Inheritance of Sugarcane Ratooning Ability and the Relationship of Younger Crop Traits to Older Crop Traits

The inheritance of ratooning ability and the relationship of traits among crops in sugarcane ( Saccharum spp. hyb.) has not been well examined. Ratooning ability (RA) was defined as the second ratoon(SR) crop yield percent of the plant cane yield. A replicated 4‐yr test at four locations of 37 genotypes was studied for two three‐crop cycles. Broad‐sense single‐plot heritabilities for RA were low (H ≤ 17%), while the genetic coefficient of variation of RA was largest for sucrose yield and cane yield (GCV ≈ 14.5%), and smallest for stalk diameter (GCV = 1.5%). Cane and sucrose yield RA demonstrated the largest potential for gain, while stalk weight, stalk diameter, and stalk length showed the least. Except for sucrose and cane yield and stalk number, other traits were highly correlated between plant cane and SR crops (r ≥ 0.78). Stalk number in the younger crop was the only trait significantly correlated to ratoon crop cane yield (r = 0.56), suggesting that selection for stalk number in the younger crops would enhance older crop yields. The results indicate that SR crop yields could be predicted by first ratoon crop yields. However, the best improvement of SR yields would be realized by selection in the SR.