Maximising the amount of root growth in oilseed rape crops could help improve final yields, according to experts.
Around half of crops suffered from sub-optimal rooting below 50cm depth and this could be limiting yields, explained John Spink, head of crop physiology at ADAS.
“In a dry summer when the crop is reliant on extracting soil water from depth, those crops with a poor root system will therefore suffer from the effects of drought.”
But, applying the growth regulating fungicide Caramba (metconazole) in the spring has been shown to encourage greater root exploration at depth, he said.
In a trial at ADAS Rosemaund last year, applying Caramba at the recommended 1.2litres/ha rate almost doubled the root length density (length of roots within each cubic centimetre of soil) at 50cm depth, compared with the untreated control (see below).
“Root systems need to be able to scavenge for soil moisture and nutrients effectively and so be able to satisfy the crop’s demands at the critical pod filling stage,” added BASF’s Diane Heath.
“At this time drought can be a problem resulting in premature crop senescence and reducing the length of the seed filling period, as some growers found out to their detriment last year.”
Source: BASF/ ADAS