Carrot is one of the major crops in the UK. The total cultivated area exceeds 9.000 ha. 60% of the acreage, approx. 5.500 ha, is stored under straw. One hectare results on average in a gross income of £8.000. This means that the total turnover of covered carrots is approx. £44 million. Losses due to cavity spot vary between years and geographical regions. Untill recently, Scotland for example, had no occurrence of cavity spot. Other regions have more severe problems. In some fields the damage exceeds 40%. On average, cavity spot destroys 3% - 7% of the yearly yield, resulting in a loss between £1.25 and £3 million. However, this percentage seems to increase over the years. Last season for example, the percentage was estimated to be between 5% and 10%, which almost doubled the losses.
The average cost of covering consist of straw (£3.000 per ha) and logistics (transport and covering). In total the costs for covering are approx. £4.000 per ha. It is clear that a high cavity spot occurrence means that a grower will not earn (instead: will lose) money on those batches. A predictive test that determines high risk fields, will support a grower to pick only low risk fields for covering. A reduction of cavity spot occurrence of only 1% on average, already makes a difference in turnover of £440.000 per year. This is exclusive of extra costs for covering, logistics and sorting. A predictive test would make UK carrot industry much more profitable.
This project will result in a practical test to determine the risk on cavity spot. The test will consist of a simple sampling kit for the grower that enables him to collect samples. The samples have to be sent to a lab either in the UK (preferably) or to NSure’s facilities in Wageningen. Within 48 hours after the samples are received, the grower will receive an indication of the risk of cavity spot. Samples can be taken throughout the season in order to support decision taking at several crucial time points during the season. Growers will be informed about the test and its background in several meetings and by a user’s guide that will be delivered together with the test kit.
Finally, the specific insight in development of Pythium violae during the season, will be shared with the growers and researchers involved in other projects concerning Pythium violae in carrots. This might be of help to better understand behaviour of Pythium violae. This better understanding could contribute to improvement of measures to prevent from Pythium violae infection and cavity spot occurrence.