magnitude of the main effects and interactions. GGEbiplot software (GGEbiplot, 2007) was applied for visual examination of the GEI pattern of the data. Results: Genotype, Location and genotype by environment (GXE) interaction were highly significant for all the traits studied (P< 0.001), indicating genetic variability between genotypes by changing environments. The partitioning of GGE through GGE biplot analysis showed that PC1 and PC2 accounted for 61.3% and 28.8% of GGE sum of squares respectively for root yield, explaining a total of 90.1% variation. Conclusion: Genotypes G4 and G15 were the highest yielding and stable genotypes. G2 and G7 were equally stable but with poor roots yield. G43, which had a mean yield similar to the grand mean, may be regarded as a desirable genotype. Mokwa and Ibadan were found to be the most discriminative and the least representative environments for root yields while Onne environment was found to be the most representative and the least discriminative.