USE OF COATED SEED

Press, Volume CVI, Issue 31161, 10 September 1966, Page 10

USE OF COATED SEED

QN a tussock grassland site in the Coleridge district of Canterbury recent field trials have confirmed the importance of Gafsa/dolomite coating of inoculated clover seed for oversowing in South Island tussock grasslands, says an article prepared by Coated Seed, Ltd., a Christ-church-based company producing coated seed for national distribution. The trials were laid down by the company.

“The site was a native sward of predominantly browntop and tussock and is typical of many hundreds of thousands of acres of tussock grasslands in Canterbury. “All seed was of the same line, all inoculation was applied equally on each treatment and the environment

was identical in each treatment apart from the inoculation and coating treatments. “The trial revealed that inoculated and Gafsa/dolomite coated seed was superior to clover seed just inoculated after the usual brief storage of both. Seed not either inoculated or coated, even when sown at a high seeding rate per acre, gave much poorer results than a low seeding rate which was inoculated and Gafsa/dolomite coated. -

Less Production “Where manure at a high rate was applied but no seed was sown, there was an increase in growth of native grass but still only minor native clover growth and much less pasture production than any plot which was oversown in addition to being topdressed equally. “The method of preparing the coated seed has been found to be most important, and in addition lime coating of inoculated clover seed has been found unsatisfactory and even sometimes harmful. Gafsa/dolomite, however, has been found an important improvement. “Lime has given consistently good results where used as a coating material on inoculated lucerne, giving better results than just inoculated lucerne seed.

“Contrary to popular belief lime coating of clovers when sown on some very low fer-

tility acid soils has caused a depression in growth, not an improvement, and it is particularly important on these soils to have clovers inoculated and Gafsa/dolomite coated. “Soon a new triple coating technique with a coating developed by the company will be available to farmers throughout New Zealand. This is expected to make an important further improvement in introducing clovers into low clover content soils. This new technique is under field test now for the first time in New Zealand.

“The triple coat technique is an adaptation of some recent Australian research combined with considerable processing experience gained in Christchurch.

“The triple coating of legumes will permit a manurial and inoculation response since the coating will contain major element plant foods without free acid and this may be an important development in agriculture. This acid free superfine coating inclusive of nitrogen, will also be used on non leguminous grasses and crop seeds soon to be available commercially and again will permit more positive establishment of cocksfoot, ryegrass, dogstail, etc. in tussock grasslands in association with clovers. Other developments may follow.”

Comment Asked to comment on this article, Dr. J. G. H. White, senior lecturer in plant science at Lincoln College, said that it was essential to lime pellet lucerne to get establishment in acid soils, but as far as pelleting of clover was concerned while he would not condemn it he would not be enthusiastic about it until there was more evidence. It might be that the Gasfa/dolomite coating would be better than lime, as the phosphate element might be providing a nutrient to the rhizobia.

As far as grass and crops seeds were concerned, they had not done any work on this and before widespread use was made of pelleted grass seed there would need to be more experimental work to support it. he said. Apart from assisting In nodulation, Dr. White said that pelleted seed facilitated sowing from aircraft and it also permitted sowing with an acid fertiliser, such as superphosphate, so that there was less damage to the bacteria on the inoculated seed. Dr. White said that the college would be trying some of the triple coated seed at its hill country property, Hunua, this year.