H.—34

Kale To provide material for certification purposes nucleus areas of the " Giant" and " Medium stemmed " types were grown ; the produce is to be passed over to the Department of Agriculture for further increase. Of the hybrid material being investigated, selections from the crosses marrow-stem kale X thousand-headed kale and marrow-stem kale X cabbage were seeded under isolation, while those from the cross marrow-stem kale X kohl rabi were again grown for observation and further selection. A digestibility trial with "Giant" marrow-stem kale, "Medium-stemmed" marrow-stem kale, thousand-headed kale, and Hungry Gap kale is being undertaken by the Grasslands Section. Swedes A further small plot trial is being carried out at the Division between Garton's Superlative, Garton's White Flesh, Sensation, and the hybrid type Grandmaster x Sensation s while at Lincoln College a large-scale field trial is being undertaken with the hybrid type and Sensation. A small increase area of the hybrid type located in Central Otago produced 22 lb. of seed ; this will be used for further field trials and further multiplication if warranted. Sweet Lupins Nucleus areas of sweet blue and sweet yellow lupins are grown each year and the produce increased under certification by the Department of Agriculture. During the past season a small area of a whiteflowering, white-seeded type was also propagated, and the strain is to be multiplied further during the coming year. Preliminary tests on seed treatment would suggest that polishing considerably improves germination, as indicated by the following results with the sweet blue variety : unpolished seed, 34 per cent, in ten days; polished seed, 90 per cent, in three days. Linen Flax To provide pure seed for distribution to the Linen Flax Section, nucleus areas of Liral Prince Stormont Cirrus, Stormont Gossamer, and Norfolk Earl were grown from hot-water-treated seed. In September, 1944, Mr. Black attended a conference of Australian linen flax research workers in Melbourne, and also visited the Waite Institute in Adelaide, Canberra, and Sydney. Much valuable information was obtained. Introductions. —Two hundredweight of Norfolk Earl seed was imported from England. Its performance at Lincoln and at Pleasant Point has been disappointing, and unless the quality of the fibre should prove to be outstanding it will be dropped. Of five Russian varieties received from Canberra, three are immune to the rust present at Timaru. A report from Werribee, Victoria, states that the same three varieties were immune to rust there when infection was so severe that Liral Prince growing alongside set no seed at all. The varieties are (1) Stakhanovetz, which is also said to be resistant to wilt; (2) 806/3 ; (3) D-83. They appear to be good fibre types, approximately equal in length to Liral Prince and Stormont Cirrus, and superior to Liral Crown and Concurrent in this respect. Small-scale trials will be carried out next season to test the yield and quality of fibre, and tests of their resistance to various races of rust are to be made in Australia, and possibly here. If their rust-resistance is confirmed, and if the yield and quality of fibre is satisfactory, these importations are likely to be of great value to the industry. Breeding. —The aim of the breeding programme is to produce a high-grade fibre flax that is resistant to rust and wilt. A second objective is to produce a high-grade seed flax (linseed) resistant to these two diseases. Many crosses have been made between Rio, the rust- and wilt-resistant linseed type parent, and various fibre varieties, Liral Crown, Liral Prince, Stormont Cirrus, Blenda, Hercules, Norfolk Queen, and Concurrent, also with New Zealand Commercial and Giza Purple for seedproduction. Most of the first crosses are now in F (i . A number of back-crosses to the fibre parents are now in F 2 and F 3 , and many of these have been tested for resistance to Polyspora browning by the Plant Diseases Division. Several hundred selections were sown both at Lincoln and at Pleasant Point, and moderate rust infection at the latter area made it possible for the first time to discard a large number for susceptibility to rust. Unfortunately the infection was not sufficiently severe to enable one to say confidently that the uninfected lines are immune—they may have escaped infection. During the season 137 successful second back-crosses were made on the 16 most promising looking back-crosses. It is essential that the resistant parents of these be tested for rust-resistance, and this test is being undertaken. The Australian authorities have presented to us some seed of tested rust-resistant and wiltresistant crosses between R.A.R. and Liral Crown, Liral Prince, and Concurrent. R.A.R. is Russian X Argentine back-crossed with Russian, and is immune to all races known in Australia and New Zealand. It is also immune or very highly resistant to the flax-wilt races of both countries, under the very severe conditions of their test (soil temperature, 75° F.). This material is too short in the straw for our conditions, and will have to be back-crossed at least once to long-straw-fibre varieties. Single Plant Selections. —Six hundred and seventy single plant selections of the following varieties were grown under netting : Rio, New Zealand Commercial, Norfolk Earl, Norfolk Queen, Liral Crown, Liral Prince, Stormont Cirrus, Stormont Gossamer, Blenda. Nucleus Lines.—Nucleus lines were grown from single plant selections as follows : Blenda, 21 ; Liral Crown, 40 ; Liral Prince, 50 ; Stormont Cirrus, 40 ; Rio, 40. The first four varieties are now being retted and scutched to determine the fibre percentage and quality, and the best lines will be bulked for increase. Mammal Trial. —A drilled manurial trial was carried out with duplicate plots of lime, super, sulphate of potash, sulphate of ammonia, and borax, both alone and in every possible combination. Small patches of high fertility on the area make it difficult to interpret the results, but during the growing season it was clear that super accelerated growth and maturity, and that sulphate of ammonia

4—II. 34.

25