Beans Restricted By Temperature

Press, Volume CVIII, Issue 31832, 9 November 1968, Page 10

Beans Restricted By Temperature

Soya bean research has been terminated at Lincoln College in the meantime. For the last two seasons Fletcher Industries have provided grants of $lOOO and $2OOO for this project. Speaking to farmers at the college field day last week, Dr C. T. Dougherty, lecturer in plant science, indicated that temperature was restricting the growth and yield of soya beans in this part of the world and also reducing the oil content of beans. Temperatures had been too low during bean formation and oil synthesis, he said.

Discussing the 1966-67 trials, when 32 plots were grown, Dr Dougherty said it had been found that water was not a limiting factor to any extent, nor was nutrition. Plant density had little effect and there was no marked response to inoculation. In that season the varieties, Harosoy and Chippewa, were grown. Dr Dougherty said it seemed the Canterbury climate was not suitable, for maximum oil synthesis in these varieties. Yields up to 33 and 34 bushels had been obtained and results had been much better in 20-inch row spacings than at greater distances between rows—the yield for 20inch spacings was 19.6 bushels to the acre and for 40-in spacings 12.2 bushels, The average yield for Harosoy had been 16.5 bushels and for Chippewa 15.3.

Because it seemed that temperatures were too low, Dr Dougherty said it was felt that it might be possible to overcome this difficulty by growing earlier maturing varieties.

Last season three varieties from the United States— Amsoy (the earliest), Wayne and Adelphia—had been grown with planting dates in

October, November and December being used. It was felt that weeds could be a problem and both interrow cultivation and herbicides had been used. Once again at all planting dates the 20-inch row spacings had given best results—the average yield at 20-inch spacings was 22.7 bushels, at 30-inch 13.2 and at 40-inch 11.1.

Amsoy as the earliest maturing variety had yielded best It had yielded up to 26.5 bushels to the acre in 20-inch rows. Adelphia at the other end of the scale had yielded very little. The average yield for Amsoy was 18.5 bushels, for Wayne 17.5 and for Adelphia 11.0. The earliest plantings had suffered from pea top yellows virus. If soya bean growing was to continue. Dr Dougherty said they would have to look for varieties earlier than Amsoy.

He said it seemed as though there would still have to be “jiggling” with planting dates, but it looked as if 20-lnch rows were right. It seemed as though earlierflowering and maturing varieties from Canada were needed but these had lower yields and also might have a lower oil content.

But in contrast, he said, block trials in the North Island bad yielded 40 to 50 bushels to the acre and in plot trials yields of up to 90 bushels to the acre had been recorded.