African Journal of Crop Science

African Journal of Crop Science ISSN 2375-1231 Vol. 7 (10), pp. 001-010, October, 2019.  © International Scholars Journals

Full Length Research Paper

Effect of proportion of component species on the productivity of Solanum aethiopicum and Amaranthus lividus under intercropping

Charles K. Ssekabembe

Department of Crop Science, Makerere University. P. O. Box 7062, Kampala, Uganda. E-mail: [email protected]. Tel. 0782896886 (Mobile).

Accepted 15 June, 2019

Abstract

In central Uganda, ‘garden egg’ (Solanum aethiopicum) is commonly intercropped with ‘spleen amaranth’ ( Amaranthus lividus) but the productivity of this mixture is unknown. The objective of the experiment was to determine the yield advantage from this mixture. Treatments tested included pure stands of Solanum aethiopicum and Amaranthus lividus, locally called nakati and ebugga, respectively, ‘additive mixtures’, and several ‘replacement series’ mixtures. Generally, pure stands gave the highest total and edible DM yields. For each species, DM yield in mixtures was significantly higher (P<0.05) in mixtures in which it constituted the highest proportion, that is 75:25% Solanumi:Amaranthus replacement series mixture in the case of S. aethiopicum, and 25:75% mixture in the case of A. lividus. Intercropping reduced total S. aethiopicum DM yield by 72% in the 25:75% Solanum:Amaranthus mixture, while A. lividus yield was reduced by 68% in the 75:25% mixture. There was high correlation between S. aethiopicum and A. lividus plant population and edible DM yield (r = 0.71 and 0.98, respectively).The difference in yield between pure stand S. aethiopicum and the 75:25% Solanum:Amaranthus mixture was not significant yet it was associated with 93 kg ha^-1 of edible DM yield of A. lividus as a ‘bonus’ yield, equivalent to 27% of the edible DM yield of pure stand A. lividus. Generally, the additive mixtures gave higher S. aethiopicum DM yield than the replacement series mixtures with less than 50% S. aethiopicum. The 37% lower edible DM yield of S. aethiopicum in the double compared to the single additive mixture was attributed to greater competition against S. aethiopicum by the double Amaranthus rows compared to the single Amaranthus rows but the double additive mixture had about 55% more edible Amaranthus DM yield than the single additive. Most mixtures gave yield advantages, with the double (47%) and single (39%) additive mixtures giving higher yield advantages than the replacement series mixtures. On the basis of gross returns, most mixtures were more profitable than the pure stands.

Key words: Garden egg (Solanum aethiopicum), spleen amaranth (Amaranthus lividus), proportion of component species, plant population, intercropping, yield advantage.

African Journal of Crop Science ISSN 2375-1231 Vol. 7 (8), pp. 001-006, August, 2019. © International Scholars Journals

Full Length Research Paper

Biological effect of ethanolic extract fractions of Ricinodendron heudelotii (Baill) Pierre ex Pax against Sitophilus zeamais Motschulsky and Callosobruchus maculatus Fabricius on stored grains

Udo, I. O.¹ and Epidi, T. T.²*

¹Department of Crop Science, University of Uyo, P.M.B.1017, Uyo, Nigeria.

²Department of Crop Production Technology, Niger Delta University, Wilberforce Island, P. M. B. 071, Yenagoa, Bayelsa State, Nigeria.

Accepted 03 June, 2019

Abstract

Ethanolic extract of dried leaves of Ricinodendron heudelotii was partitioned between equal volumes of hexane, ethylacetate, chloroform, butanol and water to obtain the various fractions. These fractions were assessed in the laboratory against Sitophilus zeamais and Callosobruchus maculatus on stored maize and cowpea, respectively. 100 g each of maize and cowpea grains were treated with the extract fractions to test for contact toxicity, damage assessment and progeny production. Furthermore, contact toxicity on filter paper and toxicity by topical application as well as repellency test were also carried out. Results obtained showed a significant (P < 0.05) insect mortality when the fractions were applied topically and by grain treatment. There was also a significant reduction in damage caused while progeny development was very low. The extract fractions significantly repelled the 2 insect species with an overall repellency of 48%. This work recommends the incorporation of R. heudeotii into storage pest management systems.

Key words: Ricinodendron heudelotii, toxicity, repellency, stored grains, Callosobruchus maculatus, Sitophillus zeamais.

African Journal of Crop Science ISSN 2375-1231 Vol. 7 (7), pp. 001-007, July, 2019. © International Scholars Journals

Full Length Research Paper

Effect of storage and heat treatments on the germination of oil palm (Elaeis guineensis Jacq.) seed

Beugré Manéhonon Martine¹, Kouakou Kouakou Laurent¹, Bognonkpé Jean Pierre¹, Konan kouakou Eugène², Kouakou Tanoh Hilaire¹and Kouadio Yatty Justin¹

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

²Programme Palmier, Laboratoire de culture in vitro, CNRA Station La Mé, 13 BP 989 Abidjan 13, Côte d’Ivoire.

Accepted 21 April, 2019

Abstract

Oil palm (Elaeis guineensis Jacq.) is a perennial tropical tree which reproduces only by seeds. In the nature, the seeds have a relative dormancy leading to very long germination process (1 to 3 years). In order to improve oil palm production, research aiming at the reduction of the dormancy period was initiated. The germination tests carried on seeds stored for different periods after harvest, showed a germination percentage of fresh seeds (not stored) significantly higher (55.39 %) than that of seeds stored for 3 months (45.78%) and 6 months (38.68%). This germination ability also varies significantly with the two palm genotypes (C70XX from LM 19954 and C24XX from linear LM 19617) developed by the Centre National de Recherche Agronomique (CNRA) in Côte d’Ivoire and used in the present study. Seeds of category C70XX from LM 19954 linear present a significant superior percentage of germination than those of the category C24XX from linear LM 19617. In order to break seeds dormancy, heat incubation at 40°C was applied for different durations (40, 60 and 80 days). Seeds incubated for 60 days at 40°C induced higher germination percentage (56.3%) compared to the current applied delay of 80 days heating. 40 days heating period appeared to reduce the germination capability. According to these results, the usual germination techniques for oil palm seedlings production can be improved by shortening germination delay of seeds.

Key words: Oil palm, Elaeis guineensis Jacq., seed, storage, heating, germination.

African Journal of Crop Science ISSN 2375-1231 Vol. 7 (7), pp. 001-009, July, 2019. © International Scholars Journals

Full Length Research Paper

Effects of carbon and nitrogen sources and ratio on the germination, growth and sporulation characteristics of Metarhizium anisopliae and Beauveria bassiana isolates

Uzma Mustafa and Gurvinder Kaur*

Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati-39, Assam, India.

Accepted 11 April, 2019

Abstract

The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana are ubiquitous and widespread with well documented broad- spectrum myco-pesticidal effects. It has been reported that nutrient source is an integral determinant of growth and virulence of entomopathogenic fungi. Nutrient based studies also impart light towards the identification of most commendable media for laboratory assays as well as selection of the tolerant isolates. With such a perspective, an in-vitro study was undertaken to evaluate conidial germination, mycelial growth and spore yield of fourteen M. anisopliae and seventeen B. bassiana isolates and the effect of different carbon and nitrogen sources on these characteristics were studied. The different isolates showed significant variation with respect to the differing preference for the nutrient sources. From this study it was inferred that isolate UM2 (M. anisoplaie) and AB1 ( B. bassiana) exhibited commendable growth potentials on almost all the nutrient sources studied, and were basically more robust isolates and holds high affirmations for commercial usage as biopesticides.

Key words: Metarhizium anisopliae, nutrition, germination, growth, sporulation, Beauveria bassiana.

African Journal of Crop Science ISSN 2375-1231 Vol. 7 (6), pp. 001-007, June, 2019. © International Scholars Journals

Full Length Research Paper

Association of maize streak virus disease and its vectors (Homoptera: Cicadelidae) with soil macronutrients and altitudes in Kenya

O. E. V. Magenya¹*, J. Mueke² and C. Omwega³

¹Kenya Agricultural research institute, Kisii Regional Research Centre, P .O. Box 523, Kisii, Kenya.

²Department of Zoology, Kenyatta University, P. O. Box 43844-00100, Nairobi Kenya.

³International Centre of Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi Kenya.

Accepted 18 March, 2019

Abstract

Maize (Zea mays L.) is a staple food for more than 100 million people in Africa. Its production is constraint by maize streak virus (MSV) disease. This study investigated the interrelationships between altitudes and levels of soil macronutrients with MSV disease and its vectors. The influence of nitrogen, phosphorus and potassium levels on MSV and on populations of Cicadulina spp. (Homoptera: Cicadellidae) were investigated at six geographically separated maize producing regions in Kenya. Comparisons of numbers of sampled Cicadulina spp showed that areas at lower than 1550 m above sea level had significantly more leafhoppers than those at higher altitudes (p < 0.05, SNK). Soil analysis showed that nitrogen was low (0.06 - 0.12%), phosphorus (13.5 - 37.3 ppm) and potassium adequate (86 - 707 ppm). The yield loss due to MSV expected by the farmers in Oyani was similar to that in Mwea (>40%) and higher than that in Bahari, Muhoroni, Kimilili and Githunguri (< 30%) and it correlated positively with numbers of Cicadulina mbila. A significant positive correlation was detected between potassium with C. mbila. This study shows that soil nutrient levels influence MSV vector (Cicadulina spp) and that this relationship is critical during the design of crop protection packages.

Key words: Agro-ecology, Cicadulina, nitrogen, phosphorus, potassium and elevation.