H.—34,

111. Timber Preservation. (See Timber Protection Research, p. 51.) IV. Pomology Investigations. (See Fruit Research Report, p. 42.) Y. Miscellaneous. Pyrethrum Production. —Two areas of freshly propagated cuttings of some six to seven thousand plants were set out at Owairaka and Oratia for a test harvest next season on a commercial scale. Cuttings were taken from the high-yielding pyrethrin strain produced in former years. Experiments in kiln-drying of the flowers have been undertaken, and samples are now awaiting analysis to ascertain effects on the pyrethrin content. Kumara Varieties. —Samples of the more promising varieties were distributed to Orchard Instructors in various kumara-growing districts for trial. Nucleus lots of all lines have been carried on at Owairaka. Linen-flax Retting. —A large number of rets under controlled laboratory conditions but following factory procedure have been carried out to study the organisms associated with retting. With three sources of linen flax three organisms are consistently found in all rets. One, comparable with B. butyricus and B. felsineus, is occasionally present. The latter group is usually considered to be the chief agent in successful retting. Experiments with addition of inoculum containing this type of organism have shown a marked reduction in objectionable odours, and also in retting-time, of twelve to twenty-four hours. Identification of the organisms associated with retting is now in progress. Plant-growth Substances. (See Fruit Research Report, p. 42.) Castor-oil Plants. —Small scale field trials of different varieties of Ricinus communis have been undertaken at Owairaka over the past two years. Although growth was vigorous, yield of seed was very small. It is considered that production of seed for oil would not be economic in the Dominion, as apart from the necessity for a long warm summer to mature the seed, the latter ripen very unevenly and the labour of harvesting would be considerable. Experimental Areas. —Owairaka : The flat was extensively tile-drained and subsoiled during the winter, treatment which has markedly improved tilth and fertility. A rotary hoe was purchased in November, and has since practically paid for itself in the saving of labour formerly required to keep the farm free from weeds. The large tractor has been completely overhauled, after four years of continuous running, and is again in first-class condition. One commercial type of glasshouse, 50 ft. by 28 ft., was erected on the area for grape culture. A combined fruit and produce store has also been completed by our carpenters. The hop garden has been demolished as plants did not thrive under Auckland conditions. It was found necessary to remove the passion-fruit area to higher land behind the laboratory, as plants suffered severely from frost injury in their former exposed position. All roads were bitumen-sealed in the late spring by the Public Works Department. Advantages was taken of the presence of their equipment to seal the car-park area at the rear of the glasshouses and strips of land between each house. Oratia : Fourteen and one-half acres were acquired for a quarantine station about one mile and a half from Henderson Township in the Oratia district. It had formerly been in orchard, but trees were so neglected that most have since been pulled out and burned. The land has been ploughed and will be planted this and next winter with apple, peach, and citrus varieties worked on standard rootstocks. Three glasshouses are on the area and will be employed in quarantine work. The spray pump installed at Huapai, has, with the closing of that area, been moved to Oratia and will be installed as soon as the pump shed has been completed to contain it. Publications.* The following papers have been published by members of the staff during the year :■ — Atkinson, J. D. (1940) : " Die-back of Lace Barks caused by Myxosporium hoheriae, n.f. sp." N.Z. Jour. Sci. & Tech., 22, 115a-120a. Baylis, G. T. S. (1940) : " Flax wilt (Fusarium lini) in New Zealand." N.Z. Jour. Sci. & Tech., 22, 157a-162a. Brien, R. M. (1940) : "' Leak,' A Watery Wound-rot of Potatoes in New Zealand." N.Z. Jour. Sci. & Tech., 22, 228a~231a. (1940) : " ' Foot-rot' of Tomatoes caused by Phytophthora cryptogea." N.Z. Jour. Sci. Tech., 22, 232a-236a. Chamberlain, E. E. (1940) : " Varieties of Garden and Field Peas Immune to Pea-Mosaic." N.Z. Jour. Agric., 60, 250. - (1940) : " A Masked Virus of Aucklander Short-top Potatoes." N.Z. Jour. Sci. & Tech., 22, 57a-71a. - (1940) : " Severe-streak of Tomatoes." N.Z. Jour. Sci. A Tech., 22, 181a-186a. (1940): "Tomato-necrosis." N.Z. Jour. Sci. & Tech., 22, 186a-197a. Cunningham, G. H. (1940) : " The Genus Mesophellia in New Zealand." N.Z. Jour. Sci. & Tech., 22, 124b. (1940) : " Richoniella pumila, a Rare Gasteromycete." N.Z. Jour. Sci. & Tech., 22, 62b. Gibbs, J. G., Baylis, G. T. S., and Blackmore, L. (1940) : " Experiments in Control of Onion Smut (Urocystis cepulae Frost)." N.Z. Jour. Sci. & Tech., 22, 162a-166a.

* Note,' —For papers on Fruit Research Projects, see Fruit Research Report, page 42.

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