The most important activity in an IPM program during the fruit development stage is monitoring the effectiveness of controls applied during the dormant and bloom stages. Fruit development activities generally occur in the period between mid-April and the start of shaking, but dates may vary according to region, variety, and weather.
Pests that are especially important during the fruit development stage are:
- Peach twig borer
- Navel orangeworm
- San Jose scale
- Ants
- Spider mites
Catching a pest problem early increases the possibility that it can be controlled with "soft" insecticides, such as oil for mites, thus avoiding the conventional insecticides (organophosphates, pyrethroids) that destroy beneficial insects and mites.
Hull split and navel orangeworm egg laying will be important events to monitor if proper mummy removal did not take place, or if there is an alternate source of infestation near the orchard. Effective Bt treatment for navel orangeworm takes place during hull split when larvae are hatching. Early harvest is another management strategy for avoiding navel orangeworm damage.
Ants should be monitored at this time to determine if baits will be needed so they can be distributed in the orchard by June 1. Monitoring continues for peach twig borer, San Jose scale, and spider mites.
The orchard floor must be prepared before harvest so that an early and rapid harvest timetable can be followed.