DUSTING PEAS FOR SOWING

Press, Volume LXXXIII, Issue 25276, 30 August 1947, Page 6

DUSTING PEAS FOR SOWING

TESTS OF SEVERAL COMPOUNDS

INSURANCE AGAINST LOSSES

Tests of various dusting compounds carried out on William Massey peas at Lincoln College on 1946 and 1947 harvest seed showed profitable increases in germination in treated as against untreated seed only in early spring and late autumn sowings. Differences were small from September on to January, but were large in August and May sowings. Half a dozen different materials were tested in the trials and showed considerable differences in effectiveness. The best were two dusts which are now being used extensively in the United States, but which are so far difficult to procure here. Their base is a compound with the jaw-breaking name of paradichloro-benzoquinine In the United States they have practically displaced other dusts for treating peas. Copper carbonate was found to be nearly as good as the American dusts. An Ellesmere farmer has had considerable success in treating peas with used crankase oil, and this was also tested. Its performance was quite good. It is simple to use, as it is merely poured into the box at the time of sowing in small quantities which allow the oeas to run through the machine freely. A comparatively poor performance was put up by two commercial dusts with an organic mercury base. Except in the earliest and latest sowings, they were frequently inferior to untreated seed. The difficulty seems to be that these dusts have inferior qualities of adhesiveness to peas, and peas to be treated with them should probably be treated beforehand with graphite to increase adhesiveness. Nine sowings were made, spread over August, September, November, and December, 1946. and January. March, and May, 1947. The mean germinations over the nine sowings were 64.7 per cent, for untreated seed, 71.6 and 71.2 for the American dusts. 70.1 for copper carbonate, 64.3 and 64.5 for the two organic mercury dusts, and 65.4 for crankcase oil.

On the results of the trials, Dr. I. D. Blair, microbiologist at the College, says: “The results of the successions! sowings reveal that pea seed treatment exhibits maximum benefit in sowings made in early spring or autumn. Soil moisture and temperature relations are known to be of primary concern in seed emergence. When the soil is highly saturated and cold, chemical treatment of the germinating seed seems to confer a marked measure of protection against pre-emergence fungus decay. This benefit seems to lessen in the mid-season and, in fact, some authorities have evidence that pea dusting when soil and growing conditions are good is of no value whatever. But seeing that soil conditions subsequent to sowing cannot be forecast, it is reasonable to suggest that dust treatment should continue, especially with early or late sowings, for the reason that it constitutes a cheap insurance against germination losses when adverse soil conditions develop after sowing. It is emphasised, however, that even the maximum germination improvement is rarely more than 10 per cent.”