Open Access Original Research Article

Growth of Individual Tomato Fruits under Assimilate Limitation Associated with Successively-later Set Fruits

M. R. Rybak, K. J. Boote, J. W. Jones

Journal of Experimental Agriculture International, Page 60-73
DOI: 10.9734/2015/14806

The time course of growth of individual tomato fruits (Solanum lycopersicum) was analyzed in relation to the fruit initiation date and cumulative degree days of growth. Experimental data of dry weight (DW), fresh weight (FW), radial diameter (FDIAM), and dry matter concentration (DMC) of three different cohorts of fruits of determinate fresh-market tomato cultivar Florida 47 were determined under field conditions in Florida during spring of 2006 and 2007. Successively later cohorts (1 week intervals) had longer lags prior to rapid growth, slower maximum growth during the rapid phase, and smaller DW, FW, and FDIAM at maturity. These growth patterns were analyzed by fitting the data to a three-parameter Gompertz function for DW, FW, and FDIAM, and to a four-parameter modified Gompertz function for DMC. The good agreement of predicted and measured values indicates that the growth of individual tomato fruits followed the classical S-shaped Gompertz function. The Gompertz function was suitable to describe the slow growth that occurs in tomato fruits immediately after fertilization. The equation was able to predict the increasing duration of this lag and slower maximum growth and smaller final DW, FW, and size for successively later initiated cohorts of fruits. These results confirm the role of sink-source relationships (time of fruit set) on the growth of tomato fruits over time. This study will provide information potentially useful to improve existing tomato crop growth models that are presently limited because they do not predict practical outputs such as fresh weight and size of individual fruits.

Open Access Original Research Article

Phosphorus Adsorption Isotherm: A Key Aspect for Soil Phosphorus Fertility Management

Lemma Wogi, J. J. Msaky, F. B. R. Rwehumbiza, Kibebew Kibret

Journal of Experimental Agriculture International, Page 74-82
DOI: 10.9734/AJEA/2015/13363

Characterization of soils in terms of phosphorus adsorption capacity is fundamental for effective soil phosphorus fertility management and for efficient utilization of phosphorus fertilizers. Thus, this study was conducted to investigate the phosphorus adsorption characteristics of soils of two farms and to elucidate the implication of soil phosphorus adsorption isotherm studies for soil phosphorus fertility management. The two farms, representing the major farming systems of the respective districts, were selected from Adele village in Haramaya district and Bala Langey village in Kersa district in eastern Ethiopia. Soil samples were collected from the crop fields at Adele and Bala Langey farms. Two different P-bearing sources, potassium dihydrogen phosphate (KH2PO4) and diammonium phosphate (DAP-(NH4)2HPO4), were used for the adsorption isotherm studies. The adsorption data were fitted to the linear and Freundlich adsorption isotherm models. Both models revealed that soils of both farms had different P adsorption capacity from the two P sources. Amount of P adsorbed from DAP solution was higher than the amount of P adsorbed from KH2PO4 solution in soils of both farms. Phosphorus adsorption capacity of Adele farm soils was higher than that of Bala Langey farm soils. Therefore, soils of the two farms should be managed differently for P fertility. Percentages of P adsorbed (% Pa) and P remained in the equilibrium solution (% EC) were also calculated. By plotting the two percentages i.e. % Pa and % EC against the initial concentration of P (IC), two regions were observed. The two regions were described as P intensity and quantity factor windows. Based on the intensity and quantity factor windows, at currently existing soil condition, between 200 and 500 kgha-1 P should be applied as fertilizer to soils of Adele at 0-30 cm depth for immediate benefits and soil P fertility maintenance.

Open Access Original Research Article

Effects of Planting Dates on Leaf and Grain Yield of Black-Eyed Bean Cowpea Type in Mashonaland East Province in Zimbabwe

A. Matikiti

Journal of Experimental Agriculture International, Page 83-92
DOI: 10.9734/AJEA/2015/11528

Aims:  To determine the effect of planting date on leaf and grain yield of Black-eyed bean (BEB) of cowpea type,

Study Design: A field experiment was carried out in a factorial arrangement in randomised complete block design with three replications. 

Place and Duration of Study: The study was conducted at both on-station (University of Zimbabwe, Crop Sciences Department experimental blocks and on-farm in Mashonaland East Province, Mutoko District, Katsukunya village during the 2005 – 6 and 2006 - 7 cropping seasons. 

Methodology: Two sowing dates (14 December and 16 January) were used. The leaf harvesting treatments were started four WACE for the cowpea to set a sufficient framework on both stations.  Leaf harvesting was done every week on Fridays for on-station and Wednesdays for on-farms sites and terminated at the 50% flowering stage for BEB after harvesting for four weeks (7 WACE) at the UZ site and for three weeks (6 WACE) in Mutoko a total of twenty-four plants were harvested per each treatment.   

Results: The results showed that planting date had significant effect on leaf, grain and biomass yield.  Highest (1492 kg/ha) grain yield was obtained with late planting in January while highest (1225.5 kg/ha) leaf yield was obtained with early planting in December

Conclusion: Planting date is an important factor influencing both leaf and grain yield of cowpea.

Open Access Original Research Article

Effects of Jatropha Seed Cake (JSC) and Different Inorganic Fertilizers on Growth and Yield of Two Groundnut Cultivars under Three Harvesting Periods

S. M. H. Elseed, S. O. Yagoub, I. S. Mohamed

Journal of Experimental Agriculture International, Page 93-103
DOI: 10.9734/AJEA/2015/11027

Aim: to investigate the effect of Jatropha Seed Cake (JSC) and different fertilizers on growth and yield of two groundnut cultivars under three harvesting periods
Study Design: The experimental design was a randomized complete block in a split-plot replicated three times. Groundnut cultivars arranged as whole plots and five fertilizers treatment as sub- plot.
Locations: field experiments were conducted for two seasons 2011/12-2012/13 under semi-arid condition of Khartoum state in demonstration farm of Sudan University of Science and Technology, Khartoum North, Shambat.
Material and methods: The treatments were Jatropha Seed Cake (2.5 t/ha), sulfur (119 kg/ha), single super phosphate (119 kg/ha), ammonium sulphate (119 kg/ha) and control on two groundnut cultivars (Sodri) and (Gebish) under three harvesting time (every 10 days).
Results: The results showed that yield increased with delayed in harvest periods for two seasons. The two tested cultivars revealed similar behavior during vegetative and reproductive growth. Except for plant height of third harvest of first season, primary branch of second harvest and yield of first and third harvest of two seasons. Results showed significant difference among fertilizers treatments and interaction between cultivars and fertilizers concerning the majority of growth and yield components. Super phosphate gave significant difference on leaf area index, plant height, number of primary branches, number of primary branches, number of pods/plant, germination %. On the other hand, sulfur and ammonium sulphate gave significant difference on number of pods/plant, germination % and yield. Ammonium sulphate and Jatropha Seed Cake reviled significant effect on yield in first and second season respectively
Conclusion: In conclusion addition of Jatropha Seed Cake and inorganic fertilizers appeared to be more promising. Delaying harvesting periods gave positive results.

Open Access Original Research Article

Standard Ear Yield and Some Agronomic Characteristics of Baby Corn var. ksc 403 su under Influence of Planting Date and Plant Density

Atena Rahmani, Majid Nasrolah Alhossini, Seyed Mohsen Nabavi Kalat

Journal of Experimental Agriculture International, Page 104-111
DOI: 10.9734/AJEA/2015/13832

In order to investigate of standard ear yield and some agronomic characteristics of baby corn under influence of planting date and plant density an experiment was conducted at Khorasan Razavi Agricultural and Natural Resources Research center, Mashhad, Iran in 2010. In this research planting date (14 June, 3 July and 24 July) and plant densities (65000, 85000 and 105000 plant    ha-1) were arranged in main and sub plots, respectively. This experiment was laid out using a split plot design with four replications. The results indicated that different planting dates had significant effects on agronomic traits such as plant height, ear height, number of leaves above ear, stem diameter, ear length, and ear diameter, dehusked and husked baby corn yield, standard and sub-standard dehusked ear yield, standard and sub-standard ear percentage. The highest husked ear yield with 13240 kg ha-1 was belonged to 24 July planting date. Although, delay in planting date, led to increase of growth period prevail suitable weather (low temperatures) at anthesis, therefore, ear yield increased but caused to the reduction of ear length and increased ear diameter. Also, ear marketing obviously decreased, not only for fresh consumption but also for industry. The highest dehusked standard ear yield (722 kg ha-1) was obtained from the highest plant density. Interaction effect of planting date × plant density had significant on standard ear percentage at a 5% level of probability. Finally, planting date of 14 June and the highest planting density of 105000 plant ha-1, is recommended in order to maximize and produce high quality standard ear that can be presentable in market.

Open Access Original Research Article

Effects of Petroleum Products in Soil on α-Amylase, Starch Phosphorylase and Peroxidase Activities in Cowpea and Maize Seedlings

F. I. Achuba, P. N. Okoh

Journal of Experimental Agriculture International, Page 112-120
DOI: 10.9734/AJEA/2015/9750

Aims: To determine the effect of petroleum products (kerosene, diesel, engine oil and petrol) contaminated soil at various concentrations on the activities of α-amylase, starch phosphorylase in the cotyledons of cowpea and maize seedlings as well as peroxidase activity in the leaves of both seedlings.

Place and Duration of Study: This study was conducted in Delta State University, Abraka, Nigeria between April 2007 and August 2011.

Methodology: Improved varieties of maize (Zea mays L) and Vigna unguiculata (L) Walp were planted in soil contaminated at different concentrations comprising six groups. Each group was replicated five times. Groups 1 to 5 contained 0.1%, 0.25%, 0.5%, 1.0% and 2.0% (v/w) respectively of each of the petroleum products while group six served as control (0.0%). Three seeds were planted in each bag and watered daily. Four days after germination the activities of α-amylase, starch phosphorylase in the cotyledons of the cowpea and maize seedlings were analysed. This was followed by the determination of peroxidase activity in the leaves of cowpea and maize seedlings four, eight and twelve days after germination.

Results: The results showed that the petroleum products caused metabolic perturbations in the seedlings. This is indicated by the significant (P<0.05) decrease in the activities of starch degrading enzymes: α-amylase and phosphorylase as well as peroxidase activity compared to their respective control values.

Conclusion: Kerosene decreased the activities of the enzymes more than the other petroleum products. The effect of petroleum products contaminated soil was more severe in cowpea seedlings relative to maize seedlings.

Open Access Original Research Article

Adoption of Improved Maize Farming Technologies by Women Farmers in Zambia

Christopher Sebatta, Mukata Wamulume

Journal of Experimental Agriculture International, Page 121-132
DOI: 10.9734/AJEA/2015/13889

The aims of this study were to identify key factors that affect women household heads’ awareness and knowledge of existing improved farming technologies and to determine the factors that influence women farmers’ adoption of animal draught (ox plough) and agroforestry in Zambia. The study was a survey in which semi structured questionnaires were used to interview women household heads. The focus of this study was mainly on women farmers who are household heads cultivating maize under draught animal (ox) and agroforestry farming practices. The study was conducted in Mkushi and Mazabuka districts in the Central and Southern provinces of Zambia respectively. Data were collected between June 2012 and September 2012.

Mkushi and Mazabuka districts were purposively selected because they lie within the “maize belt” of Southern Africa where maize production intensification technologies have been implemented since the 1990’s. The study was conducted at micro level (village level) in the selected agricultural blocks, after which stratification of women farmers was done among adopters and non adopters. Finally, simple random sampling was used in selecting 50 adopters and 114 non-adopters from the two strata. Data were analysed using STATA software. Descriptive statistics and the multi-stage logit regression model formed the basis of analysis.

Access to communication gadgets like phones and membership to farmers’ groups was found to increase the probability of awareness of technologies among women farmers by 90% and 35% respectively. The size of land under cultivation was found to increase the likelihood of adoption of ox plough technology by 29% while at the same time reducing the likelihood of adopting agroforestry technologies by 68%.Results revealed that women adopters had higher maize yields at 949 Kg/ha compared to 861.9 Kg/ha for non-adopters. This is mainly attributed to the advantages that come with sustainable agricultural practices like agroforestry.

Communication related factors are key in creating and increasing awareness of existing technologies among women farmers. Similar factors seem to promote adoption of both animal draught (ox plough) and agroforestry technologies among women farmers though expanding scale of production leads to more likelihood of ox plough adoption and later transition to more sophisticated machinery like tractors.