abstract in order to determine the critical period of weed control in euro-flour variety of sunflower (helianthus annus, l.) an experimental was conducted with a randomized complete block design with 10 treatments and three replications in islamic azad university astara-branch-agricultural college in 2006 growing season. experimental treatments were conducted in two sets, the first set included...

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop ...

Agronomic production on poorly drained soils in humid regions, such as the Central Claypan Region (MLRA), can exhibit low crop production in moderate to wet growing seasons. Extended periods of saturated soil conditions during a growing season may severely lower crop production by inhibiting plant growth, increasing the chance of disease, and providing conditions ideal for nutrient loss. Traffi...

to determine sugar beet water requirement and the effect of changing the quantity of applied water on some production components, a study was carried out in ekbatan agricultural research station of hamedān, iran in four years (1994-1997) during which optimum water requirement, root and sugar yield, water use efficiency on the basis of root yield, sugar percentage and water use efficiency on the...

The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ...

With an increasing demand of fresh water resources in arid/semi-arid parts of the world, researchers and practitioners are relying more than ever on remote sensing techniques for monitoring and evaluating crop water status and for estimating crop water use or crop actual evapotranspiration (ETa). In this present study, infrared thermometry was used in conjunction with a few weather parameters t...

one production factor influences the response to another factor. A positive interaction occurs when the influence of the combined practices exceeds the sum of the influences of the individual practices. Such positive interactions have served as the science-based justification for development of a “balanced” plant nutrition program. Positive interactions with P and other nutrients are well docum...

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...

So far, various methods have been presented for determining reference crop evapotranspiration in different parts of the world. The most popular and prestigious of them are probably the combined methods of Penman family, modified Blany-Criddle, Hargreaves - Samani and thornthwaite. Due to lack of lysimeter data in many parts of Iran, presenting an equation according to the regional condition wit...