Pollination Problems in Temperate Fruits in Himachal Pradesh and Their Improvement
Sometimes, although the tree produces abundant bloom but fails to set fruit. In colder regions it can be due to frost damage, whereas in many cases it can be due to lack of pollination i.e. pollinizers and pollinating agents.
There are many other conditions which necessitate cross pollination. For example there can be a dichogamy condition. Certain plum varieties are reported to be protogynous in one season and protoandrous in the next. Problem of pollen sterility can be a common cause in triploid varieties, whereas sexual incompatibility is general problem in many temperate fruits like apple, almond,cherry, etc.
The pollination problem temperate fruit is as :-
Commercial almond varieties are self unfruitful but they tend to pollinate each other. This is due to self incompatibility therefore, commercial varieties are planted in the following combinations:
i} Combinations of two varieties: Non Pareil-Ne Plus Ultra, Ne Plus Ultra -IXL, Non Pareil-Drake, Thinshelled-Drake.
ii) Combination of three varieties : Non Pareil-Pee:rless-Ne Plus Ulcra, Non Pareil-Ne Plus Ultra-Drake, Ne- Plus Ultra-Drake-IXL, Non Pareil-Thinshelled-Drake.
iii) Combination of more than three varieties : Non Pareil-Thin Sheiled-Drake-Dhebar, Non Pareil-Drake-IXL-Ne Plus Ultra, IXL-Ne-Plus Ultra-Drake-Texas , Non Pareil-IXL-Drake-Dhebar, Peeless-Jordonalo-Non-Pareil-Texas.
Many apple varieties are self unfruitful and set very little fruit with their own pollen. Mainly Delicious is self unfruitful and require adequate pollination for good crop.
Inadequate pollinizer proportion and their diversity is main concern of decreasing productivity. Almost 70-80 per cent of our; apple orchards have less than 20 per cent pollirilaers, whereas, UnrversitV has recommended 33 per cent proportion. For adequate, pollination it is also recommended to plant 3-4 different types of pollmizers Various diploid varieties namely Jonathan, Granny Smith. Golden Delicious, Red Gold, Black Ben Davis, Mcintosh, Grimes Golden, Wealthy, York Emperial, Rome Beauty, Lord Lambourne, Tydyman's Early Worcester and Summer Queen, etc. have been reported to be good pollinizers.
The triploid varieties viz, Baldwin group, Stayman Winesap and Brambley's Seedling have infertile pollen.
Of late, various Malus species (Crab apples) have been developed and are in use in various countries. These flower profusely and also do not have the problem of marketing of their fruits as they only bear rudimentary fruits. Manchurian, Snowdrift and Golden Hornet are some important crabs which have been shown promise under our agroclimatic conditions.
Generally all apricot varieties are self fruitful and does not require pollinizer.
A large number of cherries are self unfruitful and thus do not set crops with their own pollen. In addition to being self-incompatible, they are also cross incompatible with some commercial varieties.
Therefore, proper orchard planning of cherry is undoubtablv a serious problem. Only compatible varieties can be plant H together to get commercial crops.
Pear varieties produce better crops when cross pollinated. Satisfactory pollination can be obtained in majority of the cases if the varieties blossom at the same time. Conference, Fertility and Flemish Beauty are good pollinizers for Bartlett group of varieties. There is lot of parthenocarpy in many pear varieties.
Persimmon has varieties bearing pistillate flowers only, those bearing both pistillate and staminate flowers. Some Japanese type varieties set fruit without cross pollination but American types require pollination.
European type of plums have both types of varieties, Self fruitful are Agen, Pershore, Purple Pershore, French Damson, Starley whereas self unfruitful are Italian Prune, President Grand Duke etc.
Most of Japanese plums are self fruitful. Santa Rosa and Methley set more crops if interplanted. Low varieties like Titron, Alucha Black are reported good pollinizers.