The damage to the stems of pine seedlings during manual care in crops, the density of crops and the yield of standard planting material, as well as the basic density of wood of the stems of 2-year-old Scots pine seedlings in nurseries of the forest and forest-steppe zones of the Trans-Urals have been studied. In field conditions, seedlings have been sorted according to the nature of the damage to the stems. In the laboratory, the biometric parameters of seedlings have been measured and the basic density of the wood of the stems in the 1st and 2nd years of growth using the maximum moisture method. It has been established that the planting material of Scots pine in nurseries of forest and forest-steppe zones of the Trans-Urals is divided into 3 main categories: without signs of mechanical damage, with signs of mechanical damage and with bifurcation of the stem, arising as a result of spontaneous or induced mutations. The proportion of seedlings with mechanical damage in forest zone nurseries is small – no more than 11 %. In nurseries of the forest-steppe zone such seedlings account for 30 %. It has been shown that in forest zone nurseries, in some cases, the density of crops is increased. The yield of standard 2-year-old seedlings varies significantly across nurseries in both the forest and forest-steppe zones and does not have a clearly defined relationship with the density of the stand. It has been noted that 2-year-old pine seedlings grown in forest zone nurseries are characterized by significantly lower biometric parameters of the stems. It has been established that in the 1st year of cultivation, pine seedlings in the forest and forest-steppe zones practically do not differ in height growth rates. In the 2nd year, pine seedlings in the forest-steppe zone generally have significantly higher growth rates in height than seedlings in the forest zone. In pine seedlings in the forest zone, the basic density of the wood of the stems is significantly higher compared to seedlings in the forest-steppe zone. The ratio of this indicator for shoots of the 2nd and 1st years of cultivation for nurseries in the forest zone has averaged 0.80, and for the forest-steppe – 0.85.
М. В. Ермакова (Fri,) studied this question.