African Journal of Agriculture

African Journal of Agriculture ISSN 2375-1134 Vol. 9 (2), pp. 001-011, February, 2022. © International Scholars Journals

Full Length Research Paper

Effects of two legume crops, for organic green manure, on weed flora, under mediterranean conditions: Competitive ability of five winter season weed species

Dimitrios Bilalis*, Anestis Karkanis and Aspasia Efthimiadou

Laboratory of crop production, Department of Crop Production, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.

Accepted 30 September, 2021

Abstract

Field experiments were conducted to determine the effects of vetch (Vicia sativa c.v lexander) and red clover (Trifolium pratense c.v Nemaro) on weed flora. The design of the experiment was randomized complete block with 4 replicates and 3 treatments (a: vetch crop, b: red clover crop and c: control (fallow)). Both legume crops suppressed weed biomass. The lowest number and dry weight of weeds was found in vetch plots. The highest height of weeds was found in control plots. Moreover, the highest multiplied dominance ratio (MDR) of weeds was found in the control plot. Vetch was the most competitive legume crop. The number of shoots per plant and dry weight were considered suitable attributes for weed suppression, although competitiveness is a relative rather an absolute characteristic. In addition, red clover is considered a poor competitor because of lack of seedling vigour and slow establishment. Statistically significant negative correlation between the fraction of photosynthetically active radiation (PAR) intercepted by the canopy, weed density and weed biomass was observed. The MDR of weeds (Lamium aplexicaule, Papaver rhoeas, Sinapis arvensis, Chamomilla recutita and Phalaris minor) had a good correlation with dry weight of weeds. Analysis of MDR demonstrated that L. aplexicaule and C .recutita are poor competitors because of small leaves and low height. Final, S. arvensis and P. minor were the most competitive weeds.

Key words: Multiplied dominance ratio, photosynthetically active radiation, vetch, red clover, weed flora.

African Journal of Agriculture ISSN 2375-1134 Vol. 8 (3), pp. 001-009, March, 2021. © International Scholars Journals

Full Length Research Paper

Antioxidant substances and pesticide in parts of beet organic and conventional manure

Maria Rosecler Miranda Rossetto¹, Fabio Vianello², Suraya Abdallah da Rocha¹and Giuseppina Pace Pereira Lima¹

¹Department of Chemistry and Biochemistry, Biosciences Institute, São Paulo State University, Botucatu, São Paulo, Brazil.

²Department of Biological Chemistry, University of Padova, Padova, Italy.

Accepted 26 October, 2020

Abstract

Organic agriculture together with sustainable management systems are growing in the world due to concerns about the environment and the health of the populace: being real and exhaustively documented the damages caused by pesticides. The aim of this work was to observe the possible differences in the concentrations of free radical scavengers and substances recently classified as functional, in different beet parts cultivated following organic and conventional procedures. Regarding the total antioxidant activity (AA%), significant differences were not observed between the two cultivation procedures, being found a high AA% in every beet part analyzed. Organic plants concentrated higher vitamin C content (6.7 - 16.6 mg/100 g) with respect to the conventional ones (4.1 - 9.1 mg/100 g); higher flavonoid content (0.5 - 5.2 mg rutin/g) and, when cooked, the pulp of organic beet maintained a higher polyamine content and higher amount of total carotenoids. No significant differences were observed for total phenolic compounds.

Key words: Vitamin C, pesticides, putrescine, spermidine, spermine, index of antioxidant activity.

African Journal of Agriculture ISSN 2375-1134 Vol. 8 (1), pp. 001-007, January, 2021. © International Scholars Journals

Full Length Research Paper

Growth, nodulation and yield of black gram [Vigna mungo (L.) Hepper] as influenced by biofertilizers and soil amendments

A. Javaid

Institute of Mycology and Plant Pathology, University of the Punjab, Quaid-e-Azam Campus Lahore, Pakistan. E-mail: [email protected].

Accepted 17 August, 2020

Abstract

EM (effective microorganisms) is a commercial biofertilizer mainly consists of photosynthetic and lactic acid bacteria, yeast and actinomycetes. The present study was undertaken to investigate the effect of EM application and two strains of nitrogen fixing Bradyrhizobium japonicum (TAL- 102 and MN-S) on plant growth, nodulation and yield of black gram [Vigna mungo (L.) Hepper] in different soil amendment systems including unamended soil, farmyard manure (FYM) @ 5 g 100 g^-1, Trifolium alexandrinum green manure (GM) @ 4 g 100 g^-1 and recommended dose of NPK fertilizers. Nodule number was significantly enhanced by inoculation of either of the two B. japonicum strains in NPK and un-amended soils. A marked increase in nodule biomass was also recorded due to B. japonicum inoculation in these 2 types of soils. Grain yield was significantly increased by 46% due to either of the two B. japonicum strains in NPK amended soil. EM application markedly enhanced nodule number in FYM amended soil. Conversely, EM application in combination with either of the two B. japonicum strains resulted in pronounced reduction both in number and biomass of nodules in NPK fertilizers amendment. EM application significantly enhanced grain yield by 48% in NPK amendment without B. japonicum inoculation.

Key words: Black grams, Bradyrhizobium japonicum, effective microorganisms, nitrogen fixation, soil amendments.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (11), pp. 001-003, November, 2020. © International Scholars Journals

Short Communication

Seed coating of safflower (CARTHAMUS  TINCTORIUS  L.) in order to delay germination

Khoshnood Alizadeh Dizaj

Islamic Azad University, Mahabad Branch, Iran. Tel: +98 (421) 2248761, +98 9144212005. E-mail:[email protected]. Fax: +98 (442) 2341005.

Accepted 25 April, 2020

Abstract

The idea tested was the restriction of water uptake as a means of influencing the germination rate of the coated seed. This led to the choice of an acrylic plastic polymer to be used as coating material. Assembled spinning disc equipment was used for coating the seeds. The germination tests of the coated seeds were performed in Petri dishes in a randomized complete blocks design with five replications. With increasing coating times in different polymer concentration, there was a decrease in germination rates in the first 5 days to at least 5%. It is concluded that two times application of 150 g/l acrylic plastic polymer in alcohol was the best treatment for delay of safflower germination in controlled conditions.

Key words: Delayed germination, hydrophobic polymers, safflower.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (11), pp. 001-010, November, 2020. © International Scholars Journals

Full Length Research Paper

Effect of sowing date and planting density on seed production of carrot (Daucus carota var. sativa) in Ethiopia

Tesfu Mengistu¹ and Charles Yamoah²*

¹Department of Dryland Crop Sciences, Faculty of Dryland Agriculture, P. O. Box 1020, Jigjiga University, Jigjiga, Ethiopia.

²Department of Land Resource Management and Environmental Protection, Faculty of Dryland Agriculture, P. O. Box 231, Makelle University, Mekelle, Ethiopia.

Accepted 26 March, 2020

Abstract

An experiment was conducted in 2006 and 2007 cropping seasons to investigate the effect of sowing date and planting density on yield and quality of carrot seed. The crop was grown in factorial combination of four sowing dates (mid November, December, January and February) and four different planting densities (133 333, 200 000, 266 666, and 400 000 plants/ha) in randomized block design with three replications. The plant spacing corresponding to the aforementioned densities were 50 cm × 5 cm; 50 cm × 10 cm; 75 cm × 5 cm and 75 cm × 10 cm, respectively. Both yield and seed quality declined progressively as sowing was delayed from November to February. Increasing the planting density from 133 333 plants/ha to 400 000 plants/ha increased the overall seed yield of November and December plants. However, for January and February, seed yield was observed to decline with increased planting density, because of heavy rainfall and infestation of Alternaria leaf blight at flowering stage. Planting density had no significant effect on seed quality (p 0.05). Seed yield per plant significantly (r = 0.55*) correlated with number of branches per plant, plant height (r = 0.73**), umbel diameter(r = 0.780**), number of umbels per plant (r = 0.576**), number of umbellets per umbel (r = 0.783**) and with seed weight per umbel (r = 0.894**).

Key words: Carrot, seed production, planting density, sowing date.

African Journal of Agriculture ISSN 2375-1134 Vol. 7 (11), pp. 001-010, November, 2020. © International Scholars Journals

Full Length Research Paper

Factors influencing soil CO₂ efflux in a northeastern Indian oak forest and plantation

R. R. Pandey¹, G. Sharma¹, T. B. Singh¹ and S. K. Tripathi²*

¹Department of Life Sciences, Manipur University, Canchipur, Imphal-795 003, India.

²Department of Forestry, Mizoram University, Aizawl-796009, India.

Accepted 21 October, 2020

Abstract

Temporal changes in soil CO₂ efflux rates were measured in a subtropical natural mixed oak forest and managed oak plantation in the northeastern Himalayan region. Soil CO₂ efflux rates in two ecosystems were correlated with key soil biotic (e.g. fungal, bacterial and actinomycetes populations) and abiotic (e.g. soil moisture, temperature, pH and organic carbon concentration) variables. Rate of CO₂ efflux (mg CO₂ m^-2 h^-1) at forest and plantation sites varied between 102 - 320 and 99 - 543, respectively. The concentration of soil organic carbon was higher at plantation than natural forest. Bacteria and actinomycetes were dominant species at plantation, whereas, the fungi were dominant at forest. CO₂ efflux at both sites was significantly positively correlated with the populations of these three microbial groups. Among abiotic variables, soil temperature and pH played significant positive role on the rates of soil CO₂ efflux in forest while variables like soil moisture and organic carbon were least accountable. In contrast, at plantation soil CO ₂ efflux was significantly positively correlated with soil moisture, temperature and pH. In the present study, CO₂ efflux was not influenced by the organic C concentration, however, it was affected by the other abiotic and biotic variables. CO₂ efflux rates at plantation was regulated by the presence of bacteria and actinomycetes, whereas, it was controlled by the population of fungi in the natural forest. Management practices operated in plantation appears to affect the group of microbial populations that further affect the soil CO₂ efflux rates.

Key words: Soil CO₂ efflux, biotic and abiotic variables, natural oak forest, managed oak plantation.