Support systems and training methods for dwarf hops (Humulus lupulus L.)

摘要

An experiment was conducted over three years to determine the effects of string and netting support systems and various training methods on the growth, development, yield and quality of dwarf hops (cultivar First Gold). The crop was grown in a hop yard with wirework of 2.29 m height, in rows set 2.44 m apart. The hops were planted 45 cm apart in the rows. In one support treatment, coir strings were tied between the top and bottom wire at 22.5 cm intervals and in the other 14 cm square polypropylenenetting was threaded onto the top and bottom wire. Superimposed on these treatments were training treatments. These were full training (three rounds of hand work), delayed training (chemical defoliation in spring followed by two rounds of training), gapping (plants left to self train and one round of final training in July) and no training. Regular measurements were made of crop growth and development and at harvest, yield and alpha-acid content were measured. The highest yields were attained on the netting support system and with the full training method. However, gapping or no training would often provide a better economic return because the reduction in cost can be greater than the value of lost yield. Delayed training consistently reduced yield for little or no cost saving and is therefore not appropriate for dwarf hop systems. Better yields were associated with plants reaching the top wire earlier and producing longer laterals. Whilst not measured, it would appear that the number of laterals produced by each plant is an important determinant of yield, as the number of cones per lateral was similar in all treatments. The implications of the results for growers of dwarf hops are discussed.