In order to estimate genetic parameters for production traits and reproductive performance, 115 465 records of production traits and 90 942 records of reproductive performance from Iranian Holstein cows that were collected during 1980 to 2004 at Animal Breeding Center of Iran, were used. The estimations were performed using Restricted Maximum Likelihood method (REML) under an animal model by DF...

In this paper, we have examined the effect of climate variables on the yield average and variability of major grain crops (rice, maize, and wheat) in Iran from 1983 to 2014. For this purpose, we made use of the Just and Pope Production Function crop yields panel data. The results revealed that the influences of climate variables were different in the crops. The time trend positively influenced ...

three grass species, agropyron desertorum (agde) and agropyron elongatum (agel) and recently, bromus tomentellus (brto) are mainly used for range improvement as mixed seeding in semi-arid areas of iran. because there is little information about management of these grasses, this study was conducted at the sisab research station in northern iran to evaluate their responses to grazing management a...

decreasing water resources has made optimum water allocation in agriculture essential. planning optimum irrigation and crop production function considering accessible water and growing stage is an efficient approach to increase water productivity. studies have applied this approach to maximize crop production using the fao crop production method introduced in 1979. however, the fao introduced a...

abstract lowland rice (oryza sativa l.) in south asia is under stress, as nitrogen removals by crops are higher than their replenishment through fertilizers. limited information is available on optimizing nitrogen dose in lowland rice to turn out higher yield. the present investigation aimed to optimize nitrogen fertilization and it’s response to the growth and yield of lowland rice. we evaluat...

The aim of the paper is to address the issue of operational improvements in manufacturing firms, especially when yield losses result in a significant increase of the production cost. In a multistage production environment the firm must decide which production stage(s) should receive more “attention” in order to minimize the overall cost incurred from yield losses. Yield variability is a factor ...

stem reserve remobilization is very important to keep the grain yield in wheat under terminal drought but the importance of this mechanism is unclear under terminal salinity. in this research stem reserve remobilization under terminal salinity were studied in greenhouse on four genotypes no14 and no49, different in remobilization, and bam as salt-tolerant and ghods as salt-sensitive cultivars. ...

drought stress is a major factor limiting crop production. investigation of physiological characteristics related to drought tolerance and crop production may be useful in selecting drought tolerant cultivars as well as in improving crop yield. two drought tolerant (azar2 & back cross roshan) and two drought susceptible (marvdast & shiraz) cultivars were investigated in both greenhouse and fiel...

Fruit waste extract was selected as the sole substrate for carotenoid production and the effect of parameters like pH, temperature and agitation have been studied. A two-step simple sequential strategy was employed for the optimization of carotenoid production by Rhodotorula rubra. In the first step, one factor at a time was employed to evaluate the impact of pH on carotenoid production. Th...