Effect of planting scheme on photosynthetic activity and dry matter accumulation in apple leaves

K. Laužikė*, N. Uselis and G. Samuolienė

Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, Kauno 30, Babtai, LT-54333 Kaunas distr., Lithuania

Abstract:

This study aims to identify changes photosynthetic rate and dry matter accumulation in apple leaves with decreasing plant to plant distance of the trees. Apple tree ‘Auksis’ was grafted on dwarfing P60 rootstock and planted at different in distances: 0.5 m, 0.75 m, 1 m and 1.25 m between plant to plant distance in rows. Photosynthetic indices were measured at 1.00–1.20 m above ground inside the canopy. 20 randomly selected leaves from the whole apple tree canopy were used to determine leaf area, fresh and dry weight. Measurements were made in three different stages in May, June and September. By decreasing the distance between apple trees from 1.5 m to 0.5 m, photosynthetic rate decreases correspondingly, decreasing by 23% in spring, and decreasing by 31% in autumn. Distance between trees has no significant impact on leave mass per area (LMA), however in spring is higher by 33–51% compared to summer and 42–78% compared to autumn. Dry and fresh weight ratio (DW/FW) significantly increased in summer – by 27% and in autumn – by 37% compared to spring, also DW/FW significantly decreased by the decreasing distance from 1.5 m to 0.5 m by 4–6%. In summary, the decreasing distance reduces the photosynthetic rate, the accumulation of dry matter. Also, photosynthetic rate decreases from spring to harvest time, and on the contrary, the accumulation of dry matter increases as autumn approaches. After evaluating the obtained results, the aim is to further delve into the use and transpiration of water and the impact of the planting scheme on fruit quality.

Key words:

competitive stress, dry matter, Lithuania, Malus domestica, photosinthetic rate

The evaluation of scab resistant apple cultivars in Estonia

K. Tiirmaa, T. Univer and N. Univer

Polli Horticultural Research Centre of the Institute of Agricultural and Environmental Sciencesof Estonian University of Life Sciences, Polli, 69108, Viljandimaa, Estonia;e-mail: krista.tiirmaa@emu.ee

Abstract:

At Polli Horticultural Research Centre currently over 400 apple accessions are being maintained, including 47 local cultivars and 14 scab resistant cultivars. Cultivars „Imrus‟, „Chistotel‟, „Orlovim‟, „Pamyat Issayeva‟, „Pervinka‟, „Pioner Orlovski‟ and „Slavyanin‟ were introduced from the All-Russian Research Institute of Breeding of Horticultural Crops at Orel. Cultivars were assessed for tree phenology stage, weight of the fruit, yield per tree, occurrence of apple scab and the biochemical content of the fruit. No scab infections were found on these cultivars during the evaluation years at Polli. „Orlovim‟ was the earliest and „Pioner Orlovski‟ the latest bloomer. „Chistotel‟ and „Slavyanin‟ achieved the highest yield per tree. „Pamyat Issayeva‟ and „Pervinka‟ gave the largest fruits. All 7 cultivars possessed relatively high levels of acidity and because of that they are not best suited for fresh consumption.

Key words: