Investigation on the root distributions of Sivas 111/33 and Gerek A-79 wheat varieties grown under Central Anatolian conditions, using tracer techniques

In order to determine the vertical root distributions of Sivas 111/33 and Gerek-79 wheat varieties in the soil profile, two field experiments were conducted at Haymana in 1986, and at Lodumlu in 1987 using tracer techniques and 32p as a tracer. Randomized complete blocks design as four replications was used. The plot size was 12 m2 (240 m by 5.00 m) in which 32p isotope plots were established with dimensions of 0.07 mxl. 25 m=0.875 m2. They included 4 rows of wheat and in the middle of these rows, 15 holes (25 cam apart) were opened with a portable drill. The holes either had depths of 30, 60 or 90 cm depending on the treatment selected. 4 ml carrier-free 32p solutions were injected into the holes with the help of plastic tubes at two times, one after seedling emergence and the other at early spring. Plant samples for radioactivity measurements were taken at four different growth stages, namely tillering, shooting, heading and full maturity. The results obtained from these investigations clearly showed that: 1. The root growth of plants showed differences depending on growth stage and variety. 2. At tillering stage the roots of both wheat varieties were not able to reach to the 90 cm soil depth, however, Sivas 111/33 had relatively shallow rotting system and Gerek-79 had deep rooting system at this stage. 3. At shooting, heading and full maturity stages Sivas 111/33 had more roots than Gerek-79, while at 30 and especially 60 cm soil depths Gerek-79 had more roots. Nearly 26%, 32% and 42% of the total roots of Sivas 111/33, and 15%, 42% and 43% of the total roots of Gerek-79 were found at 90, 60 and 30 cm soil depths, respectively. 4. When compared with Gerek-79, Sivas 111/33 was found to be more suitable for drought conditions