Development and Evaluation of Paper for Seedling Raising Pots Produced by Crosslinking Wood Polysaccharide Using DMDHEU

Abstract

Transplanting is routinely performed in crop cultivation. One transplantation method involves the use of seedling pots made of paper (paper pots). Seedlings are raised in the paper pots and are subsequently transplanted. As transplanting is performed by hand or mechanical transplanters, the paper used for the seedling pots needs to be decomposition resistant. In recent years, fully automatic transplanters have been developed, and the demand for a suitable decomposition resistant paper for seedling pots has consequently increased. In order to develop a type of paper that is suitable for any type of seedling raising condition, we investigated a paper that is treated with dimethyloldihydroxyethyleneurea (DMDHEU), which is capable of crosslinking wood polysaccharide. We examined the decomposition resistance, wet strength, and dry strength of the paper, and obtained the following results. 1. The chemical crosslinking of wood polysaccharide provided the paper not only with high wet strength but also with decomposition resistance. This antidecay trait, compared to a synthetic fiber blend or paper incorporating a germicide, was less affected by seedling raising conditions and persisted longer whilst maintaining a better condition. 2. The tearing strength and folding endurance of the paper decreased with the chemical treatment. The causes of this decline are considered to be the decrease in the fiber strength attributable to degradation of the wood cellulose. On the other hand, tensile strength increased since the interfiber bonding was strengthened by the crosslinking reaction.