The quality and the healthy of products from garden have become more important to costumers. Nowadays people value more organic food and they hope to get allergic free products. Relatively few companies have specialised to gardening in Estonia and strawberry growing is more likely suitable to small enterprises, where sustainable producing is practiced. The aim of organic farming is to provide high-quality production while maintaining the biological balance of the ecosystem. This requires reduction of mineral fertilizers and pesticides, but in organic farming, the options are limited. One plant protection device is to destroy leaves by flame defoliation or fertilizing the plants with preparations containing humic and fulvic acids. However, the effect of these technologies on plants has not been thoroughly researched. The hypothesis in current research was that a defoliation machine used in market gardening is suitable for use in strawberry production. At the same time, the flame defoliation of leaves may hinder plant growth. Humic substances promote the acquisition of nutrients from the soil and therefore it may be presumed that they would strengthen the plants treated. Pursuant to this, the aim of my work was to determine the influence of flame defoliation and fertilization with Humistar on the growth, productivity and harvest quality of plants in a plantation with wood chip mulch. The results were: 1. Defoliation reduced the number of leaves and inflorescences significantly, fertilization did not result in an improvement. 2. Defoliation with fertilization significantly reduced the weight of rhizomes and roots. In comparison with the reference plants, flaming defoliation reduced their weight by 67%. Fertilization with Humistar gave a positive effect, but it was modest in comparison with the reference plants. 3. Flaming and fertilization with Humistar had a negative effect on the productivity of strawberries. The average result of the test of defoliation and defoliation combined with fertilization was negative effect on the weight of 10 fruit in comparison with the reference plants. Fertilization had a positive effect only on stage 3 fruits. 4. Flaming increased the wholesomeness of the fruits – the content of phenols and anthocyanins was increased. Flaming combined with fertilization increased the proportion of fruit dry matter and content of phenols and anthocyanins; the fruits were therefore sweeter and more wholesome. Flaming and flaming combined with fertilization reduced the content of stage 3 acids. A flame defoliation is suitable for strawberry farming during the second year, but defoliation had a negative effect on plant growth during the fourth year. The reasons may be the meteorological conditions and the aging of plants. On average over the studding years, Humistar showed a positive effect after the defoliation of leaves. The following years could test different fertilizing techniques for strengthening the plants viability.

Köögiviljanduses kasutatav leegitusmasin on sobiv kasutada ka maasikakasvatuses lehtede põletamiseks. Samas aga lehtede hävitamine võib pärssida taimede kasvu. Humiinained soodustavad toiteelementide omastamist mullast ja seetõttu võib arvata, et lisaväetamine suurendab leegitatud taimede elujõudu. Sellest lähtuvalt oli töö eesmärgiks välja selgitada leegitamise ja Humistariga väetamise mõju hakkepuidumultšiga istandikus taimede kasvutegevusele, saagikusele ja saagi kvaliteedile. Katse toimus 2013. aastal Eesti Maaülikooli Mahekeskuse katseaias Eerikal, Tartumaal, maheviljelusse sobiva sordiga ’Darselect’. Katsevariantideks olid: kontroll, leegitamine ja leegitamine koos Humistariga. Taimi leegitati Soome firma Elomestari köögiviljandusse soovitatud umbrohutõrje masinaga 3. saagiaastal kohe pärast korjeperioodi lõppu juuli kuus. Katsetulemuste põhjal selgus, et defoliatsioon vähendas oluliselt lehtede ja õisikute arvu ning risoomiharude ja juurte massi. Leegitamisel ja Humistari lahusega kastmisel oli negatiivne mõju maasika saagikusele. Samas aga muutis leegitamine viljad tervislikumaks – suurenes fenoolide ja antotsüaanide sisaldus. Leegitamine koos väetamisega suurendasid mahla kuivaine ja hapete, fenoolide ja antotsüaanide sisaldust, seega muutusid viljad magusamaks ja tervislikumaks.