Management Problem Gallery

Name: Water Split

Secondary Name:

Source: Longitudinal splitting during the water stage is driven by internal turgor pressure within the developing kernel from mid-August to early September. This is most likely to occur when trees bear a heavy crop load and soils are dry before a sudden influx of water via rainfall or irrigation. Most water-stage split occurs within 24 hours of a thunderstorm. Fruit will drop from the tree approximately seven days after splitting occurs. High relative humidity and low solar radiation can also induce minor splitting before the major episode occurs. Splitting usually occurs in the pre-dawn hours and is most common in the upper 1/3 of the tree canopy. Manage water-stage split by maintaining adequate soil moisture for at least 2-3 weeks prior to shell hardening and mechanical fruit thinning.

Description: When internal splitting occurs, a brown discoloration extends through the shuck along the split area. Later, any portion of the shuck may be discolored, and the nut falls from the tree about 7 days after rupturing occurs. The splitting occurs internally, and a split or crack in the shuck may or may not be visible. Over 30 percent of the crop on a particular tree may exhibit nut drop caused by water-stage fruit split.