Comparison of growth responses of Khaya senegalensis seedlings and stecklings to four irrigation regimes

Abstract

Khaya senegalensis is an important tree species for timber production, native to West Africa, but mahogany shoot borer attacks prevent successful plantations. This research was aimed at comparing the growth of two propagule types, seedlings and stecklings, of Khaya senegalensis subjected to four irrigation regimes, 25, 50, 75 and 100% field capacity in Burkina Faso. The relative growth rate, biomass allocation and intrinsic water use efficiency of the propagules were assessed in a full-factorial pot experiment in block design. Except the relative growth rate of stem basal diameter and specific leaf area, for which mean values were significantly higher for seedlings than stecklings, the two propagule types had similar growth patterns regarding relative growth rates of stem length, leaf, stem, root and the total plant biomass. There was no significant difference between propagule types concerning biomass fraction to total plant biomass of leaf, stem and root, root to stem ratio, leaf area productivity and carbon isotope ratio (δ 13 C). However, the irrigation regimes significantly affected all parameters. In contrast to 75 and 100% field capacity irrigation regimes, the low water supply of 25 and 50% field capacity resulted in plant stress, which was evident from the significant reduction in plant growth and biomass production and an increase in the root biomass to total plant biomass ratio and δ 13 C. It can be concluded that seedlings and stecklings have comparable growth patterns, while water stress is a major growth-limiting factor highlighting the need for selecting drought and borer resistant genotypes for successful plantations.

Effect of Watering Regimes and Water Quantity on the Early Seedling Growth of Picralimanitida (Stapf)

“…Seedlings of P. nitida which received the lowest water rate (10 ml) at the longest intervals of 5 days had the lowest biomass value, this agreed with the findings of several authors that drought water stress influences plant growth and limits productions (Ky-Dembele et al, 2010;Hsiao & Xu, 2000;Busso et al, 1998;Hampson & Simpson, 1990). In this study, excess of water alsohad negative impact on growth and biomass production of the seedlings.This result agreed with the findings of Sakio (2005) that flooding reduces the total dry weight increment in some plant species.In flooding condition, available oxygen in the soil is usually low thus, limiting nutrient absorption for species not adapted to this condition; and as stated by Predick et al (2009) growth of flood-intolerant species is often depressed in flooding.…”

Growth of Khaya senegalensis plant under water deficit

“…Later on, glucose is broken, which through respiration produces ATP to support the growth of the root system. The results of this study corroborate those found by Ky-Dembele et al (2010), who found greater root system growth when assessing growth responses of K. senegalensis under water deficit and Okali and Dodoo (1973) reported the reduction of perspiration and increase in the partitioning of assimilates to the root system of plants K. senegalensis.…”

ADAPTABILITY OF WHITE JABON (Anthocephalus cadamba MIQ.) SEEDLING FROM 12 POPULATIONS TO DROUGHT AND WATERLOGGING

“…Similar results of drought responses on the growth characteristics have been reported in several previous studies (Yang and Miao, 2010;Ky-Dembele et al, 2010). Water deficits reduce the number of leaves per plant, and individual leaf size, and leaf longevity by decreasing the soil's water potential.…”