403 Promotion of Germination and Seedling Development of Lima Beans (Phaseolus spp.) by Nickel Chloride

Abstract

Delaware is among the largest producers of lima beans in the United States, having more than 10,000 acres in this crop. The plants are raised from seeds, but seeds are notably prone to injury during handling. The seed has little or no endosperm and relies on reserve food materials in the cotyledons. Lima beans are legumes, and the seeds store nitrogenous compounds. Nickel is implicated in nitrogen metabolism, and nickel is now implicated as an essential mineral nutrient element. With the variable rate of germination of lima bean seeds, our objective was set to determine the effect of nickel on seedling development of the lima bean plant. Lima bean seeds were soaked for various periods in 10 solutions from 0 to 500 ppm nickel chloride. Soaking for 1 h in 100 ppm nickel chloride solution was determined to be the best treatment. The 100 ppm treatment then became the standard treatment for lima bean seeds. Hence, seeds were treated with distilled water of the 100 ppm nickel chloride. The results are that the nickel chloride significantly improved the rate of germination of lima bean seeds. Germination rates were improved from 60% ± 5% to 76% ± 3%. The total effect of treatments with nickel chloride varied from one batch of seeds to another; however, promotion of germiantion was significant. Osmoregulation and seed priming as well as stimulation of nitrogen metabolism by nickel are possible explanations of the positive effects of nickel chloride.