IRAQI JOURNAL OF DESERT STUDIES

A pots experiment was conducted at the Department of Biology/College of Education for Girls/University of Anbar during Autumn season of 2018-2019 to study the effect of the salinity irrigation water and spray by humic acid in some of morphological, physiological, growth and yield traits of wheat cv. IPa. The experiment was randomized complete block design (RCBD) with three replications. The first factor was assigned for irrigation by saline water at four level (S0, S1, S2 and S3), while the second factor was the foliar spraying of humic acid in three level (0.0, 1.0 and 1.5 g l-1). The results showed that there was significant reduction in plant height, vegetative dry weight, biological yield and chlorophyll leaves content when the plants were irrigated by saline water approached to 41.09 cm, 0.747 g, 0.849 g plant-1 and 38.67 SPAD, respectively at salinity level of 8.3 ds m-1 compared with the plants which irrigated by fresh water. The total carbohydrates were significantly decreased at the treatment of 8.3 ds m-1 reached 18.71 mg g-1. Spray levels humic acid achieved a significant increase in plant height, dry weight of the vegetative part, biological yield and chlorophyll leaves content sprayed at 1.0 and 1.5 g l-1 compared to no sprayed. Nitrogen concentration was significantly increased, while both phosphorus and potassium were decreased in the vegetative parts of wheat as the salinity of irrigation water increased. However, the increase of humic acid levels led to significant increasing in nitrogen, phosphorus and potassium concentration.

The study of the drought phenomenon gets considerable attention in the recent applied climatic studies since it has an enormous effect on the environment. The drought has various impacts according to its strength and the capacity of society influence, besides it affects the vegetarian sources due to reducing the vegetarian. The reduction of the vegetation is correlated with the drought, and if the range of drought has raised the reduction of the vegetation is increased. This happens when the temperature is raised in the summer seasons or dropped. When the rain comes down, the vegetarians come to spring as it is the time of their growth, expand and density according to the amounts of rain to form thick vegetarian cover in wet seasons. There are three seasons; Autumn, winter, and spring as the range of rain is between 57-58% in the fields of the study area. Where as in the drought seasons becomes between 41-42% in the same seasons. Applying the (SPI: Standardized-Precipitation Guide - Index) to evaluate the lack of rain with the exception of the summer season in which it is always dry. Consequently, we can find the relationship in plant covers via the years of study which shows a variable difference form one year to another. In 1993, the current category was weak as it reached 10240 km2, which constitutes 57.80% of the height of dry seasons. In 2017, there was the opposite of previous years due to the increase of the wet seasons which led to the increasing area of the dense variety to reach an area of 9804 km2 which constituted 55.28% of the study region