DARCOF · Research > Darcof II > Organic vegetables > Sub3

Subproject 3
Varieties, growing stability, disease resistance and quality

Participants
Gitte Kjeldsen Bjørn and Anne-Mette Fruekilde, Dept. of Horticulture, Danish Institute of Agricultural Sciences, Aarslev.

Email: GitteK.Bjorn@agrsci.dk


Purpose

The main purpose of this project is to gain knowledge about the growing stability of some vegetable crops grown organically and conventionally. There are many propagation techniques to improve organic production, but another purpose of this project is to study the effect of choosing the right varieties according to growing system.


Activities and preliminary results

Since year 2000, 5 varieties of 3 crops have been investigated: Onions, cauliflower and carrots – and in 2003 also broccoli.

Onions:

  • Yield and crop size are smaller in organic than in conventional onions
  • In general discarding is lower among organic onions than among conventional, and the growing stability of organically grown onions is at least as good as the conventionally grown.

  • Downey mildew (Peronospora destructor) was typically seen 3 weeks later in organic fields, mainly because of lower plant densities here. Lower plant densities explain some of the lower yield in organic fields which may be changed by utilizing plant onions.

Cauliflower:

  • The amount of marketable organic curds is the same as for conventional

  • Organically grown cauliflowers are slightly smaller than conventional but yet bigger than minimum limitations for sale. In average conventional curds have a diameter of 14,1 cm and a weight of 927g. Organic curds measure 13,3 cm. and weigh 794g.
  • Harvest period is longer for organically grown cauliflowers than for the conventionally grown.
  • Organically grown cauliflowers have a more open branching, but conventionally grown cauliflower seems to have more hollow stalks.

Carrots:

Carrot experiments are still on going and the results are expected spring 2004.


Publications under preparation:

Bjørn & Fruekilde: Økologisk vs. konventionelt dyrkede kepaløg (Alluium cepa L). Grøn Viden

Bjørn & Fruekilde: Mindre sygdom i økologisk dyrkede kepaløg. Økologisk Jordbrug.

Bjørn & Fruekilde: Organically vs. conventionally grown onions (Allium cepa L). Submitted to international refereed journal.

Bjørn & Fruekilde: Kvalitet af økologisk dyrkede blomkål. Grøn Viden