The response of cocoyam (Colocasia esuclenta (L.) Schott) to various rates of poultry manure (PM) and potassium(K) fertilizer was studied under field conditions in 2006 and 2007 growing seasons at Uyo, a humid forest agroecology of south eastern Nigeria. Treatment combinations comprising of four rates each of PM (0, 5, 10 and 15t/ha) and K (0, 40, 80 and 120 kg K/ha) were factorized and fitted into a andomized complete block design with three replicates. Application of PM and K at the highest rates produced significantly taller plants with higher leaf area index, shoot dry matter, corms and cormels number, compared with other treatments in both years. Weight of corms and cormels and total yield (t/ha) were however, optimized at 10t/ha and 80 kg K/ha rate. Averaged over the two years, increases in PM and K rates from zero to 15t/ha and 120 kg K/ha, increased the shoot dry matter by 51% and 29%, and the number of corms and cormels by 40% and 34%, respectively. Weight of corms and cormels and total yield obtained in the two years at 10t/ha and 15t/ha PM, and 80 kg K/ha and 120 kg K/ha were statistically similar except in 2007 where the corms and cormels weight peaked at 15t/ha PM rate. Poultry manure at 15t/ha in combination with either 80 kg K/ha or 120 kg K/ha out-yielded other treatments in terms of corms and cormels weight and total yield in the two years of trial.

Estimates of tractor repair and maintenance costs are important for farm machinery replacement decisions and for general farm budgeting. The aim of this study was to provide a statistical analysis for the repair and maintenance costs of tractors in order to present an appropriate mathematical model based on farm records and to compare the derived repair cost function with other estimates. The study was also regarded as an exploratory exercise to assess the feasibility and form of a more comprehensive study on the using of PM in agriculture projects. In this context a study was conducted to predict accumulated R&M costs of three typical tractors namely JD-3140, MF-285 and JD-3350 based on total working hours (X) by using Preventive Maintenance Program (PMP) in Kavardeh Agribusiness Company in Iran. To present the model, the stratified random sampling method on the basis of tractor age per year was used. The mean accumulated repair and maintenance costs and also the mean working hours (h/year) were calculated for per class separately. Calculated data was analyzed on the five models, linear, logarithmic, polynomial, power and exponential. Finally, it was found that power model gave better cost prediction with higher confidence and less variation than other models.

Analytical study of agricultural productivity in Sindhudurg district is presented in this paper. The technique used has considered the average yield per hectare of selected crops and land occupancy of selected crops in the study region. For the study region considered for the present study for which available ranking coefficient are given in ascending order for each crop separately then crop yield and concentration indices ranking co-efficient of each crop are summed and divided by two. From the ranking coefficient calculated for 1981-86 and 2003-08 and categories are made according to the three efficiency grades viz. high grade, moderate grade and low grade for discussing the spatiotemporal variations in the study region. In a same way, overall ranking coefficient have been worked out by summing the values of all the selected crops in each tahsil and divided by ‘n,’ where ‘n’ refer to the number of crops considered. To avoid the annual fluctuations in the level of crop productivity there is considered average productivity level and statistics of five year i.e. 1981-86 and 2003-08.

Growth and yield response of sweet maize (Zea mays L. saccharata Strut.) to rates of poultry manure (PM) and NPK 20-10-10 fertilizer was studied under field condition in 2010 late growing season in Calabar, a humid forest agro ecology of south eastern Nigeria. Treatments comprised of three rates of PM (0, 5 and 10t/ha), factorially combined with four rates of NPK (0, 200, 400 and 600 kg/ha) and arranged into a randomized complete block design with three replications. Application of PM at the highest rate significantly increased plant height, number of leaves/plant, number of cobs/plant, unhusked and dehusked green cob yields and also hastened days to 50% tasselling. The highest rates of PM and NPK maximized leaf area index (LAI), number of grains/cob and harvest index (HI) whereas total dry matter (TDM), weight of grains/cob, cob yield/ha and total grain yield peaked at 10t/ha PM and 400kg/ha NPK fertilizer. The 10t/ha PM rate and 400kg/ha NPK increased TDM by 43 and 91% and total grain yield by 101 and 34% respectively, compared with the control. Poultry manure at 10t/ha in combination with 400kg/ha NPK fertilizer out-yielded other treatments in terms of biomass yield, cob yield/ha, harvest index and total grain yield.

It has been a general belief over a long period of time that RNA molecules were essential molecules involved only in the process of protein synthesis as carriers of genetic. However recent studies have shown that most of the cells RNAome do not encode proteins. The role and diversity of these numerous non-coding RNAs has not been elucidated till date. The most unique of this plethora of non coding molecules are a class of small RNA molecules of ~21 nucleotides in length which has been reported by many workers to be involved in many of the cell process such as controls, defense and development. Short interfering RNAs (siRNA) and Micro RNA (miRNA) represent the two most abundant class of the non coding RNA cascade and both of them are key players in the process of RNA Interference. The current work focuses on the identification and development of secondary structures of available plant microRNA sequences and establishment of a relation between the formation of secondary structures and their free energy values.

This study describes the length-weight relationships (LWR) and condition factors of six fish species from six families of ecological and economic importance, found in Atbara River and Khashm el- Girba reservoir. A total of 1118 specimens were caught by using various mesh size of gill nets from January, 2007 to December, 2007. The growth coefficient (b) values obtained for the six fish species ranged between 2.278 for Clarias lazera and 3.680 for Bagrus bayad and differed significantly (p<0.005) from 3, which indicates that most of the fish species (61.1%) have negative allometric growth. The condition factors (K) of the fish species ranged from (0.506±0.416) in Clarias lazera to (3.415±0.707) in Oreochromis niloticus and about 83.3% of these condition factors fall outside the range recommended as suitable for matured fresh water fish species in the tropics.

Arbuscular Mycorrhizal (AM) fungi hold considerable potential for use as inoculant and nowadays much attention is focused on mass production of AM fungal inoculum, since this is of paramount importance in improving plant production in agriculture and horticulture. However, effectivity of these fungi on crop growth relies on their production practices, typically the substrate selected for its mass multiplication. Therefore, as an initial step, this experiment was carried out to select a suitable substrate for the AM (Glomus intraradices) inoculum production using maize (PEHM 5) as a host plant. Six different substrates namely biochar, biochar + 10% soil, vermiculite, vermiculite + 10 % soil, vermicompost and vermicompost + 10 % soil were tested with an uninoculated control in pot culture condition for the production of AM inoculum. Maize plants rose in vermicompost + 10% soil with the presence of AM fungi significantly showed an increase in the shoot length, root length, root biomass and nutritional status (N and P) over those grown in other substrates. The results also showed that vermiculite + 10% soil substrate produced the greatest colonization rate (100%) and number of spores (726 / 50 g of substrate) compared to other substrates. Considering the results, it is suggested that vermicompost + 10% soil can be used as a substrate for large scale production of AM fungal inoculum.