Effect of water stress at different development stages on vegetative and reproductive growth of corn
A field study was carried out from 1995 to 1997 in order to determine the effect of irrigation and water stress imposed at different development stages on vegetative growth, grain yield and other yield components of corn (Zea mays L.). The field trials were conducted on a silty loam Entisol soil, with Pioneer 3377 corn hybrid. A randomised complete block design with three replications was used. Four known growth stages of the plant were considered and a total of 16 (including rain fed) irrigation treatments were applied. The effect of irrigation or water stress at any stage of development on plant height, leaf area index, grain yield per hectare, as well number of ears per plant, grain yield per cob and 1000 kernels weight, were evaluated. Results of this 3-year study show that all vegetative and yield parameters were significantly affected by water shortage in the soil profile due to omitted irrigation during the sensitive tasselling and cob formation stages. Water stress occurring during vegetative and tasselling stages reduced plant height, as well as leaf area development. Short-duration water deficits during the rapid vegetative growth period caused 28–32% loss of final dry matter weight. Highest yields were observed in the fully irrigated control (VTCM) and the treatment which allowed water stress during the vegetative growth stage (TCM). Even a single irrigation omission during one of the sensitive growth stages, caused up to 40% grain yield losses during dry years such as 1996. Much greater losses of 66–93% could be expected as a result of prolonged water stress during tasselling and ear formation stages. Seasonal irrigation water amounts required for non-stressed production varied by year from 390 to 575 mm. Yield response factor (ky) values (unitless parameter) relating yield loss to water deficits) obtained for the first, second and third experimental years were determined to be 1.22, 1.36 and 0.81, respectively. 
The Growth and Yield of Corn. II. Daily Growth of Corn Kernels
Under the conditions of this experiment the stalk was an important storage organ for sugar which, under some conditions, can be translocated to maintain dry weight growth of the kernels for extended periods in the absence of photosynthesis. It seems probable that sugar storage in the stalk provides most of the reservoir of readily mobile sucrose required to maintain relatively uniform kernel growth in spite of wide diurnal and day-to-day variation in photosynthesis. 
Effect of different levels of humic acids on nutrient content and growth of corn (Zea mays L.)
The effect of humic acids on nutrient uptake and growth of corn plants (Zea mays L.) was investigated by growing corn in plastic growth pouches containing a Hoagland nutrient solution to which were added 0, 320, 640, 1,600 or 3,200 ppm HA, pH 7.0. The experiments were carried out in three replicates for a growing period of 16 days after germination. Humic acid was in general beneficial to shoot and root growth of corn plants. Dry matter yield in corn shoots was stimulated by HA, especially by treatments with 640 ppm HA. Nutrient uptake showed a number of differences as a result of treatments with HA. Moderate applications with HA resulted in a significant increase in N content of corn shoots, while large amounts of HA had a tendency to reduce the N concentration in corn shoots. As a result of the HA treatments, P concentrations in corn shoots were decreased, but differences in K contents were statistically nonsignificant and Mn contents in shoots were also nonsignificantly different among the treatments. However, Zn content showed a tendency to increase with increasing applications of HA. 
Influence of Integrated Nutrient Management on Growth and Yield of Sweet Corn (Zea mays L. saccharata) under Temperate Conditions of Kashmir Valley
The growth and yield response of sweet maize (Zea mays (L.) saccharata) to varying levels of organic and inorganic fertilizers during the growing seasons of kharif 2010 and 2011 was studied under temperate conditions of Kashmir Valley. Twelve treatments comprising of sole and combination of organic and inorganic fertilizers were laid in a randomized block design with three replications. The results revealed that application of T10 [75% (NPK) + FYM (4.5 t/ha) + Biofertilizer (Azotobacter + Phosphate solubilizing bacteria (PSB))] significantly increased the number of days taken to tasseling, silking and milky stages and various other growth characters viz., plant height, leaf area index and dry matter accumulation at 15 days interval from sowing upto harvest and crop growth rate and relative growth rate at 7 days interval from 15 DAS upto harvest whereas, the lowest values of these parameters were recorded in unfertilized control. The treatment T10[75 % (NPK) + FYM (4.5 t/ha) + Biofertilizer (Azotobacter + Phosphate solubilizing bacteria (PSB))] proved to be significantly superior to rest of the treatments including unfertilized control in increasing cob yield with and without husk, fodder yield and green biomass yield during both years of experimentation, however, ratio of cob to fodder yield during 2011 and 2012 were recorded highest in treatment T3 [FYM (18 t ha-1)] and T2 [Recommended NPK kg ha-1 (90:60:40)], respectively, whereas unfertilized control recorded the lowest ratio of cob to fodder yield.
A Study on Effects of Planting Dates on Growth and Yield of 18 Corn Hybrids (Zea mays L.)
In this study 18 new corn varieties consist of 15 foreign early and mid-mature single cross hybrids and 3 Iranian commercial hybrids (KSC704, KSC647and DC370) were evaluated at two sowing date (5 and 20 June) based on RCBD with 3 replications at Khorasan Razavi Agricultural Research Centre, Mashhad, Iran on 2009. This study showed that among all hybrids, EXP1 (16.03 ton/ha) and OSSK617 (15.51 ton/ha) had the highest yields in early planting (5 June) and EXP1 (16.52 ton/ha) and KDC370 (16.22 ton/ha) produced the highest, yields in late planting (20 June). Results of this experiment also indicated that yield component such as 300 kernel weight, kernel no. per row, kernel depth and ear length were adversely affected in delay planting condition. Delay planting reduced 300- kernel weight, kernel no. per row, kernel depth and ear length. Results of cluster analysis using Wards’ method divided the corn hybrids into 4 different clusters (low intra-group and high extra-group similarities). From the results of cluster analysis it is recommended to make crosses among genotypes in Clus1 (ZP434, BC582 and EXP2 hybrids) and Clus4 (ZP684, SIMON and KSC647) in breeding programmes. Classifying genotypes according to their agronomic traits with sophisticated multivariate techniques could reduce the time period and expenditure for crop improvement. 
 Cakir, R., 2004. Effect of water stress at different development stages on vegetative and reproductive growth of corn. Field Crops Research, 89(1), pp.1-16.
 Duncan, W.G., Hatfield, A.L. and Ragland, J.L., 1965. The growth and yield of corn. ii. daily growth of corn kernels 1. Agronomy Journal, 57(2), pp.221-223.
 Tan, K.H. and Nopamornbodi, V., 1979. Effect of different levels of humic acids on nutrient content and growth of corn (Zea mays L.). Plant and soil, 51(2), pp.283-287.
 Rasool, S., Kanth, R.H., Hamid, S., Raja, W., Alie, B.A. and Dar, Z.A., 2015. Influence of Integrated nutrient management on growth and yield of sweet corn (Zea mays L. Saccharata) under temperate conditions of Kashmir valley. Journal of Experimental Agriculture International, pp.315-325.
 Beiragi, M.A., Khorasani, S.K., Shojaei, S.H., Dadresan, M., Mostafavi, K. and Golbashy, M., 2011. A study on effects of planting dates on growth and yield of 18 corn hybrids (Zea mays L.). Journal of Experimental Agriculture International, pp.110-120.