Citrus is a complicated crop by virtue of its genetic character and most subject to the influence of environment and climatic factors…No single parameter can control flowering process in citrus
1.Generally citrus is a self pollinated crop
2.it is carrying poly embryonic characters
3.Sensitive to high and low temperatures - extreme temperature prevent flowering
4.sensitive to water logging and excessive heat
5.Sensitive to nutritional deficiency - cause rudimentary pistil which does not develop into fruits and simply fall
6.Bud dormancy and conversion of buds into fruiting flowers -sometimes the bud simply become rudimentary buds or leaf producing buds …
7.Internal physiological process like balance of growth promoters like GA acid , IAA acid and growth retardant like ABA acid control flowering so forth and so many internal as well as external factors control flowering and fruiting in citrus plants
Some general techniques of induction of flowers in citrus
1.Cause temporary stress by withholding water for a month or two
2.Exposing roots of the citrus plants which are generally shallow
3.Removing water suckers and twisted and criss cross twigs
4.Applying trace elements like ZNSO4, MNSO4, MGSO4, FESO4 either as soil application or as foliar spray
5.Split application of N,P,K along with farmyard manure in 3 time period in a year depending on the flowering and flushing period of the plants
6.Girdling of tree bark until phloem level - a sort of stress inducing mechanism
Because of the above reason farmers should select citrus seedlings carefully while selecting from the nursery
Generally budded / grafted citrus seedlings are planted which comes to bearing early and produce more flowers - because the scion grafted in the root stock is selected from disease free, healthy , heavy bearing mother plants that pass the same genetic characters to the grafted plant …
Conversely when you select seedlings raised from direct seeds might show lot of variation …it might give forth lot of non productive shoots and water suckers that wont even respond to favorable climatic as well as environmental factors - even after 5 to 10 years of planting it wont give any yield or fruits -the life of citrus plant itself is in the range of 15 to 20 years
If you feel it wont bear fruits anymore after 10 years of planting , better discard and clean your field and start afresh following scientific selection of nursery and planting techniques especially citrus …
Because general recommendation of Farmyard manure , neem cake and fertilizer nutrients wont do any good when the real fact of flowering and fruitng in citrus is something different and mystery for majority of the farmers…