Advances in Agriculture and Agricultural Sciences

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (3), pp. 001-008, March, 2018. © International Scholars Journals

Full Length Research Paper

Nitrogen budgets in crop sequences with or without phosphorus-fertilised cowpea in the maize-based cropping systems of semi-arid eastern Africa

J. M. Vesterager, N. E. Nielsen and H. Høgh-Jensen*

Department of Agricultural Sciences, Faculty of Life Sciences, University of Copenhagen, Højbakkegaard Alle 9, DK-2630 Taastrup, Denmark.

Accepted 16 January, 2018

Abstract

Advantages of cowpea were tested in terms of net N-input by cowpea mono- or intercropped with maize in a crop sequence where sparingly soluble P sources were added to the first year crop. The grain yield of maize grown after cowpea monocrop was doubled and the N uptake increased by 60% compared to maize following maize. The N-value of growing cowpea monocropped prior to maize monocrop was equivalent to the application of 50 kg N ha^-1 as mineral fertiliser. When maize followed a maize-cowpea intercrop, grain yield was increased by 67%. Around 34% of the N contained in cowpea residues was recovered in the following maize as estimated by ¹⁵N. There was however no benefit on the second season maize of applying sparingly soluble P sources to the first season legume.

Key words: Cowpea, crop sequences, maize, nitrogen budgets, sparingly soluble phosphorus.

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (3), pp. 001-009, March, 2018. © International Scholars Journals

Full Length Research Paper

Effect of differential irrigation on physical and histochemical properties of kenaf (Hibiscus cannabinus L.) grown in the field in Eastern Nigeria

Nkaa, F. A.*, Ogbonnaya, C. I. and Onyike, N.B.

Department of Plant Science and Biotechnology, Abia State University, Uturu, Nigeria.

Accepted 14 January, 2018

Abstract

The effect of moisture stress on the physical and histochemical properties of three certified improved varieties of Kenaf (Hibiscus cannabinus L.) relevant to pulp and paper production were investigated. The test plants were grown in the field on a deep sandy-loam soil in the Botanical Garden of Abia State University, Uturu. Three watering regimes representing well-watered control, moderate stress and severe water stress were imposed on the plants. Each irrigation regime was replicated three times in a split plot design with watering treatments as the main plots and the varieties as the sub-plots. Water deficit did not adversely affect the fibre dimensional properties as well as the fibre derived values. Analysis of histochemical properties of Kenaf indicated that water deficit enhanced these properties in the stressed plants when compared with well-watered plants. Thus suggesting that water stress enhances the quality of pulp and paper produced from Kenaf.

Key words: Hibiscus cannabinus, kenaf, histochemical, pulp, paper, water deficit.

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (2), pp. 001-004, February, 2018. © International Scholars Journals

Full Length Research Paper

Epidemiological studies of white rust, downy mildew and Alternaria blight of Indian mustard (Brassica juncea (Linn.) Czern. and Coss.)

Sangeetha, C.G. and A. L. Siddaramaiah

Department of Plant Pathology, G.K.V.K, University of Agricultural Sciences, Bangalore –560065.

Accepted 12 October, 2017

Abstract

White rust, downy mildew and Alternaria blight caused by Albugo candida (Pers.) Kuntze Peronospora parasitica (Pers.) (de Bary) and Alternaria brassicicola (Schw.) Wiltshire respectively are important diseases on Indian mustard causing considerable loss. Maximum temperature positively correlated with disease index of all the three diseases. Maximum temperature from 26-29ºC and average relative humidity of more than 65% favoured the development of all the three disease.

Key words: Disease incidence, maximum, minimum temperature, relative humidity.

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (1), pp. 001-005, January, 2018. © International Scholars Journals

Full Length Research Paper

A weighted relative density model applied to loblolly pine (Pinus taeda L.) stands

John M. Lhotka¹ and Edward F. Loewenstein²

¹University of Kentucky, Department of Forestry, 105 T. P. Cooper Building, Lexington, KY 40546-0073.

²Auburn University, School of Forestry and Wildlife Sciences Building, Auburn University, Alabama 36849-5418.

Accepted 09 April, 2017

Abstract

We present a weighted, individual-tree relative density approach whose reference conditions have the same distribution of crown areas and species as a subject stand. An initial evaluation of the method’s efficacy was performed within an even-aged loblolly pine (Pinus taeda L.) plantation. Species-specific reference density equations were developed using plot data and existing crown width equations. Diameter growth prediction was evaluated using data from a thinned 20-year-old plantation. Regression analysis was used to related annual diameter increment and the approach’s density indices. The predictive ability of the presented method was compared to existing approaches such as Stand Density Index (SDI) and Crown Competition Factor (CCF). Results suggest the weighted, individual-tree approach predicts diameter increment as well as traditional indices. These findings suggest an individual tree approach may not be necessary within an even-aged loblolly pine plantation with a narrow diameter range.

Key words: relative density, size-density, Pinus taeda L., loblolly pine.

Advances in Agriculture and Agricultural Sciences ISSN 2381-3911 Vol. 4 (1), pp. 001-005, January, 2018. © International Scholars Journals

Full Length Research Paper

Esterase isoenzymes are linked to embryogenic structures induction in cotton cell suspension cultures

Kouakou Tanoh Hilaire¹, Kone Daouda², Zouzou Michel², Kouadio Yatty Justin¹

¹Université d’Abobo-Adjamé, UFR des Sciences de la Nature, Laboratoire de Biologie et Amélioration des Productions Végétales, 02 BP 801 Abidjan 02, Côte d’Ivoire.

²Université de Cocody, UFR Biosciences, Laboratoire de Physiologie Végétale, 22 BP 582 Abidjan 22, Côte d’Ivoire.

Accepted 03 April, 2017

Abstract

Esterase activity and isoenzymes pattern of two cultivars of cotton ( Gossypium hirsutum L.), Coker 312 an embryogenic cultivar and ISA 205N a non embryogenic cultivar, were studied and compared during cell suspension cultures. The use of polyacrylamide gel electrophoresis allowed the identification of isoenzymes that number increased with the successive stages of cell culture of the two cultivars. At the stage of embryogenic structures induction which occurs only in Coker 312 cell suspension, we noted the presence of two isoenzymes (y and z) identified as aryl esterase, while one isoenzyme (x) identified as choline esterase was exclusively found in the cell suspensions of the non embryogenic cultivar ISA 205N. Esterase activity increased in cells of Coker 312 whereas it’s remained constant in ISA 205N. These results suggested a great implication of esterase enzyme in the induction of embryogenic structures during cotton cell suspension cultures.

Key words: Gossypium hirsutum L., cultivar, cell suspensions, embryogenic structures, Esterase; isoenzyme.