Abstract only

Tillering is one of the biological features of the wheat plant which is highly influenced by crop management practices that can both increase or decrease tillering. Number of tillers developed per wheat plant is termed as tillering rate. Two types of tillering are known : general and productive. General tillering is estimated as number of all tillers per plant, whereas productive tillering means the number of the spiked tillers per plant. Usually, the number of productive tillers is 2-3 times less than the total number of the tillers. However, this difference can be reduced under the favorable conditions. Therefore, the higher is the number of the spiked tillers per plant the higher is grain yield. Thus, it is the major trait to be considered in wheat breeding. It is noteworthy to mention that under the favorable conditions tillering of winter wheat proceeds very intensively, and is hampered under the conditions of moisture stress or shortage of nutrients in soil. The objective of our study was to evaluate response to usual, profound and simulated shortcomings of crop management practices in terms of general and productive tillering in various varieties of wheat. In 1991-1993, a trial was conducted at the Absheron Experimental Station of RI of Azerbaijan, involving two durum wheat varieties Garaqalciq-2 and Gizil-buqda. The following 3 treatments were applied: I) 3 irrigations during the vegetation period at the rate of 500- 700 m3/ha, 2) 3 irrigations + nitrogen application at the rate of 40-50% of the annual rate, and 3) no irrigation and no application of fertilizers. Observation and recording of the general and productive tillering were carried out from January including June. Under the Absheron conditions number of days between emergence and tillering in winter wheat varied and was found to be 10-17 days. Number of all tillers and number of productive tillers has been found to be influenced not only by genotype, but also by management practices and environment such as seeding rate, planting date, temperature, soil moisture, etc. According to Nosatovsky (1965), tillering may proceed at the air temperature of2-4 CO if light, water and nutrients are available, however, with the low intensity. At the same time if winter wheat is planted at optimal planting date, tillering starts in 14-15 days at 15 N. After the emergence of 3-4 leaves the upward advance of the buds stops almost completely and tiller nodes are formed in the underground. Air temperature 13-18°C proved to be optimal for winter wheat intensive tillering. Data of the study is quoted in the table. Data suggests that the highest number of productive tillers per plant in varieties Garaqalciq- 2 and Gizil-buqda (4.6 and 3.8, respectively) is observed in June. As for the non-irrigated and non- fertilized variant, the number of productive tillers in Garaqalciq-2 decreased as much as twice, while a 1.7-fold reduction was observed for Gizil buqda. Grain yield is positively associated with the number of productive tillers per plant. Thus, crop management practices can con- tribute to higher numbers of productive tillers and establish favorable conditions for obtaining high grain yield.

English

0408|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection