The Pecularities of Pollination of Various Fruit Crops

Pear

Most of the pear varieties are self fruit unfruitful. However, nearly all pears are suitable pollinizers for other varieties that bloom at the same time. One exception is Seckel, which is not a good Pollinizer for Bartlett. Even though Anjou, Bartlett and Keiffer are partially self-fruitful, they should be cross pollinated to produce heavy and regular crops. Pear flowers produce only a small amount of nectar which is low in sugar. For this reason, more pollinizers and bees are needed for pears than any other tree fruit. Conference, Fertility and Flemish Beauty are good pollinizers for Bartlett group of varieties. There is lot of parthenocarpy is found in many pear varieties.

Plum / prune

European plums have both types of varieties, Self-fruitful such as Agen, Pershore, Purple Pershore, French Damson, and Stanley whereas self-unfruitful varieties are Italian Prune, President Grand Duke Etc. Most european type plum varieties will set fruit with their own pollen, but will produce better crops with pollinizers nearby. Except for Santa Rosa which is partially self-fertile, all japanese plums require a Pollinizer. Japanese plums such as Burbank, Red heart, Shiro, Methley, and Ozark Premier, require pollination from another Japanese or American-Japanese hybrid

Cherry

Sweet cherries except the new self-fertile types (Stella, Compact Stella, Lapins, Bing, and Starkrimson) require cross-pollination between two different cultivars. Some cultivars are not compatible with each other or may not overlap sufficiently in bloom period. Tart or sour cherries are self-fertile and do not require any pollinizer variety. They are capable of fertilizing sweet cherries but bloom is generally too late to be considered a dependable pollinizers. Most other varieties of sweet cherries require cross pollination where as several varieties are inter sterile and cannot fertilize each other.

Apricot

Many apricot Varieties such as “Tilton” are self-fruitful. Provide another variety of apricot for pollination of varieties such as Goldrich, Moorpark and Perfection. Rival requires an early blooming pollinizer such as Perfection for best results. Self-unfruitful varieties of apricot include Perfection, Riland, and Rival. These self unfruitful varieties can be pollinated by any other apricot variety.

Peach

Most varieties of peach and nectarine are self-fertile, where as J.H.Hale Peach variety are self-unfruitful variety but can be pollinated by almost any other peach variety with a synchronous bloom except Elberta.The varieties where in J.H.Hale is in their parentage (Early Hale” and Hale Haven) will require another variety as a Pollinizer for adequate fruit setting.

Pollination of small fruit crops

Strawberry, raspberry, and blackberry, plants are self-fruitful. However, blueberry, varieties require cross pollination for fruit set. Thus varieties that bloom at a similar time should be placed within rows in adjacent rows.

Almond

All Commercial almond varieties are self-unfruitful. Therefore it is necessary to provide every third row in each orchard with Pollinizer variety (33% pollinizer) so that their bloom should coincide with each other. The varieties which are generally used for commercial almond cultivation as pollinizer like IXL, Jordanalo, Ne-Plus-Ultra and Waris. Due to self-incompatibility; commercial varieties needed to be planted in the following combinations:

1. Combinations of two varieties: Non Pareil-Ne Plus Ultra, Ne Plus Ultra -IXL, Non Pareil-Drake, Thin shelled-Drake.
2. Combination of three varieties: Non Pareil-Peerless-Ne Plus Ultra, Non Pareil-Ne Plus Ultra-Drake, Ne- Plus Ultra-Drake-IXL, Non Pareil-Thin shelled-Drake.
3. Combination of more than three varieties: Non Pareil-Thin Shelled-Drake-Dhebar, Non Pareil-Drake-IXL-Ne Plus Ultra, IXL-Ne-Plus Ultra-Drake-Texas, Non Pareil-IXL-Drake-Dhebar, Peerless-Jordonalo-Non-Pareil-Texas.

Walnut

English walnut is a monoecious species bearing staminate and pistillate flowers separately on the same tree. Walnuts are generally self-fruitful, cross-compatible and dichogamous, having incomplete overlap of pollen shed and female receptivity. It is this characteristic which led to the recommendation that about 10% of the trees in a commercial planting be a cultivar with a pollen shed period overlapping pistillate flower receptivity of the main cultivar. Excessive pollen load has been implicated in the “Serr” cultivar in pistillate flower abortion (PFA), the loss of the female flowers early in the season before fruit drop due to lack of pollination. PFA can be reduced and yield improved in “Serr” orchards by reducing pollen load. PFA occurs to a lesser extent in other cultivars such as “Chico”, “Chandler”, “Vina” and “Howard”. This information has led to the reevaluation of pollinizer recommendations. Research focused on optimum pollinizer levels in “Chandler”, a cultivar of increasing importance to the California walnut industry, has been inconclusive. Lack of pollinizers may impact yields to a greater extent. In any case the previously recommended 10% appears to be excessive. Two to three percent is probably adequate to limit losses due to lack of pollination without resulting in excessive PFA. Factors to consider when determining the number of pollinators to plant include: cultivar susceptibility to PFA, walnut pollen load in the area and local pollination and fruit set experiences.

Pollination plays a crucial role in horticultural production in temperate fruit crops. One can go for use of improved agricultural technologies, such as the use of quality planting material, high yielding verities, good agronomic practices like timely irrigation and fertilizers, but without pollination, neither fruit nor seed will be formed. Therefore adequate number of Pollinizers should be planted in the orchard keeping in view the recommdations.