Effects of Composition and Share of Seed Coatings on the Mobilization Efficiency of Cereal Seeds During Germination

Abstract

Cereal production systems are increasingly threatened by suboptimal water supply or intermittent drought spells early in the planting season. Seed coated with hydrophilic materials or hydro‐absorbers that increase the amount of water available for germination and seedling development is a promising approach to improving stand establishment under changing conditions. Barley, rye and wheat grains with combinations of hydro‐absorber, humic acid and Biplantol® in different shares of the total seed mass were germinated in plates at 25 °C on moist filter paper. Germination rates, resource partitioning and mobilization efficiency were assessed and compared with those of uncoated seeds. Results show a strong influence of coat thickness and composition on the germination rate and the efficiency of mobilization of carbohydrates stored in the endosperm. In general, coating significantly reduced germination rate and total germination as compared to uncoated seeds in all cereals tested. Differences in coating thickness had a distinct effect on germination rate for most combinations of coatings and species. Germination rates increased with increasing coat size. This effect was most pronounced for coatings containing hydro‐absorbers and least pronounced for coatings containing humic acid or Biplantol®. Coating generally increased the amount of carbohydrates partitioned to the roots, and thick coating increased the efficiency of grain reserve mobilization compared with the uncoated seeds. Differences between species and the implications for coating‐related changes in germination metabolism are discussed.

Seed Coating with Hydro-Absorbers as Potential Mitigation of Early Season Drought in Sorghum (Sorghum bicolor L. Moench)

“…In Piper seedlings grown from Stockosorb or Geohumus grains, biomass was lower than in those grown from uncoated seeds. This may be due to a coat-induced delay in the onset of germination as reported earlier by Gorim and Asch [ 18 ], poor leaf growth in seedlings from coated seeds ( Figure 2 e,f) and, in the case of seedlings grown from Geohumus grains, poor root development. In contrast, biomass accumulation was promoted in Susu seedlings grown from Stockosorb grains, but significantly reduced in seedlings grown from Geohumus grains as compared to uncoated seeds.…”

“…Insufficient soil moisture can be buffered by coating seeds with a water absorbing substance. Seed coating technology has a variety of applications, such as delivering nutrients [ 14 , 15 ], peroxides to provide oxygen, hormones to improve growth [ 16 ] or hydro-absorbers to improve water supply [ 17 , 18 ]. Geohumus and Stockosorb are two commercially available hydro-absorbers able to store an amount of water several times their weight.…”

The Influence of Seed Coating on the Vigor and Early Seedling Growth of Barley

“…This approach can serve to standardize the early stages of the plant for seed production. Studies on barley seed coating have been conducted by Pilar et al (2009);Pilar-Izquiedo et al (2012), and Gorim and Asch (2012). However, more information is needed about the effects that these coatings may have on germination and early seedling growth.…”

Synthesis and characterization of a stable humic–urease complex: application to barley seed encapsulation for improving N uptake

“…Germination of coated seeds can be affected by the coating composition, coat thickness and species, among others, which may increase, decrease or not affect the germination rates . In this work, a slight decrease in the germination rate of encapsulated seeds was observed.…”