THE DYNAMICS OF PHENOPHASES OF SOME FOREIGN LOLIUM PERENNE VARIETIES IN THE TIMISOARA’S PEDO-CLIMATIC CONDITIONS PUBLISHEDMihaela Corcheş, Alexandru Moisuc None
Knowing the main phonological characteristics of some perennial forage grasses varieties from the international assortment in the specific climatic conditions from the West of Romania, represent the main purpose of this paper. In this respect, in order to determinate the degree of precocity three foreign varieties of Lolium perenne, namely EMINENT, CALIBRA and LEIA., were studied and observed in stationary conditions of Timisoara. There were observed the dynamics of the main vegetation phenophases from beginning of vegetation until the harvest. The phenophases evolution, after BBCH code, it was noted in the first harvest cycle, in part for each studied variety, during 2008. The BBCH studied stages are the following: 0 = seed, 09 = emergence, 11 = was noted the date on which the first deployed leaf was visible, 29 = end of shoots, 36 = stem elongation, 59 = end formation of inflorescences, all inflorescences are made, 65 = full flowering, 50% of the anthers are mature. To express precocity was determined the precocity index (IP). For accurately determination of optimal timing of harvest for a variety, operating in different ways, have been established for grazing precocity index (IPp) in the height of apex to 10 cm from the ground and for hay precocity index (IPf) in the formation of flowering phenophase. Also, it was observed the duration of phenophase in relation to the amount accumulated degrees of temperature and amount of precipitation. After the data analysis, it was observed that Calibra variety is the earliest, followed by Leia variety and Eminent variety. Thus, with IPp 43b and IPf 51b, Calibra variety has reached the first maturity of harvest, compared with the other two varieties. Calibra variety was the earliest and related to specific climatic conditions of temperature and precipitation from the experimental area. Thus, we see that the Calibra variety accumulated the lower amount of temperatures to reach the optimal time of harvest, both for grazing (459.7 0C) and for hay (6310C), compared with the Leia variety (487.2 0C until the start of grazing and 710.4 0C until the start of harvest by mowing for hay) and Eminent variety (519.3 0C until the start of grazing and 729.2 0C until the start of harvest by mowing for hay). Considering the range of precocity of all three studied varieties, result that the first harvest cycle can space out from one variety to another in an interval of seven days, making easy for farmer to achieve the green conveyer.
Lolium perenne; foreign varieties; precocity; phenology