Further Observations on Physiological Breakdown In Stored Plums

Summary

Seeds of Fagus sylvatica, Prunus avium and Acer pseudoplatanus were sown on 10 May and covered with four materials: white polyethylene, white polypropylene, yellow net or green net for 90 d to study the effect of a temporary covering on soil and air temperature, increment in dry weight, and root cellular diameter of nursery tree seedlings in a northern climate. Root collar diameter, height and dry weight of covered seedlings were compared with those of uncovered control seedlings at the end of growing season. The increase in soil and air temperature under white polyethylene, white polypropylene and yellow net and the decrease in soil temperature under the green net influenced the growth of F. sylvatica and P. avium seedlings. Dry weight, as well as root collar diameter and height, was increased under the coverings increasing temperature. A. pseudoplatanus responded less to temperature, but increased dry weight and root collar diameter when cultivated under white polypropylene and green net. Hence temporary coverings can be used to improve the quality of seedlings grown in a northern climate.