Effect of olive cultivars and date of observation on rate of growth of fibrous roots and shoots

Abstract

This investigation was conducted during 1993 – 1995. The objective of this experiment was to determine the annual pattern of root and shoot-growth of young plants (originally propagated by stem cutting) of different olive cultivars. Uniform 5-month- old plants of four cultivars were grown in the nursery of the Faculty of Agriculture, Cairo University at Giza. The cultivars were: Picual, Koratina, Manzanillo and Agezi Shami. Olive plants were planted in above-ground rhiziotrons. Pllastic barrels rhizotrons were 50 cm in diameter and 90 cm depth were and filled with sand and clay (8:1 by volume). Samples were taken in June 1995 (the end of the experiment) and the following properties were studied (Length of the main shoot, length of secondary shoot, fresh and dry weight of main shoot and secondary shoot, length of the fibrous root and wooden root per plant, fresh and dry weight of leaves and roots per plant. The studied seasonal periodicity of the shoot and fibrous root growth rate of Koratina, Picual, Manzaniilo and Agizi Shami cultivars showed that shoot and root growth cycles differed in number according to the cultivars since it was 2 to 6 cycles during the study period and the cycle period lasted 3 to 8 months. Picual had the highest shoot growth rate (3.54 cm/day), while the Agizi shami cultivar had the lowest growth rate (1.99 cm/day) Koratina and Agizi Shami cultivars had 5 growth cycles of shoot system, whereas Picual cultivar exhibited 4 growth cycles while, Manzaniilo cultivar disclosed 3 growth cycles. The greatest growth period of shoot system was in summer. Manzaniilo cultivar had the highest fibrous root growth rate (6.12 mm/day), while the Agizi Shami cultivar had the lowest growth rate (2.31 mm/day). Picual and Agizi shami cultivars showed 5 growth cycles of fibrous root. Whereas, Koratina cultivar appeared 6 growth cycles, while, Manzaniilo cultivar had 4 growth cycles. Major periods of growth for each type generally occurred during the summer time.