Results of Pots trial after first growing season by CREA

In February 2019 after the first growing season, in CREA nursery, a complete measurement of plants of two  hybrid walnut clones (D15 and D1179) has been carried out. For each plants total height, collar diameter and ratio height/collar diameter have been measured. During the transporting from Spain to Italy the plants, in particular the D15 clones, have suffered damages.  This problem affected the plants growth and mortality because some plants presented relevant damages to the root system.

At the end of the first growing season only the 56%  of  D15 clone have shower a clear resprouting after transplanting while for D117 clone the  82% of resprouting have been found.

 

Measurement of all the plants

All the 142 plants still alive present have been measured. The measurement of total height have shown  significant difference between clones but no difference between pots (Fig 1); while no significant difference for collar diameter have been found for clones and pots (Fig 2). The superior height growth of D117 has caused also e superior  height /collar diameter ratio in comparison D15 (Fig 3).

 

Destructive measurements

A sample of 4 plants for each elementary plots has been selected for destructive measurements (48 plants). For each plants the volume of root system, the length of taproot, number of secondary roots have been measured. After all the sampled trees have been sectioned  and put in stove in order to determinate the  dry weight of stem, taproot and secondary roots.

  • Volume of root system (cm3): significant difference between different pots (Airpot=11.53 a; Traditional 15.91 b) but no significant difference between clones (D117 13.41 a; D15 14.03 a);
  • Length of tap root (cm) : significant difference between pots (Airpot 14.69 a; Traditional 18.99 b) but not between clones (D15 16.23 a; D117 17.45 a);
  • N of secondary roots (n): no significant difference bot for clones (D15  2.13 a; D117  3.46 a) and pots (Airpot 3.04 a; Traditional 2.54 a);
  • dry weight of steam (gr): significant difference between pots (Airpot  0.40 a; Traditional 0.64 b) but not between clones (D15 0.50 a; D117 0.54 a);
  • dry weight of taproot (gr): no significant difference bot for clones (D15  1.36 a; D117 1.45 a) and pots (Airpot 1.26 a; Traditional 1.55 a);

dry weight of secondary roots (gr): no significant difference bot for clones (D15 2.23  a; D117  2.99 a) and pots (Airpot  2.36 a; Traditional  2.94 a).

 

The analysis of the two pots and clones have been surely conditioned by the damages  after the transport from Spain to Italy. For this reason in 2019 the pots experiment will be replicated in Galicia SP and a new evaluation of the pot trial in Italy will be repeated after the second growing season.