Tag Archives: harvest index and diseases

Evaluating the Effects of Varieties on Sucking Insect Pests and Diseases Limiting Sesame Production in the Nigerian Guinea Savanna, Part A (Published)

Sesame yields from farmers fields are of great concern. Among the various factors that constrain production are biotic pressures associated with the reproductive phase. Sesame exhibit high genetic variability, believed to contribute to increase plants fitness and expression of tolerance (varietal) levels. Advocacy for bio-pesticides had opened a new horizon in safety precaution, eco-friendliness and more rational pest management continuum.  In this study, performance of five sesame varieties and bio-pesticides effects on these pests were evaluated in 2014 and 2015 cropping seasons, all treatments were applied as foliar sprays fortnightly. Observation for pest population count commenced at flower buds, through capsule formation to physiological maturity. Five plants per plot (subplots) were tagged, all data taken were square root transformed before analysis, and low pests population sampled across the varieties in 2014 were significantly different except for 2015.  Sesame yield significantly appreciated with the pesticides protections, Cypercal® gave 9.11± 0.47kg/ha and 14.54± 1.26kg/ha for both seasons.  Except for NCRIBEN-01M in 2014, all effects in 2015 and E-8 in 2014/2015 yields effects were not significantly different, both treatments across the varieties gave yield advantage over the control. Seed weight gains was recorded across the varieties compared to the control, these gains were statistically significant, except for Ex-sudan and ICEASE-00018. Agronomic parameters of these sesame varieties were uniform across both treatments and seasons, showing significant contribution to the yield proficiency, but were not statistically different. Both bio pesticides gave varied levels of protection to sesame against these sucking pests. The sesame varieties contributed some levels of protection, through their varietal responses, evidenced in low pests’ population per variety and yield advantage over the control, while the agronomic parameters accounted for yield increases.

Keywords: Sesame, bio-pesticides, harvest index and diseases, sucking pests

Evaluating the Effects of Varieties on Sucking Insect Pest and Diseases Limiting Sesame Production in the Nigerian Guinea Savanna, Part B (Published)

The study on impacts of insects associated with five varieties of sesame, Sesamum indicum L. (pedaliaceae) was conducted at the Teaching and Research Farm, Federal University Wukari, in 2014 and 2015 cropping season. Insect species found on the crop at reproductive phase were sampled fortnightly. Phytophagous sesame pests identified were reported in part A of the study. This study evaluates diagnostic symptoms and severity of diseases vectored by these pests as viral leaf curls, cercospora leaf spots, galled capsule, bacterial blight and phyllody. The parameters measured were, Agronomic parameters and yield parameters. Results clearly shows, severity of these disease symptoms across the varieties, with E-8 variety being most tolerant (0.97±0.15) to leaf curl disease. Highest susceptibility was recorded in Yandev 55, for Cercospora leaf spots (1.93±0.06), galled capsule (5.79±0.64) and phyllody (1.96±0.23). NCRIBEN-01M gave the highest yield index, 6.09±0.36, and 5.99±0.12 for viable capsule counts. Average seed yield of 15.13±0.64kg/ha was recorded by the same variety in 2015 season, while ICEASE-00018 gave peak 1000 seed weights 1.69±0.07g and 1.88±0.13g in both seasons. The agronomic parameters show higher plant population (9.93±0.22 and 11.06±0.33) in ICEASE-00018 variety. Yandev 55 gave, 11.66±0.33cm and 11.40±0.23cm as peak plant height, while ICEASE-00018 gave 2.30±0.12 number of branches in 2014, but were not significantly different between varieties in 2015. NCRIBEN-O1M recorded peak stem girth, which however were not significantly different across the varieties. Yandev 55 had more leaves but was not significantly different across the varieties, and leaf area 8.04±0.47 and 8.46±0.52 was highest in same Yandev 55. The implications of these findings were further discussed.

Keywords: Induced resistance, Sesame, harvest index and diseases, sucking pests