ЭлБиб

ц достигает максимального значения -

286

мг°

у сорта Уэлси и

303 мг°

у сорта Бойкен на сырой вес листьев после обрезки в

июле.

Более высокое содержание каратнноидов у всех сортов

Также отмечено в варианте с июльской обрезкой, наибольшее

их количество -

мг°

наблюдалось у сорта Бойкен.

Такое увеличение содержания пигментов в листьях деревьев в

вариантах

опыта обьясияется улучшением освещенности

ассимиляционного аппарата при обрезке в период вегетации.

THE INFLUENCE OF HEADING BACK

THE TERMINAL SHOOTS

ON THE PRODUCTIVITY OF APPLE-TREES

M. Skrivelc, I. Dimza, I. Jansone-Henkuzcne.

Dobele Horticulture Plant Breeding Experimental Station, Latvia

The trial was established in 1987. Four factors - 15 cultivars,two

rootstocks (MM 106 and Budagovaky 490),cuttmg ack or not cutting

the terminal shoots and two methods of pruning suplemcntary

branches - were aranged in a split plot design in two repetitions. The

trees were planted at the distances of 4x6 m. The basic fonn of the

tree - freely shaped, Hat canopy.The heading back of the terminal

shoots considerably reduced the yield of all cultivars on MM 106

already the years 1989 - 1990. Such influence was not -ascertained

for 'Lobo\ 'koritsnoje Novoje', Tiina\ 'Noris'on ootstock Nr.490.

During the period of the next two years the negative influence of the

heading back on the yield was proven with high level of significanse

(F=14,5 F

5=24). The interaction of the heading back and the culti-

var also was proven, but the interaction of the heading back and the

root-stock was not ascertained.The heading back increased the yield

only for the ‘Spartan’ and Sidrunkollane apples.Since 1993,the train

ing ascording to the trial desing was not continued. All trees were

trained similary. The after - influence of all the 4 factors on the crop

was established in 1993 - 94. There was a interaction between culti-

var and pruning. The most negative influence of heading back on

the productivity was in the varieties 'Kozitsnoje Novoje ' Ilga',

'Noris '. On the contrary'» the heading back increased the crop of the

'Bogatir'/Forele' and Sidrunkollane apples in 1993 - 94.

Научная электронная библиотека ЦНСХБ