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Root-development Studies. By W. A. Jaques, Massey Agricultural College. Root-development studies are being continued at Massey Agricultural College in collaboration with the Plant Research Bureau. In brief, the work is designed to give information concerning the rooting-systems of various species and strains of common pasture plants under varying environmental conditions. Preliminary work has included the development of a satisfactory and convenient technique for root sampling. Work is now proceeding on studies of development of rye-grass and white-clover roots in different soil types, the effect of fertilizer placement at different levels in the soil profile on root-development, the length of life of roots, the effect of mixed sowings and of defoliation on the root-development of the individual species, and the influence of autumn and spring sowings and top-dressing on root-development. Some of this work is essentially of a fundamental nature, but much of it will be of direct application in grassland management —e.g., time of establishment and top-dressing of pastures, harrowing, and intensity of grazing at different times of the year. PLANT CHEMISTRY LABORATORY. Officer in Charge : Dr. J. Melville. Until August, 1938, the chemical laboratory attached to the Grasslands Division of the Plant Research Bureau was engaged chiefly in a study of the relationship between soil and pasture, particularly with regard to the availability and transference of lime and phosphates. In addition, the conventional analyses of pasture for feeding trials of milking-cows were carried out for the Dairy Research Institute. These projects are being continued. It must be stressed, however, that such analyses give a very limited picture of the synthetic mechanisms of the green leaf, and this was thrown into relief by the widespread outbreaks of facial eczema last year. The fact that this disease is apparently the result of flush growth brings it into the category of stock ailments which are related to rapidly growing pasture. With a view to obtaining a better insight into the chemistry and physiology of herbage under as wide as possible a variety of environmental conditions, it was decided to reorganize and extend the scope of work of the existing laboratory, which has now been given the title of Plant Chemistry Laboratory. The proposed investigations in plant biochemistry, which will deal at first largely with the soluble organic constituents of the leaf, are in their initiatory stages. Certain special equipment has not arrived, while extra accommodation which has been arranged is not yet completed. The following is a report on the current activities of the Laboratory. Soil and Pasture Studies (Mabton). The work on this project has been continued. Much useful information regarding the rate of conversion of carbonate of lime (applied as top-dressing) into the exchangeable form has been obtained. Indications are that, under Marton conditions, carbonate of lime does not need to be ground as finely as has been sometimes recommended. It has been shown that, although limes from various localities differ considerably with regard to the rate of reversion of superphosphate, there was little difference between a hard and a soft limestone as regards availability when applied as a top-dressing to pasture. Further evidence has been obtained supporting the movement of added phosphates under Marton conditions. Phytohoemones. Investigations of the effect of various chemicals on the rate of rooting of cuttings have been carried out, and a report on this work has been published in the New Zealand Journal of Science and Technology. Considerable improvement in the rate of rooting has been obtained with some treatments when given to cuttings of certain species, but other species, normally very difficult to propagate from cuttings, have so far failed to respond to hormone treatment, butyric acid has proved the most active chemical of those tried, a-naphthalene acetic acid and /3-indole acetic acid have also been satisfactory. Considerable difficulty has been found in getting species known to respond to treatment to give consistently good results. There are at least two factors involved : (1) The condition of the wood, and (2) the temperature and humidity at the time of soaking. These factors affect the amount of chemical absorbed. With wood which is too soft, or under conditions of low humidity, an excessive amount of chemical may be absorbed, resulting in the death of some or all of the tissues. Preliminary trials using vitamin B t in conjunction with appropriate hormone treatment have been encouraging, and support the contention that in the absence of vitamin B t root growth does not take place although root primordia have been produced as a result of hormone treatment. The Relation op Pasture Plants to the Quality and Quantity op Dairy Products. The Dairy Research Institute and the Grasslands Division of the Plant Research Bureau have for a number of years been conducting nutritional experiments with milking-cows, and full reports of the investigations will be found in the reports of these units. The conventional analyses of the ration fed have been conducted by this Laboratory. It is hoped that by certain modifications these analyses will be made more informative, particularly with regard to the non-digestible fractions. These trials will also provide excellent material for metabolic studies of pure-strain grasses.

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