Effects of fertilizer, variety and location on barley production under rainfed conditions in Northern Syria 1. Root and shoot growth

Abstract

Two varieties of barley, Arabic Abiad (a two-row local landrace) and Beecher (a six-row Californian variety) were grown both with and without fertilizer at two sites with differing rainfall in Aleppo province, Northern Syria; Jindiress received 417 mm rainfall and Breda 285 mm. The addition of fertilizer doubled (Breda) or trebled (Jindiress) shoot weight and green area by the beginning of stem extension in both varieties. At maturity the mean shoot dry weights and grain yields of the sites were 8520 and 3690 kg ha−1 respectively at Jindiress and 3690 and 1575 kg ha−1 respectively at Breda. Fertilizer significantly increased shoot dry matter but the difference between the varieties was not significant. However, due to differences in harvest index between varieties, Arabic Abiad had a significantly higher grain yield than Beecher.

The number of kernels at maturity was highly correlated with the growth rate of the crops in the 3 weeks preceeding anthesis, which was in turn highly correlated with dry matter at the beginning of stem extension. Since sufficient water was available to adequately fill all kernels set there was also a good correlation between shoot weights at the beginning of stem extension and at maturity.

Fertilizer significantly increased total root length at the beginning of stem extension (Jindiress, from 51 to 89 cm cm−2; Breda from 13 to 30 cm cm−2), at anthesis at Breda (from 50 to 75 cm cm−2) and at maturity (Jindiress from 86 to 145 cm cm−2; Breda from 52 to 80 cm cm−2). There were differences between the varieties in the distribution of roots and Arabic Abiad had a longer root system than Beecher below 15 cm.

At the beginning of stem extension, root-to-total-plant weight ratios were less where fertilizer was applied (0.29 compared to 0.37). At maturity, fertilizer had little effect on the ratios which had fallen to about 0.08 at Jindiress and 0.13 at Breda.