TY - JOUR
T1 - Are specific testing protocols required for organic onion varieties? Analysis of onion variety testing under conventional and organic growing conditions
AU - Lammerts Van Bueren, E.
AU - Osman, A.M.
AU - Tiemens-Hulscher, M.
AU - Struik, P.C.
AU - Burgers, S.L.G.E.
AU - van den Broek, R.C.F.M.
PY - 2012
Y1 - 2012
N2 - Organic growers need information on variety performance under their growing conditions. A 4-year onion variety research project was carried out to investigate whether setting up a variety testing system combining conventional and organic variety trials is feasible and efficient rather than organizing separate variety trials under the two management systems. During 4 years commercial onion cultivars were tested at a certified organic and a non-organic location. Both systems were managed without chemical pest, disease and sprouting control, but differed in fertility management (organic manure in autumn versus synthetic fertilizer), soil cultivation and weed management (mechanical weeding versus application of herbicide). Management system significantly affected plant density, thickness of neck, and proportion of small and large bulbs. Variety × management system interactions were significant for bulb uniformity, earliness, proportion of large bulbs, dormancy and relative storage success but did not change the ranking of the varieties. We conclude that organic growers can profit from a more conscious variety choice when conventionally fertilised trials would refrain from using pesticides, fungicides, herbicides and sprout inhibitors. However, this would require an adaptation of the management protocol in such a way that trials might no longer represent conditions of conventional farmers. Furthermore, assessments of leaf erectness, disease resistance to downy mildew and leaf blight should be included in the protocols for organic use. We advocate better communication between breeders and growers on specific variety characteristics contributing to improving yield stability under low-input, organic growing conditions
AB - Organic growers need information on variety performance under their growing conditions. A 4-year onion variety research project was carried out to investigate whether setting up a variety testing system combining conventional and organic variety trials is feasible and efficient rather than organizing separate variety trials under the two management systems. During 4 years commercial onion cultivars were tested at a certified organic and a non-organic location. Both systems were managed without chemical pest, disease and sprouting control, but differed in fertility management (organic manure in autumn versus synthetic fertilizer), soil cultivation and weed management (mechanical weeding versus application of herbicide). Management system significantly affected plant density, thickness of neck, and proportion of small and large bulbs. Variety × management system interactions were significant for bulb uniformity, earliness, proportion of large bulbs, dormancy and relative storage success but did not change the ranking of the varieties. We conclude that organic growers can profit from a more conscious variety choice when conventionally fertilised trials would refrain from using pesticides, fungicides, herbicides and sprout inhibitors. However, this would require an adaptation of the management protocol in such a way that trials might no longer represent conditions of conventional farmers. Furthermore, assessments of leaf erectness, disease resistance to downy mildew and leaf blight should be included in the protocols for organic use. We advocate better communication between breeders and growers on specific variety characteristics contributing to improving yield stability under low-input, organic growing conditions
KW - rassenproeven
KW - uien
KW - biologische landbouw
KW - rasverschillen
KW - proefopzet
KW - variety trials
KW - onions
KW - organic farming
KW - breed differences
KW - experimental design
KW - farming systems
KW - performance
U2 - 10.1007/s10681-011-0545-4
DO - 10.1007/s10681-011-0545-4
M3 - Article
SN - 0014-2336
VL - 184
SP - 181
EP - 193
JO - Euphytica
JF - Euphytica
IS - 2
ER -