Effect of Foliar Application of Nano Nitrogen (Urea) and Chelated Zinc on Growth, Flowering, Fruiting, Yield and Quality Parameters of Guava (Psidium Guajava L.) Under Western Uttar Pradesh Conditions

Abstract

The experiment was conducted in a Factorial Randomized Block Design with 16 treatments viz. T1- control, T2- nano N 1.5 ml, T3- nano N 3.0 ml, T4- nano N 4.5 ml, T5- chelated Zn 0.4%, T6- nano N 1.5 ml + chelated Zn 0.4%, T7- nano N 3.0 ml + chelated Zn 0.4%, T8- nano N 4.5 ml + chelated Zn 0.4%, T9- chelated Zn 0.8%, T10- nano N 1.5 ml + chelated Zn 0.8%, T11- nano N 3.0 ml + chelated Zn 0.8%, T12- nano N 4.5 ml + chelated Zn 0.8%, T13- chelated Zn 1.2%, T14- nano N 1.5 ml + chelated Zn 1.2%, T15- nano N 3.0 ml + chelated Zn 1.2%, T16- nano N 4.5 ml + chelated Zn 1.2% and 3 replications during the year 2021-22 and 2022-23. Treatments were applied by foliar spray thrice, one before flowering, second at full bloom and the last spray at the time of fruit set. Different parameters i.e. shoot length (cm), shoot diameter (cm), number of leaves per shoot, number of flowers per shoot, fruit set %, fruit drop %, fruit retention %, fruit length (cm), fruit diameter (cm), fruit weight (g), fruit volume (cc), specific gravity, TSS (˚Brix), acidity (%), TSS : acidity ratio, vitamin C (mg/100 g), pectin (%), total chlorophyll (mg/g FW), total carotenoid (mg/g FW), total sugar (%), reducing sugar (%), non-reducing sugar (%), yield per tree (kg), yield per hectare (q/ha) were recorded during the experimental period. There was significant effect of nano nitrogen (urea) and chelated zinc on growth, flowering, fruiting, yield and quality parameters of guava cv. Lalit. The study revealed that combination of nano nitrogen (urea) @ 4.5 ml/tree and chelated zinc @ 0.8% recorded maximum increase in all the mentioned parameters. Among the doses of nano nitrogen (urea) applied, nano nitrogen (urea) @ 4.5 ml/tree performed the best and nano nitrogen (urea) @ 3.0 ml/tree was also found to be at par. Also, the single doses of chelated zinc applied, chelated zinc @ 0.8% recorded the best findings and chelated zinc @ 1.2% was found to be at par with it. Chelated zinc was found to perform best under quality parameters of guava where internal fruit characteristics was concerned as well as in flowering and fruiting characteristics of guava. It can be concluded foliar spray with combination of nano nitrogen (urea) (4.5 ml/tree) and chelated zinc (0.8%) when applied thrice performs best under western Uttar Pradesh conditions