The chemical defoliation of Ligitstrum vulgare L. and Spiraea x arguta Zab. shrubs in nursery

To defoliate Ligustrum vulgare and Spiraea x arguta – ethephon, KJ, Mg(ClO3)2•6H2O, CuSO4•5H2O and (NH4)2SO4 in various concentrations were used alone or in mixtures. Treating plants with potassium iodide gave the best results. KJ concentrations of 0.05-0,1% and 0.1-0.% were sufficient to defoliate Spiraea and Ligusturm respectively. Magnesium chlorate at concentration of 0.24 and 2% CuSO4 were also effective, the latter however, proved slight harmful to the plants. Spraying with defoliants on Sept. 26 gave better results than treating plants on Sept. 16. Chemical defoliation decreased negligibly the frost resistance of Ligusturm vulgare shrubs

Effect of temperature and light on foliar absorption of P and Rb by Chrysanthemum and Pilea

Young plants of Pilea cadierei Gagnep Guillaum and Chrysanthemum morifolium Ramat. 'Giant # 4 Indianapolis White' were grown in Hoagland's solution in growth chambers. Their leaves were treated with rubidium phosphate double labelled with 33P and 86Rb. Light intensity, period of pretreatment in light or dark, daylength, and air temperature had different influences on foliar uptake of each ion, as did plant species and leaf surface. With all variables tested, uptake and translocation of Rb was much greater than of P. Absorption of both P and Rb through the lower surface was as much as 8 times greater than through upper surface, especially with Pilea. Light had a greater effect upon uptake of both P and Rb by Chrysanthemum than by Pilea, but did not influence uptake as much as previously reported