Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster V20
Christina Stadler
Landbúnaðarháskóla Íslands
Kynnir / Presenter: Christina Stadler
Tengiliður / Corresponding author: Christina Stadler (christina@lbhi.is)
Growers in Iceland have adopted intensive use of supplementary lighting to maintain year-round production. Cropping methods are quested that increase yield. It was tested, whether by pruning the clusters, the method of deleafing and interplanting a yield increase could be achieved. In the research greenhouse of the Agricultural University of Iceland were grafted tomatoes (Lycopersicon esculentum Mill. 'Encore') with a plant density of 2,66 tops/m2 (2 tops/plant) grown in pumice. The plants were lighted with high-pressure vapour sodium lamps (HPS, 240 W/m2) for a maximum of 18 hours. In one chamber were clusters pruned to six fruits until the third cluster and to eight fruits after the third cluster. The cleaning of the greenhouse before planting of new plants results in a loss of yield and could be avoided by interplanting, where new plants were planted in between the old ones. The tomatoes of the younger plants were already mature, when the older plants were completely harvested. In addition, two deleafing strategies were tested. In the treatment „much deleafing“ was basically started earlier with deleafing compared to „normal deleafing“ and behind each of the newly developed cluster was a leaf removed during a specified time period. Pruning the clusters had a negative effect on the accumulated marketable yield. Interplanting resulted compared to not interplanted tomatoes in a delayed harvest by one week and the weekly yield was slightly lower. But, it could be harvested constantly, while with not interplanted tomatoes eight weeks passed before harvest started. Therefore, interplanting resulted in a significantly higher tomato yield. A further yield increase was reached with much deleafing. From an economic viewpoint it is recommended to interplant tomatoes and start soon to deleaf much, while pruning the clusters of grafted tomatoes is inadvisable.