Evaluation of rootstocks for watermelon grafting with reference to plant development, yield and fruit quality

Document Type: Research Paper

Authors

1 Laboratory of Vegetable Production, University of Thessaly, School of Agricultural Sciences, Department of Agriculture, Crop Production and Rural environment, Fytokou Street, N. Ionia, Volos 384 46, Greece.

2 Laboratory of Genetics and Plant Breeding, University of Thessaly, School of Agricultural Sciences, Department of Agriculture, Crop Production and Rural environment, Fytokou Street, N. Ionia, Volos 384 46, Greece.

3 Laboratory of Vegetable Production, Agricultural University of Athens, Iera Odos 75-77, Votanikos 11855, Athens, Greece.

Abstract

The effect of grafting and post-grafting temperature on the plant development of
two watermelon cultivars at transplantation and on subsequent fruit quality was
studied. Watermelon cv. Sugar Baby and Crimson Sweet were self-rooted
or grafted onto rootstock RS 841 F1 (Cucurbita maxima × C. moschata) or bottlegourd
[Lagenaria siceraria f. clavata] (year 1), plus L. siceraria f. pyrotheca
(year 2). After grafting, plants were held at 8 oC or 16 oC (minimum) until
transplantation (28-29 days), at which stage growth was compared with that of the
self-rooted control held under the same conditions. Plants were planted in the field
and fruit quality assessed at harvest. At the time of transplantation in year 1, plants
at 16 oC were taller and had a higher total fresh weight than those at 8 oC. The
grafted plants of both cultivars were taller and had a higher leaf area and fresh
weight than the self-rooted plants, irrespective of rootstock. In year 2, the grafted
plants of both cultivars had better development (height, leaf area, leaf number,
fresh weight) than self-rooted plants. The plants of Crimson Sweet × L. siceraria
f. pyrotheca were taller than those of the other two scion-rootstock combinations,
irrespective of temperature. Mean fruit weight at harvest was higher in grafted
plants than in self-rooted plants, and sugar content varied with scion-rootstock
combination. Grafting of watermelon results in better plant growth by the time of
transplantation, whereas the scion-rootstock combination affects fruit quality. A
minimum temperature of 16 oC is indicated during the post-grafting stage.

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