Abstract
A study of environmental effects on lateral bud growth in the sunflower, Helianthus annuus, showed that the provision of a high relative humidity (90 ± 5%) in conjunction with a high light intensity (about 30 000 lx) and an abundant N supply (420 ppm) permitted the buds at the basal nodes to escape from apical dominance and to develop as lateral branches. A reduction in any one of these three factors was sufficient to prevent the release of the buds from inhibition. The marked effect of humidity on bud growth suggested that the degree of water stress is the factor most likely to limit the growth of the lateral buds under field conditions. The mode of action of water stress and the N supply is discussed in relation to the genetic control of bud activity and to the role of nutrient competition in the mechanism of apical dominance.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
