Effects of nitrogen levels and harvest interval on the growth and yield of Moringa (Moringa Oleifera Lam) in Sudan Savanna of Nigeria

Field experiment was conducted under irrigation at Bayero University Kano, during 2011/2012 dry season to investigate the effects of different nitrogen levels and harvest interval on growth and leaf yield of Moringa  (Moringa oleifera (Lam)). The treatments consisted of four levels of nitrogen (0, 50, 100 and 150kg N ha-1) and three times of harvest interval (2, 3, and 4 weeks). These were arranged in a split plot design with the nitrogen levels allocated to the main plots while the harvest interval allocated to the sub plots and replicated four times. The data collected were subjected to analysis of variance (ANOVA) using the general linear model of GenStat and significant different means were separated using DMRT. The result shows that applications of nitrogen significantly increased plant height, number of leaflets per plant, plant stem diameter, number of  branches per plant, fresh and dry weights per plant. Generally, 150kg N ha-1 level gave highest values for all  the growth and yield characters assessed. The highest fresh and dry total leaf yields were also obtained with  150kg N ha-1 level. Increase in harvest interval significantly increased fresh and dry leaf yields of Moringa with  the highest yields obtained from 4 weeks harvest interval. Nitrogen and harvest interval interaction was found  to be significant on fresh and dry leaf yields of Moringa, which indicated that high yields were supported by  150kg N ha-1 at 4 weeks harvest interval.Keywords: Moringa, harvest interval, Nitrogen level, yiel

Effect of brood stock size on egg fertilization, hatchability and fry survival rate of African catfish (Clarias gariepinus)

This experiment was conducted to investigate the effect of size of brood stock on egg fertilization, hatchability and fry survival rate of Clarias gariepinus in an intensive culture system, for a period of four weeks. Larger brood stock size (1200-1500g) produced larger eggs and bigger fry while moderate brood stock size (795-1000)g produced moderate eggs and moderate fry. The mean size of eggs produced and the size of brood stock was however not significantly different (p > 0.05). In addition, larger eggs resulted in larger fry. The survival rate of fry after starvation increased with increase in parent brood stock size. Best on this study it was recommended that for larger eggs and fry production, brood stock of Clarias gariepinus, of average size of (1200-1500g) should be selected for use in fish hatchery operation in Nigeria. There was no significant difference (p> 0.05) in the physiochemical parameters.Keywords: Broodstock, Egg fertilization, Hatchability, Clarias gariepinu

Effect of imazapyr treated maize on Striga infestation and time of intercropping cowpea in Samaru, Nigeria

Two field experiments were conducted at the research farm of Institute for Agricultural Research (IAR) Samaru, Zaria during the 2011 cropping season, with the aim of determining the effect of imazapyr treated maize on Striga infestation and time of intercropping cowpea in Samaru, northern guinea savannah of Nigeria. There were two sets of experiments: the first experiment consisted of Six (6) hybrids (AS1128-1, AS1128-2, AS1128-3, AS1128-4, AS1128-6 and AS1128-8) of imazapyr resistant (IR) maize seeds treated with imazapyr chemical and intercropped with cowpea at 2, 4 and 6 weeks after sowing (WAS) of maize. The second experiment consisted of the same Six (6) hybrids of IR maize seeds but untreated and also intercropped with cowpea at 2, 4 and 6 WAS of maize. The experiments were laid out in a split plot design with time of intercropping cowpea as main plot and hybrid maize varieties as sub plot, and replicated three times. The cowpea variety used for the trial was IT97K-499-35. Among the treated IR-maize hybrids, only AS1128-1, AS1128-2, AS1128-3 and AS1128-4 germinated while for the untreated, all the six hybrids germinated. The grain yields per hectare of all the treated maize hybrids did not significantly differed whereas grain yields per hectare of the untreated maize hybrids AS1128-1, AS1128-2, AS1128-3 and AS1128-4 were significantly higher than the hybrid AS1128-8. The treated IR  maize hybrids exerted 100% control of Striga while the untreated supported Striga emergence. There was no visible damage symptoms observed on the cowpea intercropped with treated maize at all times of intercropping. It is therefore concluded that the IR-maize hybrids ASII28-1, ASII28-2, ASII28-3 and ASII28-4 should be used in the treated forms for the control of Striga. Moreover, the intercropping of cowpea with imazapyr treated maize can be carried out starting from 2 WAS of maize.Key words: Intercropping, imazapyr resistant maize (IR-maize), cowpea, Striga