THE EFFECT OF ROOTSTOCKS ON THE GROWTH AND YIELDING OF SOUR CHERRY CV. ‘ŁUTÓWKA’

The strength of growth of ‘Łutówka’ trees was related to the soil quality and the rootstock. Measurements of the tree trunks and the crown size showed that on fertile soil the trees grafted on Mahaleb cherry grew worse, forming by 12% thinner trunks and by over 20% (signifi cantly) smaller crowns as compared to Mazzard cherry trees. On poor sandy-loamy soil the crowns of trees grafted on Mahaleb were signifi cantly, more than 40% bigger than those on Mazzard cherry. No signifi cant differences in the yielding and productivity of trees grafted on Mahaleb and Mazzard cherry trees were found on grey brown podzolic soil. The experiment conducted on sandy-loamy soil pointed to signifi cant differences in the yielding and productivity between ‘Łutówka’ trees grafted on the studied rootstocks. The trees grafted on Mahaleb cherry in both studied years were characterized by signifi cantly greater productivity than on the other rootstocks. Signifi cantly higher yields were gathered from the trees on Mahaleb cherry than on vegetative rootstocks, and by 70% higher than on Mazzard cherry. P-HL A rootstock is of little use in the planting of ‘Łutówka’, which grown poorly on light soils. Besides poor growth and yielding, in longer dry periods the studies found the appearance of chlorosis of magnesium on older leaves, and even wilting of the leaves.


INTORODUCTION
The purpose of the studies was to estimate the usefulness of rootstocks in different habitat conditions.

MATERIALS AND METHODS
The studies were conducted in the years 2004-2006 in two production orchards.The orchard belonging to Mr Trześniewski at Strączkowo in Samborzec commune was planted on grey-brown podzolic soil of II valuation class.The experiment in the orchard belonging to Mr Henryk Warsiński at Janów of Ożarów commune was set up on sandy loamy soil included in IVb valuation class (I class -the best soil, V class -the poorest soil).
The experimental material were the trees of 'Łutówka'.
The experiment was established in a scheme of random blocks.They included 2 or 5 combinations in 5 replications.The replications were the plots where 3 trees grew on each.The experimental combinations at Strączków were 'Łutówka' trees grafted on Mahaleb cherry and Mazzard cherry planted in 2001.On the other hand, the trees of 'Łutówka' grafted on the seedlings of Mahaleb and Mazzard cherry and on vegetative rootstocks Colt and P-HL A and F 12/1 were planted in Janów in 2001.
In both experiments the trunk diameter was measured at the height of 30 cm, and the width and height of the tree crowns were measured.The yield from each tree was weighed.The area of the cross-section of the trunks, the cubic content of the crowns and the productivity of trees and crowns were calculated on the basis of these studies.
Results of studies were statistically analyzed using variance analysis and Tukey's confi dence intervals.

RESULTS AND DISCUSSION
In the case of the orchard on grey-brown podzolic soil 'Łutówka' trees grafted on Mazzard cherry formed thicker trunks and bigger crowns than on Ma-Measurements of the trees growing on sandy loamy soil did not show any signifi cant differences in the trunk thickness between the trees grafted on the above mentioned two rootstocks, but the tree crowns on Mahaleb cherry were signifi cantly, by 41% bigger than on Mazzard cherry.In the discussed habitat conditions the trees grafted on P-HL A grew signifi cantly worse.
The accessible literature does not provide any data on the effect of P-HL rootstock on the growth of sour cherry trees.P e r r y et al. (1996), conducting studies on sandy-loamy soil, pointed to a much haleb cherry.Signifi cant differences between rootstocks were shown only for the size of the crown.Similar results were obtained by T y l u s e t a l .(1986) and S e l w a et al. (1994).

Rootstocks
Trunk cross section area in cm 2

Sandy loamy soil
Grey-brown podzolie soil Table 1 Infl uence of rootstocks and kind of soil on growth of the trees of sour cherry cultivar 'Łutówka' in 2004-2006.The trees grafted on Colt rootstock grew more strongly than on the seedlings of Mazzard cherry.'Łutówka' on F 12/1 vegetative rootstock did not signifi cantly differ with the trunk thickness and the crown volume from the trees on Mazzard cherry.This confi rms the observations made by R o z p a r a (1995).
Table 2 Infl uence of rootstocks on size of crown of sour cherry cultivar 'Łutówka' in 2004-2006.Trees on Mazzard cherry on fertile soil gave a yield on average by 10% higher than on Mahaleb.No signifi cant differences between the rootstocks were shown in particular years.Fruiting of the trees grafted on Mahaleb cherry planted on poorer soil was by about 70% higher than on Mazzard cherry.In 2004 the differences between these rootstocks were signifi cant.'Łutówka' trees grafted on vegetative rootstocks yielded worse than on the seedlings.The differences between the yielding of trees on Mahaleb cherry and the three studied vegetative rootstocks proved to be signifi cant.

Rootstocks
Different views were found in the literature on the subject about the effect of Mahaleb and Mazzard cherry trees on the yielding of sour cherries.U g o l i k et al. (1993)  R o z p a r a (1995) reports a differentiated scheme of yields in the experiments comparing the fruiting of sour cherry on F 12/1 rootstock and on the seedlings of Mazzard cherry in different habitat conditions.In Albigowa and Sinołęka the trees of 'Łutówka' yielded a little better on the seedlings, like in the present experiment, while in Przybroda slightly higher yields were obtained on F 12/1.
In the case of trees grafted on P-HL A in summer the studies observed considerable intensifi cation of the symptoms of chlorosis of magnesium leading to premature falling of the leaves from the lower part of oneyear-old shoots.

Rootstocks
Sandy loamy soil Grey-brown podzolie soil No signifi cant differences in the productivity of trees grafted on the seedlings of Mahaleb and Mazzard cherry trees were observed in the orchard growing on fertile soil.On the other hand, signifi cantly greater pro-ductivity of the trees grafted on Mahaleb was observed as compared to the other rootstocks.
The present studies will be continued with the aim of studying the planting at full fruiting.

CONCLUSIONS
1.The strength of growth of 'Łutówka' trees was related to the soil quality and the rootstock.Measurements of the tree trunks and the crown size showed that on fertile soil the trees grafted on Mahaleb cherry grew worse, forming by 12% thinner trunks and by over 20% (signifi cantly) smaller crowns as compared to Mazzard cherry trees.On poor sandy-loamy soil the crowns of trees grafted on Mahaleb were significantly, more than 40% bigger than those on Mazzard cherry.2. Trees of P-HL A on sandy-loamy soil grew significantly worse as compared to the trees on the seedlings and Colt rootstock.3.No signifi cant differences in the yielding and productivity of trees grafted on Mahaleb and Mazzard cherry trees were found on grey-brown podzolic soil.4. The experiment conducted on sandy-loamy soil pointed to signifi cant differences in the yielding and productivity between 'Łutówka' trees grafted on the studied rootstocks.The trees grafted on Mahaleb cherry in both studied years were characterized by signifi cantly greater productivity than on the other rootstocks.Signifi cantly higher yields were gathered from the trees on mahaleb cherry than on vegetative rootstocks, and by 70% higher than on Mazzard cherry.5. P-HL A rootstock is of little use in the planting of 'Łutówka' cv., which grown poorly on light soils.
Besides poor growth and yielding, in longer dry periods the studies found the appearance of chlorosis of magnesium on older leaves, and even wilting of the leaves.
Poland is the biggest producer of sour cherry fruit in the European Union (M a k o s z , 2006).High yields and success in developing the fruit production were affected by the proper choice of cultivars, improvement of the production technology and intensifi cation of production objects performed through increased density of planting (G r z y b a n d G r o n e k , 1991; R o z p a r a , 1995; K r a w i e c , 2000; M i k a et al. 2000; H o r o t k o , 2005).Despite numerous papers estimating the production value of rootstocks (F u n k , 1969; G r z y b at al. 1987, G r z y b and K o l b u s z , 1989, U g o l i k et al. 1993; S e l w a et al. 1994; P e r r y et al. 1996; D e n c k e r and T o l d a m -A n d e r s e n , 2005; N y e k i and S z a b o , 2005), there is still lack of information on the choice of rootstocks in different habitat conditions.
growth of 'Montmorency' cv.cherry on Colt rootstock as compared to Mazzard and Mahaleb cherry trees.
and P e r r y et al. (1996) found out, like in the present studies conducted on poor soil, much better yielding of trees on Mahaleb as compared to Mazzard cherry.On the other hand, T y l u s et al. (1996y b and G r o n e k (1991); S e l w a et al. (1994) and G r z y b et al. (1987) obtained much better yields on Mazzard cherry than on Mahaleb.A similar tendency was observed in the present studies conducted in the orchard on fertile soil.

Table 3
Infl uence of rootstocks on yielding of sour cherry cultivar 'Łutówka'.