Research Update

Fumigant alternative showing promise

Composting in cherry replant trials has worked well in terms of plant growth and nematode suppression.

By Judie Steeves T

he trials continue this year, but initial results suggest that use of compost and a mulch when replanting to cherries helps to reduce populations of root nematodes. Tom Forge is a soil scientist at the federal Summerland Research and Development Centre who has worked on research into suppression of damaging nematodes in newly- replanted raspberries in the Fraser Valley since 2009.

The research is particularly relevant now that there are new restrictions on use of soil fumigants containing ingredients such as Chloropicrine, Daxomeet (Basamid) and Vapam. He began his Okanagan research by removal of an old apple and cherry block where there were populations of root nematodes in the soil around the roots of the trees that were removed. In some plots, the soil was fumigated, while in others compost was applied where the new trees were to be planted, in the same rows as the previous plantings. In some a thick layer of bark mulch was applied, in others none was used and one plot was left as a control plot. There is evidence from previous work that mulches help to suppress root nematodes, he notes.

In all, there were five treatments in each row, with alternating micro and drip irrigation.

Twelve rows of cherries were planted in 2014 and after one year of growth, those planted in the mulched, composted plots showed greater growth than in the control plot, but not more than those in the fumigated

20 British Columbia FRUIT GROWER • Spring 2017


Soil scientist Tom Forge, with the Summerland Research and Development Centre.

plot, he reports.

In the second year, they had caught up to the growth of those in the fumigated plots.

At the end of the second year, the lowest nematode numbers were in the plots treated with compost and mulch. In the spring of 2015, they ripped out an old cherry block that had been mulched previously, then treated some with compost, others without, some with fumigation and others without.

In the first year, the best growth was in the fumigated plots, while in the second year, growth was not as good as in the fumigated row. There was some growth improvement overall

where compost had been applied, Forge reports.

And, there was some suppression of root nematode populations where compost had been applied. This will be the third year for this experiment.

Forge says he suspects the benefits of incorporating compost into the soil at the time of replanting will have a long-term effect on soil moisture- holding capabilities as well as growth, an important factor in the dry Okanagan.

He notes that the up-front cost is similar to the cost of fumigation. To date, there has been some spectacular success in using

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36