Foliar Application Of Fertilizer: Review Of Literature

Alkier et al. (1972) concluded that protein content and yield of wheat usually increased with increases in the quantity of nitrate nitrogen present within the soil. Large increases in yield were obtained when 34 or 67 kg N ha-1was broadcasted to non-fallow land at time of seeding, but protein content decreased or increased-only slightly. Protein content increased substantially when 101-202 kg N ha-1was broadcasted to non-fallow land, whereas yield was not increased above that obtained with 67 kg N ha-1. Protein content of wheat grown on fallow land increased with increasing quantity of added nitrogen around about 134 kg N ha-1; yields did not-increase greatly with added nitrogen.

From a greenhouse experiment it was concluded that less than l% of the nitrogen from ammonium nitrate, urea or ammonium sulphate was absorbed into the grain when foliar applied is usually-greater than 30% of the nitrogen from these fertilizers was absorbed when these are soil applied. Gooding and Davies (1992) had reviewed on foliar urea fertilization of cereals and suggested that foliar urea can be an efficient way of applying N to cereal plants and can increase yield in nitrogen responsive crops, especially when applied before flag leaf emergence. Urea applied to the foliage of wheat has reduced degree of Sepioria tritici. S. nodorwn. Powdery mildew (Erysiphe graminis) and brown rust (Puccinia recondita) in certain experiments. Many studies investigating the effects of foliar urea on grain yield concern wheat, for which positive results have been reported for a wide range of sites and climates. When urea has been applied to the foliar of cereal plants, visual symptoms known as leaf scorching, burning or tipping are often noted, even at relatively low rates of nitrogen application (e. g. . 15 kg N/ha). Souza et al. (1999) studied effect of foliar spraying of nitrogen on protein levels, protein fractions and grain weight in the rice crop. The right timing for nitrogen (N) supplementation significantly increased rice grain protein with no corresponding decreased in grain yield.

The increased nitrogen doses at the rate of 40, 80, and 120 kg N ha-1, applied at 10 and 20 days after anthesis (DAA), was found to cause an rise in 13%, 27%, and 18% in grain crude protein, respectively, as compared to the control. The highest crude protein amount 86. 2 mg g-1 was observed at a nitrogen level of 40+40 kg ha-1. It had been also found that the crude protein content, resulting from the highest nitrogen dose (60+60 kg ha-1), was only 80. 0 mg g-1. Gluten was the fraction that has been found to cause maximum contribution in the increase of grain protein content. A positive relation between crude protein and gluten level (r=+0. 92**) indicated that the increase in protein content increased the grade of rice grains.

Makhdum et al, (2002) studied physiological response of cotton to methanol by foliar application. Foliar spraying of methanol have been reported to improve the yields of a number of irrigated crops under arid conditions. Cotton (Gossypium hirsutm L. ) dry matter production was reportedly increased by 50% consequently by foliar applications of methanol, while treated leaves had increased surface, thickness and turgidity. Foliar application of methanol also led to 2-week earlier maturity and increased water use efficiency. Totten et al. (2008) studied liquid and granular N fertilization on grass grade, clipping yield, and root biomass of creeping bent grass. Two annual nitrogen (N) inputs, 127 and 190 kg ha−1 doses were given using 100% granular urea fertilizer, 50% granular urea + 50% liquid urea fertilizer, or 100% liquid urea fertilizer. The outcome suggested a rate of at least 190 kg N ha-1 yr-1 is needed to keep acceptable bent grass quality.

Combining both liquid and granular doses was found to be superior when compared with single dose. Mondal et al, (2011) studied effects of foliar application of nitrogen and micronutrients on growth and yield in mungbean. The effect of foliar application of N and N plus micronutrients on yield attributes and yield was significant but hadn't shown such significant effects on harvesting index and grain protein content. The pod production was higher in plants sprayed with N and N plus other micronutrients as a result of increased number of flowers along with less aborting flowers and pods. This implies N nutrition of the plant during reproductive stage is actually a yield limiting factor. Thus, additional doses of N may be necessary during flowering and pod development to maximise seed yield and foliar application of N at reproductive stages may overcome this issue partially.