Effect of alkali water irrigation and gypsum doses on yield and chemical composition of oat (Avena sativa) varieties in an alkali soil

A field experiment was conducted during the winter (rabi) seasons of 2002–2003 and 2003–2004 at Karnal, to study the effect of gypsum application on 5 varieties of oat (Avena sativa L.) in a moderately alkali soil (pH 9.3) using alkali water (RSC 8.6 me/litre) irrigation. The yield of oat was not significantly influenced owing to gypsum application; however, variation in yield was recorded amongst the varieties. Highest yield was observed in variety ‘HJ 8’ followed by ‘OS 7’. On an average, ‘HJ 8’ and ‘OS 7’ varieties registered 16.2% and 8.3% higher yield, respectively, than ‘Kent’, a popular variety. Higher yield of ‘HJ 8’ may be attributed to its tall and broad leaves compared with remaining varieties. However, ‘OS 6’ variety showed the maximum tillers. Gypsum application did not influence chemical composition of oat. Varieties ‘Kent’, ‘HJ 8’ and ‘OL 9’ showed similar crude protein that was significantly greater than the remaining 2 varieties. ‘Kent’ and ‘OL 9’ varieties accumulated significantly lower sodium percentage than the other varieties evaluated. Application of gypsum at each level enhanced the chlorophyll content of oat. Varieties ‘HJ 8’ and ‘OS 7’ also showed significantly higher total chlorophyll content, indicating their better tissue tolerance inspite of their greater sodium content.