On an experimental basis of the Scientific Research Institute of Agriculture of the Northeast of European part of Russia (Kirov) in 1948 laid the experience in the study of thickened crops. Trees have been planted at a distance of 6X6 m (control), 6X3 and 6X2 m m. Between the trees in the series at half the experimental plots in the same year planted currants.
An area of 1 hectare set aside for the experience — an elevated plateau with a smooth surface. Sod, weakly podzolic, loamy. From the south, west and north adjacent fruit plantings.
Seedlings grafted onto an ordinary cotton material and formed into a bush. Total planted 600 trees, 23 varieties of them experimental — Borovinka and perry Moscow.
The soil in the garden kept under fallow each year have made a complete fertilizer at the rate of 120 kg of active ingredient per 1 hectare. In addition, a series of experimental trees 2 times during the experiment have 40 tons of manure per 1 ha. In summer, the trees watered promachivaya soil to a depth of 40-50 cm. Caring for trees is also to periodic thinning of the crown, spraying pesticides against pests and diseases.
Data on the growth of apple trees, depending on planting density (1953-1958 gg.) Are shown in Table 1.
Thickening placing fruit trees do not inhibit the growth of young fruit trees and contributed to the accumulation of a large layer of snow in the garden, and, consequently, an adequate supply of moisture in the soil to the period of active growth of trees (Fig. 1). Especially a lot of snow lingered on areas planted with currants. But in dry years, the lack of moisture in the soil before planting was tested in thickened than in controls. For example, in 1953 when the long drought in the summer (June — July), the soil moisture in the horizon of 0-60 cm was landing 6X6 m without berries in the ranks of 19.65% to the dry soil; 6X3 m — 14.58; 6X2 m -12.59; 6X6 m berry plantations in rows, 18.95; 6X3 m — 13.13; 6X2 m -9.0%. For this reason, berries were removed.
In the northern horticultural all agro-technical measures should be aimed at reducing the negative impact of low temperatures on fruit plants. How can affect the wintering thickening planting trees?
The first severe test was the winter of 1955-56 in January air temperature ranged from 0 to -38 °, and on the surface of the snow cover decreased to • -40,4 °. Despite this, the degree of freezing of trees in the dense plantation was lower than in the controls, and in the spring of 1956 here earlier and more uniform bud on the layers of the crown. In the control group during the growing season the leaves are paler and smaller, weaker gains.
Best wintering trees in the dense plantation explained, apparently, not only protective properties of this design, but also the fact that the trees grow moderately, better lignified shoots in autumn, the bark is not damaged by sunburn. The most important performance indicator assessment studied the reception — the yield of fruit trees. The thickened landing the first flowering of certain varieties of apple trees Grushovka Moscow observed in the third year after planting. All flowering trees had ovaries up to 48% of the number of flowers.
Abundant blooms observed in all the years of experience. This was facilitated by the presence in the garden of a large apiary and an enabling environment for bees, as well as a large number of simultaneous flowering varieties in the experimental area and the neighboring. On colder days, many bees were in dense plantings, and they were completely absent in areas with sparse placement of trees.
Since 1952 experimental fruit trees regularly. Harvest for their age moleno regarded as good, and in some years even higher. The exception was in 1956, en route to the extremely harsh winter.
The data about the harvest of apple varieties Borovinka shown in Table 2.
Gross harvest of fruit apple varieties Borovinka 1 hectare in the last seven years of planting in 6X6 m -295 n, 6X3 m — 623 n and 6X2 m — 771 p. Similar data were obtained for a variety Grushovka Moscow.
However, the number of seals in the landing difficult tillage in both directions, but we believe that, particularly in northern conditions, only enough to cultivate the soil between the rows of the garden, which is moving active part of the root system (Fig. 2). Weed control in a row can be made using chemicals or leave streaks cultural grassing.
The main drawback of thickened landing is that in 10-12 years of fruiting need to greatly lighten the crown in the ranks. In our experience, we provided to remove every other tree. Extend the use of thickened plantations can be qualified pruning method PS Gelfandbeyna.
Thickened planting method should find wide application in the area of the North-East of the European part of the USSR. It should create a large demonstration condensed gardens.
The thickened landing can be carried out, and amateur gardeners collective gardens. This will significantly improve wintering plants and dramatically increase the economic efficiency of gardening.