Wheat Project Directorate, Indian Agricultural Research Institute, New Delhi, 110 012, India
*Part of the thesis submitted by senior author for Ph.D. Degree to the P. G. School, IARI, New Delhi-12.
The problem of lodging in cereals has been investigated by many workers. Still there is no unanimity on the use of index/indices for lodging resistance. Hence the present investigations were undertaken to identify the plant characters responsible for lodging resistance in barley, standardise suitable indices for effective selection for lodging resistance in the breeding programmes.
The studies were carried out during 1974-75 with 28 different varieties of barley with a view to study the plant characters that influence lodging viz. shoot weight, mother shoot weight, root weight, plant height and straw strength along with lodging angle. The data were analysed for correlation coefficients, path coefficients and discriminant function.
Shoot characters viz. shoot weight, mother-shoot weight and plant height were positively correlated with lodging angle. All the characters were interrelated among themselves in a positive way. The positive association of shoot weight with lodging was due to its indirect effects through all other plant characters in both the directions. Mother-shoot weight had its own direct effect and also indirect effects through root weight, straw strength and plant height. Root weight had high negative direct effect on lodging but its association with other plant characters suppressed its effect resulting in low correlation. Plant height had its direct positive effect of a very high magnitude and also indirect effects through other characters. The role of straw strength was similar to that of root weight.
Thus the plant characters in order of their influence and contribution towards lodging are: plant height, root weight, mother-shoot weight, straw strength and shoot weight. It was also observed that selection index for lodging resistance could be based on two plant characters, viz., plant height and mothershoot weight as selection for root weight will be difficult in the segregating material. This index gave the relative efficiency of 75∙30% of the direct selection for lodging resistance.
