Life Sciences Commons^™

Regulating Growth Of An Aquatic Plant: Lemna Perpusilla, Willard L. Koukkari, Stanley H. Duke

Journal of the Minnesota Academy of Science

Growth rates of Lemna perpusilla 6746 can be regulated in axenic cultures by 6-benzylaminopurine (BA) . Concentrations of 10-BM BA significantly enhanced growth, while levels of 10-7M and Higher were inhibitory. These effects of BA on growth were evident when calculated as either fresh weight of frond number.

Organization Of The Primary Body In The Root Of Cyclamen Persicum Mill, Marshall D. Sundberg

Journal of the Minnesota Academy of Science

The primary body of the root of Cyclamen persicum Mill. is described. The rootcap consists of two components of separate origin. Cells of the columella are derived from the dermatocalyptrogen by periclinal wall formation. Further growth of the columella is due primarily to the increase in size of existing cells. Cells of the lateral rootcap arise from the protoderm by periclinal wall formation. Continued growth in this region is due to both increase in cell number and increase in size of existing cells. Proximal to the dermatocalyptrogen is the presumptive quiescent center. Around the periphery of this zone are located …

Faster Weed Germination With Early Cultivation, Geoffrey A. Pearce

Journal of the Department of Agriculture, Western Australia, Series 4

The key to cultural control of weeds in cereal crops is an understanding of the factors which govern germination of the weed seeds.

Covering the seed with soil keeps out light, provides a stable moisture supply and makes germination faster than if the seed is left on the soil surface.

Shallow cultivation at the start of the growing season provides the soil cover needed for fast, even germination of weed seeds.

The Art And Science Of Plant Breeding, John Sylvester Gladstones

Journal of the Department of Agriculture, Western Australia, Series 4

The first part of this article described the evolution of crop varieties and their improvement by simple selection. This part discusses cross-breeding and the other techniques which underly most modern plant breeding programmes.

The purpose cf crossing is to generate new combinations of varietal characteristics. It does not create anything basically new. All the genetic "ingredients" of a new variety must be present in one or other of the parents.

Learning To Live With Clover Scorch, A Bokor, D. L. Chatel

Journal of the Department of Agriculture, Western Australia, Series 4

Recent research has increased our understanding of clover scorch disease in Western Australia.

An economic control has yet to be developed but it appears that management can be adjusted to reduce damage to pastures and there is scope for using resistant species and less susceptible cultivars to escape the disease.

A major research programme is in progress.

Clover Disease : What Do We Know And What Can We Do, T Marshall

Journal of the Department of Agriculture, Western Australia, Series 4

A review of 30 years' study and practical experience of clover disease in Western Australia—and a summary of current recommendations for reducing problems in sheep grazing pastures based on oestrogenic subterranean clover.