The impact of other fertilizers and special products on horticultural crops 2.: Yield, pomological and biochemical characteristics of apple fruits

Abstract

One way of fast and effective impact on yield, pomological and biochemical properties of apple fruits is foliar fertilization. Thus, the fruit efficiently recharge poorly mobile secondary and micronutrients, and so the plant protects against environmental stress in sensitive developmental stages. The last hypothesis we checked during the second part of the growing seasons of 2014, which were characteristic of abundant precipitation during the first part of the season. The experiment was set in 19th May 2014, in the 18 years old apple (Malus domestica L. cv. 'Idared') orchard by a block system (10-12 trees per treatment), at a density of 1300 trees per ha. Treatments (19th May and 3rd Jun of 2014) per blocks were: control, 'Eco-Fus' (45 ml; based on algae extract), 'Vegard' (48 ml), 'Calbit-C' (20 ml), 'Zircon' (2,4 ml), 'Cropmax' (40 ml), (all based on plant extracts), 'Chitosan' (8 ml; based on shellfish extract), all dissolved in 8 l of water. The samples for biochemical analysis (determination the pH value and coefficient of refraction of the fruit extracts) were taken on 19th May, 3rd June, 2nd July, and on 9th September, when estimated yield. The yield was estimated by counting fruits on the tree in each block-treatment, followed by sampling a large number of fruits (20 and over), measuring their weight and multiplication, in order to estimate the yield per tree and per ha. All of the tested fertilizers in the given conditions are significantly higher estimated yield than in the control plants. Estimated yield of treated plants increased from +28.93% ('Calbit-C' fertilizer) to +253.26% ('Chitosan' fertilizer) per tree, ie. from +26.52% ('Calbit-C' fertilizer) to +253.27% ('Chitosan' fertilizer) per hectare, all relative to control. The average fruit weight was not significantly varied between treatments (200-230 g), but the number of fruits per tree is very influenced by the type of fertilizer, particularly in the case of 'Chitosan' fertilizer. It should be noted that the type of fertilizer affects the coefficient of refraction of the fruit extracts, particularly in the case of 'Eco-Fus' fertilizer.

Ogled je zasnovan 19.05.2014. u voćnjaku sa 18 godina starim stablima jabuke (Malus do­mestica L.; cv. 'Idared'), po blok sistemu i pri gustini od 1300 stabala/ha. Tretmani po blokovima su bili: Kontrola (bez tretmana), 'Eco-Fus' (đubrivo na bazi ekstrakta algi), 'Ve­gard', 'Calbit-C', 'Zircon', 'Cropmax', (sva đubriva na bazi biljnih ekstrakata), 'Chitosan' (homeopatski proizvod na bazi ekstrakta morskih školjki), pri čemu su đubriva rastvarana u vodi. Uzorci za biohemijsku analizu (određivanje pH vrednosti i koeficijenta refrakcije ekstrakta pulpe ploda jabuke) uzimani su četiri puta, sve do procene prinosa. Prinos je procenjivan brojanjem plodova na stablima u svakom blok-tretmanu, posle čega je sledilo uzorkovanje većeg broja plodova po blok-tretmanu, merenje težina plodova i multiplikacija težine sa brojem plodova po stablu, radi procene prinosa po stablu i po standardnoj površini (ha). Sva testirana đubriva u datim agroekološkim uslovima značajno su uvećala prinos jabuka odnosno kontrole (od +28.93% ('Calbit-C'), do +253.26% ('Chitosan') po stablu, tj. (od +26.52% ('Calbit-C'), do +253.27% ('Chitosan') po standardnoj površini (ha). Srednja masa plodova nije značajnije varirala između tretmana, ali broj plodova po stablu jeste, zavisno od tretmana, posebno u slučaju đubriva 'Chitosan'. Vidno je da tip đubriva utiče na koeficijent refrakcije ekstrakta pulpe plodova, posebno u slučaju đubriva 'Eco-Fus'.