Abstract: Some species regenerate readily from root cuttings at any time of year, whereas cuttings of other species show a well-marked seasonal fluctuation in capacity to grow. In the latter a high proportion of successes is possible only if cuttings are taken in the “ on ” season. In the “ off ” season for raspberry, not only do root cuttings fail but whole root systems, severed and left undisturbed in situ, also die. The regenerative capacity of (a) root cuttings, and (b) severed roots left in situ, has a bearing on the degree of control, which can be obtained by tillage, of weed species which are able to regenerate from roots left in the ground.

Abstract: A study of the importance of predators of the Fruit Tree Red Spider Mite, Metatelranychus ulmi (Koch), in Nova Scotian orchards twenty years ago led Gilliatt (1935) to conclude that another mite, Seiulus pomi Parrott, predacious on M. ulmi, was a major factor in the control of the latter under suitable conditions. S. pomi, however, was found to be very susceptible to the winter oil and lime-sulphur sprays applied as a routine at that time, and was unable to prevent increases of M. ulmi in such orchards. Similar increases of M. ulmi in Ohio orchards receiving sulphur sprays were attributed by Cutright (1944) to the greater susceptibility of predacious mites to this chemical.

Abstract: (1955). Apple Rootstock Studies : Malling-Merton Rootstocks. Journal of Horticultural Science: Vol. 30, No. 1, pp. 25-33.

Abstract: Previous papers have described the effects of molybdenum on the growth (3) and composition (4, 5) of cauliflower plants grown with two levels of nitrate nitrogen. It was found that molybdenum deficiency resulted in decreased contents of chlorophyll, ascorbic acid, sugars and organic nitrogen. This paper describes results obtained with cauliflower plants grown with nitrogen as nitrate, nitrite, ammonium compounds, urea or glutamic acid. The intention was to compare the effects of molybdenum on growth and composition under different conditions of nitrogen nutrition. The results were obtained in two main experiments carried out in 1951 and 1952, of which the first was briefly noted (1), and in other experiments in 1953–54 in which additional confirmation of certain points was obtained.

Abstract: 2-Naphthyloxyacetic acid (BNOA), having a side-chain 2 carbon atoms long, is highly active in stimulating seedless fruit development in tomatoes In this paper it is shown that progressive lengthening of the side-chain results in a series of compounds of which only those having an even number of carbon atoms in the side-chain are active This is thought to be due to the fact that the even carbon compounds are broken down by oxidation in the plant to the active BNOA, whereas those with odd numbers of carbon atoms are broken down to the inactive β-naphthol It is further shown that the introduction of a chlorine atom at position 3 in the naphthalene nucleus prevents this oxidation When the side-chain exceeds 6 carbon atoms in length there is a rapid falling off in the activity of the active members of the series, which is probably due to the slower penetration of these long molecules into the cell

Abstract: Many different approaches to the study of storage quality of apples have been made with the emphasis largely placed on post-harvest physiology. This has been due to the great variability encountered in individual tree performance (Hoblyn, 9) which, in turn, may be due to inherent differences in rootstock and scion or be a result of climate, soil, disease or insect pests. This variability is shown even between different parts of the tree where, as Martin (12) has noted, each branch may behave as an organic unit.

Abstract: (1955). The Biology, Life History and Methods of Control of the Leaf Curling Plum Aphid Brachycaudus Helichrysi (KLTB.) Journal of Horticultural Science: Vol. 30, No. 4, pp. 252-259.

Abstract: (1955). Seasonal Changes in the Major Nutrients of Black Currant Leaves. Journal of Horticultural Science: Vol. 30, No. 3, pp. 188-196.

Abstract: (1955). Strawberry Yellows in the Variety Auchincruive Climax. Journal of Horticultural Science: Vol. 30, No. 1, pp. 56-61.

Abstract: Experiments were carried out with aldrin, dieldrin, isodrin, endrin and DDT to ascertain whether, employed as insecticides, these compounds had any effect on cell division in onion root-tips. The doses used were equal to, or greatly in excess of, the recommended rates of application. By germinating onion seeds in direct contact with the insecticide under investigation, it has been shown that none of the compounds had any effects on germination or growth rate. High doses of aldrin, dieldrin or isodrin had a slight toxic effect on the resting cell, which, with aldrin, was also caused by the recrystallized compound. Aldrin and dieldrin had no effect on the dividing cell. Isodrin and endrin caused slight stickiness between chromatids in anaphase, which was insufficient to prevent the completion of division in the cell, and DDT caused a delay in the early stages of prophase and a shortening of chromosomes in metaphase.Pot experiments, with high doses of each compound, showed that germination and growth rate we...

Abstract: Experiments were carried out with technical chlordane and toxaphene to ascertain whether, employed as insecticides, they had any effect on cell division. Root-tips of onion seedlings were used as test material and the doses used were equivalent to 20 and 200 lb. per acre of 10 per cent, dusts on gypsum. By germinating onion seeds in direct contact with the insecticide under investigation, it was shown that neither chlordane nor toxaphene affected germination, but chlordane reduced the growth rate. The frequency of nuclear divisions was unaffected by toxaphene, but reduced by chlordane. Both compounds affected the dividing cell by causing a delay in pro-metaphase and preventing nuclear reconstruction in telophase. In addition, chlordane had a lethal effect on the resting cell. The effect on telophase was evident for a period of at least four days after removal from the insecticides.Pot experiments showed that the low dose of toxaphene had little effect on cell division, but the low dose of chlordane and th...

Abstract: (1955). Greenhouse Testing of Fungicides Against Botrytis Rot (Grey Mould) of Strawberry and other Soft Fruits. Journal of Horticultural Science: Vol. 30, No. 4, pp. 213-219.

Abstract: The behaviour of hardwood cuttings is influenced by factors that have operated upon the parent plant. A comprehensive study, not only of such " source ” effects but also of their interaction with growth substance treatment and subsequent environment, aims to extend this method of propagation. Patterns of behaviour of varieties of very different rooting capacity are clearly related, layer cuttings being better than hedge, with a declining gradient from the base of the shoot. The etiolated basal cutting from a layer shoot normally roots well whenever planted, but non-etiolated cuttings derive considerable benefit from over-wintering in soil.With the readily rooting Myrobalan B, growth substance application in the autumn is not essential ; such treatment is advocated for the moderately rooting Brompton plum while, with the shyly rooting Crab C, accelerative influence has, so far, proved inadequate. Success with Crab C could derive from the ability of the cutting to survive, though unrooted, into the second y...

Abstract: The Raspberry Cane Midge is principally important as a precursor of the fungal disease “ Midge Blight This disease may kill a substantial proportion of the canes of varieties such as Newburgh and Mailing Enterprise before they can bear fruit in the following spring (Pitcher and Webb, 1952) ; in addition, the yield of many of the surviving canes is reduced. Fortunately the midge is not a universal pest of raspberries ; in Britain its range is restricted to the south and the Midlands and several varieties, such as Norfolk Giant and Mailing Landmark, are highly resistant.

Abstract: (1955). Steam Pressure in Soil Sterilization: II. Glasshouse in Situ Sterilizing. Journal of Horticultural Science: Vol. 30, No. 1, pp. 43-55.

Abstract: The entrance of phytopathogenic bacteria into host tissues is a comparatively simple process. Unlike many pathogenic fungi they are incapable of active penetration of protective surfaces and gain a...