H.—29.

REPORT OF THE PLANT RESEARCH STATION, PALMERSTON NORTH. The activities of the Plant Research Station have been well maintained during the past year, 1933-34, notwithstanding the prevailing financial restrictions. The appended reports of the several Section heads outline the main features of the work, and afford a good indication of its wide scope. As previously, the Department of Agriculture has had. the co-operation of the Scientific and Industrial Research Department in certain parts of the work. A. H. Cockayne, Director.

AGRONOMY SECTION. J. W. Hadfield, Agronomist. PLANT RESEARCH STATION, PALMERSTON NORTH. The work at this Station in the Agronomy Section deals mainly with investigations bearing on problems relating to seed and crop production. Rape. —Previous investigations had revealed the fact that three main types of rape were available on the New Zealand market. One of these, a swede-like rape, proved to be very unproductive, and seed importation and seed production of this type has ceased. The other rapes offered were either Giant, Dwarf Essex, or a mixture of these. It became necessary to determine the relative agronomic value of these types. Fattening trials were therefore conducted at Marton Experimental Area by the Crop Experimentalist during the seasons 1932-33 and 1933-34, and by the Fields Division in several centres. Some of these results have already been published. Arising out of this, steps were taken to raise pure seed of these types so that such seed could be passed over to growers and further distribution effected under certification. This stage has been reached and several farmers are now raising commercial seed of pure types. As a further stage we have pure lines of the two types, which are now being seeded for distribution next season, and should prove better than any commercial seed offered in the past. Finally, wo have crossed the best of the inbred lines, thereby regaining lost vigor. The best of these have to be selected, and they should form the final product of our work. We have also crossed the two types, and have Fl plants now growing, but it is too early to predict any possible development in this direction. Swedes and Turnips. —Trials this season may be regarded as the final of a series laid down in connection with varietal nomenclature, and it is intended shortly to publish results of observations made. Brassica Crosses. —In view of the interest being taken in the production of seed of swedes, turnips, and rape, it was thought desirable to study the results of hybridization between these crops and with wild turnip. The Fl plants have been studied this past season, and it is hoped to publish results in the near future. Lucerne. —Breeding and selection work on lucerne commenced in 1931, and as the work has progressed several problems have presented themselves. The breeding proper has resolved itself into the selfing of the best plants within the best families. L2 seed is now being threshed, and L2 families will be under trial next season. Selfing has resulted in such marked reduction in plant vigor and seed production that it seems impracticable to proceed further in this direction. It may be that the lost vigor will be re-established when unrelated L2 plants are crossed ; but even if this does not eventuate the selfing will have indicated the best parental types, and all parents, both original and LI, have been preserved. Thus it will be possible to return to those parents which are indicated as the most promising by the behaviour of their selfed progenies. Clones have been raised from what are judged to be the best original parents, and bulk seed from these has been produced. This will be tried against commercial seed next season. Clones are now being propagated from the most promising LI parents. These will be allowed to interpollinate next season and produce seed. Observations on bees and other agencies which might bring about tripping and cross-pollination have beenmade in the field. This led to a controlled experiment in which bumble bees, black, Italian, and hybrid honey bees have been used as pollinating agents. Results are not yet complete. Since self-pollination no doubt commonly occurs in lucerne, a measure of heterosis has been made, and results demonstrate beyond doubt the desirability of establishing insects capable, not merely of tripping flowers, but of effecting cross-pollination, The yield of seed under various pollinating conditions has also been studied and further supports the desirability of cross-pollination. Peas. —In an endeavour to improve the yield and quality of our field peas, numerous crosses have been made, and from these F3 segregates, homozygous for the main seed characters, have been retained. Such material will be grown at the Pure Seed Station in Canterbury for fixing and the study of yield and other characters not expressed in this district. Other F3 material heterozygous for the desired seed characters but desirable in other respects will be grown on at this station for the purpose of extracting homozygotes. The following varieties are receiving attention : Partridge, White Ivory, Blue Prussians, and Harrison's Glory. Single-plant selections of all standard varieties of garden peas are made each year and increased once at this Station. They are then transferred to the Pure Seed Station, Lincoln, and increased to commercial proportions. The only breeding has been in connection with Greenfeast. F3 segregates from Greenfeast x Great Crop are now being studied. A genetical analysis of the transmission of the seed character, smooth, dimpled, and wrinkled, has been completed and is shortly to be published. Investigation on these matters was found essential to the satisfactory performance of our breeding work. It has revealed the genetical constitution of the smooth and wrinkled as more complicated than has been supposed. Oats. —Seed samples were collected from numerous sources and grown to determine the general standard of seed oats in respect to varietal purity and smut infection. The trials afforded material from which type descriptions have been prepared of all the more important varieties. Results of this work have now been published. Potatoes. —A trial of lines of seed potatoes collected from farmers in the Manawatu district has revealed a very serious position. Varieties are badly mixed or wrongly named, often unsuitable varieties are grown, and except for those not many years removed from certification, virus infection is said to render the seed quite unproductive. GOVERNMENT PURE SEED STATION, LINCOLN. Satisfactory progress has been maintained in the production and distribution of pure-seed stocks. Wheat. —There was a ready sale for the seed wheat produced in the 1932-33 season. The present harvest has been very satisfactory. Pure lines of all the commercial varieties are being maintained, but there is little demand

31