The evolution of the concepts of growth, development and other related, during the last decades

The evolution of such terms as growth, differentiation, development, morphogenesis etc. is discussed. It is proposed that the term (notion) development should be understood to comprise "growth", "differentiation" and even "abscission, abortion and necrosis". The term "development" is already used in such a way by some authors. The relations among the phenomena denoted by the above terms are presented in a graphic form to show that they partly overlap. The concept that growth and development represent quantitative and qualitative aspects (respectively) of plant augmentation is criticized. The newly introduced terms "development hormone" or "development regulator" seem more suitable than "growth hormone" and "growth regulator", however, these later ones are correct and may be used. The traditional term "phytohormone" and the newly introduced one "phytoregulator" seem convenient, but it must be kept in mind that such substances may transmit information both on a chemical basis as well as on a biophysical one. An example here can be auxin; a change in the wavy character of its transport may serve as information. In some cases a complex of two or more substances may play the role of a hormone, for instance ACC and ethylene, of which one is easily transportable but little active and the other is very active but exerts its action rather locally. Other combinations of activities may exist in other such pairs

Inhibition of spinach bolting by growth regulators

Spinach (Spinacia oleracea L.) plants must be harvested during a short period of time because they bolt just after producing some edible leaves. Maleic hydrazide (MH) and its commercial preparation "Antyrost" were found to inhibit bolting very strongly. The preparation Off-shoot-O showed very weak activity in suppressing bolting but diminished markedly the resistance of spinach plants to fungus diseases. Triiodobenzoic acid stimulated bolting, and the retardant succinic acid-2-2-dimethylhydrazide (SADH) did not affect bolting. Application of MH to inhibit spinach bolting cannot be recommended in practice before investigating the residues of this compound in leaves

Effect of chlormequat chloride, ß-naphthoxyacetic acid and ethephon on early and total yield of tomato in open field

Tomato seedlings in hotbed with Antywylegacz (chlormequat chloride) to suppress their excessive elongation before transplanting, were used. Their first 2-3 flower clusters were dipped in the field in Betokson (ß-naphthoxyacetic acid) to induce better early fruit set and the plants were sprayed with Ethrel (ethephon) just before the first fruits become pink, to stimulate earlier ripening and increase early yield. The experiment was carried out during 3 years with the cultivars 'Venture', 'New Yorker' and 'Nesthackchen' (only in 1975). Application of chlormequat alone prevented excessive growth of the seedlings but did not increase early yield significantly. ß-naphthoxyacetic acid alone was effectiveevery year and always increased early yield. Chlormequat followed by ß-naphthoxyacetic treatment showed always a tendency to increase early yield more than ß-naphthoxyacetic acid alone. Treatment with ß-naphthoxyacetic acid, alone or in combination with other treatments, lowered the total yield. Ethephon used solely or in combination with other treatments usually was ineffective

Inhibition of spinach bolting by growth regulators

Spinach (Spinacia oleracea L.) plants must be harvested during a short period of time because they bolt just after producing some edible leaves. Maleic hydrazide (MH) and its commercial preparation "Antyrost" were found to inhibit bolting very strongly. The preparation Off-shoot-O showed very weak activity in suppressing bolting but diminished markedly the resistance of spinach plants to fungus diseases. Triiodobenzoic acid stimulated bolting, and the retardant succinic acid-2-2-dimethylhydrazide (SADH) did not affect bolting. Application of MH to inhibit spinach bolting cannot be recommended in practice before investigating the residues of this compound in leaves

Anatomical structure and surface micromorphology of tomatillo leaf and flower (Physalis ixocarpa Brot., Solanaceae)

Tomatillo (Physalis ixocarpa Brot.) is a newly introduced cultivated plant in Poland. Its anatomy was investigated in light and scanning electron microscopes. Tomatillo adult leaf had one layer of palisade parenchyma. The 1-2 cell layers of spongy parenchyma situated just below the palisade parenchyma showed large, tightly packed cells with great druses. The remaining spongy parenchyma was built of cells showing several extensions. Peculiarity of the sepals were the stomata situated on columns or hills formed of many cells. The petals had a very loose mesophyl. Their adaxial epidermis was composed of papillate cells. Such structure of the petal epidermis probably contributes to light dispersion and prevents glittering. There were several types of trichomes on the leaves, sepals and petals, some of them glandular and some simple. The large, very ramified, dendritic trichomes situated on the petals at the entry to the ovary might eventually protect it against excessive drying. The pollen grain was spherical, three-colpate. The style had a hollow channel inside. The stigma was of a wet, pa-pillate type. Sometimes thorny trichomes were found among papillae