Before a crop is harvested, one must determine whether the crop is matured (ready to be harvested) by means of maturity indexing. Maturity indexing is the process of monitoring the physiological development of the crop as it ripens. The basic parameters that are assessed and monitored during maturity indexing are parameters such as internal quality parameters, fruit colour, water content etc... Various industries have their own specific guidelines and procedures for determining maturity. These are available from growers’ associations, retailers and exporters, and should be available on-farm for use by harvest personnel.
Sampling is a process of gathering individual fruit from randomly selected trees in an orchard or from a number of plants within a field. In some cases, a visual assessment of maturity is done without having to sample the produce. The idea is that the condition of the sampled fruit is representative of the field or orchards as a whole. The sampling procedure is designed to ensure that samples are in fact statistically representative of the field. Even if the fruit is not used, it must still represent the field as a whole.
Harvest readiness does not necessarily mean that the fruit is mature or ripe. Different crops are harvested at different stages of development. Baby vegetables, for example, are harvested at a young stage, mostly before the crop is mature. Vegetables (carrots, beetroot and lettuce) are harvested when it reached a specific size as required by the market or consumer.
The sampling approach is similar to the sampling for nutrient analyses or for pest and disease management. Although the procedures are crop or even site-specific, the general rule should be that; the initial selection of produce and sampled plants must represent the field\orchid as a whole.