Morphological, Leaf Nutrient, and Fruit Quality Characteristics of Diverse Tomato Cultivars under Organic Low-Input Management

Leangsrun Chea,Inga Smit,Cut Erika,Marcel Naumann,Bernd Horneburg,Elke Pawelzik

doi:10.3390/su132112326

Abstract

Increasing fruit yield and quality of tomatoes under organic low-input conditions remains a challenge for producers and breeders. Therefore, it is necessary to identify superior tomato cultivars that are suitable for production and use as parents in breeding programmes. In the present study, the variations in plant morphology and fruit quality characteristics of tomato cultivars were assessed to reveal the traits associated with improved yield and fruit quality. Sixty diverse tomato cultivars were screened in 2015, and in 2016, a subset of 20 cultivars was selected for further evaluation under organic low-input conditions. The results showed high variability among cultivars in all 28 traits that were observed. Salad cultivars had lower plant growth and fruit quality (minerals, dry matter, total soluble solids, and total phenolics) by 10–70%, but they displayed 10–60% higher fruit yield and leaf minerals than cocktail cultivars. Salad tomato cultivars with superior yield and harvest index were mainly derived from breeding for intensive indoor production. Cocktail cultivars with superior yield were mainly derived from organic and outdoor breeding programs. There was a trade-off between fruit yield and quality, indicating a challenge for simultaneous improvement of yield and quality. The importance of Mg was highlighted because of its contribution to the fruit mineral concentration and fruit quality. Cultivars superior in one trait or trait combination under organic low-input conditions were identified to be used by producers and breeders as superior cultivars to meet their production targets and breeding objectives. The importance of Mg provides a novel path for further research on improving soil-available Mg in organic tomato production to enhance fruit mineral concentration and fruit quality in general.

Highlights

IntroductionTomato production and consumption have grown rapidly worldwide over the past 25 years [1]
Our study revealed high genotypic variability in the plant morphology and fruit quality of 60 tomato cultivars in organic low-input management
The different response patterns of salad and cocktail cultivars provide an outlook on improving fruit yield and quality in each group

Summary

Introduction

Tomato production and consumption have grown rapidly worldwide over the past 25 years [1]. The tomato fruit is a valuable source of minerals and vitamins necessary in the human diet [2]. The demand for organically grown tomatoes has increased [3], driven by consumer perception that organic food is more sustainable and of better quality than food derived from conventional farming [4]. There is a lack of tomato cultivars bred for organic production that are both high-yielding and of superior fruit quality [5]. Tomato cultivars suitable for organic production require an adaptation strategy with more efficient nutrient uptake and utilisation under limited nutrient availability in the soils [6]

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Results

Discussion

Conclusion