Open Access Original Research Article

Impact of Nitrogen Levels and Weed Control Methods on Growth and Yield of Okra (Abelmoschus esculentus (L.) Moench) in the Nigerian Forest-Savanna Transition Zone

J. A. Adigun, O. S. Daramola, O. R. Adeyemi, A. O. Ogungbesan, P. M. Olorunmaiye, O. A. Osipitan

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/JEAI/2018/39107

Aim: To evaluate the effect of nitrogen levels and weed control methods on the growth and yield of okra.

Study Design: Treatments were laid out in a split-plot design.

Place and Duration of Study: Field trials were conducted at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta, Nigeria in the early and late wet seasons of 2015.

Methodology: The main plot treatments comprised of three nitrogen (N) levels (0, 60 and 90 kg N/ha), while the sub-plot treatments were made up of seven weed control methods (probaben® [metolachlor 20%  w/v + prometryn 20% w/v] at 2 kg a.i/ha; probaben® at 2 kg a.i/ha followed by supplementary hoe weeding (SHW) at 6 weeks after sowing [WAS]; butachlor [50% w/v]  at 2.0 kg a.i/ha; butachlor at 2.0 kg a.i/ha followed by SHW at 6 WAS; 2 hoe weedings at 3 and 6 WAS; 3 hoe weedings at 3, 6 and 9 WAS; and weedy check). 

Results: Unchecked weed growth throughout the crop life cycle resulted in 51 and 59% reduction in potential okra fruit yield in the early and late wet seasons, respectively.

Application of N at 90 kg/ha compared to lower rates, increased weed density and weed dry matter production in both seasons. N application at 90 kg/ha resulted in significant increase in growth and fruit yield of okra. All weed control methods resulted in significant reduction in weed growth, and subsequently increased okra fruit yield. The most effective weed control methods were pre-emergence application of probaben® and butachlor at 2.0 kg a.i/ha each followed by SHW at 6 WAS.

Conclusion: Results suggest that farmers can reduce the burden of hoe weeding and cut down on labour input with the use of pre-emergence herbicides for weed control in okra production, and increase okra yield with application of N into the low fertile soils of the forest-savanna transition zones.

Open Access Original Research Article

Comparison of Castor Beans Hybrids Produced by the Conventional Method and by the Cryptic Hybrid Method

Eder Victor Braganti Toppa, Jackson da Silva, Maria Márcia Pereira Sartori, Mauricio Dutra Zanotto

Journal of Experimental Agriculture International, Page 1-12
DOI: 10.9734/JEAI/2018/38569

In Castor beans population’s improvement, new ideas and methods are required in seeking to improve efficiency of obtaining lines and hybrids, as well as decreasing the development time. In this context, the Cryptic Hybrids method appears as an alternative to these questions, which can be configured as an effective tool in breeding programs of species that have the\ZZ mixed type reproductive system. Thus, the objective of this study was of to compare of castor bean hybrids produced by the conventional method, with those of the Cryptic Hybrids method. Experiments to evaluate hybrids on grain productivity were developed in the 2006/2007, 2007/2008 and 2008/2009 agricultural years simultaneously in the municipalities of Lins-SP and Penápolis-SP. This was conducted using randomized block design with four replications. The oil productivity and plant height were determined over the last two years. The results of the castor hybrids grain and oil productivity demonstrated the ability of the cryptic hybrids to overcome the hybrids obtained conventionally. In addition, it was verified that there were no differences in the oil content of the seeds as a function of the method of obtaining hybrids. Regarding the size of the plants, good agronomic characteristics and low size was observed, yet, compared to conventional hybrids, had, on average, greater stature. Thus, the Cryptic Hybrids method was efficient in obtaining superior lines and hybrids of castor bean, when compared to conventional "Standard" method.


Open Access Original Research Article

Comparative Studies on Bioactive Components of Fluted Pumpkin, Telfairia occidentalis Hook F. Grown in Three Selected Solid Media

Kalu Okonwu, Love Akaja Akonye, Stephen Ikechukwu Mensah

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/JEAI/2018/38334

The amino acids, vitamins and proximate composition of fluted pumpkin, Telfairia occidentalis grown in three different selected solid media; humus soil, white-sand and wood sawdust were assessed and compared. Standard procedure and equipment were followed and used, respectively for the determination of the bioactive components of T. occidentalis leaf. Proximate composition of T. occidentalis in the three media were: carbohydrate (12.76%, 20.40% and 6.37%), crude fibre (4.76%, 5.70% and 5.59%), ash content (0.47%, 0.58% and 0.73%), crude lipid (0.30%, 1.00% and 0.10%) and moisture content (81.41%, 72.02% and 86.91%) for humus soil, white-sand and wood sawdust, respectively while the crude protein was constant at 0.30%. In that same order, the total amino acids were 9.75 g/100g, 7.53 g/100 g and 13.46%. The essential amino acids (5.85%, 4.49% and 7.94%) and non-essential amino acids (3.90 g/100 g, 3.04 g/100 g and 5.52 g/100 g) varied for humus soil, white-sand and sawdust, respectively. Among the amino acids, histidine (1.73 g/100 g, 1.34 g/100 g, and 2.45 g/100 g), cysteine (1.26 g/100 g, 0.98 g/100 g and 1.78 g/100 g) and threonine (1.23 g/100 g, 0.96 g/100 g and 1.75 g/100 g) were the most abundant while proline (0.01 g/100 g) was the least for humus soil, white-sand and sawdust as a medium of growth for pumpkin. The percentage water soluble vitamins (B1, B2, B3, B6, B12 and C): 26.16%, 71.42% and 135.53% and fat-soluble vitamins (A, E and K): 18.87%, 19.95% and 41.73% for humus soil, white-sand and sawdust, respectively. The water-soluble vitamins accounted for the high total vitamins obtained. The study has shown that T. occidentalis can be grown in white-sand and sawdust without losing the bioactive compounds rather improving its availability.


Open Access Original Research Article

Importance of NPK Foliar Fertilization for Improving Performance of Tomato (Solanum lycopersicum L.), Managing Diseases and Leafminer (Tuta absoluta)

Christopher Ngosong, Clovis B. Tanyi, Cyril A. Njume, Priscilla M. Mfombep, Justin N. Okolle, Thomas E. Njock, Raymond N. Nkongho, Aaron S. Tening

Journal of Experimental Agriculture International, Page 1-14
DOI: 10.9734/JEAI/2018/39034

Aim: To improve tomato performance, manage diseases and leafminer via NPK foliar fertilization as compared to soil fertilization.

Methodology: Six treatments (control, soil NPK, Soil+Foliar NPK, Mucuna, Tithonia and Mucuna+Tithonia) were evaluated for their potential to improve tomato performance, manage diseases and leafminer.

Results: Tomato disease incidence ranged from 12−100% across treatments that differed (P = .001) significantly, with lowest in Soil+Foliar NPK and highest in control compared to the other treatments (P = .05). A negative correlation occurred between disease incidence and treatments (r = −0.78). Highest tomato blight occurred in control (P = .05) that correlated negatively with treatments (r = −0.79). Highest septoria leaf spot occurred in control (P = .05) that correlated negatively with treatments (r = −0.73). No leafminer was recorded in Soil+Foliar NPK, followed by Mucuna+Tithonia as compared to other treatments (P = .05). Leafminer correlated negatively with treatments (r = −0.88). Tomato disease severity correlated negatively with treatments (= −0.73) and ranged from 9−93% across treatments that differed (P = .001) significantly. Lowest disease severity occurred in Soil+Foliar NPK with the highest in control compared to other treatments (P = .05). Tomato fruit rot correlated negatively with treatments (r = −0.63) and positively with blight (r = 0.52), ranging from 1-17 across treatments that differed (P = .001) significantly, with highest in control compared to other treatments (P = .05). Tomato yield ranged from 10−20 t ha-1 and differed (P = .001) significantly across treatments, with highest in Soil+Foliar NPK treatment and lowest in control (P = .05). Tomato yield correlated positively with treatments (r = 0.92) and negatively with disease severity (r = −0.68).

Conclusion: NPK foliar fertilization demonstrated strong potential to improve tomato performance, manage diseases and leafminer as compared to soil amendments.

Open Access Review Article

Processes of Soil Infiltration and Water Retention and Strategies to Increase Their Capacity

Renan Pan, Alexandra da Silva Martinez, Tauane Santos Brito, Edleusa Pereira Seidel

Journal of Experimental Agriculture International, Page 1-14
DOI: 10.9734/JEAI/2018/39132

Water is one of the most important natural resources for agricultural development and livestock activities since these economic activities are highly dependent on the natural resource for their development. The adoption of strategies that optimize water infiltration and retention processes, in agricultural systems, directly influence agricultural yield and productive and, consequently, the systems sustainability. In this sense, this review aims to discuss some important aspects to understand how water infiltration and retention occurs in the soil and which agricultural administrations should be adopted to optimize these processes. The main processes that interfere in direct and indirect water infiltration, and retention in the soil, are related to texture, structure, porosity, organic matter content, clay type, retention capacity and hydraulic conductivity, precipitation, humidity, temperatures, microstructure, compaction and surface roughness. To improve these processes, management that promote the addition of organic matter to the soil, conservation techniques of soil preparation, crop rotation with the production of straw and irrigation control and drainage processes are extremely important. All managements that improve soil physical conditions are recommended to optimize the processes of infiltration, retention, and availability of water to the plants, recharge of the aquifers and maintenance of the fountains, in sufficient quantity and quality to ensure that the crops develop satisfactorily under various climatic conditions. Systems in which only one tool is used to improve soil infiltration usually work for a short time, such as the soil tillage system and all of its variables, requiring the use of more than one activity with it, for example: crop rotation, manure spread, mulch, to provide better conditions for the soil water infiltration and retention.