Effect of Some Agronomic Practices to Increase Maize Yield in Ghana
Low plant densities of maize are often observed in fields of farmers practising no-till agriculture which causes low grain yield in Ghana. With the increasing population and consumption of maize in the country, research must be directed to solve this problem to enhance maize production. In this paper, a 2x3 factorial experiment in randomized complete block design with 4 replications was carried out at Wioso in the Atwima-Nwabiagya District in the Ashanti Region of Ghana during the major season of 2007 in order to come out with the best practices in maize production. The objectives of the study were to determine the right period of refilling maize field and the comparative effect of refilling with seed and seedling on the growth, optimum population density, and yield of maize. The factors were material for refill, which was either seeds or seedlings, and time of refilling either at 5, 10, and 15 days after planting. The results showed that refilling with seedlings produced the greatest positive effect in the number of leaves per plant, leaf length, leaf diameter, plant height and stem girth. Furthermore, refilling with seedlings contributed more to the optimum plant population density. Total grain yield when seedlings were used as refill was 967kg per hectare more than when seeds were used as refill material. On the other hand, plants from seeds refill were weak, lodged more and allowed much solar radiation penetration to the ground. Grain yield from seed refill plants was 6%, whilst seedling refill plants contributed 34% to the total grain yield. Refilling at 5 days after planting induced greater growth than 10 or 15 days after planting. The results indicate that it is possible to do refilling in maize field by using seedling as this contributes more than the traditional method of using seeds.
Comparison of Farmer's Agriculture Information Channels and Farming Practice in Tanzania
There are mixed empirical evidences on the effectiveness of Farmer Field School (FFS). The evidences on various studies vary because of the setting, evaluation methods and yardstick used. This paper aims to investigate the impact of District Agricultural Sector Investment Project (DASIP) on knowledge and productivity. The study was conducted in the area where (DASIP) operated. This covered five regions namely Kagera, Mwanza, Mara, Simiyu and Kigoma. Within those regions, the study focused on agro-ecological zone where corn was cultivated. The data was collected from 878 farmers out of 971, who were targeted. Among them, 359 were participant and 519 were non-participant farmers. This study employed a five-stage sampling technique. The findings show that the effects of DASIP on participating farmers are very little as they resemble non-participating farmers in terms of knowledge and farming practices. Despite that, non-participating farmers are 8.724 times the odds of corn yield not to increase compared to participating farmers. Based on findings, it may recommended that, agriculture programmes should run smoothly by providing technical and financial commitment to improve the performance of extension officers.
Immune dysfunction following infection with chicken anemia agent and infectious bursal disease virus. II. Alterations of in vitro lymphoproliferation and in vivo immune responses.
To determine the functional impact of alterations in lymphocyte concentrations and ratios following infection with chicken anemia agent (CAA) alone or in combination with infectious bursal disease virus (IBDV) on the immune system of young chickens, in vitro lymphoproliferation assays and in vivo responses to vaccination with several common viral agents were assessed at various time intervals post-inoculation (PI). Concanavalin A (Con A), phytohemagglutinin (PHA) and pokeweed mitogen (PWM) stimulation of splenic lymphocytes (SPL) collected from control birds could not be detected until 10-14 days PI. Infection with CAA was characterized by significantly higher PWM stimulation of SPL at 17 days PI and significantly lower PWM stimulation of peripheral blood lymphocytes (PBL) at 14 days PI, compared with uninfected controls. Concanavalin A and PWM stimulation of SPL was significantly increased in birds inoculated with IBDV alone. Lymphocytes harvested from birds inoculated simultaneously with CAA and IBDV had significantly lower responses. Effects on humoral and cell-mediated immunity following CAA and/or IBDV were determined by evaluating vaccination responses to Newcastle disease virus (NDV), fowl pox virus (FPV) and infectious laryngotracheitis virus (ILTV) during the acute phase of CAA infection (2 weeks PI). Vaccination of birds 2 weeks following CAA infection at 1 day of age resulted in decreased protection against NDV (85.7%) and ILTV (7.1%) challenge compared with protection rates in control birds (100% and 53.3% respectively). Infectious bursal disease virus infection was associated with decreased protection against NDV (60%) only. Concomitant infection at 1 day of age resulted in a greater reduction in NDV challenge protection (33.3%), slightly decreased FPV protection (87.5%), increased numbers of persistent FPV vaccination lesions and increased protection against ILTV challenge (71.4%). Vaccination of birds 2 weeks following CAA infection at 2 weeks of age resulted in slightly decreased NDV humoral antibody, development of persistent FPV vaccination lesions (17%) and increased immunity to ILTV challenge compared with control birds (83.3% vs. 66.7%). Chickens inoculated with IBDV alone displayed a more severe depression in NDV antibody titers and only a slight decrease in ILTV protection. Vaccination following concomitant infection at 2 weeks of age resulted in a higher percentage of FPV persistent vaccination lesions (39%) and greatly enhanced immunity to ILTV challenge (100%).