Effect of Sowing Dates, Intra-Row Spacings and Nitrogen Fertilizers of the Productivity of Red Variant Roselle (Hibiscus sabdarifa L)

Field experiments were conducted during the rainy seasons (June - Odober) of 1999 and 2000, at the research farm of Abubakar Tafawa Balewa University, Bauchi, Nigeria to study the effects of some agronomic practices on the growth and yield of roselle. Three agronomic practices (sowing dates, intra-row spacing and nitrogenous fertilizer levels) at three levels each, were factorially combined to give a total of 27 treatment combinations. These were laid out in a randomized complete block design with three replications. Most of the results obtained were highly significant (P50.01). Sowing dates (June) gave the highest mean calyx (2035.15 kg/ha) and seed (2391.19 kg/ha) yields in both years. Intra-row spacing (80 em) gave the highest mean calyx (1651.11 kg/ha) and seed (2024.40 kg/ha) yields. Also, application of 60 kg N/ha gave the highest mean calyx (1671.99 kg/ha) and seed (2067.36 kg/ha) yields. It is evident from the results of this experiment that, the earlier the sowing of dates, the wider the intra-row spacing and the higher the nitrogenous fertilizer level, the higher the productivity of red variant roselle. Sequel to these facts, roselle sown in June at intra-row spacing of 80 em should be applied with 60 kg N / ha for optimum productivity in the study area

Modulus of rapture (MOR) of porcelain by substitution of quartz with rice husk ash (RHA) and palm oil fuel ash (POFA) at different temperatures

This paper investigates to effects RHA and POFA in porcelain body as substitute materials for quartz. In order to collect experimental data, the effects of ground RHA and POFA replacement rate from 0 wt% up to 25 wt% in porcelain body was studied. The RHA and POFA were grounded in a ball mill until the median particle size was reduced to about 50 μm. They were used to substitute quartz in porcelain body from 0 wt% to 25 wt%. The mixed powder was pressed into pellets at mould pressure of 91 MPa. All the pellets were sintered at a temperatures of 1000 ºC, 1100 ºC, 1200 ºC and 1300 ºC for the soaking times of 2 hours. It was found out among other things that the Modulus of Rapture (MOR) of the samples increases with increase in substitution and also with the increase in temperature. With a value of 35 MPa the MOR of the samples containing 20 wt% sintered at a soaking time of 2 hours were higher than the standard porcelain. This could be attributed to the formation of larger amount of SiO2 glass, in the presence of fluxing components such as MgO, CaO and Na2O), more abundant in samples containing RHA and POFA

Effect of maize-legume mixture and nitrogen rates on the n-uptake and fertilizer n-recovery by maize inercrop

No Abstract. IJOTAFS Vol. 1 (2) 2007: pp. 149-15

Fabrication of Probe Trap for Monitoring Cowpea Weevil Infesting Stored Cowpea

Insect probe traps are effective in detecting grain insects but neglected because it is time consuming and precise method of interpreting the catch have not been adequately specified. Interestingly, this is not readily available in Nigeria and where available, it is expensive due to foreign exchange rates. Therefore, there is need for a locally available and more acceptable insect probe trap for integrated pest management practice during postharvest handling of cowpea. Locally sourced materials were used to fabricate a probe trap for monitoring Callosobruchus maculatus (Coleoptera: Chrysomelidae) infesting stored cowpea. The fabricated probe trap was evaluated together with a standard probe trap. Treatments were repeated three times, and also tried in three different insect densities (3, 7 and 15 insects per kg respectively) artificially infested into 10 kg cowpea grains contained in plastic storage buckets, and traps were inspected after every 24 hours for five days. The probe trap was also evaluated in 100 kg cowpea sample contained in sack bag to determine the effect of grain volume on the performance of the trap. Data collected were subjected to ANOVA and means were separated using Student Newman Keuls test (SNK) at 5 % confidence level. The result of total trap catches revealed that the fabricated traps’ mean catch (36.6) was significantly (P ≤ 0.05) higher than the standard probe trap which had lower trap catch mean (12.7) value. Thresholds for management decisions were also determined and the fabricated trap was found to be economically profitable (N 936.75 cheaper); hence, objectives of the study were achieved.  It is recommended for cowpea handlers in Nigeria to use the fabricated insect probe trap because it is effective in monitoring beetles, it is less expensive and also locally available. &nbsp