Effect of Recurrent Selection for Stalk Crushing Strength on Agronomic Characteristics and Soluble Stalk Solids in Maize1

Our objectives were to determine responses to selection for crushing strength and the associated changes in yield, stalk strength, field stalk lodging, flowering dates, and soluble stalk solids. The MoSQA and MoSQB maize ( Zea mays L.) synthetics that had undergone five cycles of recurrent selection for high and low stalk crushing strength were used. Selection for high crushing strength in MoSQA and MoSQB did not affect grain yield and significantly decreased stalk lodging. Soluble stalk solids and days to flowering were significantly increased in MoSQB. Selection for low crushing strength reduced grain yield in MoSQB but not in MoSQA, increased stalk lodging in MoSQB, and caused slightly earlier flowering and a decline in soluble stalk solids in MoSQA. Grain yield was positively correlated with crushing strength (r = 0.50**) and soluble solids (r = 0.41**) but atively correlated with natural occurring stalk lodging (r = ‐0.60**) (**Significant at the 0.01 level.). The negative relationship may have occurred because significant changes in yield occurred only for selection for low crushing strength in MoSQB. Stalk crushing strength was negatively correlated with stalk lodging and positively correlated with flowering dates and soluble stalk solids. Stalk lodging was negatively correlated with flowering dates and stalk soluble solids. Flowering dates were positively correlated with stalk soluble solids. The observed relationships between soluble stalk solids and other traits agree with other reported results on stalk quality. The high experimental error and erratic behavior of estimates of soluble stalk solids among cycles of selection indicate either an insufficient sample size or a lack of precision in determination.