in order to study the effects of different sowing dates by some of companion crops on the weeds control, morphological traits and yield of corn sc 504, a field experiment was carried out of research field at tabriz university during 2010 growing season. treatments were arranged in a factorial experiment using randomized complete blocks design with three replicatins. factors was include four lev...

The concept of planting trees in widely spaced rows and growing cash crops in the alleyways is a special form of agroforestry called alley cropping. To be successful, the companion crop’s physiological requirements (i.e., light, water and nutrients) must be accommodated by the tree. Black walnut’s (Juglans nigra L.) foliage and root system are unique and readily adapted to the growth of compani...

Purpose. To investigate the allelopathic compatibility of common bean seeds and companion crops, to establish interaction patterns using water extracts from other plant parts crops. Methods. Laboratory, statistical. Results. Biotest: germinating crops in Petri dishes. Biologically active substances winter spring triticale (the seeds/seeds ratio was 1:10) negatively affected seedlings, which see...

management of a companion crop is critical to successful establishment of perennial forages (Albrecht and Hall, Weed control during alfalfa (Medicago sativa L.) establishment is 1995). a primary concern of forage producers. Companion crops and clearWeed management is important for decreasing comseeding with an herbicide are commonly used methods for establishing alfalfa. This study evaluated an...

This paper describes the 'push-pull' or 'stimulo-deterrent diversionary' strategy in relation to current and potential examples from our own experiences. The push-pull effect is established by exploiting semiochemicals to repel insect pests from the crop ('push') and to attract them into trap crops ('pull'). The systems exemplified here have been developed for subsistence farming in Africa and ...

Food insecurity is a chronic problem in Africa and is likely to worsen with climate change and population growth. It is largely due to poor yields of the cereal crops caused by factors including stemborer pests, striga weeds and degraded soils. A platform technology, 'push-pull', based on locally available companion plants, effectively addresses these constraints resulting in substantial grain ...

Hamkins and Löwe proved that the modal logic of forcing is S4.2. In this paper, we consider its modal companion, the intermediate logic KC and relate it to the fatal Heyting algebra HZFC of forcing persistent sentences. This Heyting algebra is equationally generic for the class of fatal Heyting algebras. Motivated by these results, we further analyse the class of fatal Heyting algebras.