Effects of Different Pretreatments to the Seed on Seedling Emergence and Growth ofAcacia polyacantha

Abstract

Acacia polyacanthaWilld. is a multipurpose tree species prioritised as one of the agroforestry tree species in Malawi. However, its use in agroforestry practices is limited by the low seedling growth and survival at the nursery stage. A study was conducted to evaluate the seedling growth and survival ofAcacia polyacanthaas affected by different pretreatments on the seeds at Malawi College of Forestry and Wildlife nursery, Malawi. Seeds were subjected to five presowing seed treatments methods, namely, immersion in cold water at room temperature for 24 hours, immersion in hot water (100°C) for 5 minutes, immersion in concentrated sulfuric acid (0.3 M H2SO4) for 20 minutes, scarification by mechanically nicking using secateurs, and a control where seeds were sown without any treatment. The results indicate that presowing seed treatments have positive influence on the seedling growth and survival percentage. Nicked seeds exhibited the highest significant (P<0.001) performance for vegetative characteristics of height, root collar diameter, number of leaves, and survival percentage compared to other pretreatments. Therefore, it is suggested to use nicking as a pretreatment method onAcacia polyacanthaseeds in order to enhance the speed and the amount of early seedling growth at the nursery stage.

Provenance and pretreatment effect on seed germination of six provenances of Faidherbia albida (Delile) A. Chev

“…Mechanical and chemical scarification were more effective in rendering seeds of F. albida permeable, leading to a mean germination of up to 69.67 and 67.67 % respectively. Mechanical scarification which recorded highest germination percentage is known to break physical dormancy of hard seed coats by enhancing gases and water uptake especially in Acacia species (Missanjo et al 2014). The enhanced germination observed in the mechanical treatment could be attributed to water uptake by the quiescent dry seed, which ended up with the elongation of the embryonic axis (Botsheleng et al 2014).…”

Seed Scarification Reduces Seedling Survival and Tree Growth and Longevity in Senegalia Polyacantha at a Site in Central Zambia, Southern Africa

“…Firstly, the best subset regression analysis was carried out to select predictor variables that explained the largest variation in tree growth rate [16,17]. When two independent variables are highly correlated the analytical procedure used automatically drops one of the predictor variables to avoid problems of collinearity (Analytical Software, 1985-2008) [13,18]. Best subset regression analysis simultaneously compares models with single variables and all their possible combinations.…”

“…Untreated seeds were sown on 77 stations with five seeds per station and scarified seeds were sown on 72 stations with two seeds per station in two separate rows. The stations and rows were 1.0 m apart and the planting stations were marked by aluminum stakes for easy resighting during subsequent inspections [13]. Seeds were sown in shallow holes (2 -3 cm deep) and seedling emergence (used as a proxy for seed germination) was monitored at weekly intervals during the wet (rainy) season for three years to obtain data on phased seed germination.…”

Seedlings Growth assessment of Acacia Polycantha as affected by Soil Media and Seed Origin

“…On the other hand, shoot/root weight ratio of seedlings of clay and mixture media were identical. The study which conducted by [5] illustrated that, the polybag size has main effects on performance of tree seedlings propagation in the nurseries. …”

“…Root restriction is an inherent problem with container grown trees, According to [4] (Appleton & Whitcomb, 1983) plants grown in standard plastic containers for too long often have deformed roots that are kinked or grow along the sides or bottom of the root ball. Results from literature of [5] revealed that tree seedlings raised in poly bags were taller than those from root trainers; probably because many of the poly bags grown seedlings had rooted in the nursery soil and so they were accessing additional resources not available to the root trainer-grown seedlings.in addition, [6] stated that nursery containers have been testified as one of the crucial factors that enhance the successful growth of tree seedlings. Although this provided additional resources to seedlings in bags, it also resulted in severing of roots during transplanting to the field.…”