POLLINATION

Pollination, the process whereby fruit set is initiated, may be by wind, as in the case of sweetcorn for example, or insects, as is the case with squashes. Some types, such as beans, self pollinate even before the flower opens. Some cabbage cultivars have a mechanism of self incompatibility to prevent self pollination, thus ensuring cross pollination for seed set. It is a wide range of conditions governing the pollination process

All this is important for both commercial seed production and growing vegetable crops. Lack of insects or unsuitable weather conditions can result in poor seed set. Temperatures high enough to cause pollen burn result in uneven seed set in the pod or on the cob. Introduction of beehives, especially for cucurbits, or sowing to avoid flowering in high temperature periods, will help.

Most of the old cultivars are ‘open’ pollinated. By that is meant the plants in the bed or field pollinate themselves, they remain true to type and seed from the crop can be kept back - if so required. Cross pollination between cultivars results in contamination of the lines by mixing up the genes of the two parents for the following generation. So isolation, either in time or distance, is important for those wanting to keep their own seed.

Hybrids are the result of controlled cross-pollination between two parent lines which have been selected or bred specially to introduce required characteristics into the end product. This impacts on resultant plant characters such as vigour, uniformity, even maturity, disease resistance, better yield and on fruit characteristics such as shape, size and colour, to name but a few.

GENETIC ENGINEERING

GMO, now the nemesis of some modern breeding programmes, should not be confused with hybrids. The latter is the result of introduction of required characteristic by natural breeding processes. It is usually accompanied by the transfer of other characteristics, which are not necessarily always beneficial. The introduction of a specific gene by engineering techniques, although more targeted, has raised the ire in certain sectors.

The parent lines used in producing Premier’s hybrids have been developed by natural selection and not genetic engineering.

The introduction of specialised genes, while advancing the quality of a product in one direction, can adversely influence other qualities. For example, the long shelf-life gene, which improves shelf life in tomatoes, can delay onset of colouring in the fruit, especially after harvest; flavour too tends to be indifferent.

SEED STORAGE

Seed should be stored in a cool dry environment. A constant 5 degrees Celcius is ideal. For all practical purposes the refrigerator is well suited for small lots. Seal the packet to prevent moisture absorption; ironing the mouth closed with medium heat is usually adequate for this purpose.

Seed should not be allowed to heat up. The build-up of heat doesn’t necessarily ‘cook’ the contents but it can seriously harm the seed’s viability. In the case of lettuce temperature of over 30 degree induces dormancy which, in some cultivars, is irreversible. So don’t throw the newly purchased packet of seed on the dashboard whilst driving home!

GERMINATION

Generally a temperature of 20 – 25 degree Celsius is ideal. If necessary germination in the seedling tray can be initiated at this temperature for a few days and then trays are removed to another room to complete the physiological processes.

Germination vigour should not be confused with germination itself. It is the rate at which the seed germinates. Old seed will tend to take longer and emerge unevenly compared to fresh seed. Keep the seed moist at all times whilst it is germinating.

Seed of some plants will need scarifying before it germinates. This can be by filing the tip of the seed to break the tough testa and allow moisture to enter, as in the case of some Acacia species, or by pouring boiling water over it to break down inhibitor toxins in the seed.

SEEDLINGS vs DIRECT SOWING

Some plants, such as radish, carrots, turnips etc are sown direct where they are to grow. When sowing by hand mix the seed with a medium, such as moist sand, to ensure a more even stand The mixture is then trickled into the furrow with the seed more widely spaced. Shake regularly to ensure the mixture does not settle out into its two components.

With the present high cost of seed, especially hybrid seed, the role of specialised seedling growers has come into tits own. And introduction of seedling trays into which seed is sown mechanically has enabled even further reduction in wastage when compared to the old fashion seedbed style of seedling production. It is advisable to  use a reputable nursery to avoid risk of introducing plant diseases, or even inadvertant mixing up of cultivars.

BABY vs MINI VEGETABLES

There is a clear distinction between these two categories. Baby vegetables are picked when still small and immature. This is classical zucchini or courgette fruit. Mini vegetables are picked mature but are very small. This can be an expression of its genetic makeup, such as with cherry tomatoes, or from management practices such as spacing very closely without room to develop properly, such as is the case with pickled onions.