Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI

Pretoria, South Africa

Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI

Pretoria, South Africa

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Maboko M.M.,Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI | Du Plooy C.P.,Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI
Acta Agriculturae Scandinavica Section B: Soil and Plant Science | Year: 2013

The objective of this study was to determine the combined effect of plant densities and leaf harvesting method on yield of hydroponically grown basil. The experiment was carried out during the spring/summer (September-December 2012) and during summer/fall (January-April 2013) seasons. Basil plantlets were transplanted 30 days after seeding, utilising a gravel-film technique hydroponic system under a 40% black-and-white shadenet structure. Plants were subjected to five plant densities, i.e. 10, 16, 20, 25 and 40 plants/m2, with two harvesting methods, i.e. tipping and cutting. Experimental layout was a randomised complete block design with four replicates. During the spring/summer season, the results showed no significant differences in plant growth and total yield per unit area at plant densities of 20, 25 or 40 plants/m2. Results during the summer/fall season showed the highest leaf fresh mass, leaf area and total plant fresh mass at the highest plant density of 40 plants/m2. Harvesting method did not have a significant effect on yield or on the total fresh and dry mass of basil. Results demonstrate that a plant density of 40 plants/m2 can improve growth and yield of basil significantly during the summer/fall season. However, during the spring/summer season, a plant density of 20 and 25 plants/m2 will be more cost effective with no significant effect on yield. Plant density recommendations are, therefore, 40 plants/m2 during the summer/fall season and 20 or 25 plants/m2 during spring/summer season. © 2013 © 2013 Taylor & Francis.


Maboko M.M.,Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI | Du Plooy C.P.,Agricultural Research Council ARC Vegetable and Ornamental Plant Institute VOPI
Acta Agriculturae Scandinavica Section B: Soil and Plant Science | Year: 2013

Decapitation of tomato growing point's results in a shortened growth season with no new flower trusses initiated thereafter. Since less flower trusses could lead to reduced yield, this study was conducted to investigate whether increased plant density could contribute to increase yield per unit area. The response of nine tomato cultivars with early decapitation of growing points at different plant densities (10, 16, 20 and 25 plants/m2) was investigated in a closed hydroponic system under a 40% white shadenet structure. The growing points of all plants were removed between the second and third inflorescence, with two leaves remaining above the second inflorescence. Fruit physiological disorders, number of fruits, as well as total and marketable yield were recorded. Cultivar 'Miramar', gave the highest marketable and total yield, followed by cultivars 'Rodade' and 'Alfar'. Cultivars 'Alexis', 'Star9006' and 'Zeal' produced highest average fruit mass compared to other cultivars. There was no significant interaction effect between cultivars and plant densities on tomato yield. Fruit cracking was significantly higher for 'Linares' and 'Star9006', while raincheck was higher for cultivars 'Alexis' and 'FA593'. 'Rodade' showed high incidence of zippering. Plant densities of 20 or 25 plants/m2 produced significantly higher marketable and total yield, while plant densities of 10 or 16 plants/m2 resulted in higher average fruit mass and highest incidence of fruit cracking. Nutrient uptake, as revealed in the mineral content of fruit, was not affected by plant density. Cultivar 'Rodade', an open-pollinated determinate cultivar, especially shows potential to compete with more expensive hybrid cultivars in such a production system in terms of yield. Results demonstrate that high-density planting of tomato with decapitated growing points increased yield per unit area in a closed hydroponic system. © 2013 © 2013 Taylor & Francis.

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