What is a disadvantage of cordon training in spur pruning?

Cordon training in spur pruning is indeed considered to be the most laborious to establish due to the specific requirements it has during the initial setup phase. This training method involves creating a permanent framework (the cordons) along which the vines will grow, which requires careful planning and significant initial labor to ensure that the cordons are positioned and supported correctly.

The establishment phase is critical because it lays the foundation for future growth and fruit production. The process includes selecting appropriate shoots, training them to develop into the cordon system, and then ensuring they are pruned back properly to promote healthy development. This level of attention to detail and hands-on work makes cordon training more labor-intensive at the outset compared to other training methods.

Once established, however, cordon systems can lead to easier maintenance in subsequent seasons, but the initial investment of time and effort is a key drawback that must be considered. In contrast, other options listed do not accurately reflect the nature and challenges of the cordon training methodology in the context of spur pruning.