Without new innovations, present rates of increase in yields of food crops globally are inadequate to meet the projected rising food demand for 2050 and beyond. A prevailing response of crops to rising [CO2 ] is an increase in leaf area. This is especially marked in soybean, the world's fourth largest food crop in terms of seed production, and the most important vegetable protein source. Is thi...

The effects on sugarcane yields of deep tillage for land preparation on five different soil types in the coast lowlands of Natal are presented. Yields from the. rainfed plant and first ratoon crops indicate that, in general, there is little advantage in ploughing or subsoiling to depths greater than the conventional 20-25 cm. The only worthwhile response to deep tillage was obtained in a recent...

an experiment was conducted at zahak research station in zabol in 1996-97 to determine the best method of planting and plant density for mixed culture of cucumber and eggplant. in this experiment, yields of two crops were compared in individual and mixed cultures. in both systems the distances between two plant were 25 and 50 cm, and in the mixed culture eggplants were planted in the opposite o...

Agriculture is the process of managing plant communities to obtain useful materials from the small set of species we call crops. Weeds comprise the “other” set of plant species found in agroecosystems. Although they are not intentionally sown, weed species are well adapted to environments dominated by humans and have been associated with crop production since the origins of agriculture (Harlan,...

Twenty-two cover crops were evaluated for their ability to reduce damage by root-knot nematode, Meloidogyne javanica, to taro, Colocastia esculenta, in a tropical cropping system. Cover crops were grown and incorporated into the soil before taro was planted. Barley, greenpanic, glycine, marigold, sesame, sunn hemp, and sorghum x sudangrass DeKalb ST6E were poor or nonhosts to the nematode as me...

A dynamic model of nematode populations under a crop rotation that includes both host and nonhost crops is developed and used to conceptualize the problem of economic control. The steady state of the dynamic system is used to devise an approximately optimal decision policy, which is then applied to cyst nematode (Heterodera schachtii) control in a rotation of sugarbeet with nonhost crops. Long-...

Cereal crops are used throughout the world for livestock feed. When they are managed properly they provide excellent grazing and high-quality silage or hay. It is important to remember that grazing should occur during the vegetative stage and silage or hay harvest should occur during flowering to early seed fill. Corn is one of the few annual crops that will provide quality forage after seed ma...

1 The attractiveness of pitfall traps baited with a synthetic host volatile attractant to colonizing adult Colorado potato beetle, Leptinotarsa decemlineata (Say) was evaluated in a field setting. 2 Significantly more postdiapause, colonizing adult L. decemlineata were captured in baited than unbaited pitfall traps. 3 The potential for this synthetic kairomone to enhance the efficacy of trap cr...

The most effective management program for soybean cyst nematode, Heterodera glycines, is a crop rotation that uses nonhost crops and resistant soybean cultivars. However, little is known about the effects of rotation crops and overwintering on H. glycines biology. These experiments were initiated to determine the effects of seven alternative crops on H. glycines' ability to infect and mature on...

Cell wall proteins play key roles in cell structure and metabolism, cell enlargement, signal transduction, responses to environmental stress, and many other physiological events. Agricultural crops are often used for investigating stress tolerance because cultivars with differing degrees of tolerance are available. Abiotic and biotic stress factors markedly influence the geographical distributi...