MECHANISTIC PROCESS-LEVEL CROP SIMULATION MODELS FOR ASSESSMENT OF AGRICULTURAL SYSTEMS
Location: Crop Systems & Global Change
Title: Potato stem density effects on canopy development and production
Submitted to: Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 23, 2011
Publication Date: June 1, 2011
Citation: Fleisher, D.H., Timlin, D.J., Yang, Y., Reddy, V. 2011. Potato stem density effects on canopy development and production. Potato Research. 54:137-155.
Interpretive Summary: A considerable amount of potato research has been conducted in controlled environments, such as greenhouses and growth chambers, for many years. Under normal field conditions, an individual potato plant can form multiple stems. However, in controlled environment research, potato plants are frequently pruned so that only a single stem forms. Many scientists have assumed that the experimental results from controlled environments studies using these single stem potatoes can be applied to ‘real-world’ field production where multiple stems occur. In order to test this assumption, two separate experiments were conducted in growth chambers. The growth and development of potato plants pruned to have different stem numbers was studied. It was found that all potato plants produced the same amount of growth independent of the number of stems. This result was primarily due to an ability of potato plants to continue to produce new leaves and branches throughout the growing season. Information on this growth characteristic was collected. This information indicates that results from other controlled environment potato studies, that use single stem potatoes, can be used for field production when the plants have adequate nutrition. Therefore, this research helps to validate the assumption described above. Scientists, such as potato modelers, who use controlled environment research to study how potatoes respond to environmental and nutrient factors will benefit. Crop consultants, farmers, and other scientists, who use this type of data to help farmers more efficiently manage water and fertilizer usage, will also benefit.
Controlled environment studies with potato frequently assume responses from single-stem potato plants can be extrapolated to the field where multiple-stem plants are common. Two controlled environment studies were conducted in order to characterize differences in canopy growth, development, and dry matter production among single- and multiple-stemmed potatoes. Leaf area distribution was significantly influenced by stem density, with mainstem and apical lateral branch leaf area 150 to 200 percent larger in triple-stemmed (3S) versus single-stemmed (1S) potato pots (p < 0.01), while basal lateral branch leaf area was 50 percent less (p < 0.01). Basal lateral branches were more developed in 1S pots with longer branch lengths, more leaf area, and higher orders of branching. In the second experiment, more leaves were initiated in higher density pots; however, individual leaf areas were approximately 50 percent smaller when compared to those in 1S pots. Total leaf area and total, vegetative, and yield dry matter production were unaffected by stem density in either experiment on a per pot basis. The development and growth of lower basal lateral branches in the single-stemmed potato canopy offset any initial advantage in leaf numbers in the multiple-stemmed plant. These results appeared to validate the assumption that, given a late maturing cultivar and adequate nutrition, responses from single stemmed plants can be extended to multiple stemmed plants when expressed on a production area basis. These findings have practical considerations for potato researchers who conduct growth chamber experiments and potato modelers.